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com.unity.uiwidgets/Runtime/widgets/framework.cs

2993 行
115 KiB
原始文件 文件历史

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.rendering;
using Unity.UIWidgets.ui;
using UnityEngine;
namespace Unity.UIWidgets.widgets {
public class UniqueKey : LocalKey {
public UniqueKey() {
}
public override string ToString() {
return $"[#{Diagnostics.shortHash(this)}]";
}
}
public class ObjectKey : LocalKey, IEquatable<ObjectKey> {
public ObjectKey(object value) {
this.value = value;
}
public readonly object value;
public bool Equals(ObjectKey other) {
if (ReferenceEquals(null, other)) {
return false;
}
if (ReferenceEquals(this, other)) {
return true;
}
return ReferenceEquals(this.value, other.value);
}
public override bool Equals(object obj) {
if (ReferenceEquals(null, obj)) {
return false;
}
if (ReferenceEquals(this, obj)) {
return true;
}
if (obj.GetType() != this.GetType()) {
return false;
}
return this.Equals((ObjectKey) obj);
}
public override int GetHashCode() {
return (this.value != null ? RuntimeHelpers.GetHashCode(this.value) : 0);
}
public static bool operator ==(ObjectKey left, ObjectKey right) {
return Equals(left, right);
}
public static bool operator !=(ObjectKey left, ObjectKey right) {
return !Equals(left, right);
}
public override string ToString() {
if (this.GetType() == typeof(ObjectKey)) {
return $"[{Diagnostics.describeIdentity(this.value)}]";
}
return $"[{this.GetType()} {Diagnostics.describeIdentity(this.value)}]";
}
}
public class CompositeKey : Key, IEquatable<CompositeKey> {
readonly object componentKey1;
readonly object componentKey2;
public CompositeKey(object componentKey1, object componentKey2) {
this.componentKey1 = componentKey1;
this.componentKey2 = componentKey2;
}
public bool Equals(CompositeKey other) {
if (ReferenceEquals(null, other)) {
return false;
}
if (ReferenceEquals(this, other)) {
return true;
}
return Equals(this.componentKey1, other.componentKey1) &&
Equals(this.componentKey2, other.componentKey2);
}
public override bool Equals(object obj) {
if (ReferenceEquals(null, obj)) {
return false;
}
if (ReferenceEquals(this, obj)) {
return true;
}
if (obj.GetType() != this.GetType()) {
return false;
}
return this.Equals((CompositeKey) obj);
}
public override int GetHashCode() {
return (this.componentKey1 != null ? this.componentKey1.GetHashCode() : 0) ^
(this.componentKey2 != null ? this.componentKey2.GetHashCode() : 0);
}
public static bool operator ==(CompositeKey left, CompositeKey right) {
return Equals(left, right);
}
public static bool operator !=(CompositeKey left, CompositeKey right) {
return !Equals(left, right);
}
public override string ToString() {
return this.GetType() + $"({this.componentKey1},{this.componentKey2})";
}
}
public abstract class GlobalKey : Key {
protected GlobalKey() {
}
public new static GlobalKey key(string debugLabel = null) {
return new LabeledGlobalKey<State<StatefulWidget>>(debugLabel);
}
static readonly Dictionary<CompositeKey, Element> _registry =
new Dictionary<CompositeKey, Element>();
static readonly HashSet<Element> _debugIllFatedElements = new HashSet<Element>();
static readonly Dictionary<CompositeKey, Element> _debugReservations =
new Dictionary<CompositeKey, Element>();
internal void _register(Element element) {
CompositeKey compKey = new CompositeKey(Window.instance, this);
D.assert(() => {
if (_registry.ContainsKey(compKey)) {
D.assert(element.widget != null);
D.assert(_registry[compKey].widget != null);
D.assert(element.widget.GetType() != _registry[compKey].widget.GetType());
_debugIllFatedElements.Add(_registry[compKey]);
}
return true;
});
_registry[compKey] = element;
}
internal void _unregister(Element element) {
CompositeKey compKey = new CompositeKey(Window.instance, this);
D.assert(() => {
if (_registry.ContainsKey(compKey) && _registry[compKey] != element) {
D.assert(element.widget != null);
D.assert(_registry[compKey].widget != null);
D.assert(element.widget.GetType() != _registry[compKey].widget.GetType());
}
return true;
});
if (_registry[compKey] == element) {
_registry.Remove(compKey);
}
}
internal void _debugReserveFor(Element parent) {
CompositeKey compKey = new CompositeKey(Window.instance, this);
D.assert(() => {
D.assert(parent != null);
if (_debugReservations.ContainsKey(compKey) && _debugReservations[compKey] != parent) {
string older = _debugReservations[compKey].ToString();
string newer = parent.ToString();
if (older != newer) {
throw new UIWidgetsError(
"Multiple widgets used the same GlobalKey.\n" +
$"The key {this} was used by multiple widgets. The parents of those widgets were:\n" +
$"- {older}\n" + $"- {newer}\n" +
"A GlobalKey can only be specified on one widget at a time in the widget tree.");
}
throw new UIWidgetsError(
"Multiple widgets used the same GlobalKey.\n" +
$"The key {this} was used by multiple widgets. The parents of those widgets were " +
"different widgets that both had the following description:\n" + $" {newer}\n" +
"A GlobalKey can only be specified on one widget at a time in the widget tree.");
}
_debugReservations[compKey] = parent;
return true;
});
}
internal static void _debugVerifyIllFatedPopulation() {
D.assert(() => {
Dictionary<GlobalKey, HashSet<Element>> duplicates = null;
foreach (Element element in _debugIllFatedElements) {
if (element._debugLifecycleState != _ElementLifecycle.defunct) {
D.assert(element != null);
D.assert(element.widget != null);
D.assert(element.widget.key != null);
GlobalKey key = (GlobalKey) element.widget.key;
CompositeKey compKey = new CompositeKey(Window.instance, key);
D.assert(_registry.ContainsKey(compKey));
duplicates = duplicates ?? new Dictionary<GlobalKey, HashSet<Element>>();
var elements = duplicates.putIfAbsent(key, () => new HashSet<Element>());
elements.Add(element);
elements.Add(_registry[compKey]);
}
}
_debugIllFatedElements.Clear();
_debugReservations.Clear();
if (duplicates != null) {
var buffer = new StringBuilder();
buffer.AppendLine("Multiple widgets used the same GlobalKey.\n");
foreach (GlobalKey key in duplicates.Keys) {
HashSet<Element> elements = duplicates[key];
buffer.AppendLine($"The key {key} was used by {elements.Count} widgets:");
foreach (Element element in elements) {
buffer.AppendLine("- " + element);
}
}
buffer.Append("A GlobalKey can only be specified on one widget at a time in the widget tree.");
throw new UIWidgetsError(buffer.ToString());
}
return true;
});
}
internal Element _currentElement {
get {
Element result;
CompositeKey compKey = new CompositeKey(Window.instance, this);
_registry.TryGetValue(compKey, out result);
return result;
}
}
public BuildContext currentContext {
get { return this._currentElement; }
}
public Widget currentWidget {
get { return this._currentElement == null ? null : this._currentElement.widget; }
}
public State currentState {
get {
Element element = this._currentElement;
if (element is StatefulElement) {
var statefulElement = (StatefulElement) element;
State state = statefulElement.state;
if (state is State) {
return (State) state;
}
}
return null;
}
}
}
public abstract class GlobalKey<T> : GlobalKey where T : State {
public new static GlobalKey<T> key(string debugLabel = null) {
return new LabeledGlobalKey<T>(debugLabel);
}
public new T currentState {
get {
Element element = this._currentElement;
if (element is StatefulElement) {
var statefulElement = (StatefulElement) element;
State state = statefulElement.state;
if (state is T) {
return (T) state;
}
}
return null;
}
}
}
public class LabeledGlobalKey<T> : GlobalKey<T> where T : State {
public LabeledGlobalKey(string _debugLabel = null) {
this._debugLabel = _debugLabel;
}
readonly string _debugLabel;
public override string ToString() {
string label = this._debugLabel != null ? " " + this._debugLabel : "";
if (this.GetType() == typeof(LabeledGlobalKey<T>)) {
return $"[GlobalKey#{Diagnostics.shortHash(this)}{label}]";
}
return $"[{Diagnostics.describeIdentity(this)}{label}]";
}
}
public class GlobalObjectKey<T> : GlobalKey<T>, IEquatable<GlobalObjectKey<T>> where T : State {
public GlobalObjectKey(object value) {
this.value = value;
}
public readonly object value;
public bool Equals(GlobalObjectKey<T> other) {
if (ReferenceEquals(null, other)) {
return false;
}
if (ReferenceEquals(this, other)) {
return true;
}
return ReferenceEquals(this.value, other.value);
}
public override bool Equals(object obj) {
if (ReferenceEquals(null, obj)) {
return false;
}
if (ReferenceEquals(this, obj)) {
return true;
}
if (obj.GetType() != this.GetType()) {
return false;
}
return this.Equals((GlobalObjectKey<T>) obj);
}
public override int GetHashCode() {
return (this.value != null ? RuntimeHelpers.GetHashCode(this.value) : 0);
}
public static bool operator ==(GlobalObjectKey<T> left, GlobalObjectKey<T> right) {
return Equals(left, right);
}
public static bool operator !=(GlobalObjectKey<T> left, GlobalObjectKey<T> right) {
return !Equals(left, right);
}
public override string ToString() {
string selfType = this.GetType().ToString();
string suffix = "`1[UIWidgets.widgets.State]";
if (selfType.EndsWith(suffix)) {
selfType = selfType.Substring(0, selfType.Length - suffix.Length);
}
return $"[{selfType} {Diagnostics.describeIdentity(this.value)}]";
}
}
public interface TypeMatcher {
bool check(object obj);
}
public class TypeMatcher<T> : TypeMatcher {
public bool check(object obj) {
return obj is T;
}
}
public abstract class Widget : CanonicalMixinDiagnosticableTree {
protected Widget(Key key = null) {
this.key = key;
}
public readonly Key key;
public abstract Element createElement();
public override string toStringShort() {
return this.key == null ? this.GetType().ToString() : this.GetType() + "-" + this.key;
}
public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
base.debugFillProperties(properties);
properties.defaultDiagnosticsTreeStyle = DiagnosticsTreeStyle.dense;
}
public static bool canUpdate(Widget oldWidget, Widget newWidget) {
return oldWidget.GetType() == newWidget.GetType() && Equals(oldWidget.key, newWidget.key);
}
}
public abstract class StatelessWidget : Widget {
protected StatelessWidget(Key key = null) : base(key: key) {
}
public override Element createElement() {
return new StatelessElement(this);
}
public abstract Widget build(BuildContext context);
}
public abstract class StatefulWidget : Widget {
protected StatefulWidget(Key key = null) : base(key: key) {
}
public override Element createElement() {
return new StatefulElement(this);
}
public abstract State createState();
}
enum _StateLifecycle {
created,
initialized,
ready,
defunct,
}
public delegate void StateSetter(VoidCallback fn);
public abstract class State : Diagnosticable {
public StatefulWidget widget {
get { return this._widget; }
}
internal StatefulWidget _widget;
internal _StateLifecycle _debugLifecycleState = _StateLifecycle.created;
public virtual bool _debugTypesAreRight(Widget widget) {
return widget is StatefulWidget;
}
public BuildContext context {
get { return this._element; }
}
internal StatefulElement _element;
public bool mounted {
get { return this._element != null; }
}
public virtual void initState() {
D.assert(this._debugLifecycleState == _StateLifecycle.created);
}
public virtual void didUpdateWidget(StatefulWidget oldWidget) {
}
public void setState(VoidCallback fn = null) {
D.assert(() => {
if (this._debugLifecycleState == _StateLifecycle.defunct) {
throw new UIWidgetsError(
"setState() called after dispose(): " + this + "\n" +
"This error happens if you call setState() on a State object for a widget that " +
"no longer appears in the widget tree (e.g., whose parent widget no longer " +
"includes the widget in its build). This error can occur when code calls " +
"setState() from a timer or an animation callback. The preferred solution is " +
"to cancel the timer or stop listening to the animation in the dispose() " +
"callback. Another solution is to check the \"mounted\" property of this " +
"object before calling setState() to ensure the object is still in the " +
"tree.\n" +
"This error might indicate a memory leak if setState() is being called " +
"because another object is retaining a reference to this State object " +
"after it has been removed from the tree. To avoid memory leaks, " +
"consider breaking the reference to this object during dispose()."
);
}
if (this._debugLifecycleState == _StateLifecycle.created && !this.mounted) {
throw new UIWidgetsError(
"setState() called in constructor: " + this + "\n" +
"This happens when you call setState() on a State object for a widget that " +
"hasn\"t been inserted into the widget tree yet. It is not necessary to call " +
"setState() in the constructor, since the state is already assumed to be dirty " +
"when it is initially created."
);
}
return true;
});
if (fn != null) {
fn();
}
this._element.markNeedsBuild();
}
public virtual void deactivate() {
}
public virtual void dispose() {
D.assert(this._debugLifecycleState == _StateLifecycle.ready);
D.assert(() => {
this._debugLifecycleState = _StateLifecycle.defunct;
return true;
});
}
public abstract Widget build(BuildContext context);
public virtual void didChangeDependencies() {
}
public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
base.debugFillProperties(properties);
D.assert(() => {
properties.add(new EnumProperty<_StateLifecycle>(
"lifecycle state", this._debugLifecycleState,
defaultValue: _StateLifecycle.ready));
return true;
});
properties.add(new ObjectFlagProperty<StatefulWidget>(
"_widget", this._widget, ifNull: "no widget"));
properties.add(new ObjectFlagProperty<StatefulElement>(
"_element", this._element, ifNull: "not mounted"));
}
}
public abstract class State<T> : State where T : StatefulWidget {
public new T widget {
get { return (T) base.widget; }
}
public override bool _debugTypesAreRight(Widget widget) {
return widget is T;
}
}
public abstract class ProxyWidget : Widget {
protected ProxyWidget(Key key = null, Widget child = null) : base(key: key) {
this.child = child;
}
public readonly Widget child;
}
public abstract class ParentDataWidget : ProxyWidget {
public ParentDataWidget(Key key = null, Widget child = null)
: base(key: key, child: child) {
}
public abstract bool debugIsValidAncestor(RenderObjectWidget ancestor);
public abstract string debugDescribeInvalidAncestorChain(
string description = null,
string ownershipChain = null,
bool foundValidAncestor = false,
IEnumerable<Widget> badAncestors = null
);
public abstract void applyParentData(RenderObject renderObject);
public virtual bool debugCanApplyOutOfTurn() {
return false;
}
}
public abstract class ParentDataWidget<T> : ParentDataWidget where T : RenderObjectWidget {
public ParentDataWidget(Key key = null, Widget child = null)
: base(key: key, child: child) {
}
public override Element createElement() {
return new ParentDataElement(this);
}
public override bool debugIsValidAncestor(RenderObjectWidget ancestor) {
D.assert(typeof(T) != typeof(RenderObjectWidget));
return ancestor is T;
}
public override string debugDescribeInvalidAncestorChain(
string description = null,
string ownershipChain = null,
bool foundValidAncestor = false,
IEnumerable<Widget> badAncestors = null
) {
D.assert(typeof(T) != typeof(RenderObjectWidget));
string result;
if (!foundValidAncestor) {
result = string.Format(
"{0} widgets must be placed inside {1} widgets.\n" +
"{2} has no {1} ancestor at all.\n", this.GetType(), typeof(T), description);
}
else {
D.assert(badAncestors != null);
D.assert(badAncestors.Any());
result = string.Format(
"{0} widgets must be placed directly inside {1} widgets.\n" +
"{2} has a {1} ancestor, but there are other widgets between them:\n",
this.GetType(), typeof(T), description);
foreach (Widget ancestor in badAncestors) {
if (ancestor.GetType() == this.GetType()) {
result +=
$"- {ancestor} (this is a different {this.GetType()} than the one with the problem)\n";
}
else {
result += $"- {ancestor}\n";
}
}
result += "These widgets cannot come between a " + this.GetType() + " and its " + typeof(T) + ".\n";
}
result += "The ownership chain for the parent of the offending "
+ this.GetType() + " was:\n " + ownershipChain;
return result;
}
}
public abstract class InheritedWidget : ProxyWidget {
protected InheritedWidget(Key key = null, Widget child = null) : base(key, child) {
}
public override Element createElement() {
return new InheritedElement(this);
}
public abstract bool updateShouldNotify(InheritedWidget oldWidget);
}
public abstract class RenderObjectWidget : Widget {
protected RenderObjectWidget(Key key = null) : base(key) {
}
public abstract RenderObject createRenderObject(BuildContext context);
public virtual void updateRenderObject(BuildContext context, RenderObject renderObject) {
}
public virtual void didUnmountRenderObject(RenderObject renderObject) {
}
}
public abstract class LeafRenderObjectWidget : RenderObjectWidget {
protected LeafRenderObjectWidget(Key key = null) : base(key: key) {
}
public override Element createElement() {
return new LeafRenderObjectElement(this);
}
}
public abstract class SingleChildRenderObjectWidget : RenderObjectWidget {
protected SingleChildRenderObjectWidget(Key key = null, Widget child = null) : base(key: key) {
this.child = child;
}
public readonly Widget child;
public override Element createElement() {
return new SingleChildRenderObjectElement(this);
}
}
public abstract class MultiChildRenderObjectWidget : RenderObjectWidget {
protected MultiChildRenderObjectWidget(Key key = null, List<Widget> children = null) : base(key: key) {
children = children ?? new List<Widget>();
D.assert(!children.Any(child => child == null));
this.children = children;
}
public readonly List<Widget> children;
public override Element createElement() {
return new MultiChildRenderObjectElement(this);
}
}
enum _ElementLifecycle {
initial,
active,
inactive,
defunct,
}
class _InactiveElements {
bool _locked = false;
readonly HashSet<Element> _elements = new HashSet<Element>();
internal void _unmount(Element element) {
D.assert(element._debugLifecycleState == _ElementLifecycle.inactive);
D.assert(() => {
if (WidgetsD.debugPrintGlobalKeyedWidgetLifecycle) {
if (element.widget.key is GlobalKey) {
Debug.LogFormat("Discarding {0} from inactive elements list.", element);
}
}
return true;
});
element.visitChildren(child => {
D.assert(child._parent == element);
this._unmount(child);
});
element.unmount();
D.assert(element._debugLifecycleState == _ElementLifecycle.defunct);
}
internal void _unmountAll() {
this._locked = true;
List<Element> elements = this._elements.ToList();
elements.Sort(Element._sort);
this._elements.Clear();
try {
elements.Reverse();
elements.ForEach(this._unmount);
}
finally {
D.assert(this._elements.isEmpty());
this._locked = false;
}
}
internal void _deactivateRecursively(Element element) {
D.assert(element._debugLifecycleState == _ElementLifecycle.active);
element.deactivate();
D.assert(element._debugLifecycleState == _ElementLifecycle.inactive);
element.visitChildren(this._deactivateRecursively);
D.assert(() => {
element.debugDeactivated();
return true;
});
}
internal void add(Element element) {
D.assert(!this._locked);
D.assert(!this._elements.Contains(element));
D.assert(element._parent == null);
if (element._active) {
this._deactivateRecursively(element);
}
this._elements.Add(element);
}
internal void remove(Element element) {
D.assert(!this._locked);
D.assert(this._elements.Contains(element));
D.assert(element._parent == null);
this._elements.Remove(element);
D.assert(!element._active);
}
internal bool debugContains(Element element) {
bool result = false;
D.assert(() => {
result = this._elements.Contains(element);
return true;
});
return result;
}
}
public delegate void ElementVisitor(Element element);
public delegate bool ElementVisitorBool(Element element);
public interface BuildContext {
Widget widget { get; }
BuildOwner owner { get; }
RenderObject findRenderObject();
Size size { get; }
InheritedWidget inheritFromElement(InheritedElement ancestor, object aspect = null);
InheritedWidget inheritFromWidgetOfExactType(Type targetType, object aspect = null);
InheritedElement ancestorInheritedElementForWidgetOfExactType(Type targetType);
Widget ancestorWidgetOfExactType(Type targetType);
State ancestorStateOfType(TypeMatcher matcher);
State rootAncestorStateOfType(TypeMatcher matcher);
RenderObject ancestorRenderObjectOfType(TypeMatcher matcher);
void visitAncestorElements(ElementVisitorBool visitor);
void visitChildElements(ElementVisitor visitor);
}
public class BuildOwner {
public BuildOwner(VoidCallback onBuildScheduled = null) {
this.onBuildScheduled = onBuildScheduled;
}
public VoidCallback onBuildScheduled;
internal readonly _InactiveElements _inactiveElements = new _InactiveElements();
readonly List<Element> _dirtyElements = new List<Element>();
bool _scheduledFlushDirtyElements = false;
bool? _dirtyElementsNeedsResorting = null;
bool _debugIsInBuildScope {
get { return this._dirtyElementsNeedsResorting != null; }
}
public readonly FocusManager focusManager = new FocusManager();
public void scheduleBuildFor(Element element) {
D.assert(element != null);
D.assert(element.owner == this);
D.assert(() => {
if (WidgetsD.debugPrintScheduleBuildForStacks) {
Debug.Log("scheduleBuildFor() called for " + element +
(this._dirtyElements.Contains(element) ? " (ALREADY IN LIST)" : ""));
}
if (!element.dirty) {
throw new UIWidgetsError(
"scheduleBuildFor() called for a widget that is not marked as dirty.\n" +
"The method was called for the following element:\n" +
" " + element + "\n" +
"This element is not current marked as dirty. Make sure to set the dirty flag before " +
"calling scheduleBuildFor().\n" +
"If you did not attempt to call scheduleBuildFor() yourself, then this probably " +
"indicates a bug in the widgets framework."
);
}
return true;
});
if (element._inDirtyList) {
D.assert(() => {
if (WidgetsD.debugPrintScheduleBuildForStacks) {
Debug.LogFormat(
"BuildOwner.scheduleBuildFor() called; _dirtyElementsNeedsResorting was {0} (now true); dirty list is: {1}",
this._dirtyElementsNeedsResorting, this._dirtyElements);
}
if (!this._debugIsInBuildScope) {
throw new UIWidgetsError(
"BuildOwner.scheduleBuildFor() called inappropriately.\n" +
"The BuildOwner.scheduleBuildFor() method should only be called while the " +
"buildScope() method is actively rebuilding the widget tree."
);
}
return true;
});
this._dirtyElementsNeedsResorting = true;
return;
}
if (!this._scheduledFlushDirtyElements && this.onBuildScheduled != null) {
this._scheduledFlushDirtyElements = true;
this.onBuildScheduled();
}
this._dirtyElements.Add(element);
element._inDirtyList = true;
D.assert(() => {
if (WidgetsD.debugPrintScheduleBuildForStacks) {
Debug.Log("...dirty list is now: " + this._dirtyElements);
}
return true;
});
}
int _debugStateLockLevel = 0;
internal bool _debugStateLocked {
get { return this._debugStateLockLevel > 0; }
}
internal bool debugBuilding {
get { return this._debugBuilding; }
}
bool _debugBuilding = false;
internal Element _debugCurrentBuildTarget;
public void lockState(VoidCallback callback) {
D.assert(callback != null);
D.assert(this._debugStateLockLevel >= 0);
D.assert(() => {
this._debugStateLockLevel += 1;
return true;
});
try {
callback();
}
finally {
D.assert(() => {
this._debugStateLockLevel -= 1;
return true;
});
}
D.assert(this._debugStateLockLevel >= 0);
}
public void buildScope(Element context, VoidCallback callback = null) {
if (callback == null && this._dirtyElements.isEmpty()) {
return;
}
D.assert(context != null);
D.assert(this._debugStateLockLevel >= 0);
D.assert(!this._debugBuilding);
D.assert(() => {
if (WidgetsD.debugPrintBuildScope) {
Debug.LogFormat("buildScope called with context {0}; dirty list is: {1}",
context, this._dirtyElements);
}
this._debugStateLockLevel += 1;
this._debugBuilding = true;
return true;
});
try {
this._scheduledFlushDirtyElements = true;
if (callback != null) {
D.assert(this._debugStateLocked);
Element debugPreviousBuildTarget = null;
D.assert(() => {
context._debugSetAllowIgnoredCallsToMarkNeedsBuild(true);
debugPreviousBuildTarget = this._debugCurrentBuildTarget;
this._debugCurrentBuildTarget = context;
return true;
});
this._dirtyElementsNeedsResorting = false;
try {
callback();
}
finally {
D.assert(() => {
context._debugSetAllowIgnoredCallsToMarkNeedsBuild(false);
D.assert(this._debugCurrentBuildTarget == context);
this._debugCurrentBuildTarget = debugPreviousBuildTarget;
this._debugElementWasRebuilt(context);
return true;
});
}
}
this._dirtyElements.Sort(Element._sort);
this._dirtyElementsNeedsResorting = false;
int dirtyCount = this._dirtyElements.Count;
int index = 0;
while (index < dirtyCount) {
D.assert(this._dirtyElements[index] != null);
D.assert(this._dirtyElements[index]._inDirtyList);
D.assert(!this._dirtyElements[index]._active ||
this._dirtyElements[index]._debugIsInScope(context));
try {
this._dirtyElements[index].rebuild();
}
catch (Exception ex) {
WidgetsD._debugReportException(
"while rebuilding dirty elements", ex,
informationCollector: (information) => {
information.AppendLine(
"The element being rebuilt at the time was index "
+ index + " of " + dirtyCount + ":");
information.Append(" " + this._dirtyElements[index]);
}
);
}
index++;
if (dirtyCount < this._dirtyElements.Count || this._dirtyElementsNeedsResorting.Value) {
this._dirtyElements.Sort(Element._sort);
this._dirtyElementsNeedsResorting = false;
dirtyCount = this._dirtyElements.Count;
while (index > 0 && this._dirtyElements[index - 1].dirty) {
index -= 1;
}
}
}
D.assert(() => {
if (this._dirtyElements.Any(element => element._active && element.dirty)) {
throw new UIWidgetsError(
"buildScope missed some dirty elements.\n" +
"This probably indicates that the dirty list should have been resorted but was not.\n" +
"The list of dirty elements at the end of the buildScope call was:\n" +
" " + this._dirtyElements);
}
return true;
});
}
finally {
foreach (Element element in this._dirtyElements) {
D.assert(element._inDirtyList);
element._inDirtyList = false;
}
this._dirtyElements.Clear();
this._scheduledFlushDirtyElements = false;
this._dirtyElementsNeedsResorting = null;
D.assert(this._debugBuilding);
D.assert(() => {
this._debugBuilding = false;
this._debugStateLockLevel -= 1;
if (WidgetsD.debugPrintBuildScope) {
Debug.Log("buildScope finished");
}
return true;
});
}
D.assert(this._debugStateLockLevel >= 0);
}
Dictionary<Element, HashSet<GlobalKey>> _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans;
internal void _debugTrackElementThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans(Element node, GlobalKey key) {
this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans =
this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans ??
new Dictionary<Element, HashSet<GlobalKey>>();
var keys = this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans
.putIfAbsent(node, () => new HashSet<GlobalKey>());
keys.Add(key);
}
internal void _debugElementWasRebuilt(Element node) {
if (this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans != null) {
this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.Remove(node);
}
}
public void finalizeTree() {
try {
this.lockState(() => { this._inactiveElements._unmountAll(); });
D.assert(() => {
try {
GlobalKey._debugVerifyIllFatedPopulation();
if (this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans != null &&
this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.isNotEmpty()) {
var keys = new HashSet<GlobalKey>();
foreach (Element element in this
._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans
.Keys) {
if (element._debugLifecycleState != _ElementLifecycle.defunct) {
keys.UnionWith(
this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans[element]);
}
}
if (keys.isNotEmpty()) {
var keyStringCount = new Dictionary<string, int>();
foreach (string key in keys.Select(key => key.ToString())) {
if (keyStringCount.ContainsKey(key)) {
keyStringCount[key] += 1;
}
else {
keyStringCount[key] = 1;
}
}
var keyLabels = new List<string>();
foreach (var entry in keyStringCount) {
var key = entry.Key;
var count = entry.Value;
if (count == 1) {
keyLabels.Add(key);
}
else {
keyLabels.Add(
$"{key} ({count} different affected keys had this toString representation)");
}
}
var elements = this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.Keys;
var elementStringCount = new Dictionary<string, int>();
foreach (string element in elements.Select(element => element.ToString())) {
if (elementStringCount.ContainsKey(element)) {
elementStringCount[element] += 1;
}
else {
elementStringCount[element] = 1;
}
}
var elementLabels = new List<string>();
foreach (var entry in elementStringCount) {
var element = entry.Key;
var count = entry.Value;
if (count == 1) {
elementLabels.Add(element);
}
else {
elementLabels.Add(
$"{element} ({count} different affected elements had this toString representation)");
}
}
D.assert(keyLabels.isNotEmpty());
throw new UIWidgetsError(
"Duplicate GlobalKeys detected in widget tree.\n" +
"The following GlobalKeys were specified multiple times in the widget tree. This will lead to " +
"parts of the widget tree being truncated unexpectedly, because the second time a key is seen, " +
"the previous instance is moved to the new location. The keys were:\n" +
"- " + string.Join("\n ", keyLabels.ToArray()) + "\n" +
"This was determined by noticing that after the widgets with the above global keys were moved " +
"out of their respective previous parents, those previous parents never updated during this frame, meaning " +
"that they either did not update at all or updated before the widgets were moved, in either case " +
"implying that they still think that they should have a child with those global keys.\n" +
"The specific parents that did not update after having one or more children forcibly removed " +
"due to GlobalKey reparenting are:\n" +
"- " + string.Join("\n ", elementLabels.ToArray()) + "\n" +
"A GlobalKey can only be specified on one widget at a time in the widget tree."
);
}
}
}
finally {
if (this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans != null) {
this._debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.Clear();
}
}
return true;
});
}
catch (Exception ex) {
WidgetsD._debugReportException("while finalizing the widget tree", ex);
}
}
}
public abstract class Element : DiagnosticableTree, BuildContext {
protected Element(Widget widget) {
D.assert(widget != null);
this._widget = widget;
}
internal Element _parent;
public override bool Equals(object obj) {
return ReferenceEquals(this, obj);
}
static int _nextHashCode = 1;
readonly int _cachedHash = _nextHashCode = (_nextHashCode + 1) % 0xffffff;
public override int GetHashCode() {
return this._cachedHash;
}
internal object _slot;
public object slot {
get { return this._slot; }
}
internal int _depth;
public int depth {
get { return this._depth; }
}
internal static int _sort(Element a, Element b) {
if (a.depth < b.depth) {
return -1;
}
if (b.depth < a.depth) {
return 1;
}
if (b.dirty && !a.dirty) {
return -1;
}
if (a.dirty && !b.dirty) {
return 1;
}
return 0;
}
internal Widget _widget;
public Widget widget {
get { return this._widget; }
}
internal BuildOwner _owner;
public BuildOwner owner {
get { return this._owner; }
}
public bool _active = false;
internal bool _debugIsInScope(Element target) {
Element current = this;
while (current != null) {
if (target == current) {
return true;
}
current = current._parent;
}
return false;
}
public virtual RenderObject renderObject {
get {
RenderObject result = null;
ElementVisitor visit = null;
visit = (element) => {
D.assert(result == null);
if (element is RenderObjectElement) {
result = element.renderObject;
}
else {
element.visitChildren(visit);
}
};
visit(this);
return result;
}
}
internal _ElementLifecycle _debugLifecycleState = _ElementLifecycle.initial;
public virtual void visitChildren(ElementVisitor visitor) {
}
public virtual void debugVisitOnstageChildren(ElementVisitor visitor) {
this.visitChildren(visitor);
}
public void visitChildElements(ElementVisitor visitor) {
D.assert(() => {
if (this.owner == null || !this.owner._debugStateLocked) {
return true;
}
throw new UIWidgetsError(
"visitChildElements() called during build.\n" +
"The BuildContext.visitChildElements() method can\"t be called during " +
"build because the child list is still being updated at that point, " +
"so the children might not be constructed yet, or might be old children " +
"that are going to be replaced."
);
});
this.visitChildren(visitor);
}
protected virtual Element updateChild(Element child, Widget newWidget, object newSlot) {
D.assert(() => {
if (newWidget != null && newWidget.key is GlobalKey) {
GlobalKey key = (GlobalKey) newWidget.key;
key._debugReserveFor(this);
}
return true;
});
if (newWidget == null) {
if (child != null) {
this.deactivateChild(child);
}
return null;
}
if (child != null) {
if (Equals(child.widget, newWidget)) {
if (!Equals(child.slot, newSlot)) {
this.updateSlotForChild(child, newSlot);
}
return child;
}
if (Widget.canUpdate(child.widget, newWidget)) {
if (!Equals(child.slot, newSlot)) {
this.updateSlotForChild(child, newSlot);
}
child.update(newWidget);
D.assert(child.widget == newWidget);
D.assert(() => {
child.owner._debugElementWasRebuilt(child);
return true;
});
return child;
}
this.deactivateChild(child);
D.assert(child._parent == null);
}
return this.inflateWidget(newWidget, newSlot);
}
public virtual void mount(Element parent, object newSlot) {
D.assert(this._debugLifecycleState == _ElementLifecycle.initial);
D.assert(this.widget != null);
D.assert(this._parent == null);
D.assert(parent == null || parent._debugLifecycleState == _ElementLifecycle.active);
D.assert(this.slot == null);
D.assert(this.depth == 0);
D.assert(!this._active);
this._parent = parent;
this._slot = newSlot;
this._depth = this._parent != null ? this._parent.depth + 1 : 1;
this._active = true;
if (parent != null) {
this._owner = parent.owner;
}
if (this.widget.key is GlobalKey) {
GlobalKey key = (GlobalKey) this.widget.key;
key._register(this);
}
this._updateInheritance();
D.assert(() => {
this._debugLifecycleState = _ElementLifecycle.active;
return true;
});
}
public virtual void update(Widget newWidget) {
D.assert(this._debugLifecycleState == _ElementLifecycle.active
&& this.widget != null
&& newWidget != null
&& newWidget != this.widget
&& this.depth != 0
&& this._active
&& Widget.canUpdate(this.widget, newWidget));
this._widget = newWidget;
}
protected void updateSlotForChild(Element child, object newSlot) {
D.assert(this._debugLifecycleState == _ElementLifecycle.active);
D.assert(child != null);
D.assert(child._parent == this);
ElementVisitor visit = null;
visit = (element) => {
element._updateSlot(newSlot);
if (!(element is RenderObjectElement)) {
element.visitChildren(visit);
}
};
visit(child);
}
internal virtual void _updateSlot(object newSlot) {
D.assert(this._debugLifecycleState == _ElementLifecycle.active);
D.assert(this.widget != null);
D.assert(this._parent != null);
D.assert(this._parent._debugLifecycleState == _ElementLifecycle.active);
D.assert(this.depth != 0);
this._slot = newSlot;
}
void _updateDepth(int parentDepth) {
int expectedDepth = parentDepth + 1;
if (this._depth < expectedDepth) {
this._depth = expectedDepth;
this.visitChildren(child => { child._updateDepth(expectedDepth); });
}
}
public virtual void detachRenderObject() {
this.visitChildren(child => { child.detachRenderObject(); });
this._slot = null;
}
public virtual void attachRenderObject(object newSlot) {
D.assert(this._slot == null);
this.visitChildren(child => { child.attachRenderObject(newSlot); });
this._slot = newSlot;
}
Element _retakeInactiveElement(GlobalKey key, Widget newWidget) {
Element element = key._currentElement;
if (element == null) {
return null;
}
if (!Widget.canUpdate(element.widget, newWidget)) {
return null;
}
D.assert(() => {
if (WidgetsD.debugPrintGlobalKeyedWidgetLifecycle) {
Debug.LogFormat("Attempting to take {0} from {1} to put in {2}.",
element, element._parent == null ? "inactive elements list" : element._parent.ToString(), this);
}
return true;
});
Element parent = element._parent;
if (parent != null) {
D.assert(() => {
if (parent == this) {
throw new UIWidgetsError(
"A GlobalKey was used multiple times inside one widget\"s child list.\n" +
$"The offending GlobalKey was: {key}\n" +
$"The parent of the widgets with that key was:\n {parent}\n" +
$"The first child to get instantiated with that key became:\n {element}\n" +
$"The second child that was to be instantiated with that key was:\n {this.widget}\n" +
"A GlobalKey can only be specified on one widget at a time in the widget tree.");
}
parent.owner._debugTrackElementThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans(
parent,
key
);
return true;
});
parent.forgetChild(element);
parent.deactivateChild(element);
}
D.assert(element._parent == null);
this.owner._inactiveElements.remove(element);
return element;
}
protected Element inflateWidget(Widget newWidget, object newSlot) {
D.assert(newWidget != null);
Key key = newWidget.key;
Element newChild;
if (key is GlobalKey) {
newChild = this._retakeInactiveElement((GlobalKey) key, newWidget);
if (newChild != null) {
D.assert(newChild._parent == null);
D.assert(() => {
this._debugCheckForCycles(newChild);
return true;
});
newChild._activateWithParent(this, newSlot);
Element updatedChild = this.updateChild(newChild, newWidget, newSlot);
D.assert(newChild == updatedChild);
return updatedChild;
}
}
newChild = newWidget.createElement();
D.assert(() => {
this._debugCheckForCycles(newChild);
return true;
});
newChild.mount(this, newSlot);
D.assert(newChild._debugLifecycleState == _ElementLifecycle.active);
return newChild;
}
void _debugCheckForCycles(Element newChild) {
D.assert(newChild._parent == null);
D.assert(() => {
Element node = this;
while (node._parent != null) {
node = node._parent;
}
D.assert(node != newChild);
return true;
});
}
protected void deactivateChild(Element child) {
D.assert(child != null);
D.assert(child._parent == this);
child._parent = null;
child.detachRenderObject();
this.owner._inactiveElements.add(child);
D.assert(() => {
if (WidgetsD.debugPrintGlobalKeyedWidgetLifecycle) {
if (child.widget.key is GlobalKey) {
Debug.LogFormat("Deactivated {0} (keyed child of {1})", child, this);
}
}
return true;
});
}
protected abstract void forgetChild(Element child);
void _activateWithParent(Element parent, object newSlot) {
D.assert(this._debugLifecycleState == _ElementLifecycle.inactive);
this._parent = parent;
D.assert(() => {
if (WidgetsD.debugPrintGlobalKeyedWidgetLifecycle) {
Debug.LogFormat("Reactivating {0} (now child of {1}).", this, this._parent);
}
return true;
});
this._updateDepth(this._parent.depth);
_activateRecursively(this);
this.attachRenderObject(newSlot);
D.assert(this._debugLifecycleState == _ElementLifecycle.active);
}
static void _activateRecursively(Element element) {
D.assert(element._debugLifecycleState == _ElementLifecycle.inactive);
element.activate();
D.assert(element._debugLifecycleState == _ElementLifecycle.active);
element.visitChildren(_activateRecursively);
}
public virtual void activate() {
D.assert(this._debugLifecycleState == _ElementLifecycle.inactive);
D.assert(this.widget != null);
D.assert(this.owner != null);
D.assert(this.depth != 0);
D.assert(!this._active);
bool hadDependencies = (this._dependencies != null && this._dependencies.isNotEmpty()) ||
this._hadUnsatisfiedDependencies;
this._active = true;
if (this._dependencies != null) {
this._dependencies.Clear();
}
this._hadUnsatisfiedDependencies = false;
this._updateInheritance();
D.assert(() => {
this._debugLifecycleState = _ElementLifecycle.active;
return true;
});
if (this._dirty) {
this.owner.scheduleBuildFor(this);
}
if (hadDependencies) {
this.didChangeDependencies();
}
}
public virtual void deactivate() {
D.assert(this._debugLifecycleState == _ElementLifecycle.active);
D.assert(this.widget != null);
D.assert(this.depth != 0);
D.assert(this._active);
if (this._dependencies != null && this._dependencies.isNotEmpty()) {
foreach (InheritedElement dependency in this._dependencies) {
dependency._dependents.Remove(this);
}
}
this._inheritedWidgets = null;
this._active = false;
D.assert(() => {
this._debugLifecycleState = _ElementLifecycle.inactive;
return true;
});
}
public virtual void debugDeactivated() {
D.assert(this._debugLifecycleState == _ElementLifecycle.inactive);
}
public virtual void unmount() {
D.assert(this._debugLifecycleState == _ElementLifecycle.inactive);
D.assert(this.widget != null);
D.assert(this.depth != 0);
D.assert(!this._active);
if (this.widget.key is GlobalKey) {
GlobalKey key = (GlobalKey) this.widget.key;
key._unregister(this);
}
D.assert(() => {
this._debugLifecycleState = _ElementLifecycle.defunct;
return true;
});
}
public RenderObject findRenderObject() {
return this.renderObject;
}
public Size size {
get {
D.assert(() => {
if (this._debugLifecycleState != _ElementLifecycle.active) {
throw new UIWidgetsError(
"Cannot get size of inactive element.\n" +
"In order for an element to have a valid size, the element must be " +
"active, which means it is part of the tree. Instead, this element " +
"is in the " + this._debugLifecycleState + " state.\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n");
}
if (this.owner.debugBuilding) {
throw new UIWidgetsError(
"Cannot get size during build.\n" +
"The size of this render object has not yet been determined because " +
"the framework is still in the process of building widgets, which " +
"means the render tree for this frame has not yet been determined. " +
"The size getter should only be called from paint callbacks or " +
"interaction event handlers (e.g. gesture callbacks).\n" +
"\n" +
"If you need some sizing information during build to decide which " +
"widgets to build, consider using a LayoutBuilder widget, which can " +
"tell you the layout constraints at a given location in the tree." +
"\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n");
}
return true;
});
RenderObject renderObject = this.findRenderObject();
D.assert(() => {
if (renderObject == null) {
throw new UIWidgetsError(
"Cannot get size without a render object.\n" +
"In order for an element to have a valid size, the element must have " +
"an associated render object. This element does not have an associated " +
"render object, which typically means that the size getter was called " +
"too early in the pipeline (e.g., during the build phase) before the " +
"framework has created the render tree.\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n");
}
if (renderObject is RenderSliver) {
throw new UIWidgetsError(
"Cannot get size from a RenderSliver.\n" +
"The render object associated with this element is a " +
renderObject.GetType() + ", which is a subtype of RenderSliver. " +
"Slivers do not have a size per se. They have a more elaborate " +
"geometry description, which can be accessed by calling " +
"findRenderObject and then using the \"geometry\" getter on the " +
"resulting object.\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n" +
"The associated render sliver was:\n" +
" " + renderObject.toStringShallow(joiner: "\n "));
}
if (!(renderObject is RenderBox)) {
throw new UIWidgetsError(
"Cannot get size from a render object that is not a RenderBox.\n" +
"Instead of being a subtype of RenderBox, the render object associated " +
"with this element is a " + renderObject.GetType() + ". If this type of " +
"render object does have a size, consider calling findRenderObject " +
"and extracting its size manually.\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n" +
"The associated render object was:\n" +
" " + renderObject.toStringShallow(joiner: "\n "));
}
RenderBox box = (RenderBox) renderObject;
if (!box.hasSize) {
throw new UIWidgetsError(
"Cannot get size from a render object that has not been through layout.\n" +
"The size of this render object has not yet been determined because " +
"this render object has not yet been through layout, which typically " +
"means that the size getter was called too early in the pipeline " +
"(e.g., during the build phase) before the framework has determined " +
"the size and position of the render objects during layout.\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n" +
"The render object from which the size was to be obtained was:\n" +
" " + box.toStringShallow(joiner: "\n "));
}
if (box.debugNeedsLayout) {
throw new UIWidgetsError(
"Cannot get size from a render object that has been marked dirty for layout.\n" +
"The size of this render object is ambiguous because this render object has " +
"been modified since it was last laid out, which typically means that the size " +
"getter was called too early in the pipeline (e.g., during the build phase) " +
"before the framework has determined the size and position of the render " +
"objects during layout.\n" +
"The size getter was called for the following element:\n" +
" " + this + "\n" +
"The render object from which the size was to be obtained was:\n" +
" \n" + box.toStringShallow(joiner: "\n ") +
"Consider using debugPrintMarkNeedsLayoutStacks to determine why the render " +
"object in question is dirty, if you did not expect this.");
}
return true;
});
if (renderObject is RenderBox) {
return ((RenderBox) renderObject).size;
}
return null;
}
}
internal Dictionary<Type, InheritedElement> _inheritedWidgets;
internal HashSet<InheritedElement> _dependencies;
bool _hadUnsatisfiedDependencies = false;
bool _debugCheckStateIsActiveForAncestorLookup() {
D.assert(() => {
if (this._debugLifecycleState != _ElementLifecycle.active) {
throw new UIWidgetsError(
"Looking up a deactivated widget\"s ancestor is unsafe.\n" +
"At this point the state of the widget\"s element tree is no longer " +
"stable. To safely refer to a widget\"s ancestor in its dispose() method, " +
"save a reference to the ancestor by calling inheritFromWidgetOfExactType() " +
"in the widget\"s didChangeDependencies() method.\n");
}
return true;
});
return true;
}
public virtual InheritedWidget inheritFromElement(InheritedElement ancestor, object aspect = null) {
D.assert(ancestor != null);
this._dependencies = this._dependencies ?? new HashSet<InheritedElement>();
this._dependencies.Add(ancestor);
ancestor.updateDependencies(this, aspect);
return ancestor.widget;
}
public virtual InheritedWidget inheritFromWidgetOfExactType(Type targetType, object aspect = null) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
InheritedElement ancestor = null;
if (this._inheritedWidgets != null) {
this._inheritedWidgets.TryGetValue(targetType, out ancestor);
}
if (ancestor != null) {
return this.inheritFromElement(ancestor, aspect: aspect);
}
this._hadUnsatisfiedDependencies = true;
return null;
}
public virtual InheritedElement ancestorInheritedElementForWidgetOfExactType(Type targetType) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
InheritedElement ancestor = null;
if (this._inheritedWidgets != null) {
this._inheritedWidgets.TryGetValue(targetType, out ancestor);
}
return ancestor;
}
internal virtual void _updateInheritance() {
D.assert(this._active);
this._inheritedWidgets = this._parent == null ? null : this._parent._inheritedWidgets;
}
public virtual Widget ancestorWidgetOfExactType(Type targetType) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
Element ancestor = this._parent;
while (ancestor != null && ancestor.widget.GetType() != targetType) {
ancestor = ancestor._parent;
}
return ancestor == null ? null : ancestor.widget;
}
public virtual State ancestorStateOfType(TypeMatcher matcher) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
Element ancestor = this._parent;
while (ancestor != null) {
var element = ancestor as StatefulElement;
if (element != null && matcher.check(element.state)) {
break;
}
ancestor = ancestor._parent;
}
var statefulAncestor = ancestor as StatefulElement;
return statefulAncestor == null ? null : statefulAncestor.state;
}
public virtual State rootAncestorStateOfType(TypeMatcher matcher) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
Element ancestor = this._parent;
StatefulElement statefulAncestor = null;
while (ancestor != null) {
var element = ancestor as StatefulElement;
if (element != null && matcher.check(element.state)) {
statefulAncestor = element;
}
ancestor = ancestor._parent;
}
return statefulAncestor == null ? null : statefulAncestor.state;
}
public virtual RenderObject ancestorRenderObjectOfType(TypeMatcher matcher) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
Element ancestor = this._parent;
while (ancestor != null) {
var element = ancestor as RenderObjectElement;
if (element != null && matcher.check(ancestor.renderObject)) {
break;
}
ancestor = ancestor._parent;
}
var renderObjectAncestor = ancestor as RenderObjectElement;
return renderObjectAncestor == null ? null : renderObjectAncestor.renderObject;
}
public virtual void visitAncestorElements(ElementVisitorBool visitor) {
D.assert(this._debugCheckStateIsActiveForAncestorLookup());
Element ancestor = this._parent;
while (ancestor != null && visitor(ancestor)) {
ancestor = ancestor._parent;
}
}
public virtual void didChangeDependencies() {
D.assert(this._active);
D.assert(this._debugCheckOwnerBuildTargetExists("didChangeDependencies"));
this.markNeedsBuild();
}
internal bool _debugCheckOwnerBuildTargetExists(string methodName) {
D.assert(() => {
if (this.owner._debugCurrentBuildTarget == null) {
throw new UIWidgetsError(
methodName + " for " + this.widget.GetType() + " was called at an " +
"inappropriate time.\n" +
"It may only be called while the widgets are being built. A possible " +
"cause of this error is when $methodName is called during " +
"one of:\n" +
" * network I/O event\n" +
" * file I/O event\n" +
" * timer\n" +
" * microtask (caused by Future.then, async/await, scheduleMicrotask)"
);
}
return true;
});
return true;
}
public string debugGetCreatorChain(int limit) {
var chain = new List<string>();
Element node = this;
while (chain.Count < limit && node != null) {
chain.Add(node.toStringShort());
node = node._parent;
}
if (node != null) {
chain.Add("\u22EF");
}
return string.Join(" \u2190 ", chain.ToArray());
}
public List<Element> debugGetDiagnosticChain() {
var chain = new List<Element>();
Element node = this._parent;
while (node != null) {
chain.Add(node);
node = node._parent;
}
return chain;
}
public override string toStringShort() {
return this.widget != null ? this.widget.toStringShort() : this.GetType().ToString();
}
public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
base.debugFillProperties(properties);
properties.defaultDiagnosticsTreeStyle = DiagnosticsTreeStyle.dense;
properties.add(new ObjectFlagProperty<int>("depth", this.depth, ifNull: "no depth"));
properties.add(new ObjectFlagProperty<Widget>("widget", this.widget, ifNull: "no widget"));
if (this.widget != null) {
properties.add(new DiagnosticsProperty<Key>("key",
this.widget.key, showName: false, defaultValue: Diagnostics.kNullDefaultValue,
level: DiagnosticLevel.hidden));
this.widget.debugFillProperties(properties);
}
properties.add(new FlagProperty("dirty", value: this.dirty, ifTrue: "dirty"));
if (this._dependencies != null && this._dependencies.isNotEmpty()) {
List<DiagnosticsNode> diagnosticsDependencies = this._dependencies
.Select((InheritedElement element) => element.widget.toDiagnosticsNode(style: DiagnosticsTreeStyle.sparse))
.ToList();
properties.add(new DiagnosticsProperty<List<DiagnosticsNode>>("dependencies", diagnosticsDependencies));
}
}
public override List<DiagnosticsNode> debugDescribeChildren() {
var children = new List<DiagnosticsNode>();
this.visitChildren(child => {
if (child != null) {
children.Add(child.toDiagnosticsNode());
}
else {
children.Add(DiagnosticsNode.message("<null child>"));
}
});
return children;
}
internal bool _dirty = true;
public bool dirty {
get { return this._dirty; }
}
internal bool _inDirtyList = false;
bool _debugBuiltOnce = false;
bool _debugAllowIgnoredCallsToMarkNeedsBuild = false;
internal bool _debugSetAllowIgnoredCallsToMarkNeedsBuild(bool value) {
D.assert(this._debugAllowIgnoredCallsToMarkNeedsBuild == !value);
this._debugAllowIgnoredCallsToMarkNeedsBuild = value;
return true;
}
public void markNeedsBuild() {
D.assert(this._debugLifecycleState != _ElementLifecycle.defunct);
if (!this._active) {
return;
}
D.assert(this.owner != null);
D.assert(this._debugLifecycleState == _ElementLifecycle.active);
D.assert(() => {
if (this.owner.debugBuilding) {
D.assert(this.owner._debugCurrentBuildTarget != null);
D.assert(this.owner._debugStateLocked);
if (this._debugIsInScope(this.owner._debugCurrentBuildTarget)) {
return true;
}
if (!this._debugAllowIgnoredCallsToMarkNeedsBuild) {
throw new UIWidgetsError(
"setState() or markNeedsBuild() called during build.\n" +
"This " + this.widget.GetType() +
" widget cannot be marked as needing to build because the framework " +
"is already in the process of building widgets. A widget can be marked as " +
"needing to be built during the build phase only if one of its ancestors " +
"is currently building. This exception is allowed because the framework " +
"builds parent widgets before children, which means a dirty descendant " +
"will always be built. Otherwise, the framework might not visit this " +
"widget during this build phase.\n" +
"The widget on which setState() or markNeedsBuild() was called was:\n" +
" " + this + "\n" +
(this.owner._debugCurrentBuildTarget == null
? ""
: "The widget which was currently being built when the offending call was made was:\n " +
this.owner._debugCurrentBuildTarget)
);
}
D.assert(this.dirty);
}
else if (this.owner._debugStateLocked) {
D.assert(!this._debugAllowIgnoredCallsToMarkNeedsBuild);
throw new UIWidgetsError(
"setState() or markNeedsBuild() called when widget tree was locked.\n" +
"This " + this.widget.GetType() + " widget cannot be marked as needing to build " +
"because the framework is locked.\n" +
"The widget on which setState() or markNeedsBuild() was called was:\n" +
" " + this + "\n"
);
}
return true;
});
if (this.dirty) {
return;
}
this._dirty = true;
this.owner.scheduleBuildFor(this);
}
public void rebuild() {
D.assert(this._debugLifecycleState != _ElementLifecycle.initial);
if (!this._active || !this._dirty) {
return;
}
D.assert(() => {
if (WidgetsD.debugPrintRebuildDirtyWidgets) {
if (!this._debugBuiltOnce) {
Debug.Log("Building " + this);
this._debugBuiltOnce = true;
}
else {
Debug.Log("Rebuilding " + this);
}
}
return true;
});
D.assert(this._debugLifecycleState == _ElementLifecycle.active);
D.assert(this.owner._debugStateLocked);
Element debugPreviousBuildTarget = null;
D.assert(() => {
debugPreviousBuildTarget = this.owner._debugCurrentBuildTarget;
this.owner._debugCurrentBuildTarget = this;
return true;
});
this.performRebuild();
D.assert(() => {
D.assert(this.owner._debugCurrentBuildTarget == this);
this.owner._debugCurrentBuildTarget = debugPreviousBuildTarget;
return true;
});
D.assert(!this._dirty);
}
protected abstract void performRebuild();
}
public delegate Widget ErrorWidgetBuilder(UIWidgetsErrorDetails details);
public class ErrorWidget : LeafRenderObjectWidget {
public ErrorWidget(Exception exception) : base(key: new UniqueKey()) {
this.message = _stringify(exception);
}
public static ErrorWidgetBuilder builder = (details) => new ErrorWidget(details.exception);
public readonly string message;
static string _stringify(Exception exception) {
try {
return exception.ToString();
}
catch {
}
return "Error";
}
public override RenderObject createRenderObject(BuildContext context) {
return null;
// return new RenderErrorBox(message);
}
public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
base.debugFillProperties(properties);
properties.add(new StringProperty("message", this.message, quoted: false));
}
}
public delegate Widget WidgetBuilder(BuildContext context);
public delegate Widget IndexedWidgetBuilder(BuildContext context, int index);
public delegate Widget TransitionBuilder(BuildContext context, Widget child);
public abstract class ComponentElement : Element {
protected ComponentElement(Widget widget) : base(widget) {
}
Element _child;
public override void mount(Element parent, object newSlot) {
base.mount(parent, newSlot);
D.assert(this._child == null);
D.assert(this._active);
this._firstBuild();
D.assert(this._child != null);
}
protected virtual void _firstBuild() {
this.rebuild();
}
protected override void performRebuild() {
D.assert(this._debugSetAllowIgnoredCallsToMarkNeedsBuild(true));
Widget built;
try {
built = this.build();
WidgetsD.debugWidgetBuilderValue(this.widget, built);
}
catch (Exception e) {
built = ErrorWidget.builder(WidgetsD._debugReportException("building " + this, e));
}
finally {
this._dirty = false;
D.assert(this._debugSetAllowIgnoredCallsToMarkNeedsBuild(false));
}
try {
this._child = this.updateChild(this._child, built, this.slot);
D.assert(this._child != null);
}
catch (Exception e) {
built = ErrorWidget.builder(WidgetsD._debugReportException("building " + this, e));
this._child = this.updateChild(null, built, this.slot);
}
}
protected abstract Widget build();
public override void visitChildren(ElementVisitor visitor) {
if (this._child != null) {
visitor(this._child);
}
}
protected override void forgetChild(Element child) {
D.assert(child == this._child);
this._child = null;
}
}
public class StatelessElement : ComponentElement {
public StatelessElement(StatelessWidget widget) : base(widget) {
}
public new StatelessWidget widget {
get { return (StatelessWidget) base.widget; }
}
protected override Widget build() {
return this.widget.build(this);
}
public override void update(Widget newWidget) {
base.update(newWidget);
D.assert(this.widget == newWidget);
this._dirty = true;
this.rebuild();
}
}
public class StatefulElement : ComponentElement {
public StatefulElement(StatefulWidget widget) : base(widget) {
this._state = widget.createState();
D.assert(() => {
if (!this._state._debugTypesAreRight(widget)) {
throw new UIWidgetsError(
"StatefulWidget.createState must return a subtype of State<" + widget.GetType() + ">\n" +
"The createState function for " + widget.GetType() + " returned a state " +
"of type " + this._state.GetType() + ", which is not a subtype of " +
"State<" + widget.GetType() + ">, violating the contract for createState.");
}
return true;
});
D.assert(this._state._element == null);
this._state._element = this;
D.assert(this._state._widget == null);
this._state._widget = widget;
D.assert(this._state._debugLifecycleState == _StateLifecycle.created);
}
public new StatefulWidget widget {
get { return (StatefulWidget) base.widget; }
}
protected override Widget build() {
return this.state.build(this);
}
public State state {
get { return this._state; }
}
State _state;
protected override void _firstBuild() {
D.assert(this._state._debugLifecycleState == _StateLifecycle.created);
try {
this._debugSetAllowIgnoredCallsToMarkNeedsBuild(true);
this._state.initState();
}
finally {
this._debugSetAllowIgnoredCallsToMarkNeedsBuild(false);
}
D.assert(() => {
this._state._debugLifecycleState = _StateLifecycle.initialized;
return true;
});
this._state.didChangeDependencies();
D.assert(() => {
this._state._debugLifecycleState = _StateLifecycle.ready;
return true;
});
base._firstBuild();
}
public override void update(Widget newWidget) {
base.update(newWidget);
D.assert(this.widget == newWidget);
StatefulWidget oldWidget = this._state._widget;
this._dirty = true;
this._state._widget = this.widget;
try {
this._debugSetAllowIgnoredCallsToMarkNeedsBuild(true);
this._state.didUpdateWidget(oldWidget);
}
finally {
this._debugSetAllowIgnoredCallsToMarkNeedsBuild(false);
}
this.rebuild();
}
public override void activate() {
base.activate();
D.assert(this._active);
this.markNeedsBuild();
}
public override void deactivate() {
this._state.deactivate();
base.deactivate();
}
public override void unmount() {
base.unmount();
this._state.dispose();
D.assert(() => {
if (this._state._debugLifecycleState == _StateLifecycle.defunct) {
return true;
}
throw new UIWidgetsError(
this._state.GetType() + ".dispose failed to call base.dispose.\n" +
"dispose() implementations must always call their superclass dispose() method, to ensure " +
"that all the resources used by the widget are fully released.");
});
this._state._element = null;
this._state = null;
}
public override InheritedWidget inheritFromElement(InheritedElement ancestor, object aspect = null) {
D.assert(ancestor != null);
D.assert(() => {
Type targetType = ancestor.widget.GetType();
if (this.state._debugLifecycleState == _StateLifecycle.created) {
throw new UIWidgetsError(
"inheritFromWidgetOfExactType(" + targetType + ") or inheritFromElement() was called before " +
this._state.GetType() + ".initState() completed.\n" +
"When an inherited widget changes, for example if the value of Theme.of() changes, " +
"its dependent widgets are rebuilt. If the dependent widget\"s reference to " +
"the inherited widget is in a constructor or an initState() method, " +
"then the rebuilt dependent widget will not reflect the changes in the " +
"inherited widget.\n" +
"Typically references to inherited widgets should occur in widget build() methods. Alternatively, " +
"initialization based on inherited widgets can be placed in the didChangeDependencies method, which " +
"is called after initState and whenever the dependencies change thereafter."
);
}
if (this.state._debugLifecycleState == _StateLifecycle.defunct) {
throw new UIWidgetsError(
"inheritFromWidgetOfExactType(" + targetType +
") or inheritFromElement() was called after dispose(): " + this + "\n" +
"This error happens if you call inheritFromWidgetOfExactType() on the " +
"BuildContext for a widget that no longer appears in the widget tree " +
"(e.g., whose parent widget no longer includes the widget in its " +
"build). This error can occur when code calls " +
"inheritFromWidgetOfExactType() from a timer or an animation callback. " +
"The preferred solution is to cancel the timer or stop listening to the " +
"animation in the dispose() callback. Another solution is to check the " +
"\"mounted\" property of this object before calling " +
"inheritFromWidgetOfExactType() to ensure the object is still in the " +
"tree.\n" +
"This error might indicate a memory leak if " +
"inheritFromWidgetOfExactType() is being called because another object " +
"is retaining a reference to this State object after it has been " +
"removed from the tree. To avoid memory leaks, consider breaking the " +
"reference to this object during dispose()."
);
}
return true;
});
return base.inheritFromElement(ancestor, aspect: aspect);
}
public override void didChangeDependencies() {
base.didChangeDependencies();
this._state.didChangeDependencies();
}
public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
base.debugFillProperties(properties);
properties.add(new DiagnosticsProperty<State>("state", this.state,
defaultValue: Diagnostics.kNullDefaultValue));
}
}
public abstract class ProxyElement : ComponentElement {
protected ProxyElement(Widget widget) : base(widget) {
}
public new ProxyWidget widget {
get { return (ProxyWidget) base.widget; }
}
protected override Widget build() {
return this.widget.child;
}
public override void update(Widget newWidget) {
ProxyWidget oldWidget = this.widget;
D.assert(this.widget != null);
D.assert(this.widget != newWidget);
base.update(newWidget);
D.assert(this.widget == newWidget);
this.updated(oldWidget);
this._dirty = true;
this.rebuild();
}
protected virtual void updated(ProxyWidget oldWidget) {
this.notifyClients(oldWidget);
}
protected abstract void notifyClients(ProxyWidget oldWidget);
}
public class ParentDataElement : ProxyElement {
public ParentDataElement(ParentDataWidget widget) : base(widget) {
}
public new ParentDataWidget widget {
get { return (ParentDataWidget) base.widget; }
}
public override void mount(Element parent, object newSlot) {
D.assert(() => {
var badAncestors = new List<Widget>();
Element ancestor = parent;
while (ancestor != null) {
if (ancestor is ParentDataElement) {
badAncestors.Add(ancestor.widget);
}
else if (ancestor is RenderObjectElement) {
if (this.widget.debugIsValidAncestor(((RenderObjectElement) ancestor).widget)) {
break;
}
badAncestors.Add(ancestor.widget);
}
ancestor = ancestor._parent;
}
if (ancestor != null && badAncestors.isEmpty()) {
return true;
}
throw new UIWidgetsError(
"Incorrect use of ParentDataWidget.\n" +
this.widget.debugDescribeInvalidAncestorChain(
description: this.ToString(),
ownershipChain: parent.debugGetCreatorChain(10),
foundValidAncestor: ancestor != null,
badAncestors: badAncestors
)
);
});
base.mount(parent, newSlot);
}
void _applyParentData(ParentDataWidget widget) {
ElementVisitor applyParentDataToChild = null;
applyParentDataToChild = child => {
if (child is RenderObjectElement) {
((RenderObjectElement) child)._updateParentData(widget);
}
else {
D.assert(!(child is ParentDataElement));
child.visitChildren(applyParentDataToChild);
}
};
this.visitChildren(applyParentDataToChild);
}
public void applyWidgetOutOfTurn(ParentDataWidget newWidget) {
D.assert(newWidget != null);
D.assert(newWidget.debugCanApplyOutOfTurn());
D.assert(newWidget.child == this.widget.child);
this._applyParentData(newWidget);
}
protected override void notifyClients(ProxyWidget oldWidget) {
this._applyParentData(this.widget);
}
}
public class InheritedElement : ProxyElement {
public InheritedElement(Widget widget) : base(widget) {
}
public new InheritedWidget widget {
get { return (InheritedWidget) base.widget; }
}
internal readonly Dictionary<Element, object> _dependents = new Dictionary<Element, object>();
internal override void _updateInheritance() {
Dictionary<Type, InheritedElement> incomingWidgets =
this._parent == null ? null : this._parent._inheritedWidgets;
if (incomingWidgets != null) {
this._inheritedWidgets = new Dictionary<Type, InheritedElement>(incomingWidgets);
}
else {
this._inheritedWidgets = new Dictionary<Type, InheritedElement>();
}
this._inheritedWidgets[this.widget.GetType()] = this;
}
public override void debugDeactivated() {
D.assert(() => {
D.assert(this._dependents.isEmpty());
return true;
});
base.debugDeactivated();
}
public object getDependencies(Element dependent) {
return this._dependents[dependent];
}
public void setDependencies(Element dependent, object value) {
object existing;
if (this._dependents.TryGetValue(dependent, out existing)) {
if (Equals(existing, value)) {
return;
}
}
this._dependents[dependent] = value;
}
public void updateDependencies(Element dependent, object aspect) {
this.setDependencies(dependent, null);
}
public void notifyDependent(InheritedWidget oldWidget, Element dependent) {
dependent.didChangeDependencies();
}
protected override void updated(ProxyWidget oldWidget) {
if (this.widget.updateShouldNotify((InheritedWidget) oldWidget)) {
base.updated(oldWidget);
}
}
protected override void notifyClients(ProxyWidget oldWidgetRaw) {
var oldWidget = (InheritedWidget) oldWidgetRaw;
D.assert(this._debugCheckOwnerBuildTargetExists("notifyClients"));
foreach (Element dependent in this._dependents.Keys) {
D.assert(() => {
Element ancestor = dependent._parent;
while (ancestor != this && ancestor != null) {
ancestor = ancestor._parent;
}
return ancestor == this;
});
D.assert(dependent._dependencies.Contains(this));
this.notifyDependent(oldWidget, dependent);
}
}
}
public abstract class RenderObjectElement : Element {
protected RenderObjectElement(RenderObjectWidget widget) : base(widget) {
}
public new RenderObjectWidget widget {
get { return (RenderObjectWidget) base.widget; }
}
RenderObject _renderObject;
public override RenderObject renderObject {
get { return this._renderObject; }
}
RenderObjectElement _ancestorRenderObjectElement;
RenderObjectElement _findAncestorRenderObjectElement() {
Element ancestor = this._parent;
while (ancestor != null && !(ancestor is RenderObjectElement)) {
ancestor = ancestor._parent;
}
return ancestor as RenderObjectElement;
}
ParentDataElement _findAncestorParentDataElement() {
Element ancestor = this._parent;
while (ancestor != null && !(ancestor is RenderObjectElement)) {
var element = ancestor as ParentDataElement;
if (element != null) {
return element;
}
ancestor = ancestor._parent;
}
return null;
}
public override void mount(Element parent, object newSlot) {
base.mount(parent, newSlot);
this._renderObject = this.widget.createRenderObject(this);
D.assert(() => {
this._debugUpdateRenderObjectOwner();
return true;
});
D.assert(this.slot == newSlot);
this.attachRenderObject(newSlot);
this._dirty = false;
}
public override void update(Widget newWidget) {
base.update(newWidget);
D.assert(this.widget == newWidget);
D.assert(() => {
this._debugUpdateRenderObjectOwner();
return true;
});
this.widget.updateRenderObject(this, this.renderObject);
this._dirty = false;
}
void _debugUpdateRenderObjectOwner() {
D.assert(() => {
this._renderObject.debugCreator = new _DebugCreator(this);
return true;
});
}
protected override void performRebuild() {
this.widget.updateRenderObject(this, this.renderObject);
this._dirty = false;
}
protected List<Element> updateChildren(List<Element> oldChildren, List<Widget> newWidgets,
HashSet<Element> forgottenChildren = null) {
D.assert(oldChildren != null);
D.assert(newWidgets != null);
var replaceWithNullIfForgotten = new Func<Element, Element>(child =>
forgottenChildren != null && forgottenChildren.Contains(child) ? (Element) null : child);
int newChildrenTop = 0;
int oldChildrenTop = 0;
int newChildrenBottom = newWidgets.Count - 1;
int oldChildrenBottom = oldChildren.Count - 1;
var newChildren = oldChildren.Count == newWidgets.Count
? oldChildren
: CollectionUtils.CreateRepeatedList<Element>(null, newWidgets.Count);
Element previousChild = null;
while ((oldChildrenTop <= oldChildrenBottom) && (newChildrenTop <= newChildrenBottom)) {
Element oldChild = replaceWithNullIfForgotten(oldChildren[oldChildrenTop]);
Widget newWidget = newWidgets[newChildrenTop];
D.assert(oldChild == null || oldChild._debugLifecycleState == _ElementLifecycle.active);
if (oldChild == null || !Widget.canUpdate(oldChild.widget, newWidget)) {
break;
}
Element newChild = this.updateChild(oldChild, newWidget, previousChild);
D.assert(newChild._debugLifecycleState == _ElementLifecycle.active);
newChildren[newChildrenTop] = newChild;
previousChild = newChild;
newChildrenTop += 1;
oldChildrenTop += 1;
}
while ((oldChildrenTop <= oldChildrenBottom) && (newChildrenTop <= newChildrenBottom)) {
Element oldChild = replaceWithNullIfForgotten(oldChildren[oldChildrenBottom]);
Widget newWidget = newWidgets[newChildrenBottom];
D.assert(oldChild == null || oldChild._debugLifecycleState == _ElementLifecycle.active);
if (oldChild == null || !Widget.canUpdate(oldChild.widget, newWidget)) {
break;
}
oldChildrenBottom -= 1;
newChildrenBottom -= 1;
}
bool haveOldChildren = oldChildrenTop <= oldChildrenBottom;
Dictionary<Key, Element> oldKeyedChildren = null;
if (haveOldChildren) {
oldKeyedChildren = new Dictionary<Key, Element>();
while (oldChildrenTop <= oldChildrenBottom) {
Element oldChild = replaceWithNullIfForgotten(oldChildren[oldChildrenTop]);
D.assert(oldChild == null || oldChild._debugLifecycleState == _ElementLifecycle.active);
if (oldChild != null) {
if (oldChild.widget.key != null) {
oldKeyedChildren[oldChild.widget.key] = oldChild;
}
else {
this.deactivateChild(oldChild);
}
}
oldChildrenTop += 1;
}
}
// Update the middle of the list.
while (newChildrenTop <= newChildrenBottom) {
Element oldChild = null;
Widget newWidget = newWidgets[newChildrenTop];
if (haveOldChildren) {
Key key = newWidget.key;
if (key != null) {
oldChild = oldKeyedChildren.getOrDefault(key);
if (oldChild != null) {
if (Widget.canUpdate(oldChild.widget, newWidget)) {
oldKeyedChildren.Remove(key);
}
else {
oldChild = null;
}
}
}
}
D.assert(oldChild == null || Widget.canUpdate(oldChild.widget, newWidget));
Element newChild = this.updateChild(oldChild, newWidget, previousChild);
D.assert(newChild._debugLifecycleState == _ElementLifecycle.active);
D.assert(oldChild == newChild || oldChild == null ||
oldChild._debugLifecycleState != _ElementLifecycle.active);
newChildren[newChildrenTop] = newChild;
previousChild = newChild;
newChildrenTop += 1;
}
D.assert(oldChildrenTop == oldChildrenBottom + 1);
D.assert(newChildrenTop == newChildrenBottom + 1);
D.assert(newWidgets.Count - newChildrenTop == oldChildren.Count - oldChildrenTop);
newChildrenBottom = newWidgets.Count - 1;
oldChildrenBottom = oldChildren.Count - 1;
while ((oldChildrenTop <= oldChildrenBottom) && (newChildrenTop <= newChildrenBottom)) {
Element oldChild = oldChildren[oldChildrenTop];
D.assert(replaceWithNullIfForgotten(oldChild) != null);
D.assert(oldChild._debugLifecycleState == _ElementLifecycle.active);
Widget newWidget = newWidgets[newChildrenTop];
D.assert(Widget.canUpdate(oldChild.widget, newWidget));
Element newChild = this.updateChild(oldChild, newWidget, previousChild);
D.assert(newChild._debugLifecycleState == _ElementLifecycle.active);
D.assert(oldChild == newChild || oldChild == null ||
oldChild._debugLifecycleState != _ElementLifecycle.active);
newChildren[newChildrenTop] = newChild;
previousChild = newChild;
newChildrenTop += 1;
oldChildrenTop += 1;
}
if (haveOldChildren && oldKeyedChildren.isNotEmpty()) {
foreach (Element oldChild in oldKeyedChildren.Values) {
if (forgottenChildren == null || !forgottenChildren.Contains(oldChild)) {
this.deactivateChild(oldChild);
}
}
}
return newChildren;
}
public override void deactivate() {
base.deactivate();
D.assert(!this.renderObject.attached,
() => "A RenderObject was still attached when attempting to deactivate its " +
"RenderObjectElement: " + this.renderObject);
}
public override void unmount() {
base.unmount();
D.assert(!this.renderObject.attached,
() => "A RenderObject was still attached when attempting to unmount its " +
"RenderObjectElement: " + this.renderObject);
this.widget.didUnmountRenderObject(this.renderObject);
}
internal void _updateParentData(ParentDataWidget parentData) {
parentData.applyParentData(this.renderObject);
}
internal override void _updateSlot(object newSlot) {
D.assert(this.slot != newSlot);
base._updateSlot(newSlot);
D.assert(this.slot == newSlot);
this._ancestorRenderObjectElement.moveChildRenderObject(this.renderObject, this.slot);
}
public override void attachRenderObject(object newSlot) {
D.assert(this._ancestorRenderObjectElement == null);
this._slot = newSlot;
this._ancestorRenderObjectElement = this._findAncestorRenderObjectElement();
if (this._ancestorRenderObjectElement != null) {
this._ancestorRenderObjectElement.insertChildRenderObject(this.renderObject, newSlot);
}
ParentDataElement parentDataElement = this._findAncestorParentDataElement();
if (parentDataElement != null) {
this._updateParentData(parentDataElement.widget);
}
}
public override void detachRenderObject() {
if (this._ancestorRenderObjectElement != null) {
this._ancestorRenderObjectElement.removeChildRenderObject(this.renderObject);
this._ancestorRenderObjectElement = null;
}
this._slot = null;
}
protected abstract void insertChildRenderObject(RenderObject child, object slot);
protected abstract void moveChildRenderObject(RenderObject child, object slot);
protected abstract void removeChildRenderObject(RenderObject child);
public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
base.debugFillProperties(properties);
properties.add(new DiagnosticsProperty<RenderObject>("renderObject", this.renderObject,
defaultValue: Diagnostics.kNullDefaultValue));
}
}
public abstract class RootRenderObjectElement : RenderObjectElement {
protected RootRenderObjectElement(RenderObjectWidget widget) : base(widget) {
}
public void assignOwner(BuildOwner owner) {
this._owner = owner;
}
public override void mount(Element parent, object newSlot) {
D.assert(parent == null);
D.assert(newSlot == null);
base.mount(parent, newSlot);
}
}
public class LeafRenderObjectElement : RenderObjectElement {
public LeafRenderObjectElement(LeafRenderObjectWidget widget) : base(widget) {
}
protected override void forgetChild(Element child) {
D.assert(false);
}
protected override void insertChildRenderObject(RenderObject child, object slot) {
D.assert(false);
}
protected override void moveChildRenderObject(RenderObject child, object slot) {
D.assert(false);
}
protected override void removeChildRenderObject(RenderObject child) {
D.assert(false);
}
public override List<DiagnosticsNode> debugDescribeChildren() {
return this.widget.debugDescribeChildren();
}
}
public class SingleChildRenderObjectElement : RenderObjectElement {
public SingleChildRenderObjectElement(SingleChildRenderObjectWidget widget) : base(widget) {
}
public new SingleChildRenderObjectWidget widget {
get { return (SingleChildRenderObjectWidget) base.widget; }
}
Element _child;
public override void visitChildren(ElementVisitor visitor) {
if (this._child != null) {
visitor(this._child);
}
}
protected override void forgetChild(Element child) {
D.assert(child == this._child);
this._child = null;
}
public override void mount(Element parent, object newSlot) {
base.mount(parent, newSlot);
this._child = this.updateChild(this._child, this.widget.child, null);
}
public override void update(Widget newWidget) {
base.update(newWidget);
D.assert(this.widget == newWidget);
this._child = this.updateChild(this._child, this.widget.child, null);
}
protected override void insertChildRenderObject(RenderObject child, object slot) {
var renderObject = (RenderObjectWithChildMixin) this.renderObject;
D.assert(slot == null);
D.assert(renderObject.debugValidateChild(child));
renderObject.child = child;
D.assert(renderObject == this.renderObject);
}
protected override void moveChildRenderObject(RenderObject child, object slot) {
D.assert(false);
}
protected override void removeChildRenderObject(RenderObject child) {
var renderObject = (RenderObjectWithChildMixin) this.renderObject;
D.assert(renderObject.child == child);
renderObject.child = null;
D.assert(renderObject == this.renderObject);
}
}
public class MultiChildRenderObjectElement : RenderObjectElement {
public MultiChildRenderObjectElement(MultiChildRenderObjectWidget widget)
: base(widget) {
D.assert(!WidgetsD.debugChildrenHaveDuplicateKeys(widget, widget.children));
}
public new MultiChildRenderObjectWidget widget {
get { return (MultiChildRenderObjectWidget) base.widget; }
}
protected IEnumerable<Element> children {
get { return this._children.Where((child) => !this._forgottenChildren.Contains(child)); }
}
List<Element> _children;
readonly HashSet<Element> _forgottenChildren = new HashSet<Element>();
protected override void insertChildRenderObject(RenderObject child, object slotRaw) {
Element slot = (Element) slotRaw;
var renderObject = (ContainerRenderObjectMixin) this.renderObject;
D.assert(renderObject.debugValidateChild(child));
renderObject.insert(child, after: slot == null ? null : slot.renderObject);
D.assert(renderObject == this.renderObject);
}
protected override void moveChildRenderObject(RenderObject child, object slotRaw) {
Element slot = (Element) slotRaw;
var renderObject = (ContainerRenderObjectMixin) this.renderObject;
D.assert(child.parent == renderObject);
renderObject.move(child, after: slot == null ? null : slot.renderObject);
D.assert(renderObject == this.renderObject);
}
protected override void removeChildRenderObject(RenderObject child) {
var renderObject = (ContainerRenderObjectMixin) this.renderObject;
D.assert(child.parent == renderObject);
renderObject.remove(child);
D.assert(renderObject == this.renderObject);
}
public override void visitChildren(ElementVisitor visitor) {
foreach (Element child in this._children) {
if (!this._forgottenChildren.Contains(child)) {
visitor(child);
}
}
}
protected override void forgetChild(Element child) {
D.assert(this._children.Contains(child));
D.assert(!this._forgottenChildren.Contains(child));
this._forgottenChildren.Add(child);
}
public override void mount(Element parent, object newSlot) {
base.mount(parent, newSlot);
this._children = CollectionUtils.CreateRepeatedList<Element>(null, this.widget.children.Count);
Element previousChild = null;
for (int i = 0; i < this._children.Count; i += 1) {
Element newChild = this.inflateWidget(this.widget.children[i], previousChild);
this._children[i] = newChild;
previousChild = newChild;
}
}
public override void update(Widget newWidget) {
base.update(newWidget);
D.assert(this.widget == newWidget);
this._children = this.updateChildren(this._children, this.widget.children,
forgottenChildren: this._forgottenChildren);
this._forgottenChildren.Clear();
}
}
class _DebugCreator {
internal _DebugCreator(RenderObjectElement element) {
this.element = element;
}
public readonly RenderObjectElement element;
public override string ToString() {
return this.element.debugGetCreatorChain(12);
}
}
}