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using System.Collections.Generic;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.gestures;
using Unity.UIWidgets.rendering;
using Unity.UIWidgets.ui;
namespace Unity.UIWidgets.widgets {
public interface CustomPainter : Listenable {
void paint(Canvas canvas, Size size);
bool shouldRepaint(CustomPainter oldDelegate);
bool? hitTest(Offset position);
}
public abstract class AbstractCustomPainter : CustomPainter {
public AbstractCustomPainter(Listenable repaint = null) {
_repaint = repaint;
}
readonly Listenable _repaint;
public void addListener(VoidCallback listener) {
_repaint?.addListener(listener);
}
public void removeListener(VoidCallback listener) {
_repaint?.removeListener(listener);
}
public abstract void paint(Canvas canvas, Size size);
public abstract bool shouldRepaint(CustomPainter oldDelegate);
public virtual bool? hitTest(Offset position) {
return null;
}
public override string ToString() {
return $"{foundation_.describeIdentity(this)}({_repaint?.ToString() ?? ""})";
}
}
public class RenderCustomPaint : RenderProxyBox {
public RenderCustomPaint(
CustomPainter painter = null,
CustomPainter foregroundPainter = null,
Size preferredSize = null,
bool isComplex = false,
bool willChange = false,
RenderBox child = null
) : base(child) {
preferredSize = preferredSize ?? Size.zero;
this.preferredSize = preferredSize;
_painter = painter;
_foregroundPainter = foregroundPainter;
this.isComplex = isComplex;
this.willChange = willChange;
}
CustomPainter _painter;
public CustomPainter painter {
get { return _painter; }
set {
if (_painter == value) {
return;
}
CustomPainter oldPainter = _painter;
_painter = value;
_didUpdatePainter(_painter, oldPainter);
}
}
CustomPainter _foregroundPainter;
public CustomPainter foregroundPainter {
get { return _foregroundPainter; }
set {
if (_foregroundPainter == value) {
return;
}
CustomPainter oldPainter = _foregroundPainter;
_foregroundPainter = value;
_didUpdatePainter(_foregroundPainter, oldPainter);
}
}
void _didUpdatePainter(CustomPainter newPainter, CustomPainter oldPainter) {
if (newPainter == null) {
D.assert(oldPainter != null);
markNeedsPaint();
}
else if (oldPainter == null ||
newPainter.GetType() != oldPainter.GetType() ||
newPainter.shouldRepaint(oldPainter)) {
markNeedsPaint();
}
if (attached) {
oldPainter?.removeListener(markNeedsPaint);
newPainter?.addListener(markNeedsPaint);
}
}
Size _preferredSize;
public Size preferredSize {
get { return _preferredSize; }
set {
D.assert(value != null);
if (preferredSize == value) {
return;
}
_preferredSize = value;
markNeedsLayout();
}
}
public bool isComplex;
public bool willChange;
public override void attach(object owner) {
base.attach(owner);
_painter?.addListener(markNeedsPaint);
_foregroundPainter?.addListener(markNeedsPaint);
}
public override void detach() {
_painter?.removeListener(markNeedsPaint);
_foregroundPainter?.removeListener(markNeedsPaint);
base.detach();
}
protected override bool hitTestChildren(BoxHitTestResult result, Offset position = null) {
if (_foregroundPainter != null && ((_foregroundPainter.hitTest(position)) ?? false)) {
return true;
}
return base.hitTestChildren(result, position: position);
}
protected override bool hitTestSelf(Offset position) {
return _painter != null && (_painter.hitTest(position) ?? true);
}
protected override void performResize() {
size = constraints.constrain(preferredSize);
}
void _paintWithPainter(Canvas canvas, Offset offset, CustomPainter painter) {
int debugPreviousCanvasSaveCount = 0;
canvas.save();
D.assert(() => {
debugPreviousCanvasSaveCount = canvas.getSaveCount();
return true;
});
if (offset != Offset.zero) {
canvas.translate(offset.dx, offset.dy);
}
painter.paint(canvas, size);
D.assert(() => {
int debugNewCanvasSaveCount = canvas.getSaveCount();
if (debugNewCanvasSaveCount > debugPreviousCanvasSaveCount) {
throw new UIWidgetsError(new List<DiagnosticsNode>{
new ErrorSummary(
$"The {painter} custom painter called canvas.save() or canvas.saveLayer() at least " +
$"{debugNewCanvasSaveCount - debugPreviousCanvasSaveCount} more " +
"times than it called canvas.restore()."
),
new ErrorDescription("This leaves the canvas in an inconsistent state and will probably result in a broken display."),
new ErrorHint("You must pair each call to save()/saveLayer() with a later matching call to restore().")
});
}
if (debugNewCanvasSaveCount < debugPreviousCanvasSaveCount) {
throw new UIWidgetsError(new List<DiagnosticsNode>{
new ErrorSummary(
$"The {painter} custom painter called canvas.restore() " +
$"{debugPreviousCanvasSaveCount - debugNewCanvasSaveCount} more " +
"times than it called canvas.save() or canvas.saveLayer()."
),
new ErrorDescription("This leaves the canvas in an inconsistent state and will result in a broken display."),
new ErrorHint("You should only call restore() if you first called save() or saveLayer().")
});
}
return debugNewCanvasSaveCount == debugPreviousCanvasSaveCount;
});
canvas.restore();
}
public override void paint(PaintingContext context, Offset offset) {
if (_painter != null) {
_paintWithPainter(context.canvas, offset, _painter);
_setRasterCacheHints(context);
}
base.paint(context, offset);
if (_foregroundPainter != null) {
_paintWithPainter(context.canvas, offset, _foregroundPainter);
_setRasterCacheHints(context);
}
}
void _setRasterCacheHints(PaintingContext context) {
if (isComplex) {
context.setIsComplexHint();
}
if (willChange) {
context.setWillChangeHint();
}
}
}
}