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using System.Collections.Generic;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.service;
using Unity.UIWidgets.ui;
using UnityEngine;
using Canvas = Unity.UIWidgets.ui.Canvas;
using Rect = Unity.UIWidgets.ui.Rect;
namespace Unity.UIWidgets.painting {
class _CaretMetrics {
public _CaretMetrics(Offset offset, float? fullHeight) {
this.offset = offset;
this.fullHeight = fullHeight;
}
public Offset offset;
public float? fullHeight;
}
public class TextPainter {
TextSpan _text;
TextAlign _textAlign;
TextDirection? _textDirection;
float _textScaleFactor;
Paragraph _layoutTemplate;
Paragraph _paragraph;
bool _needsLayout = true;
int? _maxLines;
string _ellipsis;
float _lastMinWidth;
float _lastMaxWidth;
public TextPainter(TextSpan text = null,
TextAlign textAlign = TextAlign.left,
TextDirection textDirection = TextDirection.ltr,
float textScaleFactor = 1.0f,
int? maxLines = null,
string ellipsis = "",
StrutStyle strutStyle = null) {
this._text = text;
this._textAlign = textAlign;
this._textDirection = textDirection;
this._textScaleFactor = textScaleFactor;
this._maxLines = maxLines;
this._ellipsis = ellipsis;
this._strutStyle = strutStyle;
}
public float textScaleFactor {
get { return this._textScaleFactor; }
set {
if (this._textScaleFactor == value) {
return;
}
this._textScaleFactor = value;
this._layoutTemplate = null;
this._needsLayout = true;
Paragraph.release(ref this._paragraph);
}
}
public string ellipsis {
get { return this._ellipsis; }
set {
if (this._ellipsis == value) {
return;
}
this._ellipsis = value;
Paragraph.release(ref this._paragraph);
this._needsLayout = true;
}
}
public TextSpan text {
get { return this._text; }
set {
if ((this._text == null && value == null) || (this._text != null && this.text.Equals(value))) {
return;
}
if (!Equals(this._text == null ? null : this._text.style, value == null ? null : value.style)) {
this._layoutTemplate = null;
}
this._text = value;
Paragraph.release(ref this._paragraph);
this._needsLayout = true;
}
}
public Size size {
get {
Debug.Assert(!this._needsLayout);
return new Size(this.width, this.height);
}
}
public TextDirection? textDirection {
get { return this._textDirection; }
set {
if (this.textDirection == value) {
return;
}
this._textDirection = value;
Paragraph.release(ref this._paragraph);
this._layoutTemplate = null;
this._needsLayout = true;
}
}
public TextAlign textAlign {
get { return this._textAlign; }
set {
if (this._textAlign == value) {
return;
}
this._textAlign = value;
Paragraph.release(ref this._paragraph);
this._needsLayout = true;
}
}
public bool didExceedMaxLines {
get {
Debug.Assert(!this._needsLayout);
return this._paragraph.didExceedMaxLines;
}
}
public int? maxLines {
get { return this._maxLines; }
set {
if (this._maxLines == value) {
return;
}
this._maxLines = value;
Paragraph.release(ref this._paragraph);
this._needsLayout = true;
}
}
public StrutStyle strutStyle {
get { return this._strutStyle; }
set {
if (this._strutStyle == value) {
return;
}
this._strutStyle = value;
this._paragraph = null;
this._needsLayout = true;
}
}
StrutStyle _strutStyle;
public float minIntrinsicWidth {
get {
Debug.Assert(!this._needsLayout);
return this._applyFloatingPointHack(this._paragraph.minIntrinsicWidth);
}
}
public float maxIntrinsicWidth {
get {
Debug.Assert(!this._needsLayout);
return this._applyFloatingPointHack(this._paragraph.maxIntrinsicWidth);
}
}
public float height {
get {
Debug.Assert(!this._needsLayout);
return this._applyFloatingPointHack(this._paragraph.height);
}
}
public float width {
get {
Debug.Assert(!this._needsLayout);
return this._applyFloatingPointHack(this._paragraph.width);
}
}
public float computeDistanceToActualBaseline(TextBaseline baseline) {
Debug.Assert(!this._needsLayout);
switch (baseline) {
case TextBaseline.alphabetic:
return this._paragraph.alphabeticBaseline;
case TextBaseline.ideographic:
return this._paragraph.ideographicBaseline;
}
return 0.0f;
}
public void layout(float minWidth = 0.0f, float maxWidth = float.PositiveInfinity) {
Debug.Assert(this.text != null,
"TextPainter.text must be set to a non-null value before using the TextPainter.");
Debug.Assert(this.textDirection != null,
"TextPainter.textDirection must be set to a non-null value before using the TextPainter.");
if (!this._needsLayout && minWidth == this._lastMinWidth && maxWidth == this._lastMaxWidth) {
return;
}
this._needsLayout = false;
if (this._paragraph == null) {
var builder = new ParagraphBuilder(this._createParagraphStyle());
this._text.build(builder, this.textScaleFactor);
this._paragraph = builder.build();
}
this._lastMinWidth = minWidth;
this._lastMaxWidth = maxWidth;
this._paragraph.layout(new ParagraphConstraints(maxWidth));
if (minWidth != maxWidth) {
var newWidth = MathUtils.clamp(this.maxIntrinsicWidth, minWidth, maxWidth);
if (newWidth != this.width) {
this._paragraph.layout(new ParagraphConstraints(newWidth));
}
}
}
public void paint(Canvas canvas, Offset offset) {
Debug.Assert(!this._needsLayout);
this._paragraph.paint(canvas, offset);
}
public Offset getOffsetForCaret(TextPosition position, Rect caretPrototype) {
this._computeCaretMetrics(position, caretPrototype);
return this._caretMetrics.offset;
}
public float? getFullHeightForCaret(TextPosition position, Rect caretPrototype) {
this._computeCaretMetrics(position, caretPrototype);
return this._caretMetrics.fullHeight;
}
_CaretMetrics _caretMetrics;
TextPosition _previousCaretPosition;
Rect _previousCaretPrototype;
void _computeCaretMetrics(TextPosition position, Rect caretPrototype) {
D.assert(!this._needsLayout);
if (position == this._previousCaretPosition && caretPrototype == this._previousCaretPrototype) {
return;
}
var offset = position.offset;
Rect rect;
switch (position.affinity) {
case TextAffinity.upstream:
rect = this._getRectFromUpstream(offset, caretPrototype) ??
this._getRectFromDownStream(offset, caretPrototype);
break;
case TextAffinity.downstream:
rect = this._getRectFromDownStream(offset, caretPrototype) ??
this._getRectFromUpstream(offset, caretPrototype);
break;
default:
throw new UIWidgetsError("Unknown Position Affinity");
}
this._caretMetrics = new _CaretMetrics(
offset: rect != null ? new Offset(rect.left, rect.top) : this._emptyOffset,
fullHeight: rect != null ? (float?) (rect.bottom - rect.top) : null);
// Cache the caret position. This was forgot in flutter until https://github.com/flutter/flutter/pull/38821
this._previousCaretPosition = position;
this._previousCaretPrototype = caretPrototype;
}
public Paragraph.LineRange getLineRange(int lineNumber) {
D.assert(!this._needsLayout);
return this._paragraph.getLineRange(lineNumber);
}
public Paragraph.LineRange getLineRange(TextPosition textPosition) {
return this.getLineRange(this.getLineIndex(textPosition));
}
public List<TextBox> getBoxesForSelection(TextSelection selection) {
D.assert(!this._needsLayout);
var results = this._paragraph.getRectsForRange(selection.start, selection.end);
return results;
}
public TextPosition getPositionForOffset(Offset offset) {
D.assert(!this._needsLayout);
var result = this._paragraph.getGlyphPositionAtCoordinate(offset.dx, offset.dy);
return new TextPosition(result.position, result.affinity);
}
public TextRange getWordBoundary(TextPosition position) {
D.assert(!this._needsLayout);
var range = this._paragraph.getWordBoundary(position.offset);
return new TextRange(range.start, range.end);
}
public TextPosition getPositionVerticalMove(TextPosition position, int move) {
D.assert(!this._needsLayout);
var offset = this.getOffsetForCaret(position, Rect.zero);
var lineIndex = Mathf.Min(Mathf.Max(this._paragraph.getLine(position) + move, 0),
this._paragraph.getLineCount() - 1);
var targetLineStart = this._paragraph.getLineRange(lineIndex).start;
var newLineOffset = this.getOffsetForCaret(new TextPosition(targetLineStart), Rect.zero);
return this.getPositionForOffset(new Offset(offset.dx, newLineOffset.dy));
}
public int getLineIndex(TextPosition position) {
D.assert(!this._needsLayout);
return this._paragraph.getLine(position);
}
public int getLineCount() {
D.assert(!this._needsLayout);
return this._paragraph.getLineCount();
}
public TextPosition getWordRight(TextPosition position) {
D.assert(!this._needsLayout);
var offset = position.offset;
while (true) {
var range = this._paragraph.getWordBoundary(offset);
if (range.end == range.start) {
break;
}
if (!char.IsWhiteSpace((char) (this.text.codeUnitAt(range.start) ?? 0))) {
return new TextPosition(range.end);
}
offset = range.end;
}
return new TextPosition(offset, position.affinity);
}
public TextPosition getWordLeft(TextPosition position) {
D.assert(!this._needsLayout);
var offset = Mathf.Max(position.offset - 1, 0);
while (true) {
var range = this._paragraph.getWordBoundary(offset);
if (!char.IsWhiteSpace((char) (this.text.codeUnitAt(range.start) ?? 0))) {
return new TextPosition(range.start);
}
offset = Mathf.Max(range.start - 1, 0);
if (offset == 0) {
break;
}
}
return new TextPosition(offset, position.affinity);
}
ParagraphStyle _createParagraphStyle(TextDirection defaultTextDirection = TextDirection.ltr) {
if (this._text.style == null) {
return new ParagraphStyle(
textAlign: this.textAlign,
textDirection: this.textDirection ?? defaultTextDirection,
maxLines: this.maxLines,
ellipsis: this.ellipsis,
strutStyle: this._strutStyle
);
}
return this._text.style.getParagraphStyle(this.textAlign, this.textDirection ?? defaultTextDirection,
this.ellipsis, this.maxLines, this.textScaleFactor);
}
public float preferredLineHeight {
get {
if (this._layoutTemplate == null) {
var builder = new ParagraphBuilder(this._createParagraphStyle(TextDirection.ltr)
); // direction doesn't matter, text is just a space
if (this.text != null && this.text.style != null) {
builder.pushStyle(this.text.style, this.textScaleFactor);
}
builder.addText(" ");
this._layoutTemplate = builder.build();
this._layoutTemplate.layout(new ParagraphConstraints(float.PositiveInfinity));
}
return this._layoutTemplate.height;
}
}
float _applyFloatingPointHack(float layoutValue) {
return Mathf.Ceil(layoutValue);
}
const int _zwjUtf16 = 0x200d;
Rect _getRectFromUpstream(int offset, Rect caretPrototype) {
string flattenedText = this._text.toPlainText();
var prevCodeUnit = this._text.codeUnitAt(Mathf.Max(0, offset - 1));
if (prevCodeUnit == null) {
return null;
}
bool needsSearch = _isUtf16Surrogate(prevCodeUnit.Value) || this._text.codeUnitAt(offset) == _zwjUtf16;
int graphemeClusterLength = needsSearch ? 2 : 1;
List<TextBox> boxes = null;
while ((boxes == null || boxes.isEmpty()) && flattenedText != null) {
int prevRuneOffset = offset - graphemeClusterLength;
boxes = this._paragraph.getRectsForRange(prevRuneOffset, offset);
if (boxes.isEmpty()) {
if (!needsSearch) {
break;
}
if (prevRuneOffset < -flattenedText.Length) {
break;
}
graphemeClusterLength *= 2;
continue;
}
TextBox box = boxes[0];
const int NEWLINE_CODE_UNIT = 10;
if (prevCodeUnit == NEWLINE_CODE_UNIT) {
return Rect.fromLTRB(this._emptyOffset.dx, box.bottom,
this._emptyOffset.dx, box.bottom + box.bottom - box.top);
}
float caretEnd = box.end;
float dx = box.direction == TextDirection.rtl ? caretEnd - caretPrototype.width : caretEnd;
return Rect.fromLTRB(Mathf.Min(dx, this.width), box.top,
Mathf.Min(dx, this.width), box.bottom);
}
return null;
}
Rect _getRectFromDownStream(int offset, Rect caretPrototype) {
string flattenedText = this._text.toPlainText();
var nextCodeUnit =
this._text.codeUnitAt(Mathf.Min(offset, flattenedText == null ? 0 : flattenedText.Length - 1));
if (nextCodeUnit == null) {
return null;
}
bool needsSearch = _isUtf16Surrogate(nextCodeUnit.Value) || nextCodeUnit == _zwjUtf16;
int graphemeClusterLength = needsSearch ? 2 : 1;
List<TextBox> boxes = null;
while ((boxes == null || boxes.isEmpty()) && flattenedText != null) {
int nextRuneOffset = offset + graphemeClusterLength;
boxes = this._paragraph.getRectsForRange(offset, nextRuneOffset);
if (boxes.isEmpty()) {
if (!needsSearch) {
break;
}
if (nextRuneOffset >= flattenedText.Length << 1) {
break;
}
graphemeClusterLength *= 2;
continue;
}
TextBox box = boxes[boxes.Count - 1];
float caretStart = box.start;
float dx = box.direction == TextDirection.rtl ? caretStart - caretPrototype.width : caretStart;
return Rect.fromLTRB(Mathf.Min(dx, this.width), box.top,
Mathf.Min(dx, this.width), box.bottom);
}
return null;
}
Offset _emptyOffset {
get {
D.assert(!this._needsLayout);
switch (this.textAlign) {
case TextAlign.left:
return Offset.zero;
case TextAlign.right:
return new Offset(this.width, 0.0f);
case TextAlign.center:
return new Offset(this.width / 2.0f, 0.0f);
case TextAlign.justify:
if (this.textDirection == TextDirection.rtl) {
return new Offset(this.width, 0.0f);
}
return Offset.zero;
}
return null;
}
}
static bool _isUtf16Surrogate(int value) {
return (value & 0xF800) == 0xD800;
}
}
}