decorate method

@override void decorate(TreeMapRendererElement<D> rendererElement, ChartCanvas canvas, GraphicsFactory graphicsFactory, { required Rectangle<num> drawBounds, required double animationPercent, bool rtl = false, bool renderVertically = false, bool renderMultiline = false, })

Paints decorator on top of rendererElement.

Implementation

@override
void decorate(TreeMapRendererElement<D> rendererElement, ChartCanvas canvas,
    GraphicsFactory graphicsFactory,
    {required Rectangle drawBounds,
    required double animationPercent,
    bool rtl = false,
    bool renderVertically = false,
    bool renderMultiline = false}) {
  // Decorates the renderer elements when animation is completed.
  if (animationPercent != 1.0) return;

  // Creates [TextStyle] from [TextStyleSpec] to be used by all the elements.
  // The [GraphicsFactory] is needed since it cannot be created earlier.
  final labelStyle = _asTextStyle(graphicsFactory, labelStyleSpec);

  final labelFn = rendererElement.series.labelAccessorFn;
  final datumIndex = rendererElement.index;
  final label = labelFn != null ? labelFn(datumIndex) : null;

  // Skips if this element has no label.
  if (label == null || label.isEmpty) return;

  // Uses datum specific label style if provided.
  final datumLabelStyle = _datumStyle(
      rendererElement.series.insideLabelStyleAccessorFn,
      datumIndex,
      graphicsFactory,
      defaultStyle: labelStyle);
  final rect = rendererElement.boundingRect;
  final labelElement = graphicsFactory.createTextElement(label)
    ..textStyle = datumLabelStyle
    ..textDirection = rtl ? TextDirection.rtl : TextDirection.ltr;
  final labelHeight = labelElement.measurement.verticalSliceWidth;
  final maxLabelHeight =
      (renderVertically ? rect.width : rect.height) - (labelPadding * 2);
  final maxLabelWidth =
      (renderVertically ? rect.height : rect.width) - (labelPadding * 2);
  final multiline = enableMultiline && renderMultiline;
  final parts = wrapLabelLines(
      labelElement, graphicsFactory, maxLabelWidth, maxLabelHeight,
      allowLabelOverflow: allowLabelOverflow, multiline: multiline);

  for (var index = 0; index < parts.length; index++) {
    final segment = _createLabelSegment(
        rect, labelHeight, parts[index], index,
        rtl: rtl, rotate: renderVertically);

    // Draws a label inside of a treemap renderer element.
    canvas.drawText(segment.text, segment.xOffet, segment.yOffset,
        rotation: segment.rotationAngle);
  }
}