PictureLayer _highlightConflictingLayer(PhysicalModelLayer child)
{
PictureRecorder recorder = new PictureRecorder();
var canvas = new RecorderCanvas(recorder);
canvas.drawPath(child.clipPath, new Paint()
{
color = new Color(0xFFAA0000),
style = PaintingStyle.stroke,
strokeWidth = child.elevation + 10.0f,
});
PictureLayer pictureLayer = new PictureLayer(child.clipPath.getBounds());
pictureLayer.picture = recorder.endRecording();
pictureLayer.debugCreator = child;
child.append(pictureLayer);
return(pictureLayer);
}
List <PictureLayer> _processConflictingPhysicalLayers(PhysicalModelLayer predecessor, PhysicalModelLayer child)
{
UIWidgetsError.reportError(new UIWidgetsErrorDetails(
exception: new UIWidgetsError("Painting order is out of order with respect to elevation.\n" +
"See https://api.flutter.dev/flutter/rendering/debugCheckElevations.html " +
"for more details."),
context: "during compositing",
informationCollector: (StringBuilder builder) => {
builder.AppendLine("Attempted to composite layer");
builder.AppendLine(child.ToString());
builder.AppendLine("after layer");
builder.AppendLine(predecessor.ToString());
builder.AppendLine("which occupies the same area at a higher elevation.");
}
));
return(new List <PictureLayer> {
this._highlightConflictingLayer(predecessor),
this._highlightConflictingLayer(child)
});
}
protected List <PictureLayer> _debugCheckElevations()
{
List <PhysicalModelLayer> physicalModelLayers =
this.depthFirstIterateChildren().OfType <PhysicalModelLayer>().ToList();
List <PictureLayer> addedLayers = new List <PictureLayer>();
for (int i = 0; i < physicalModelLayers.Count; i++)
{
PhysicalModelLayer physicalModelLayer = physicalModelLayers[i];
D.assert(physicalModelLayer.lastChild?.debugCreator != physicalModelLayer,
() => "debugCheckElevations has either already visited this layer or failed to remove the" +
" added picture from it.");
float accumulatedElevation = physicalModelLayer.elevation;
Layer ancestor = physicalModelLayer.parent;
while (ancestor != null)
{
if (ancestor is PhysicalModelLayer modelLayer)
{
accumulatedElevation += modelLayer.elevation;
}
ancestor = ancestor.parent;
}
for (int j = 0; j <= i; j++)
{
PhysicalModelLayer predecessor = physicalModelLayers[j];
float predecessorAccumulatedElevation = predecessor.elevation;
ancestor = predecessor.parent;
while (ancestor != null)
{
if (ancestor == predecessor)
{
continue;
}
if (ancestor is PhysicalModelLayer modelLayer)
{
predecessorAccumulatedElevation += modelLayer.elevation;
}
ancestor = ancestor.parent;
}
if (predecessorAccumulatedElevation <= accumulatedElevation)
{
continue;
}
Path intersection = Path.combine(
PathOperation.intersect,
predecessor._debugTransformedClipPath,
physicalModelLayer._debugTransformedClipPath);
if (intersection != null && intersection.computeMetrics().Any((metric) => metric.length > 0))
{
addedLayers.AddRange(this._processConflictingPhysicalLayers(predecessor, physicalModelLayer));
}
}
}
return(addedLayers);
}