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();
}
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, this.size);
D.assert(() => {
int debugNewCanvasSaveCount = canvas.getSaveCount();
if (debugNewCanvasSaveCount > debugPreviousCanvasSaveCount)
{
throw new UIWidgetsError(
$"{debugNewCanvasSaveCount - debugPreviousCanvasSaveCount} more " +
$"time{((debugNewCanvasSaveCount - debugPreviousCanvasSaveCount == 1) ? "" : "s")} " +
"than it called canvas.restore().\n" +
"This leaves the canvas in an inconsistent state and will probably result in a broken display.\n" +
"You must pair each call to save()/saveLayer() with a later matching call to restore()."
);
}
if (debugNewCanvasSaveCount < debugPreviousCanvasSaveCount)
{
throw new UIWidgetsError(
$"The {painter} custom painter called canvas.restore() " +
$"{debugPreviousCanvasSaveCount - debugNewCanvasSaveCount} more " +
$"time{(debugPreviousCanvasSaveCount - debugNewCanvasSaveCount == 1 ? "" : "s")} " +
"than it called canvas.save() or canvas.saveLayer().\n" +
"This leaves the canvas in an inconsistent state and will result in a broken display.\n" +
"You should only call restore() if you first called save() or saveLayer()."
);
}
return(debugNewCanvasSaveCount == debugPreviousCanvasSaveCount);
});
canvas.restore();
}
