Be more detailed in assert messages from _paintWithContext (#9409)
diff --git a/packages/flutter/lib/src/rendering/object.dart b/packages/flutter/lib/src/rendering/object.dart
index 3db759a..7ba2451 100644
--- a/packages/flutter/lib/src/rendering/object.dart
+++ b/packages/flutter/lib/src/rendering/object.dart
@@ -2167,9 +2167,47 @@
}
void _paintWithContext(PaintingContext context, Offset offset) {
- assert(!_debugDoingThisPaint);
- assert(!_needsLayout);
- assert(!_needsCompositingBitsUpdate);
+ assert(() {
+ if (_debugDoingThisPaint) {
+ throw new FlutterError(
+ 'Tried to paint a RenderObject reentrantly.\n'
+ 'The following RenderObject was already being painted when it was '
+ 'painted again:\n'
+ ' ${toStringShallow("\n ")}\n'
+ 'Since this typically indicates an infinite recursion, it is '
+ 'disallowed.'
+ );
+ }
+ if (_needsLayout) {
+ throw new FlutterError(
+ 'Tried to paint a RenderObject before it was laid out.\n'
+ 'The following RenderObject was marked as dirty for layout at the '
+ 'time that it was painted:\n'
+ ' ${toStringShallow("\n ")}\n'
+ 'A RenderObject that is still dirty for layout cannot be painted '
+ 'because it does not know its own geometry yet.\n'
+ 'Maybe one of the ancestors of this RenderObject was skipped '
+ 'during the layout phase, but not skipped during the paint phase. '
+ 'If the ancestor in question is below the nearest relayout boundary, '
+ 'but is not below the nearest repaint boundary, that could cause '
+ 'this error.'
+ );
+ }
+ if (_needsCompositingBitsUpdate) {
+ throw new FlutterError(
+ 'Tried to paint a RenderObject before its compositing bits were '
+ 'updated.\n'
+ 'The following RenderObject was marked as having dirty compositing '
+ 'bits at the time that it was painted:\n'
+ ' ${toStringShallow("\n ")}\n'
+ 'A RenderObject that still has dirty compositing bits cannot be '
+ 'painted because this indicates that the tree has not yet been '
+ 'properly configured for creating the layer tree.\n'
+ 'This usually indicates an error in the Flutter framework itself.'
+ );
+ }
+ return true;
+ });
RenderObject debugLastActivePaint;
assert(() {
_debugDoingThisPaint = true;
