CDebugOverflowIndicatorMixin mixin
An mixin indicator that is drawn when a RenderObject overflows its container.
This is used by some RenderObjects that are containers to show where, and by how much, their children overflow their containers. These indicators are typically only shown in a debug build (where the call to paintOverflowIndicator is surrounded by an assert).
This class will also print a debug message to the console when the container overflows. It will print on the first occurrence, and once after each time that reassemble is called.
{@tool snippet}
class MyRenderObject extends RenderAligningShiftedBox with DebugOverflowIndicatorMixin {
MyRenderObject({
super.alignment = Alignment.center,
required super.textDirection,
super.child,
});
late Rect _containerRect;
late Rect _childRect;
@override
void performLayout() {
// ...
final BoxParentData childParentData = child!.parentData! as BoxParentData;
_containerRect = Offset.zero & size;
_childRect = childParentData.offset & child!.size;
}
@override
void paint(PaintingContext context, Offset offset) {
// Do normal painting here...
// ...
assert(() {
paintOverflowIndicator(context, offset, _containerRect, _childRect);
return true;
}());
}
}
{@end-tool}
See also:
- RenderConstraintsTransformBox and RenderFlex for examples of classes that use this indicator mixin.
- Superclass constraints
- Mixin applications
Properties
- alwaysNeedsCompositing → bool
-
Whether this render object always needs compositing.
no setterinherited
- attached → bool
-
Whether the render tree this render object belongs to is attached to a PipelineOwner.
no setterinherited
- constraints → Constraints
-
The layout constraints most recently supplied by the parent.
no setterinherited
- debugCanParentUseSize → bool
-
Whether the parent render object is permitted to use this render object's
size.
no setterinherited
- debugCreator ↔ Object?
-
The object responsible for creating this render object.
getter/setter pairinherited
- debugDisposed → bool?
-
Whether this has been disposed.
no setterinherited
- debugDoingThisLayout → bool
-
Whether performLayout for this render object is currently running.
no setterinherited
- debugDoingThisLayoutWithCallback → bool
-
Whether invokeLayoutCallback for this render object is currently running.
no setterinherited
- debugDoingThisPaint → bool
-
Whether paint for this render object is currently running.
no setterinherited
- debugDoingThisResize → bool
-
Whether performResize for this render object is currently running.
no setterinherited
- debugLayer → ContainerLayer?
-
In debug mode, the compositing layer that this render object uses to repaint.
no setterinherited
- debugLayoutParent → RenderObject?
-
The RenderObject that's expected to call layout on this RenderObject
in its performLayout implementation.
no setterinherited
- debugNeedsCompositedLayerUpdate → bool
-
Whether this render object's layer information is dirty.
no setterinherited
- debugNeedsLayout → bool
-
Whether this render object's layout information is dirty.
no setterinherited
- debugNeedsPaint → bool
-
Whether this render object's paint information is dirty.
no setterinherited
- debugNeedsSemanticsUpdate → bool
-
Whether the semantics of this render object is dirty and await the update.
no setterinherited
- debugSemantics → SemanticsNode?
-
The semantics of this render object.
no setterinherited
- depth → int
-
The depth of this render object in the render tree.
no setterinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- isRepaintBoundary → bool
-
Whether this render object repaints separately from its parent.
no setterinherited
- layer ↔ ContainerLayer?
-
The compositing layer that this render object uses to repaint.
getter/setter pairinherited
- needsCompositing → bool
-
Whether we or one of our descendants has a compositing layer.
no setterinherited
- owner → PipelineOwner?
-
The owner for this render object (null if unattached).
no setterinherited
- paintBounds → Rect
-
An estimate of the bounds within which this render object will paint.
Useful for debugging flags such as debugPaintLayerBordersEnabled.
no setterinherited
- parent → RenderObject?
-
The parent of this render object in the render tree.
no setterinherited
- parentData ↔ ParentData?
-
Data for use by the parent render object.
getter/setter pairinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- semanticBounds → Rect
-
The bounding box, in the local coordinate system, of this
object, for accessibility purposes.
no setterinherited
- semanticsParent → RenderObject?
-
The semantics parent of this render object in the semantics tree.
no setterinherited
- sizedByParent → bool
-
Whether the constraints are the only input to the sizing algorithm (in
particular, child nodes have no impact).
no setterinherited
Methods
-
adoptChild(
RenderObject child) → void -
Called by subclasses when they decide a render object is a child.
inherited
-
applyPaintTransform(
covariant RenderObject child, Matrix4 transform) → void -
Applies the transform that would be applied when painting the given child
to the given matrix.
inherited
-
assembleSemanticsNode(
SemanticsNode node, SemanticsConfiguration config, Iterable< SemanticsNode> children) → void -
Assemble the SemanticsNode for this RenderObject.
inherited
-
attach(
PipelineOwner owner) → void -
Mark this render object as attached to the given owner.
inherited
-
clearSemantics(
) → void -
Removes all semantics from this render object and its descendants.
inherited
-
debugAssertDoesMeetConstraints(
) → void -
Verify that the object's constraints are being met. Override this function
in a subclass to verify that your state matches the constraints object.
This function is only called when asserts are enabled (i.e. in debug mode)
and only when needsLayout is false. If the constraints are not met, it
should assert or throw an exception.
inherited
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of DiagnosticsNode objects describing this node's
children.
inherited
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
inherited
-
debugPaint(
PaintingContext context, Offset offset) → void -
Override this method to paint debugging information.
inherited
-
debugRegisterRepaintBoundaryPaint(
{bool includedParent = true, bool includedChild = false}) → void -
Called, in debug mode, if isRepaintBoundary is true, when either the
this render object or its parent attempt to paint.
inherited
-
debugResetSize(
) → void -
If a subclass has a "size" (the state controlled by
parentUsesSize
, whatever it is in the subclass, e.g. the actualsize
property of RenderBox), and the subclass verifies that in debug mode this "size" property isn't used when debugCanParentUseSize isn't set, then that subclass should override debugResetSize to reapply the current values of debugCanParentUseSize to that state.inherited -
describeApproximatePaintClip(
covariant RenderObject child) → Rect? -
Returns a rect in this object's coordinate system that describes
the approximate bounding box of the clip rect that would be
applied to the given child during the paint phase, if any.
inherited
-
describeForError(
String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.shallow}) → DiagnosticsNode -
Adds a debug representation of a RenderObject optimized for including in
error messages.
inherited
-
describeSemanticsClip(
covariant RenderObject? child) → Rect? -
Returns a rect in this object's coordinate system that describes
which SemanticsNodes produced by the
child
should be included in the semantics tree. SemanticsNodes from thechild
that are positioned outside of this rect will be dropped. Child SemanticsNodes that are positioned inside this rect, but outside of describeApproximatePaintClip will be included in the tree marked as hidden. Child SemanticsNodes that are inside of both rect will be included in the tree as regular nodes.inherited -
describeSemanticsConfiguration(
SemanticsConfiguration config) → void -
Report the semantics of this node, for example for accessibility purposes.
inherited
-
detach(
) → void -
Mark this render object as detached from its PipelineOwner.
inherited
-
dispose(
) → void -
Release any resources held by this render object.
override
-
dropChild(
RenderObject child) → void -
Called by subclasses when they decide a render object is no longer a child.
inherited
-
getTransformTo(
RenderObject? target) → Matrix4 -
Applies the paint transform from this RenderObject to the
target
RenderObject.inherited -
handleEvent(
PointerEvent event, covariant HitTestEntry< HitTestTarget> entry) → void -
Override this method to handle pointer events that hit this render object.
inherited
-
invokeLayoutCallback<
T extends Constraints> (LayoutCallback< T> callback) → void -
Allows mutations to be made to this object's child list (and any
descendants) as well as to any other dirty nodes in the render tree owned
by the same PipelineOwner as this object. The
callback
argument is invoked synchronously, and the mutations are allowed only during that callback's execution.inherited -
layout(
Constraints constraints, {bool parentUsesSize = false}) → void -
Compute the layout for this render object.
inherited
-
markNeedsCompositedLayerUpdate(
) → void -
Mark this render object as having changed a property on its composited
layer.
inherited
-
markNeedsCompositingBitsUpdate(
) → void -
Mark the compositing state for this render object as dirty.
inherited
-
markNeedsLayout(
) → void -
Mark this render object's layout information as dirty, and either register
this object with its PipelineOwner, or defer to the parent, depending on
whether this object is a relayout boundary or not respectively.
inherited
-
markNeedsLayoutForSizedByParentChange(
) → void -
Mark this render object's layout information as dirty (like
markNeedsLayout), and additionally also handle any necessary work to
handle the case where sizedByParent has changed value.
inherited
-
markNeedsPaint(
) → void -
Mark this render object as having changed its visual appearance.
inherited
-
markNeedsSemanticsUpdate(
) → void -
Mark this node as needing an update to its semantics description.
inherited
-
markParentNeedsLayout(
) → void -
Mark this render object's layout information as dirty, and then defer to
the parent.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
paint(
PaintingContext context, Offset offset) → void -
Paint this render object into the given context at the given offset.
inherited
-
paintCustomOverflowIndicator(
PaintingContext context, Offset offset, Rect containerRect, Rect childRect, {List< DiagnosticsNode> ? overflowHints}) → void - To be called when the overflow indicators should be painted.
-
paintOverflowIndicator(
PaintingContext context, Offset offset, Rect containerRect, Rect childRect, {List< DiagnosticsNode> ? overflowHints}) → void -
To be called when the overflow indicators should be painted.
inherited
-
paintsChild(
covariant RenderObject child) → bool -
Whether the given child would be painted if paint were called.
inherited
-
performLayout(
) → void -
Do the work of computing the layout for this render object.
inherited
-
performResize(
) → void -
Updates the render objects size using only the constraints.
inherited
-
reassemble(
) → void -
Cause the entire subtree rooted at the given RenderObject to be marked
dirty for layout, paint, etc, so that the effects of a hot reload can be
seen, or so that the effect of changing a global debug flag (such as
debugPaintSizeEnabled) can be applied.
override
-
redepthChild(
RenderObject child) → void -
Adjust the depth of the given
child
to be greater than this node's own depth.inherited -
redepthChildren(
) → void -
Adjust the depth of this node's children, if any.
inherited
-
replaceRootLayer(
OffsetLayer rootLayer) → void -
Replace the layer. This is only valid for the root of a render
object subtree (whatever object scheduleInitialPaint was
called on).
inherited
-
scheduleInitialLayout(
) → void -
Bootstrap the rendering pipeline by scheduling the very first layout.
inherited
-
scheduleInitialPaint(
ContainerLayer rootLayer) → void -
Bootstrap the rendering pipeline by scheduling the very first paint.
inherited
-
scheduleInitialSemantics(
) → void -
Bootstrap the semantics reporting mechanism by marking this node
as needing a semantics update.
inherited
-
sendSemanticsEvent(
SemanticsEvent semanticsEvent) → void -
Sends a SemanticsEvent associated with this render object's SemanticsNode.
inherited
-
setupParentData(
covariant RenderObject child) → void -
Override to setup parent data correctly for your children.
inherited
-
showOnScreen(
{RenderObject? descendant, Rect? rect, Duration duration = Duration.zero, Curve curve = Curves.ease}) → void -
Attempt to make (a portion of) this or a descendant RenderObject visible
on screen.
inherited
-
toDiagnosticsNode(
{String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode -
Returns a debug representation of the object that is used by debugging
tools and by DiagnosticsNode.toStringDeep.
inherited
-
toString(
{DiagnosticLevel minLevel = DiagnosticLevel.info}) → String -
A string representation of this object.
inherited
-
toStringDeep(
{String prefixLineOne = '', String? prefixOtherLines = '', DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String -
Returns a description of the tree rooted at this node.
If the prefix argument is provided, then every line in the output
will be prefixed by that string.
inherited
-
toStringShallow(
{String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String -
Returns a one-line detailed description of the render object.
This description is often somewhat long.
inherited
-
toStringShort(
) → String -
Returns a human understandable name.
inherited
-
updateCompositedLayer(
{required covariant OffsetLayer? oldLayer}) → OffsetLayer -
Update the composited layer owned by this render object.
inherited
-
visitChildren(
RenderObjectVisitor visitor) → void -
Calls visitor for each immediate child of this render object.
inherited
-
visitChildrenForSemantics(
RenderObjectVisitor visitor) → void -
Called when collecting the semantics of this node.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited