RenderErrorBox class

A render object used as a placeholder when an error occurs.

The box will be painted in the color given by the RenderErrorBox.backgroundColor static property.

A message can be provided. To simplify the class and thus help reduce the likelihood of this class itself being the source of errors, the message cannot be changed once the object has been created. If provided, the text will be painted on top of the background, using the styles given by the RenderErrorBox.textStyle and RenderErrorBox.paragraphStyle static properties.

Again to help simplify the class, this box tries to be 100000.0 pixels wide and high, to approximate being infinitely high but without using infinities.

Inheritance

Constructors

RenderErrorBox([String message = '' ])
Creates a RenderErrorBox render object. [...]

Properties

message String
The message to attempt to display at paint time.
final
sizedByParent bool
Whether the constraints are the only input to the sizing algorithm (in particular, child nodes have no impact). [...]
read-only, override
alwaysNeedsCompositing bool
Whether this render object always needs compositing. [...]
@protected, read-only, inherited
attached bool
Whether this node is in a tree whose root is attached to something. [...]
read-only, inherited
constraints BoxConstraints
The box constraints most recently received from the parent.
read-only, inherited
debugCanParentUseSize bool
Whether the parent render object is permitted to use this render object's size. [...]
read-only, inherited
debugCreator ↔ dynamic
The object responsible for creating this render object. [...]
read / write, inherited
debugDoingThisLayout bool
Whether performLayout for this render object is currently running. [...]
read-only, inherited
debugDoingThisPaint bool
Whether paint for this render object is currently running. [...]
read-only, inherited
debugDoingThisResize bool
Whether performResize for this render object is currently running. [...]
read-only, inherited
debugLayer OffsetLayer
In debug mode, the compositing layer that this render object uses to repaint. [...]
read-only, inherited
debugNeedsLayout bool
Whether this render object's layout information is dirty. [...]
read-only, inherited
debugNeedsPaint bool
Whether this render object's paint information is dirty. [...]
read-only, inherited
debugSemantics SemanticsNode
The semantics of this render object. [...]
read-only, inherited
depth int
The depth of this node in the tree. [...]
read-only, inherited
hashCode int
The hash code for this object. [...]
read-only, inherited
hasSize bool
Whether this render object has undergone layout and has a size.
read-only, inherited
isRepaintBoundary bool
Whether this render object repaints separately from its parent. [...]
read-only, inherited
layer OffsetLayer
The compositing layer that this render object uses to repaint. [...]
read-only, inherited
needsCompositing bool
Whether we or one of our descendants has a compositing layer. [...]
read-only, inherited
owner PipelineOwner
The owner for this node (null if unattached). [...]
read-only, inherited
paintBounds Rect
Returns a rectangle that contains all the pixels painted by this box. [...]
read-only, inherited
parent AbstractNode
The parent of this node in the tree.
read-only, inherited
parentData ParentData
Data for use by the parent render object. [...]
read / write, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
semanticBounds Rect
The bounding box, in the local coordinate system, of this object, for accessibility purposes.
read-only, inherited
size Size
The size of this render box computed during layout. [...]
@protected, read / write, inherited

Methods

computeMaxIntrinsicHeight(double width) double
Computes the value returned by getMaxIntrinsicHeight. Do not call this function directly, instead, call getMaxIntrinsicHeight. [...]
override
computeMaxIntrinsicWidth(double height) double
Computes the value returned by getMaxIntrinsicWidth. Do not call this function directly, instead, call getMaxIntrinsicWidth. [...]
override
hitTestSelf(Offset position) bool
Override this method if this render object can be hit even if its children were not hit. [...]
override
paint(PaintingContext context, Offset offset) → void
Paint this render object into the given context at the given offset. [...]
override
performResize() → void
Updates the render objects size using only the constraints. [...]
override
adoptChild(covariant RenderObject child) → void
Called by subclasses when they decide a render object is a child. [...]
inherited
applyPaintTransform(covariant RenderObject child, Matrix4 transform) → void
Multiply the transform from the parent's coordinate system to this box's coordinate system into the given transform. [...]
inherited
assembleSemanticsNode(SemanticsNode node, SemanticsConfiguration config, Iterable<SemanticsNode> children) → void
Assemble the SemanticsNode for this RenderObject. [...]
inherited
attach(covariant PipelineOwner owner) → void
Mark this node as attached to the given owner. [...]
inherited
clearSemantics() → void
Removes all semantics from this render object and its descendants. [...]
@mustCallSuper, inherited
computeDistanceToActualBaseline(TextBaseline baseline) double
Returns the distance from the y-coordinate of the position of the box to the y-coordinate of the first given baseline in the box's contents, if any, or null otherwise. [...]
@protected, inherited
computeMinIntrinsicHeight(double width) double
Computes the value returned by getMinIntrinsicHeight. Do not call this function directly, instead, call getMinIntrinsicHeight. [...]
@protected, inherited
computeMinIntrinsicWidth(double height) double
Computes the value returned by getMinIntrinsicWidth. Do not call this function directly, instead, call getMinIntrinsicWidth. [...]
@protected, inherited
debugAdoptSize(Size value) Size
Claims ownership of the given Size. [...]
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 in checked 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
debugHandleEvent(PointerEvent event, HitTestEntry entry) bool
Implements the debugPaintPointersEnabled debugging feature. [...]
inherited
debugPaint(PaintingContext context, Offset offset) → void
Override this method to paint debugging information.
inherited
debugPaintBaselines(PaintingContext context, Offset offset) → void
In debug mode, paints a line for each baseline. [...]
@protected, inherited
debugPaintPointers(PaintingContext context, Offset offset) → void
In debug mode, paints a rectangle if this render box has counted more pointer downs than pointer up events. [...]
@protected, inherited
debugPaintSize(PaintingContext context, Offset offset) → void
In debug mode, paints a border around this render box. [...]
@protected, inherited
debugRegisterRepaintBoundaryPaint({bool includedParent: true, bool includedChild: false }) → void
Called, in checked 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 actual size property of RenderBox), and the subclass verifies that in checked 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
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 the child 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. [...]
@protected, inherited
detach() → void
Mark this node as detached. [...]
@mustCallSuper, inherited
dropChild(covariant RenderObject child) → void
Called by subclasses when they decide a render object is no longer a child. [...]
inherited
getDistanceToActualBaseline(TextBaseline baseline) double
Calls computeDistanceToActualBaseline and caches the result. [...]
@mustCallSuper, @protected, inherited
getDistanceToBaseline(TextBaseline baseline, { bool onlyReal: false }) double
Returns the distance from the y-coordinate of the position of the box to the y-coordinate of the first given baseline in the box's contents. [...]
inherited
getMaxIntrinsicHeight(double width) double
Returns the smallest height beyond which increasing the height never decreases the preferred width. The preferred width is the value that would be returned by getMinIntrinsicWidth for that height. [...]
@mustCallSuper, inherited
getMaxIntrinsicWidth(double height) double
Returns the smallest width beyond which increasing the width never decreases the preferred height. The preferred height is the value that would be returned by getMinIntrinsicHeight for that width. [...]
@mustCallSuper, inherited
getMinIntrinsicHeight(double width) double
Returns the minimum height that this box could be without failing to correctly paint its contents within itself, without clipping. [...]
@mustCallSuper, inherited
getMinIntrinsicWidth(double height) double
Returns the minimum width that this box could be without failing to correctly paint its contents within itself, without clipping. [...]
@mustCallSuper, inherited
getTransformTo(RenderObject ancestor) Matrix4
Applies the paint transform up the tree to ancestor. [...]
inherited
globalToLocal(Offset point, { RenderObject ancestor }) Offset
Convert the given point from the global coordinate system in logical pixels to the local coordinate system for this box. [...]
inherited
handleEvent(PointerEvent event, covariant BoxHitTestEntry entry) → void
Override this method to handle pointer events that hit this render object. [...]
inherited
hitTest(HitTestResult result, { Offset position }) bool
Determines the set of render objects located at the given position. [...]
inherited
hitTestChildren(HitTestResult result, { Offset position }) bool
Override this method to check whether any children are located at the given position. [...]
@protected, 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. [...]
@protected, inherited
layout(Constraints constraints, { bool parentUsesSize: false }) → void
Compute the layout for this render object. [...]
inherited
localToGlobal(Offset point, { RenderObject ancestor }) Offset
Convert the given point from the local coordinate system for this box to the global coordinate system in logical pixels. [...]
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. [...]
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
performLayout() → void
Do the work of computing the layout for this render object. [...]
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. [...]
inherited
redepthChild(AbstractNode child) → void
Adjust the depth of the given child to be greater than this node's own depth. [...]
@protected, 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
rotate({int oldAngle, int newAngle, Duration time }) → void
Rotate this render object (not yet implemented).
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 toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel }) String
Returns a string representation of this object.
inherited
toStringDeep({String prefixLineOne: '', String prefixOtherLines: '', DiagnosticLevel minLevel: DiagnosticLevel.debug }) 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
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 ==(dynamic other) bool
The equality operator. [...]
inherited

Static Properties

backgroundColor Color
The color to use when painting the background of RenderErrorBox objects.
read / write
paragraphStyle ParagraphStyle
The paragraph style to use when painting RenderErrorBox objects.
read / write
textStyle TextStyle
The text style to use when painting RenderErrorBox objects.
read / write