RenderAbstractViewport class

An interface for render objects that are bigger on the inside.

Some render objects, such as RenderViewport, present a portion of their content, which can be controlled by a ViewportOffset. This interface lets the framework recognize such render objects and interact with them without having specific knowledge of all the various types of viewports.

Inheritance
Implemented by

Properties

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 Constraints
The layout constraints most recently supplied by the parent.
@protected, 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
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
An estimate of the bounds within which this render object will paint. Useful for debugging flags such as debugPaintLayerBordersEnabled.
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
sizedByParent bool
Whether the constraints are the only input to the sizing algorithm (in particular, child nodes have no impact). [...]
@protected, read-only, inherited

Methods

getOffsetToReveal(RenderObject target, double alignment) double
Returns the offset that would be needed to reveal the target render object. [...]
adoptChild(RenderObject child) → void
Called by subclasses when they decide a render object is a child. [...]
inherited
applyPaintTransform(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 node as attached to the given owner. [...]
inherited
clearSemantics() → void
Removes all semantics from this render object and its descendants. [...]
@mustCallSuper, 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.
@protected, inherited
debugDescribeChildren() List<DiagnosticsNode>
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
@protected, inherited
debugPaint(PaintingContext context, Offset offset) → void
Override this method to paint debugging information.
@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.
@protected, inherited
describeApproximatePaintClip(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(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(RenderObject child) → void
Called by subclasses when they decide a render object is no longer a child. [...]
inherited
getTransformTo(RenderObject ancestor) Matrix4
Applies the paint transform up the tree to ancestor. [...]
inherited
handleEvent(PointerEvent event, HitTestEntry 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. [...]
@protected, inherited
layout(Constraints constraints, { bool parentUsesSize: false }) → void
Compute the layout for this render object. [...]
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
paint(PaintingContext context, Offset offset) → void
Paint this render object into the given context at the given offset. [...]
inherited
performLayout() → void
Do the work of computing the layout for this render object. [...]
@protected, inherited
performResize() → void
Updates the render objects size using only the constraints. [...]
@protected, 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(RenderObject child) → void
Override to setup parent data correctly for your children. [...]
inherited
showOnScreen([RenderObject child ]) → void
Attempt to make this or a descendant RenderObject visible on screen. [...]
inherited
toDiagnosticsNode({String name, DiagnosticsTreeStyle style }) DiagnosticsNode
inherited
toString({DiagnosticLevel minLevel }) String
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 Methods

of(RenderObject object) RenderAbstractViewport
Returns the RenderAbstractViewport that most tightly encloses the given render object. [...]

Constants

defaultCacheExtent → const double
The default value for the cache extent of the viewport. [...]
@protected
250.0