RenderSliverHelpers class
Mixin for RenderSliver subclasses that provides some utility functions.
- Implemented types
- Implementers
Constructors
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
- centerOffsetAdjustment → double
-
For a center sliver, the distance before the absolute zero scroll offset
that this sliver can cover. [...]
read-only, inherited
- constraints → SliverConstraints
-
The layout constraints most recently supplied by 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
- geometry ↔ SliverGeometry
-
The amount of space this sliver occupies. [...]
read / write, 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
-
applyPaintTransformForBoxChild(
RenderBox child, Matrix4 transform) → void -
Utility function for applyPaintTransform for use when the children are
RenderBox widgets. [...]
@protected
-
hitTestBoxChild(
HitTestResult result, RenderBox child, { double mainAxisPosition, double crossAxisPosition }) → bool -
Utility function for hitTestChildren for use when the children are
RenderBox widgets. [...]
@protected
-
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 -
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(
covariant PipelineOwner owner) → void -
Mark this node as attached to the given owner. [...]
inherited
-
calculateCacheOffset(
SliverConstraints constraints, { double from, double to }) → double -
Computes the portion of the region from
from
toto
that is within the cache extent of the viewport, assuming that only the region from the SliverConstraints.cacheOrigin that is SliverConstraints.remainingCacheExtent high is visible, and that the relationship between scroll offsets and paint offsets is linear. [...]inherited -
calculatePaintOffset(
SliverConstraints constraints, { double from, double to }) → double -
Computes the portion of the region from
from
toto
that is visible, assuming that only the region from the SliverConstraints.scrollOffset that is SliverConstraints.remainingPaintExtent high is visible, and that the relationship between scroll offsets and paint offsets is linear. [...]inherited -
childCrossAxisPosition(
covariant RenderObject child) → double -
Returns the distance along the cross axis from the zero of the cross axis
in this sliver's paint coordinate space to the nearest side of the given
child. [...]
@protected, inherited
-
childMainAxisPosition(
covariant RenderObject child) → double -
Returns the distance from the leading visible edge of the sliver to the
side of the given child closest to that edge. [...]
@protected, inherited
-
childScrollOffset(
covariant RenderObject child) → double -
Returns the scroll offset for the leading edge of the given child. [...]
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.
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 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 actualsize
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 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. [...]
@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
-
getAbsoluteSizeRelativeToOrigin(
) → Size -
This returns a Size with dimensions relative to the leading edge of the
sliver, specifically the same offset that is given to the paint method.
This means that the dimensions may be negative. [...]
@protected, inherited
-
getTransformTo(
RenderObject ancestor) → Matrix4 -
Applies the paint transform up the tree to
ancestor
. [...]inherited -
handleEvent(
PointerEvent event, covariant SliverHitTestEntry entry) → void -
Override this method to handle pointer events that hit this render object.
inherited
-
hitTest(
HitTestResult result, { double mainAxisPosition, double crossAxisPosition }) → bool -
Determines the set of render objects located at the given position. [...]
inherited
-
hitTestChildren(
HitTestResult result, { double mainAxisPosition, double crossAxisPosition }) → bool -
Override this method to check whether any children are located at the
given position. [...]
@protected, inherited
-
hitTestSelf(
{double mainAxisPosition, double crossAxisPosition }) → bool -
Override this method if this render object can be hit even if its
children were not hit. [...]
@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
-
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. [...]
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(
) → 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