RenderMetricsProvider class
Provides RenderMetricsHolder to the widget tree via InheritedWidget.
Unlike a typical InheritedWidget, this never notifies dependents —
updateShouldNotify always returns false. The holder's data is
mutated in-place by WidgetApp, and widgets read from it lazily
when they rebuild for other reasons (e.g. when _dirty is set for
a real state change or the periodic debug overlay repaint).
- Inheritance
-
- Object
- Widget
- InheritedWidget
- RenderMetricsProvider
Constructors
- RenderMetricsProvider({required RenderMetricsHolder holder, required Widget child, Key? key})
Properties
- child → Widget
-
The descendant subtree that can depend on this widget's data.
finalinherited
-
children
→ List<
Widget> -
Child widgets that receive forwarded messages.
no setterinherited
- debugRenderObjectPassthrough → bool
-
Whether this widget is intentionally transparent to render-object layouts.
no setterinherited
- focusable → bool
-
Whether this widget can receive keyboard focus.
no setterinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- holder → RenderMetricsHolder
-
final
- id → String
-
Unique identifier for this widget.
no setterinherited
- key → Key?
-
Key for preserving widget identity.
finalinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- theme → Theme
-
Access the current theme.
no setterinherited
Methods
-
buildCachedView<
T> (T builder(), Object? cacheKey) → T -
Returns a cached view if the cache key matches.
inherited
-
handleInit(
) → Cmd? -
Override this instead of init for widget-specific initialization.
inherited
-
handleIntercept(
Msg msg) → (Widget, Cmd?) -
Override this to handle messages before they reach children.
inherited
-
handleUpdate(
Msg msg) → (Widget, Cmd?) -
Override this to handle messages specific to this widget.
inherited
-
init(
) → Cmd? -
Called once when the widget is first mounted.
inherited
-
invalidateCachedView(
) → void -
Clears any cached view for this widget.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
-
update(
Msg msg) → (Model, Cmd?) -
Handles messages by forwarding to children then calling handleUpdate.
inherited
-
updateShouldNotify(
covariant RenderMetricsProvider oldWidget) → bool -
Whether dependents should rebuild when this widget updates.
override
-
view(
) → Object -
Renders the widget to a string or View.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Static Methods
-
maybeOf(
BuildContext context) → RenderMetricsHolder? -
Returns the RenderMetricsHolder from the nearest ancestor, or
null.