TransparentPointer class

This widget is invisible for its parent to hit testing, but still allows its subtree to receive pointer events.

{@tool snippet}

In this example, a drag can be started anywhere in the widget, including on top of the text button, even though the button is visually in front of the background gesture detector. At the same time, the button is tappable.

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        GestureDetector(
          behavior: HitTestBehavior.opaque,
          onVerticalDragStart: (_) => print("Background drag started"),
        ),
        Positioned(
          top: 60,
          left: 60,
          height: 60,
          width: 60,
          child: TransparentPointer(
            child: TextButton(
              child: Text("Tap me"),
              onPressed: () => print("You tapped me"),
            ),
          ),
        ),
      ],
    );
  }
}

{@end-tool}

See also:

• IgnorePointer, which is also invisible for its parent during hit testing, but does not allow its subtree to receive pointer events.
• AbsorbPointer, which is visible during hit testing, but prevents its subtree from receiving pointer event. The opposite of this widget.

Inheritance

• Object
• DiagnosticableTree
• Widget
• RenderObjectWidget
• SingleChildRenderObjectWidget
• TransparentPointer

Constructors

TransparentPointer({Key? key, bool transparent = true, required Widget child})

Creates a widget that is invisible for its parent to hit testing, but still allows its subtree to receive pointer events.

const

Properties

child → Widget?

The widget below this widget in the tree.

final, inherited

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

transparent → bool

Whether this widget is invisible to its parent during hit testing.

final

Methods

createElement() → SingleChildRenderObjectElement

RenderObjectWidgets always inflate to a RenderObjectElement subclass.

inherited

createRenderObject(BuildContext context) → RenderTransparentPointer

Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.

override

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.

override

didUnmountRenderObject(covariant RenderObject renderObject) → void

A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

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}) → String

Returns a string representation of this node and its descendants.

inherited

toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String

Returns a one-line detailed description of the object.

inherited

toStringShort() → String

A short, textual description of this widget.

inherited

updateRenderObject(BuildContext context, covariant RenderTransparentPointer renderObject) → void

Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited