BackdropTransform class abstract
Describes how the content behind a sheet/drawer (the backdrop) is
transformed as the sheet animates between closed (t == 0) and fully
open (t == 1).
Implementations control both the visual wrapping (wrapBackdrop) and the amount of layout space the transform frees along each axis (resolveExtraSize). The freed space is what allows a drawer to slide into the gap opened by scaling the backdrop down, and is propagated across nested sheets via BackdropTransformData.
The default implementation is ScaleBackdropTransform, which scales the
backdrop from 1.0 down to a smaller factor (see kBackdropScaleDown).
- Implementers
Constructors
- BackdropTransform()
-
Const constructor for subclasses.
const
Properties
- hashCode → int
-
The hash code for this object.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
resolveExtraSize(
Size size, double t, {bool isRoot = true}) → Size -
The amount of space (per axis) freed by this transform for a backdrop of
sizeat progresst. Returns Size.zero when nothing is freed. -
toString(
) → String -
A string representation of this object.
inherited
-
wrapBackdrop(
BuildContext context, Widget child, double t, {bool isRoot = true}) → Widget -
Wraps
child(the backdrop content) with the visual transform for progresst(0 = closed, 1 = fully open).
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Constants
- none → const BackdropTransform
- A transform that does nothing: the backdrop is untouched and no extra layout space is produced. Used by sheets that do not scale the backdrop.