InteractiveViewerModifier class

A widget that enables pan and zoom interactions with its child.

The user can transform the child by dragging to pan or pinching to zoom.

By default, InteractiveViewer clips its child using Clip.hardEdge. To prevent this behavior, consider setting clipBehavior to Clip.none. When clipBehavior is Clip.none, InteractiveViewer may draw outside of its original area of the screen, such as when a child is zoomed in and increases in size. However, it will not receive gestures outside of its original area. To prevent dead areas where InteractiveViewer does not receive gestures, don't set clipBehavior or be sure that the InteractiveViewer widget is the size of the area that should be interactive.

The child must not be null.

See also:

• The Flutter Gallery's transformations demo, which includes the use of InteractiveViewer.
• The flutter-go demo, which includes robust positioning of an InteractiveViewer child that works for all screen sizes and child sizes.
• The Lazy Flutter Performance Session, which includes the use of an InteractiveViewer to performantly view subsets of a large set of widgets using the builder constructor.

{@tool dartpad} This example shows a simple Container that can be panned and zoomed.

** See code in examples/api/lib/widgets/interactive_viewer/interactive_viewer.0.dart ** {@end-tool}

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• SingleChildStatelessModifier
• InteractiveViewerModifier

Available extensions

• ModifierTransformer

Annotations

• @immutable

Constructors

InteractiveViewerModifier({Key? key, Widget? child, Key? modifierKey, Clip clipBehavior = Clip.hardEdge, bool alignPanAxis = false, EdgeInsets boundaryMargin = EdgeInsets.zero, bool constrained = true, double maxScale = 2.5, double minScale = 0.8, GestureScaleEndCallback? onInteractionEnd, GestureScaleStartCallback? onInteractionStart, GestureScaleUpdateCallback? onInteractionUpdate, bool panEnabled = true, bool scaleEnabled = true, double scaleFactor = 200.0, TransformationController? transformationController})

Create an InteractiveViewer.

const

InteractiveViewerModifier.builder({Key? key, Widget? child, Key? modifierKey, Clip clipBehavior = Clip.hardEdge, bool alignPanAxis = false, EdgeInsets boundaryMargin = EdgeInsets.zero, double maxScale = 2.5, double minScale = 0.8, GestureScaleEndCallback? onInteractionEnd, GestureScaleStartCallback? onInteractionStart, GestureScaleUpdateCallback? onInteractionUpdate, bool panEnabled = true, bool scaleEnabled = true, double scaleFactor = 200.0, TransformationController? transformationController, required InteractiveViewerModifierBuilder builder})

Creates an InteractiveViewer for a child that is created on demand.

const

Properties

alignPanAxis → bool

If true, panning is only allowed in the direction of the horizontal axis or the vertical axis.

final

boundaryMargin → EdgeInsets

A margin for the visible boundaries of the child.

final

builder → InteractiveViewerModifierBuilder?

Builds the child of this widget.

final

clipBehavior → Clip

If set to Clip.none, the child may extend beyond the size of the InteractiveViewer, but it will not receive gestures in these areas. Be sure that the InteractiveViewer is the desired size when using Clip.none.

final

constrained → bool

Whether the normal size constraints at this point in the widget tree are applied to the child.

final

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

maxScale → double

The maximum allowed scale.

final

minScale → double

The minimum allowed scale.

final

modifierKey → Key?

The actual key of the widget, which Modifier wrapped

final, inherited

onInteractionEnd → GestureScaleEndCallback?

Called when the user ends a pan or scale gesture on the widget.

final

onInteractionStart → GestureScaleStartCallback?

Called when the user begins a pan or scale gesture on the widget.

final

onInteractionUpdate → GestureScaleUpdateCallback?

Called when the user updates a pan or scale gesture on the widget.

final

panEnabled → bool

If false, the user will be prevented from panning.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

scaleEnabled → bool

If false, the user will be prevented from scaling.

final

scaleFactor → double

Determines the amount of scale to be performed per pointer scroll.

final

transformationController → TransformationController?

A TransformationController for the transformation performed on the child.

final

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

inherited

buildWithChild(BuildContext context, Widget? child) → Widget

A build method that receives an extra child parameter.

override

createElement() → SingleChildStatelessElement

Create a SingleChildStatelessElement

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

modified() → Modifier

Available on Widget, provided by the ModifierTransformer extension

Transform normal widget to Modifier

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, int wrapWidth = 65}) → 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

Operators

operator ==(Object other) → bool

The equality operator.

inherited