dart:ui library

Classes

AccessibilityFeatures: Additional accessibility features that may be enabled by the platform.
BackdropFilterEngineLayer: An opaque handle to a backdrop filter engine layer.
CallbackHandle: A wrapper for a raw callback handle.
Canvas: An interface for recording graphical operations.
ChannelBuffers: The buffering and dispatch mechanism for messages sent by plugins on the engine side to their corresponding plugin code on the framework side.
ClipPathEngineLayer: An opaque handle to a clip path engine layer.
ClipRectEngineLayer: An opaque handle to a clip rect engine layer.
ClipRRectEngineLayer: An opaque handle to a clip rounded rect engine layer.
Codec: A handle to an image codec.
Color: An immutable 32 bit color value in ARGB format.
ColorFilter: A description of a color filter to apply when drawing a shape or compositing a layer with a particular Paint. A color filter is a function that takes two colors, and outputs one color. When applied during compositing, it is independently applied to each pixel of the layer being drawn before the entire layer is merged with the destination.
ColorFilterEngineLayer: An opaque handle to a color filter engine layer.
DartPluginRegistrant: Helper functions for Dart Plugin Registrants.
Display: A configurable display that a FlutterView renders on.
DisplayFeature: Area of the display that may be obstructed by a hardware feature.
EngineLayer: A handle for the framework to hold and retain an engine layer across frames.
FlutterView: A view into which a Flutter Scene is drawn.
FontFeature: A feature tag and value that affect the selection of glyphs in a font.
FontVariation: An axis tag and value that can be used to customize variable fonts.
FontWeight: The thickness of the glyphs used to draw the text.
FragmentProgram: An instance of FragmentProgram creates Shader objects (as used by Paint.shader).
FragmentShader: A Shader generated from a FragmentProgram.
FrameData: Additional data available on each flutter frame.
FrameInfo: Information for a single frame of an animation.
FrameTiming: Time-related performance metrics of a frame.
GestureSettings: Platform specific configuration for gesture behavior, such as touch slop.
GlyphInfo: The measurements of a character (or a sequence of visually connected characters) within a paragraph.
Gradient: A shader (as used by Paint.shader) that renders a color gradient.
Image: Opaque handle to raw decoded image data (pixels).
ImageDescriptor: A descriptor of data that can be turned into an Image via a Codec.
ImageFilter: A filter operation to apply to a raster image.
ImageFilterEngineLayer: An opaque handle to an image filter engine layer.
ImageShader: A shader (as used by Paint.shader) that tiles an image.
ImmutableBuffer: A handle to a read-only byte buffer that is managed by the engine.
IsolateNameServer: Static methods to allow for simple sharing of SendPorts across Isolates.
KeyData: Information about a key event.
LineMetrics: LineMetrics stores the measurements and statistics of a single line in the paragraph.
Locale: An identifier used to select a user's language and formatting preferences.
LocaleStringAttribute: A string attribute that causes the assistive technologies, e.g. VoiceOver, to treat string as a certain language.
MaskFilter: A mask filter to apply to shapes as they are painted. A mask filter is a function that takes a bitmap of color pixels, and returns another bitmap of color pixels.
Offset: An immutable 2D floating-point offset.
OffsetBase: Base class for Size and Offset, which are both ways to describe a distance as a two-dimensional axis-aligned vector.
OffsetEngineLayer: An opaque handle to an offset engine layer.
OpacityEngineLayer: An opaque handle to an opacity engine layer.
Paint: A description of the style to use when drawing on a Canvas.
Paragraph: A paragraph of text.
ParagraphBuilder: Builds a Paragraph containing text with the given styling information.
ParagraphConstraints: Layout constraints for Paragraph objects.
ParagraphStyle: An opaque object that determines the configuration used by ParagraphBuilder to position lines within a Paragraph of text.
Path: A complex, one-dimensional subset of a plane.
PathMetric: Utilities for measuring a Path and extracting sub-paths.
PathMetricIterator: Used by PathMetrics to track iteration from one segment of a path to the next for measurement.
PathMetrics: An iterable collection of PathMetric objects describing a Path.
Picture: An object representing a sequence of recorded graphical operations.
PictureRecorder: Records a Picture containing a sequence of graphical operations.
PlatformDispatcher: Platform event dispatcher singleton.
PluginUtilities: Functionality for Flutter plugin authors.
PointerData: Information about the state of a pointer.
PointerDataPacket: A sequence of reports about the state of pointers.
Radius: A radius for either circular or elliptical shapes.
Rect: An immutable, 2D, axis-aligned, floating-point rectangle whose coordinates are relative to a given origin.
RootIsolateToken: A token that represents a root isolate.
RRect: An immutable rounded rectangle with the custom radii for all four corners.
RSTransform: A transform consisting of a translation, a rotation, and a uniform scale.
Scene: An opaque object representing a composited scene.
SceneBuilder: Builds a Scene containing the given visuals.
SemanticsAction: The possible actions that can be conveyed from the operating system accessibility APIs to a semantics node.
SemanticsActionEvent: An event to request a SemanticsAction of type to be performed on the SemanticsNode identified by nodeId owned by the FlutterView identified by viewId.
SemanticsFlag: A Boolean value that can be associated with a semantics node.
SemanticsUpdate: An opaque object representing a batch of semantics updates.
SemanticsUpdateBuilder: An object that creates SemanticsUpdate objects.
Shader: Base class for objects such as Gradient and ImageShader which correspond to shaders as used by Paint.shader.
ShaderMaskEngineLayer: An opaque handle to a shader mask engine layer.
Shadow: A single shadow.
SingletonFlutterWindow: Deprecated. Will be removed in a future version of Flutter.
Size: Holds a 2D floating-point size.
SpellOutStringAttribute: A string attribute that causes the assistive technologies, e.g. VoiceOver, to spell out the string character by character.
StringAttribute: An abstract interface for string attributes that affects how assistive technologies, e.g. VoiceOver or TalkBack, treat the text.
StrutStyle: See also:
Tangent: The geometric description of a tangent: the angle at a point.
TargetImageSize: A specification of the size to which an image should be decoded.
TextBox: A rectangle enclosing a run of text.
TextDecoration: A linear decoration to draw near the text.
TextHeightBehavior: Defines how to apply TextStyle.height over and under text.
TextPosition: A position in a string of text.
TextRange: A range of characters in a string of text.
TextStyle: An opaque object that determines the size, position, and rendering of text.
TransformEngineLayer: An opaque handle to a transform engine layer.
Vertices: A set of vertex data used by Canvas.drawVertices.
ViewConstraints: Immutable layout constraints for FlutterViews.
ViewFocusEvent: An event for the engine to communicate view focus changes to the app.
ViewPadding: A representation of distances for each of the four edges of a rectangle, used to encode the view insets and padding that applications should place around their user interface, as exposed by FlutterView.viewInsets and FlutterView.padding. View insets and padding are preferably read via MediaQuery.of.

Enums

AppExitResponse: The possible responses to a request to exit the application.
AppExitType: The type of application exit to perform when calling ServicesBinding.exitApplication.
AppLifecycleState: States that an application can be in once it is running.
BlendMode: Algorithms to use when painting on the canvas.
BlurStyle: Styles to use for blurs in MaskFilter objects.
BoxHeightStyle: Defines various ways to vertically bound the boxes returned by Paragraph.getBoxesForRange.
BoxWidthStyle: Defines various ways to horizontally bound the boxes returned by Paragraph.getBoxesForRange.
Brightness: Describes the contrast of a theme or color palette.
Clip: Different ways to clip a widget's content.
ClipOp: Defines how a new clip region should be merged with the existing clip region.
ColorSpace: The color space describes the colors that are available to an Image.
DartPerformanceMode: Various performance modes for tuning the Dart VM's GC performance.
DisplayFeatureState: State of the display feature, which contains information about the posture for foldable features.
DisplayFeatureType: Type of DisplayFeature, describing the DisplayFeature behaviour and if it obstructs the display.
FilterQuality: Quality levels for image sampling in ImageFilter and Shader objects that sample images and for Canvas operations that render images.
FontStyle: Whether to use the italic type variation of glyphs in the font.
FramePhase: Various important time points in the lifetime of a frame.
ImageByteFormat: The format in which image bytes should be returned when using Image.toByteData.
KeyEventDeviceType: The source device for the key event.
KeyEventType: The type of a key event.
PaintingStyle: Strategies for painting shapes and paths on a canvas.
PathFillType: Determines the winding rule that decides how the interior of a Path is calculated.
PathOperation: Strategies for combining paths.
PixelFormat: The format of pixel data given to decodeImageFromPixels.
PlaceholderAlignment: Where to vertically align the placeholder relative to the surrounding text.
PointerChange: How the pointer has changed since the last report.
PointerDeviceKind: The kind of pointer device.
PointerSignalKind: The kind of pointer signal event.
PointMode: Defines how a list of points is interpreted when drawing a set of points.
StrokeCap: Styles to use for line endings.
StrokeJoin: Styles to use for line segment joins.
TextAffinity: A way to disambiguate a TextPosition when its offset could match two different locations in the rendered string.
TextAlign: Whether and how to align text horizontally.
TextBaseline: A horizontal line used for aligning text.
TextDecorationStyle: The style in which to draw a text decoration
TextDirection: A direction in which text flows.
TextLeadingDistribution: How the "leading" is distributed over and under the text.
TileMode: Defines what happens at the edge of a gradient or the sampling of a source image in an ImageFilter.
VertexMode: Defines how a list of points is interpreted when drawing a set of triangles.
ViewFocusDirection: Represents the direction in which the focus transitioned across FlutterViews.
ViewFocusState: Represents the focus state of a given FlutterView.

Constants

keepToString → const pragma: Annotation to keep Object.toString overrides as-is instead of removing them for size optimization purposes.
kTextHeightNone → const double: A TextStyle.height value that indicates the text span should take the height defined by the font, which may not be exactly the height of TextStyle.fontSize.

Properties

channelBuffers → ChannelBuffers: ChannelBuffers that allow the storage of messages between the Engine and the Framework. Typically messages that can't be delivered are stored here until the Framework is able to process them.
final
isRunningOnPlatformThread → bool: Whether the current isolate is running on the platform thread.
final
window → SingletonFlutterWindow: Deprecated. Will be removed in a future version of Flutter.
final

Functions

clampDouble(double x, double min, double max) → double: Same as num.clamp but optimized for a non-null double.
decodeImageFromList(Uint8List list, ImageDecoderCallback callback) → void: Loads a single image frame from a byte array into an Image object.
decodeImageFromPixels(Uint8List pixels, int width, int height, PixelFormat format, ImageDecoderCallback callback, {int? rowBytes, int? targetWidth, int? targetHeight, bool allowUpscaling = true}) → void: Convert an array of pixel values into an Image object.
hashList(Iterable<Object?>? arguments) → int: Combine the Object.hashCode values of an arbitrary number of objects from an Iterable into one value. This function will return the same value if given null as if given an empty list.
hashValues(Object? arg01, Object? arg02, [Object? arg03 = _hashEnd, Object? arg04 = _hashEnd, Object? arg05 = _hashEnd, Object? arg06 = _hashEnd, Object? arg07 = _hashEnd, Object? arg08 = _hashEnd, Object? arg09 = _hashEnd, Object? arg10 = _hashEnd, Object? arg11 = _hashEnd, Object? arg12 = _hashEnd, Object? arg13 = _hashEnd, Object? arg14 = _hashEnd, Object? arg15 = _hashEnd, Object? arg16 = _hashEnd, Object? arg17 = _hashEnd, Object? arg18 = _hashEnd, Object? arg19 = _hashEnd, Object? arg20 = _hashEnd]) → int: Combine up to twenty objects' hash codes into one value.
instantiateImageCodec(Uint8List list, {int? targetWidth, int? targetHeight, bool allowUpscaling = true}) → Future<Codec>: Instantiates an image Codec.
instantiateImageCodecFromBuffer(ImmutableBuffer buffer, {int? targetWidth, int? targetHeight, bool allowUpscaling = true}) → Future<Codec>: Instantiates an image Codec.
instantiateImageCodecWithSize(ImmutableBuffer buffer, {TargetImageSizeCallback? getTargetSize}) → Future<Codec>: Instantiates an image Codec.
lerpDouble(num? a, num? b, double t) → double?: Linearly interpolate between two numbers, a and b, by an extrapolation factor t.
loadFontFromList(Uint8List list, {String? fontFamily}) → Future<void>: Loads a font from a buffer and makes it available for rendering text.
runOnPlatformThread<R>(FutureOr<R> computation()) → Future<R>: Runs computation on the platform thread and returns the result.

Typedefs

ChannelCallback = void Function(ByteData? data, PlatformMessageResponseCallback callback): Signature for ChannelBuffers.setListener's callback argument.
DrainChannelCallback = Future<void> Function(ByteData? data, PlatformMessageResponseCallback callback): Deprecated. Migrate to ChannelCallback instead.
ErrorCallback = bool Function(Object exception, StackTrace stackTrace): Signature for PlatformDispatcher.onError.
FrameCallback = void Function(Duration duration): Signature for PlatformDispatcher.onBeginFrame.
ImageDecoderCallback = void Function(Image result): Callback signature for decodeImageFromList.
ImageEventCallback = void Function(Image image): Signature for Image lifecycle events.
KeyDataCallback = bool Function(KeyData data): Signature for PlatformDispatcher.onKeyData.
PictureEventCallback = void Function(Picture picture): Signature for Picture lifecycle events.
PlatformMessageCallback = void Function(String name, ByteData? data, PlatformMessageResponseCallback? callback): Deprecated. Migrate to ChannelBuffers.setListener instead.
PlatformMessageResponseCallback = void Function(ByteData? data): Signature for responses to platform messages.
PointerDataPacketCallback = void Function(PointerDataPacket packet): Signature for PlatformDispatcher.onPointerDataPacket.
PointerDataRespondCallback = void Function({bool allowPlatformDefault}): A function that implements the PointerData.respond method.
SemanticsActionEventCallback = void Function(SemanticsActionEvent action): Signature for PlatformDispatcher.onSemanticsActionEvent.
TargetImageSizeCallback = TargetImageSize Function(int intrinsicWidth, int intrinsicHeight): Signature for a callback that determines the size to which an image should be decoded given its intrinsic size.
TimingsCallback = void Function(List<FrameTiming> timings): Signature for PlatformDispatcher.onReportTimings.
ViewFocusChangeCallback = void Function(ViewFocusEvent viewFocusEvent): Signature for PlatformDispatcher.onViewFocusChange.
VoidCallback = void Function(): Signature of callbacks that have no arguments and return no data.
WindowPadding = ViewPadding: Deprecated. Will be removed in a future version of Flutter.

Exceptions / Errors

PictureRasterizationException: An exception thrown by Canvas.drawImage and related methods when drawing an Image created via Picture.toImageSync that is in an invalid state.

Classes

Enums

Constants

Properties

Functions

Typedefs

Exceptions / Errors

Flutter package

dart:ui library