MediaQueryData class Null safety

Information about a piece of media (e.g., a window).

For example, the MediaQueryData.size property contains the width and height of the current window.

To obtain the current MediaQueryData for a given BuildContext, use the MediaQuery.of function. For example, to obtain the size of the current window, use MediaQuery.of(context).size.

If no MediaQuery is in scope then the MediaQuery.of method will throw an exception. Alternatively, MediaQuery.maybeOf may be used, which returns null instead of throwing if no MediaQuery is in scope.

Insets and Padding

A diagram of padding, viewInsets, and viewPadding in correlation with each other

This diagram illustrates how padding relates to viewPadding and viewInsets, shown here in its simplest configuration, as the difference between the two. In cases when the viewInsets exceed the viewPadding, like when a software keyboard is shown below, padding goes to zero rather than a negative value. Therefore, padding is calculated by taking max(0.0, viewPadding - viewInsets).

In this diagram, the black areas represent system UI that the app cannot draw over. The red area represents view padding that the application may not be able to detect gestures in and may not want to draw in. The grey area represents the system keyboard, which can cover over the bottom view padding when visible.

MediaQueryData includes three EdgeInsets values: padding, viewPadding, and viewInsets. These values reflect the configuration of the device and are used and optionally consumed by widgets that position content within these insets. The padding value defines areas that might not be completely visible, like the display "notch" on the iPhone X. The viewInsets value defines areas that aren't visible at all, typically because they're obscured by the device's keyboard. Similar to viewInsets, viewPadding does not differentiate padding in areas that may be obscured. For example, by using the viewPadding property, padding would defer to the iPhone "safe area" regardless of whether a keyboard is showing.

The viewInsets and viewPadding are independent values, they're measured from the edges of the MediaQuery widget's bounds. Together they inform the padding property. The bounds of the top level MediaQuery created by WidgetsApp are the same as the window that contains the app.

Widgets whose layouts consume space defined by viewInsets, viewPadding, or padding should enclose their children in secondary MediaQuery widgets that reduce those properties by the same amount. The removePadding, removeViewPadding, and removeViewInsets methods are useful for this.

See also:

Annotations

Constructors

MediaQueryData({Size size = Size.zero, double devicePixelRatio = 1.0, double textScaleFactor = 1.0, Brightness platformBrightness = Brightness.light, EdgeInsets padding = EdgeInsets.zero, EdgeInsets viewInsets = EdgeInsets.zero, EdgeInsets systemGestureInsets = EdgeInsets.zero, EdgeInsets viewPadding = EdgeInsets.zero, bool alwaysUse24HourFormat = false, bool accessibleNavigation = false, bool invertColors = false, bool highContrast = false, bool disableAnimations = false, bool boldText = false, NavigationMode navigationMode = NavigationMode.traditional, DeviceGestureSettings gestureSettings = const DeviceGestureSettings(touchSlop: kTouchSlop), List<DisplayFeature> displayFeatures = const <ui.DisplayFeature>[]})
Creates data for a media query with explicit values.
const
MediaQueryData.fromWindow(FlutterView window)
Creates data for a media query based on the given window.

Properties

accessibleNavigation → bool
Whether the user is using an accessibility service like TalkBack or VoiceOver to interact with the application.
final
alwaysUse24HourFormat → bool
Whether to use 24-hour format when formatting time.
final
boldText → bool
Whether the platform is requesting that text be drawn with a bold font weight.
final
devicePixelRatio → double
The number of device pixels for each logical pixel. This number might not be a power of two. Indeed, it might not even be an integer. For example, the Nexus 6 has a device pixel ratio of 3.5.
final
disableAnimations → bool
Whether the platform is requesting that animations be disabled or reduced as much as possible.
final
displayFeatures → List<DisplayFeature>
Areas of the display that are obstructed by hardware features.
final
gestureSettings → DeviceGestureSettings
The gesture settings for the view this media query is derived from.
final
hashCode → int
The hash code for this object.
read-onlyoverride
highContrast → bool
Whether the user requested a high contrast between foreground and background content on iOS, via Settings -> Accessibility -> Increase Contrast.
final
invertColors → bool
Whether the device is inverting the colors of the platform.
final
Describes the navigation mode requested by the platform.
final
orientation → Orientation
The orientation of the media (e.g., whether the device is in landscape or portrait mode).
read-only
padding → EdgeInsets
The parts of the display that are partially obscured by system UI, typically by the hardware display "notches" or the system status bar.
final
platformBrightness → Brightness
The current brightness mode of the host platform.
final
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
size → Size
The size of the media in logical pixels (e.g, the size of the screen).
final
systemGestureInsets → EdgeInsets
The areas along the edges of the display where the system consumes certain input events and blocks delivery of those events to the app.
final
textScaleFactor → double
The number of font pixels for each logical pixel.
final
viewInsets → EdgeInsets
The parts of the display that are completely obscured by system UI, typically by the device's keyboard.
final
viewPadding → EdgeInsets
The parts of the display that are partially obscured by system UI, typically by the hardware display "notches" or the system status bar.
final

Methods

copyWith({Size? size, double? devicePixelRatio, double? textScaleFactor, Brightness? platformBrightness, EdgeInsets? padding, EdgeInsets? viewPadding, EdgeInsets? viewInsets, EdgeInsets? systemGestureInsets, bool? alwaysUse24HourFormat, bool? highContrast, bool? disableAnimations, bool? invertColors, bool? accessibleNavigation, bool? boldText, NavigationMode? navigationMode, DeviceGestureSettings? gestureSettings, List<DisplayFeature>? displayFeatures}) → MediaQueryData
Creates a copy of this media query data but with the given fields replaced with the new values.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
removeDisplayFeatures(Rect subScreen) → MediaQueryData
Creates a copy of this media query data by removing displayFeatures that are completely outside the given sub-screen and adjusting the padding, viewInsets and viewPadding to be zero on the sides that are not included in the sub-screen.
removePadding({bool removeLeft = false, bool removeTop = false, bool removeRight = false, bool removeBottom = false}) → MediaQueryData
Creates a copy of this media query data but with the given paddings replaced with zero.
removeViewInsets({bool removeLeft = false, bool removeTop = false, bool removeRight = false, bool removeBottom = false}) → MediaQueryData
Creates a copy of this media query data but with the given viewInsets replaced with zero.
removeViewPadding({bool removeLeft = false, bool removeTop = false, bool removeRight = false, bool removeBottom = false}) → MediaQueryData
Creates a copy of this media query data but with the given viewPadding replaced with zero.
toString() → String
A string representation of this object.
override

Operators

operator ==(Object other) → bool
The equality operator.
override