StandardFabLocation class Null safety

A base class that simplifies building FloatingActionButtonLocations when used with mixins FabTopOffsetY, FabFloatOffsetY, FabDockedOffsetY, FabStartOffsetX, FabCenterOffsetX, FabEndOffsetX, and FabMiniOffsetAdjustment.

A subclass of FloatingActionButtonLocation which implements its getOffset method using three other methods: getOffsetX, getOffsetY, and isMini.

Different mixins on this class override different methods, so that combining a set of mixins creates a floating action button location.

For example: the location FloatingActionButtonLocation.miniEndTop is based on a class that extends StandardFabLocation with mixins FabMiniOffsetAdjustment, FabEndOffsetX, and FabTopOffsetY.

You can create your own subclass of StandardFabLocation to implement a custom FloatingActionButtonLocation.

This is an example of a user-defined FloatingActionButtonLocation.

The example shows a Scaffold with an AppBar, a BottomAppBar, and a FloatingActionButton using a custom FloatingActionButtonLocation.

The new FloatingActionButtonLocation is defined by extending StandardFabLocation with two mixins, FabEndOffsetX and FabFloatOffsetY, and overriding the getOffsetX method to adjust the FAB's x-coordinate, creating a FloatingActionButtonLocation slightly different from FloatingActionButtonLocation.endFloat.

To create a local project with this code sample, run:
flutter create --sample=material.StandardFabLocation.1 mysample



Abstract const constructor. This constructor enables subclasses to provide const constructors so that they can be used in const expressions.


hashCode int
The hash code for this object. [...]
read-only, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


getOffset(ScaffoldPrelayoutGeometry scaffoldGeometry) Offset
Places the FloatingActionButton based on the Scaffold's layout. [...]
getOffsetX(ScaffoldPrelayoutGeometry scaffoldGeometry, double adjustment) double
Obtains the x-offset to place the FloatingActionButton based on the Scaffold's layout. [...]
getOffsetY(ScaffoldPrelayoutGeometry scaffoldGeometry, double adjustment) double
Obtains the y-offset to place the FloatingActionButton based on the Scaffold's layout. [...]
isMini() bool
A function returning whether this StandardFabLocation is optimized for mini FloatingActionButtons.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
toString() String
A string representation of this object. [...]


operator ==(Object other) bool
The equality operator. [...]