LayoutAnimation Class

Triggers when the layout of an element changes

When an Element has certain properties like Width, Height or Margin (collectively reffered to as "layout properties") changed or when its location in the visual tree changes, we can trigger a LayoutAnimation.

Calculating layout for a large UX-document can be quite costly. When animating layout properties with Change animators, we run the risk of forcing a new layout to be calculated each frame. This can very easily lead to frame drops.

The LayoutAnimation trigger can be used to make this more pleasant. For example, instead of animating the Width of an Element using Change, we can use Set and react to this change using a LayoutAnimation. Inside LayoutAnimation we specify how our element should move/resize from its previous position to its new position.

Example

This example shows three rectangles, a teal, a red and a blue one. If the red or blue rectangle is clucked, the Width and Alignment properties of the teal rectangle gets smoothly animated.

<StackPanel>
    <Rectangle ux:Name="panel" Width="100" Height="100" CornerRadius="5" Color="Teal" Alignment="Center">
        <LayoutAnimation>
            <Resize X="1" Y="1" RelativeTo="SizeChange" Duration="0.25"/>
            <Move X="1" Y="1" RelativeTo="PositionChange" Duration="0.25"/>
        </LayoutAnimation>
    </Rectangle>
    <Rectangle Color="Red" CornerRadius="5" Width="100" Height="50">
        <Clicked>
            <Set panel.Alignment="Left"/>
            <Set panel.Width="200"/>
        </Clicked>
    </Rectangle>
    <Rectangle Color="Blue" CornerRadius="5" Width="100" Height="50">
        <Clicked>
            <Set panel.Alignment="Right"/>
            <Set panel.Width="50"/>
        </Clicked>
    </Rectangle>
</StackPanel>

Location

Namespace
Fuse.Triggers
Package
Fuse.Elements 1.4.0

Interface of LayoutAnimation

Inherited from Trigger

BackwardAnimation : TriggerAnimation ux

Specifies an explicit backward animation instead of using the implied backward animation of the animators involved. Be aware that actions are not part of the animation.

CrossFadeDuration : double ux

If there is a transition between forward/backward playback and two timeilnes are being used (implicit or explicit) this specifies the cross-fade time.

Deactivate uno

Deactivates the trigger (target progress of 0).

Pulse uno

Plays the trigger to progress 1 then back to 0.

RequireLayout(Visual) uno

Indicates the trigger is bound to the layout of a visual. This will keep the trigger in Bypass mode until after the first layout of the element is obtained. This is required since layout does not happen in the same root grouping/update phase as the creation of the element, yet not having a layout should qualify as part of the rooting period.

Inherited from NodeGroupBase

Nodes : IList of Node ux

Nodes to add to the Parent when this trigger is any non-deactivated state (Progress > 0)

Inherited from Node

ContextParent : Node uno

The context parent is the semantic parent of this node. It is where non-UI structure should be resolved, like looking for the DataContext, a Navigation, or other semantic item.

FindNodeByName(Selector, Predicate<Node> (Node)) : Node uno

Finds the first node with a given name that satisfies the given acceptor. The serach algorithm works as follows: Nodes in the subtree are matched first, then it matches the nodes in the subtrees ofthe ancestor nodes by turn all the way to the root. If no matching node is found, the function returns null.

IsRootingStarted : bool uno

Whether rooting of this node has started. Note that even if this property returns true, rooting may not yet be completed for the node. See also IsRootingCompleted.

Name : Selector ux

Run-time name of the node. This property is automatically set using the ux:Name attribute.

OnRooted uno

If you override OnRooted you must call base.OnRooted() first in your derived class. No other processing should happen first, otherwise you might end up in an undefined state.

Inherited from PropertyObject

Inherited from object

Attached UX Attributes

GlobalKey (attached by Resource) : string ux

The ux:Global attribute creates a global resource that is accessible everywhere in UX markup.

Implemented Interfaces

IScriptObject uno

Interface for objects that can have a script engine representation