The Keyframe class defines the value of a property at a specific time during an effect.
For example, you can create three keyframes that define the value of a property at
the beginning of the effect, at the midpoint of the effect, and at the end of the effect.
The effect animates the property change on the target from keyframe to keyframe
over the effect duration.
The collection of keyframes for an effect is called the effect's motion path.
A motion path can define any number of keyframes.
The effect then calculates the value of the property by interpolating between
the values specified by two key frames.
Use the MotionPath class to hold the collection of Keyframe objects that
represent the motion path of the effect.
The MotionPath class specifies the name of the property on the target,
and the collection of Keyframes objects specify the values of the property at different
times during the effect.
The easing behavior applied to the motion between the previous
Keyframe object in motion path and this Keyframe object.
By default, the easing is linear, or no easing at all.
Note that the parent effect
might have easing applied already over the entire
animation. Therefore, if easing per keyframe interval is desired
instead, it is necessary to set the overall effect
easer to linear easing (spark.effects.easing.Linear) and then
set the easer on each Keyframe as appropriate.
Because this property acts on the interval between the previous
Keyframe object in a sequence and this Keyframe object, the easer
property is ignored on the first Keyframe object in a sequence.
The default value is Linear.
time
property
public var time:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The time, in milliseconds, at which the effect target
for this keyframe should have the value
specified by the value property. This time
is relative to the starting time of the effect defined
with this keyframe.
value
property
public var value:Object
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The value that the property of the effect target should have
at the time specified by the time property.
valueBy
property
public var valueBy:Object
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Optional parameter which, if specified, is used to
calculate value in this keyframe or
the previous one. If value is not set in
the previous keyframe, but this keyframe defines both
value and valueBy, then value
in the previous keyframe is calculated as value
in this keyframe minus valueBy in this keyframe.
Similarly, if value in this keyframe is not
defined, but valueBy in this keyframe and
value in the previous keyframe are both set,
then value in this keyframe is calculated as
value in the previous keyframe plus
valueBy in this keyframe.
valueBy is ignored for the first
keyframe in a sequence, since it applies only to the interval
preceding a keyframe, and there is no preceding interval for the
first keyframe.
Constructor Detail
Keyframe
()
Constructor
public function Keyframe(time:Number, value:Object = null, valueBy:Object = null)
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Constructor.
Parameters
time:Number (default = NaN) — The time, in milliseconds, at which the effect target
of this keyframe should have the value
specified by the value parameter.
value:Object (default = null) — The value that the effect target should have
at the given time.
valueBy:Object (default = null) — Optional parameter which, if provided,
causes value to be calculated dynamically by
adding valueBy to the value of
the previous keyframe in the set of keyframes in a MotionPath
object. This value is ignored if this is the first
Keyframe in a sequence.
<?xml version="1.0"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Simple example to demonstrate the s:Keyframe and s:MotionPath classes. -->
<s:Application
xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:mx="library://ns.adobe.com/flex/mx"
xmlns:s="library://ns.adobe.com/flex/spark">
<fx:Declarations>
<fx:Vector id="kf" type="spark.effects.animation.MotionPath">
<s:MotionPath property="scaleX">
<s:Keyframe time="250" value="0.5"/>
<s:Keyframe time="500" value="1.0"/>
<s:Keyframe time="750" value="0.5"/>
<s:Keyframe time="1000" value="1.0"/>
<s:Keyframe time="1250" value="0.5"/>
<s:Keyframe time="1500" value="1.0"/>
</s:MotionPath>
<s:MotionPath property="scaleY">
<s:Keyframe time="250" value="0.5"/>
<s:Keyframe time="500" value="1.0"/>
<s:Keyframe time="750" value="0.5"/>
<s:Keyframe time="1000" value="1.0"/>
<s:Keyframe time="1250" value="0.5"/>
<s:Keyframe time="1500" value="1.0"/>
</s:MotionPath>
</fx:Vector>
<s:Animate id="shrinkEffect"
motionPaths="{kf}"
target="{myImage}"/>
</fx:Declarations>
<s:Panel id="examplePanel"
title="Keyframe and MotionPath Effect Example"
width="75%" height="75%">
<s:layout>
<s:VerticalLayout paddingTop="10" paddingLeft="10"/>
</s:layout>
<!-- Directions -->
<s:VGroup id="detailsBox" width="50%" left="0">
<s:Label width="99%" color="blue"
text="Click the Adobe logo to watch the effect."/>
</s:VGroup>
<mx:Image id="myImage"
source="@Embed(source='assets/logo.jpg')"
click="shrinkEffect.end();shrinkEffect.play();"/>
</s:Panel>
</s:Application>
Object
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