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GlowFilter

Package | spark.filters
Class | public class GlowFilter
Inheritance | GlowFilter BaseDimensionFilter BaseFilter flash.events.EventDispatcher
Implements | IBitmapFilter

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

The GlowFilter class lets you apply a glow effect to display objects. You have several options for the style of the glow, including inner or outer glow and knockout mode. The glow filter is similar to the drop shadow filter with the `distance` and `angle` properties of the drop shadow filter set to 0. You can apply the filter to any display object (that is, objects that inherit from the DisplayObject class), such as MovieClip, SimpleButton, TextField, and Video objects, as well as to BitmapData objects.

The use of filters depends on the object to which you apply the filter:

- To apply filters to display objects, use the `filters` property (inherited from DisplayObject). Setting the `filters` property of an object does not modify the object, and you can remove the filter by clearing the `filters` property.
- To apply filters to BitmapData objects, use the `BitmapData.applyFilter()` method. Calling `applyFilter()` on a BitmapData object takes the source BitmapData object and the filter object and generates a filtered image as a result.

If you apply a filter to a display object, the `cacheAsBitmap` property of the display object is set to `true`. If you clear all filters, the original value of `cacheAsBitmap` is restored.

This filter supports Stage scaling. However, it does not support general scaling, rotation, and skewing. If the object itself is scaled (if `scaleX` and `scaleY` are set to a value other than 1.0), the filter is not scaled. It is scaled only when the user zooms in on the Stage.

A filter is not applied if the resulting image exceeds the maximum dimensions. In AIR 1.5 and Flash Player 10, the maximum is 8,191 pixels in width or height, and the total number of pixels cannot exceed 16,777,215 pixels. (So, if an image is 8,191 pixels wide, it can only be 2,048 pixels high.) For example, if you zoom in on a large movie clip with a filter applied, the filter is turned off if the resulting image exceeds the maximum dimensions.

MXML Syntax Show MXML Syntax
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The `<s:GlowFilter>` tag inherits all of the tag attributes of its superclass and adds the following tag attributes:

      <s:GlowFilter
        Properties
        alpha="1"
        color="0xFF0000"
        inner="false"
      />

View the examples

See also

flash.filters.GlowFilter
flash.display.BitmapData.applyFilter()
flash.display.DisplayObject.filters
flash.display.DisplayObject.cacheAsBitmap
flash.display.DisplayObject.scaleX
flash.display.DisplayObject.scaleY
flash.filters.DropShadowFilter.distance
flash.filters.DropShadowFilter.angle

Public Properties
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| Property | Defined By
--- | --- | ---
|  | alpha : Number The alpha transparency value for the color. | GlowFilter
|  | blurX : Number The amount of horizontal blur. | BaseDimensionFilter
|  | blurY : Number The amount of vertical blur. | BaseDimensionFilter
|  | color : uint The color of the glow. | GlowFilter
|  | inner : Boolean Specifies whether the glow is an inner glow. | GlowFilter
|  | knockout : Boolean Specifies whether the object has a knockout effect. | BaseDimensionFilter
|  | quality : int The number of times to apply the filter. | BaseDimensionFilter
|  | strength : Number The strength of the imprint or spread. | BaseDimensionFilter

Public Methods
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| Method | Defined By
--- | --- | ---
|  | GlowFilter(color:uint = 0xFF0000, alpha:Number = 1.0, blurX:Number = 4.0, blurY:Number = 4.0, strength:Number = 1, quality:int = 1, inner:Boolean = false, knockout:Boolean = false) Constructor. | GlowFilter
|  | clone():BitmapFilter Returns a copy of this filter object. | GlowFilter
|  | notifyFilterChanged():void Propagates a change event when the filter has changed. | BaseFilter

Public Constants
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| Constant | Defined By
--- | --- | ---
|  | CHANGE : String = change [static] The string "change". | BaseFilter

Property Detail

alpha | property

`alpha:Number`

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

The alpha transparency value for the color. Valid values are 0 to 1. For example, .25 sets a transparency value of 25%.

The default value is `1`.

Implementation
`public function get alpha():Number`
`public function set alpha(value:Number):void`

color | property |

`color:uint`

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

The color of the glow. Valid values are in the hexadecimal format 0xRRGGBB.

The default value is `0xFF0000`.

Implementation
`public function get color():uint`
`public function set color(value:uint):void`

inner | property |

`inner:Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

Specifies whether the glow is an inner glow. The value true indicates an inner glow. The default is false, meaning an outer glow (a glow around the outer edges of the object).

The default value is `false`.

Implementation
`public function get inner():Boolean`
`public function set inner(value:Boolean):void`
Constructor Detail

GlowFilter | () | Constructor

`public function GlowFilter(color:uint = 0xFF0000, alpha:Number = 1.0, blurX:Number = 4.0, blurY:Number = 4.0, strength:Number = 1, quality:int = 1, inner:Boolean = false, knockout:Boolean = false)`

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

Constructor.

Parameters

| `color:uint` (default = `0xFF0000`)`` — The color of the glow, in the hexadecimal format 0xRRGGBB. The default value is 0xFF0000.
| `alpha:Number` (default = `1.0`)`` — The alpha transparency value for the color. Valid values are 0 to 1. For example, .25 sets a transparency value of 25%.
| `blurX:Number` (default = `4.0`)`` — The amount of horizontal blur. Valid values are 0 to 255 (floating point). Values that are a power of 2 (such as 2, 4, 8, 16 and 32) are optimized to render more quickly than other values.
| `blurY:Number` (default = `4.0`)`` — The amount of vertical blur. Valid values are 0 to 255 (floating point). Values that are a power of 2 (such as 2, 4, 8, 16 and 32) are optimized to render more quickly than other values.
| `strength:Number` (default = `1`)`` — The strength of the imprint or spread. The higher the value, the more color is imprinted and the stronger the contrast between the glow and the background. Valid values are 0 to 255.
| `quality:int` (default = `1`)`` — The number of times to apply the filter. Use the BitmapFilterQuality constants: `BitmapFilterQuality.LOW` `BitmapFilterQuality.MEDIUM` `BitmapFilterQuality.HIGH` For more information, see the description of the `quality` property.
| `inner:Boolean` (default = `false`)`` — Specifies whether the glow is an inner glow. The value `true` specifies an inner glow. The value `false` specifies an outer glow (a glow around the outer edges of the object).
| `knockout:Boolean` (default = `false`)`` — Specifies whether the object has a knockout effect. The value `true` makes the object's fill transparent and reveals the background color of the document.

See also

BitmapFilterQuality
Method Detail

clone | () | method

`public function clone():BitmapFilter`

Language Version : | ActionScript 3.0

Product Version : | Flex 4

Runtime Versions : | Flash Player 10, AIR 1.5

Returns a copy of this filter object.

Returns

| `BitmapFilter` — A new GlowFilter instance with all the properties of the original GlowFilter instance.

Examples
GlowFilterExample.mxml

    <?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.

    -->
    <!-- filters/examples/GlowFilterExample .mxml -->
    <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"
        creationComplete="createFilters()">

      <fx:Script><![CDATA[
         import spark.filters.*;
         import flash.filters.BitmapFilterQuality;
         import flash.filters.BitmapFilterType;

         private var myGlowFilter:GlowFilter;
         private var color:Number = 0xFF33FF;

         public function createFilters():void {
            myGlowFilter = new GlowFilter(color, .8, 6, 6, .65, BitmapFilterQuality.MEDIUM,
                false, false);
            b1.filters = [myGlowFilter];
         }

      ]]></fx:Script>

        <s:VGroup>
            <!-- This button has a filter applied in ActionScript. -->
            <s:Button id="b1" label="Click me"/>

            <!-- This button has a filter applied in MXML. -->
            <s:Button id="b2" label="Click me">
                <s:filters>
                    <s:GlowFilter
                        color="0xFF33FF"
                        alpha=".8"
                        blurX="6"
                        blurY="6"
                        strength=".65"
                        quality="{BitmapFilterQuality.MEDIUM}"
                        inner="false"
                        knockout="false"/>
                </s:filters>
            </s:Button>

        </s:VGroup>
    </s:Application>

Wed Nov 15 2017, 09:50 AM +01:00