ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with AIR native windows
System chrome is managed by the system. Your application has no direct access to the controls themselves, but can
react to the events dispatched when the controls are used. When you use standard chrome for a window, the
transparent property must be set to false and the type property must be normal or utility.
Flex chrome
When you use the Flex WindowedApplication or Window components, the window can be use either system chrome
or chrome provided by the Flex framework. To use the Flex chrome, set the systemChrome property used to create the
window to none. When using the Flex 4 spark components rather than the mx components, you must specify the skin
class in order to use Flex chrome. You can use the built-in skins or provide your own. The following example
demonstrates how to use the built-in spark WindowedApplication skin class to provide the window chrome:
@namespace "library://ns.adobe.com/flex/spark";
WindowedApplication
{
skinClass:ClassReference("spark.skins.spark.SparkChromeWindowedApplicationSkin");
}
For more information, see Using Flex 4: About the AIR window containers: Controlling window chrome
Custom chrome
When you create a window with no system chrome, then you must add your own chrome controls to handle the
interactions between a user and the window. You are also free to make transparent, non-rectangular windows.
To use custom chrome with the mx:WindowedApplication or mx:Window components, you must set the
showFlexChrome style to false. Otherwise, Flex will add its own chrome to your windows.
Window transparency
Adobe AIR 1.0 and later
To allow alpha blending of a window with the desktop or other windows, set the window transparent property to
true. The transparent property must be set before the window is created and cannot be changed.
A transparent window has no default background. Any window area not containing an object drawn by the application
is invisible. If a displayed object has an alpha setting of less than one, then anything below the object shows through,
including other display objects in the same window, other windows, and the desktop.
Transparent windows are useful when you want to create applications with borders that are irregular in shape or that
“fade out” or appear to be invisible. However, rendering large alpha-blended areas can be slow, so the effect should be
used conservatively.
Important: On Linux, mouse events do not pass through fully transparent pixels. You should avoid creating windows
with large, fully transparent areas since you may invisibly block the user’s access to other windows or items on their
desktop. On Mac OS X and Windows, mouse events do pass through fully transparent pixels.
Transparency cannot be used with windows that have system chrome. In addition, SWF and PDF content in HTML
may not display in transparent windows. For more information, see “Considerations when loading SWF or PDF
content in an HTML page” on page 1001.
Last updated 6/6/2012
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