ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with AIR native windows
The static NativeWindow.supportsTransparency property reports whether window transparency is available.
When transparency is not supported, the application is composited against a black background. In these cases, any
transparent areas of the application display as an opaque black. It is a good practice to provide a fallback in case this
property tests false. For example, you could display a warning dialog to the user, or display a rectangular, nontransparent
user interface.
Note that transparency is always supported by the Mac and Windows operating systems. Support on Linux operating
systems requires a compositing window manager, but even when a compositing window manager is active,
transparency can be unavailable because of user display options or hardware configuration.
Transparency in an MXML application window
Adobe AIR 1.0 and later
By default, the background of an MXML window is opaque, even if you create the window as transparent. (Notice the
transparency effect at the corners of the window.) To present a transparent background for the window, set a
background color and alpha value in the style sheet or element contained in your application MXML file.
For example, the following style declaration gives the background a slightly transparent green shade:
WindowedApplication
{
background-alpha:".8";
background-color:"0x448234";
}
Transparency in an HTML application window
Adobe AIR 1.0 and later
By default the background of HTML content displayed in HTML windows and HTMLLoader objects is opaque, event
if the containing window is transparent. To turn off the default background displayed for HTML content, set the
paintsDefaultBackground property to false. The following example creates an HTMLLoader and turns off the
default background:
var htmlView:HTMLLoader = new HTMLLoader();
htmlView.paintsDefaultBackground = false;
This example uses JavaScript to turn off the default background of an HTML window:
window.htmlLoader.paintsDefaultBackground = false;
If an element in the HTML document sets a background color, the background of that element is not transparent.
Setting a partial transparency (or opacity) value is not supported. However, you can use a transparent PNG-format
graphic as the background for a page or a page element to achieve a similar visual effect.
Window ownership
One window can own one or more other windows. These owned windows always appear in front of the master
window, are minimized and restored along with the master window, and are closed when the master window is closed.
Window ownership cannot be transfered to another window or removed. A window can only be owned by one master
window, but can own any number of other windows.
You can use window ownership to make it easier to manage windows used for tool palettes and dialogs. For example,
if you displayed a Save dialog in association with a document window, making the document window own the dialog
will keep the dialog in front of the document window automatically.
NativeWindow.owner
Last updated 6/6/2012
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