By Adobe
26 August 2010
When specifying the Adobe Flash Professional publish settings for SWF files, you can select a Window Mode option, which controls the HTML wmode attribute in the object and embed tags. The Window Mode modifies the relationship of the content bounding box or virtual window with content in the HTML page as described in the following list:
  • Window (default setting): Does not embed any window-related attributes in the object and embed tags. The background of the content is opaque and uses the HTML background color. The HTML code cannot render above or below the SWF content.
  • Opaque Windowless: Sets the background of the SWF content to opaque, obscuring anything under the content. Lets HTML content appear above or on top of the content.
  • Transparent Windowless: Sets the background of the SWF content to transparent, allowing the HTML content to appear above and below the content. For browsers that support windowless modes, see Parameters and attributes for object and embed tags in the Flash documentation.
Note: For people who utilize assistive technologies such as screen readers, accessibility requires that Flash Player have a window (a screen reader gets no data if there is no window). Neither the Opaque nor the Transparent Windowless setting presently allows communication between the player and assistive technologies.
If you turn on Hardware Acceleration in the Flash tab of the Publish Settings dialog box, the Window Mode you select is ignored and it defaults to the Window setting.
Setting the Window Mode
For a demonstration of setting the Window Mode, see the TechNote titled Create a transparent background in a SWF file.
Note: In some cases, complex rendering in Transparent Windowless mode can result in slower animation when the HTML images are also complex.

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