Your application’s ability to access sound data can be limited
according to the Flash Player or AIR security model. Each sound
is subject to the restrictions of two different security sandboxes,
the sandbox for the content itself (the “content sandbox”), and
the sandbox for the application or object that loads and plays the sound
(the “owner sandbox”). For AIR application content in the application security
sandbox, all sounds, including those loaded from other domains,
are accessible to content in the application security sandbox. However,
content in other security security sandboxes observe the same rules
as content running in Flash Player. For more information about the
Flash Player security model in general, and the definition of sandboxes,
see
Security
.
The content sandbox controls whether detailed sound data can
be extracted from the sound using the
id3
property
or the
SoundMixer.computeSpectrum()
method. It
doesn’t restrict the loading or playing of the sound file itself.
The domain of origin of the sound file defines the security limitations
of the content sandbox. Generally, if a sound file is located in
the same domain or folder as the SWF file of the application or
object that loads it, the application or object will have full access
to that sound file. If the sound comes from a different domain than
the application does, it can still be brought within the content
sandbox by using a policy file.
Your application can pass a SoundLoaderContext object with a
checkPolicyFile
property
as a parameter to the
Sound.load()
method. Setting
the
checkPolicyFile
property to
true
tells
Flash Player or AIR to look for a policy file on the server from
which the sound is loaded. If a policy file exists, and it grants
access to the domain of the loading SWF file, the SWF file can load
the sound file, access the
id3
property of the
Sound object, and call the
SoundMixer.computeSpectrum()
method
for loaded sounds.
The owner sandbox controls local playback of the sounds. The
application or object that starts playing a sound defines the owner
sandbox.
The
SoundMixer.stopAll()
method silences the
sounds in all SoundChannel objects that are currently playing, as
long as they meet the following criteria:
-
The sounds were started by objects within the same owner
sandbox.
-
The sounds are from a source with a policy file that grants
access to the domain of the application or object that calls the
SoundMixer.stopAll()
method.
However, in an AIR application, content in the application security
sandbox (content installed with the AIR application) are not restricted
by these security limitations.
To find out if the
SoundMixer.stopAll()
method
will indeed stop all playing sounds, your application can call the
SoundMixer.areSoundsInaccessible()
method.
If that method returns a value of
true,
some of
the sounds being played are outside the control of the current owner
sandbox and will not be stopped by the
SoundMixer.stopAll()
method.
The
SoundMixer.stopAll()
method also stops the
playhead from continuing for all sounds that were loaded from external
files. However, sounds that are embedded in FLA files and attached
to frames in the timeline using the Flash Authoring tool might start
playing again if the animation moves to a new frame.
