ActionScript 3.0 Cookbook: Chapter 3, Runtime Environment
Pages: 1, 2, 3, 4, 5

Section 3.10: Detecting the Device's Video Capabilities

Problem

You want to determine the video capabilities of the device on which the Flash Player is running.

Solution

Use the hasEmbeddedVideo, hasStreamingVideo, and hasVideoEncoder properties of the flash.system.Capabilities class.

Discussion

Before you attempt to deliver video content to a user, it is important to check whether his system is capable of playing video, and how it should be delivered. The most efficient way to deliver Flash video is to stream it to the player. This allows the user to view the video as it is coming in, rather than waiting until the entire (often quite large) file has downloaded. However, the user's system may not be capable of receiving streaming video. To check this, use the flash.system.Capabilities.hasStreamingVideo property. If this returns false, one option is to have the player load another .swf that contains an embedded video. However, before doing this, you should check the property flash.system.Capabilities.hasEmbeddedVideo to ensure that the user can view this content before initiating this download. Your code would look something like this:

if(flash.system.Capabilities.hasStreamingVideo) {
  // Code to set up a video stream and start streaming a 
  // specific video
}
else if(flash.system.Capabilities.hasEmbeddedVideo) {
  // Code to load an external .swf containing an embedded video
}
else {
  // Alternate content without any video
}

Similarly, if your application requires video stream encoding, such as the use of a web cam to transmit live video from the user's system, you want to ensure that the system is capable of doing such encoding. You can test this with the flash.system.Capabilities.hasVideoEncoder property. Like the earlier example, you would probably test this property in an if statement and set up the video streaming only if it tested true. Otherwise, you could display a message to the user explaining the situation or redirect him to another page.

Section 3.11: Prompting the User to Change Player Settings

Problem

You want to open the user's Flash Player Settings dialog box to prompt her to allow greater access to her local system.

Solution

Use the flash.system.Security.showSettings( ) method.

This excerpt is from ActionScript 3.0 Cookbook. Well before Ajax and Windows Presentation Foundation, Macromedia Flash provided the first method for building "rich" web pages. Now, Adobe is making Flash a full-fledged development environment, and learning ActionScript 3.0 is key. That's a challenge for even the most experienced Flash developer. This Cookbook offers more than 300 solutions to solve a wide range of coding dilemmas, so you can learn to work with the new version right away.

Discussion

The flash.system.Security.showSettings( ) method opens the Flash Player Settings dialog box, which includes several tabs. You'll pass a string as a parameter to indicate which tab you want it to open. These strings have been made static properties of the flash.system.SecurityPanel class, to avoid typographical errors. The possible values are:

SecurityPanel.CAMERA

Allows the user to select a camera to use.

SecurityPanel.DEFAULT

Shows whichever tab was opened the last time the Security Panel was open.

SecurityPanel.LOCAL_STORAGE

Allows the user to specify how local shared objects are stored, including the maximum allowable disk usage.

SecurityPanel.MICROPHONE

Allows the user to select a microphone and adjust the volume.

SecurityPanel.PRIVACY

Allows the user to specify whether to allow Flash access to her camera and microphone.

SecurityPanel.SETTINGS_MANAGER

Opens a new browser window and loads the Settings Manager page, which gives the user several more detailed options and the ability to make global changes, rather than just to the domain of the specific movie that is active.

If you don't pass any parameters to the showSettings( ) method, it uses SecurityPanel.DEFAULT. Here, we open the Settings dialog box to the Local Storage tab by explicitly specifying a value of 1.

// Open the Settings dialog box to the Local Storage tab.
flash.system.Security.showSettings(SecurityPanel.LOCAL_STORAGE);

Section 3.12: Dealing with System Security

Problem

You want to load a .swf from another domain into your application and allow it to have access to the ActionScript in the application.

Solution

Use one of the following: flash.system.Security.allowDomain( ), flash.system.Security.allowInsecureDomain( ), or a policy file.

Discussion

In many cases, all of the .swfs in a multi-.swf application would live on the same server (thus the same domain). There may be cases, however, when your application needs to load in an external .swf from another domain. In such a case, neither the .swf nor the loading application would be able to access the other's code. You can allow such access by using flash.system.Security.allowDomain( ), flash.system.Security.allowInsecureDomain( ), or a policy file.