Secure Global Desktop 4.40 Administration Guide > Applications, Documents, and Application Servers > Users Have Problems Displaying High Color X Applications

Users Have Problems Displaying High Color X Applications

Several problems can occur when displaying high color X applications:

• The X Application Fails With a "can't allocate enough color planes" or Similar Error
• The Colors Appear Strange
• The X Application Uses Too Much Bandwidth
• The Color Quality Declines When a Session is Shadowed
• 8-bit Applications Exit With a PseudoColor Visual Error

The X Application Fails With a "can't allocate enough color planes" or Similar Error

If an X application fails to run and exits with errors such as "can't allocate enough color planes", the application probably only displays 8-bit color. Check the display specification of the application and adjust the color depth of the application object as follows.

1. In the SGD Administration Console, click the Applications tab and select the application. The General tab is displayed.
2. Click the Presentation tab.
3. From the Color Depth list, select 8-bit - 256 colors.
4. Click Save.

Alternatively, use the following command:

$ tarantella object edit --name obj --depth 8

The Colors Appear Strange

If there are any problems with appearance in 16-bit or 24-bit color applications, change the color quality of the application object as follows.

1. In the SGD Administration Console, click the Applications tab and select the application. The General tab is displayed.
2. Click the Performance tab.
3. From the Color Quality list, select 16-bit for 16-bit applications or 24-bit for 24-bit applications.
4. Click Save.

Alternatively, use the following command:

$ tarantella object edit --name obj --quality 16 | 24

The X Application Uses Too Much Bandwidth

If bandwidth is critical, try reducing the color quality of the application object as follows.

1. In the SGD Administration Console, click the Applications tab and select the application. The General tab is displayed.
2. Click the Performance tab.
3. From the Color Quality list, select 9-bit or 6-bit.
4. Click Save.

Alternatively, use the following command:

$ tarantella object edit --name obj --quality 9 | 6

Note There is no guarantee on the bandwidth saving or how badly the appearance might be affected.

The Color Quality Declines When a Session is Shadowed

When you shadow a user's application session, either you or the user might experience a decline in the color quality. If the SGD Emulator Shadow application and the X application have different color depth settings, the color format is converted and colors dithered. By default the Emulator Shadow application uses 8-bit color. To increase the color depth of the Emulator Shadow application:

1. In the SGD Administration Console, click the Applications tab.
2. In the navigation tree, click System Objects. The System Objects table is displayed.
3. In the System Objects table, click Emulator Shadow. The General tab is displayed.
4. Click the Presentation tab.
5. From the Color Depth list, select 16-bit - Thousands of colors or 24-bit - Millions of colors.
6. Click Save.

Alternatively, use the following command:

$ tarantella object edit --name "o=Tarantella System Objects/cn=Emulator Shadow" --depth 16 | 24

For the colors to match exactly, both the color depth and color quality settings of the two applications must match. If the color quality setting for either application object is Adjust Dynamically (auto) or Best at Application Start (best), the Emulator Shadow application might end up with different color quality levels to that of the X application. This might happen for example if the user has a low bandwidth connection and you have a high bandwidth connection.

8-bit Applications Exit With a PseudoColor Visual Error

If you run an 8-bit application within a 16 or 24-bit high color X application session, for example from a CDE desktop, you might find the application exits with an error such as "Cannot find a matching 8-bit PseudoColor visual".

To fix this, change the color depth the X application so that it supports multiple color depths. You do this as follows:

1. In the SGD Administration Console, click the Applications tab and select the application. The General tab is displayed.
2. Click the Presentation tab.
3. From the Color Depth list, select 16/8-bit - Thousands of colors or 24/8-bit - Millions of colors.

   If the 8-bit application requires the primary color depth to be 8-bit, select 8/16-bit - Thousands of colors or 8/24-bit - Millions of colors.

4. Click Save.

Alternatively, use the following command:

$ tarantella object edit --name obj --depth 16/8 | 24/8

Note There are memory and performance effects of using these settings.

If the application still exits after changing the color depth, the only solution is to create a separate X application object for the application and set the color depth to 8-bit.

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