15.7 Screen Saver

To prevent monitor damage, an X server implements a screen saver function which blanks screens during periods of unuse. The screen saver can be in one of three states:

• Disabled – No screen blanking is done and screen content remains unchanged.
• Deactivated – The server is being used. When the server input devices are unused for a specific amount of time, the screen saver becomes activated.
• Activated – The server input devices are unused. The screen saver blanks all server screens or displays a server-dependent image. As soon as an input event from either the pointer or the keyboard occurs, the screen saver is deactivated and its timer is reset.

The following paragraphs describe the CLX functions used to:

• Return or change screen saver control values.
• Activate or reset the screen saver

Function: activate-screen-saver display

display

A display.

Activates the screen saver for the display server.

Function: reset-screen-saver display

display

A display.

Deactivates the screen saver for the display server (if necessary) and resets its timer, just as if a pointer or keyboard event had occurred.

Function: screen-saver display

display

A display.

Returns the current control values for the display server screen saver. See set-screen-saver.

timeout

period

Type int16.

blanking

exposures

One of :yes or :no.

Function: set-screen-saver display timeout period blanking exposures

display

A display.

timeout

Specifies the delay until timeout takes over.

period

Specifies the periodic change interval, if used.

blanking

Specifies whether the blanking option is available.

exposures

Specifies whether exposures are allowed during blanking.

Changes the current control values for the display server screen saver. The screen saver is reset. The screen saver is also disabled if:

• timeout is zero, or
• Both blanking and exposures are disabled and the server cannot regenerate the screen contents without sending :exposure events.

The timeout specifies the (non-negative) number of seconds of input device inactivity that must elapse before the screen saver is activated. The timeout can be set to :default to restore the server default timeout interval.

If blanking is :yes and the screen hardware supports blanking, blanking is enabled; that is, the screen saver will simply blank all screens when it is activated. blanking can be set to :default to restore the server default state for blanking.

If exposures is :yes, exposures are enabled. If exposures are enabled, or if the server is capable of regenerating screen contents without sending :exposure events, the screen saver will display some server-dependent image when activated. Frequently, this image will consist of a repeating animation sequence, in which case period specifies the ( non-negative) number of seconds for each repetition. A period of zero is a hint that no repetition should occur.