Display Geometry

Only display managers are permitted to change the geometry of displays. Window managers are also display managers.

When a display shows its own content

When a display is showing its own content, the following properties are applicable:

Display property Description
SCREEN_PROPERTY_PROTECTION_ENABLE

An indicator as to whether content protection is needed for the window(s) targeted on the display. Content protection is considered enabled as long as one window on the display has its content protection enabled and is visible. The SCREEN_PROPERTY_PROTECTION_ENABLE property of a display is dynamic; its value depends on the SCREEN_PROPERTY_PROTECTION_ENABLE property of the window(s) that are targeted on the display.

SCREEN_PROPERTY_ROTATION

The current rotation of the display. The rotation value can be one of: 0, 90, 180, or 270 degrees clockwise. Changing the display rotation doesn't implicitly change any window properties.

SCREEN_PROPERTY_SIZE

The width and height, in pixels, of the display area. The display size changes with the display rotation. For example, if the video mode is 1024x768 and the rotation is 0 degrees, the display size will indicate 1024x768. However, when the display rotation is set to 90 degrees, the display size will show 768x1024.

SCREEN_PROPERTY_TRANSPARENCY

An indicator as to how multiple layers are combined. Valid transparencies are:

  • SCREEN_TRANSPARENCY_SOURCE_COLOR
  • SCREEN_TRANSPARENCY_SOURCE_OVER

Refer to Screen transparency types. Note that actual transparency applied is dependent on your hardware.

SCREEN_PROPERTY_VIEWPORT_SIZE

The width and height, in pixels, of a rectangular region of the display area that's within the display resolution.

SCREEN_PROPERTY_VIEWPORT_POSITION

The x and y coordinates of the top left corner of a rectangular region that indicates the location of the display area within the display resolution.

When a display clones the content of another display

When you have multiple displays, you can have a non-primary display clone the content of your primary display. The display that's configured as the default-display in the globals section of graphics.conf is your primary display. Screen designates one of the available displays as the primary display if you don't specify a primary display in your configuration file.

Set the SCREEN_PROPERTY_MIRROR_MODE property of the non-primary display that you want cloning the content of the primary display. Refer to Screen mirror types for the different modes that can be specified for the SCREEN_PROPERTY_MIRROR_MODE property.