3.7 Configuring Windows

Xlib provides functions that you can use to move a window, resize a window, move and resize a window, or change a window's border width. To change one of these parameters, set the appropriate member of the XWindowChanges structure and OR in the corresponding value mask in subsequent calls to XConfigureWindow(). The symbols for the value mask bits and the XWindowChanges structure are:



/* Configure window value mask bits */

#define CWX		(1<<0)
#define CWY		(1<<1)
#define CWWidth		(1<<2)
#define CWHeight	(1<<3)
#define CWBorderWidth	(1<<4)
#define CWSibling	(1<<5)
#define CWStackMode	(1<<6)


/* Values */

typedef struct {
	int x, y;
	int width, height;
	int border_width;
	Window sibling;
	int stack_mode;
} XWindowChanges;

The x and y members are used to set the window's x and y coordinates, which are relative to the parent's origin and indicate the position of the upper-left outer corner of the window. The width and height members are used to set the inside size of the window, not including the border, and must be nonzero, or a BadValue error results. Attempts to configure a root window have no effect.

The border_width member is used to set the width of the border in pixels. Note that setting just the border width leaves the outer-left corner of the window in a fixed position but moves the absolute position of the window's origin. If you attempt to set the border-width attribute of an InputOnly window nonzero, a BadMatch error results.

The sibling member is used to set the sibling window for stacking operations. The stack_mode member is used to set how the window is to be restacked and can be set to Above, Below, TopIf, .PN BottomIf , or Opposite.

If the override-redirect flag of the window is False and if some other client has selected SubstructureRedirectMask on the parent, the X server generates a ConfigureRequest event, and no further processing is performed. Otherwise, if some other client has selected ResizeRedirectMask on the window and the inside width or height of the window is being changed, a ResizeRequest event is generated, and the current inside width and height are used instead. Note that the override-redirect flag of the window has no effect on ResizeRedirectMask and that SubstructureRedirectMask on the parent has precedence over ResizeRedirectMask on the window.

When the geometry of the window is changed as specified, the window is restacked among siblings, and a ConfigureNotify event is generated if the state of the window actually changes. GravityNotify events are generated after ConfigureNotify events. If the inside width or height of the window has actually changed, children of the window are affected as specified.

If a window's size actually changes, the window's subwindows move according to their window gravity. Depending on the window's bit gravity, the contents of the window also may be moved (see "Gravity Attributes").

If regions of the window were obscured but now are not, exposure processing is performed on these formerly obscured windows, including the window itself and its inferiors. As a result of increasing the width or height, exposure processing is also performed on any new regions of the window and any regions where window contents are lost.

The restack check (specifically, the computation for BottomIf, TopIf, and Opposite) is performed with respect to the window's final size and position (as controlled by the other arguments of the request), not its initial position. If a sibling is specified without a stack_mode, a BadMatch error results.

If a sibling and a stack_mode are specified, the window is restacked as follows:

Above The window is placed just above the sibling.
Below The window is placed just below the sibling.
TopIf If the sibling occludes the window, the window is placed at the top of the stack.
BottomIf If the window occludes the sibling, the window is placed at the bottom of the stack.
Opposite If the sibling occludes the window, the window is placed at the top of the stack. If the window occludes the sibling, the window is placed at the bottom of the stack.

If a stack_mode is specified but no sibling is specified, the window is restacked as follows:

Above The window is placed at the top of the stack.
Below The window is placed at the bottom of the stack.
TopIf If any sibling occludes the window, the window is placed at the top of the stack.
BottomIf If the window occludes any sibling, the window is placed at the bottom of the stack.
Opposite If any sibling occludes the window, the window is placed at the top of the stack. If the window occludes any sibling, the window is placed at the bottom of the stack.

Attempts to configure a root window have no effect.

To configure a window's size, location, stacking, or border, use XConfigureWindow().

To move a window without changing its size, use XMoveWindow().

To change a window's size without changing the upper-left coordinate, use XResizeWindow().

To change the size and location of a window, use XMoveResizeWindow().

To change the border width of a given window, use XSetWindowBorderWidth().

Next: Changing Window Stacking Order

Christophe Tronche, ch@tronche.com

Above	The window is placed just above the sibling.
Below	The window is placed just below the sibling.
TopIf	If the sibling occludes the window, the window is placed at the top of the stack.
BottomIf	If the window occludes the sibling, the window is placed at the bottom of the stack.
Opposite	If the sibling occludes the window, the window is placed at the top of the stack. If the window occludes the sibling, the window is placed at the bottom of the stack.

Above	The window is placed at the top of the stack.
Below	The window is placed at the bottom of the stack.
TopIf	If any sibling occludes the window, the window is placed at the top of the stack.
BottomIf	If the window occludes any sibling, the window is placed at the bottom of the stack.
Opposite	If any sibling occludes the window, the window is placed at the top of the stack. If the window occludes any sibling, the window is placed at the bottom of the stack.