XClearArea, XClearWindow - clear area or window
XClearArea(display, w, x, y, width, height, exposures)
int x, y;
unsigned int width, height;
Specifies the connection to the X server.
Specifies a Boolean value that indicates if
events are to be generated.
Specifies the window.
Specify the width and height, which are the dimensions of
the rectangle. and specify the upper-left corner of the rectangle
Specify the x and y coordinates, which are relative to the
origin of the window and specify the upper-left corner of the rectangle.
The XClearArea function paints a rectangular area in the specified window according to the specified dimensions with the window's background pixel or pixmap. The subwindow-mode effectively is ClipByChildren. If width is zero, it is replaced with the current width of the window minus x. If height is zero, it is replaced with the current height of the window minus y. If the window has a defined background tile, the rectangle clipped by any children is filled with this tile. If the window has background None, the contents of the window are not changed. In either case, if exposures is True, one or more Expose events are generated for regions of the rectangle that are either visible or are being retained in a backing store. If you specify a window whose class is InputOnly, a BadMatch error results.
XClearArea can generate BadMatch, BadValue, and BadWindow errors.
The XClearWindow function clears the entire area in the specified window and is equivalent to XClearArea (display, w, 0, 0, 0, 0, False). If the window has a defined background tile, the rectangle is tiled with a plane-mask of all ones and GXcopy function. If the window has background None, the contents of the window are not changed. If you specify a window whose class is InputOnly, a BadMatch error results.
window is used as a Drawable.
Some numeric value falls outside the range of values accepted
by the request. Unless a specific range is specified for an argument, the
full range defined by the argument's type is accepted. Any argument defined
as a set of alternatives can generate this error.
A value for a Window argument does not name a defined Window.
Xlib -- C Language X Interface