If the returned format is 8, the returned data is represented as a char array. If the returned format is 16, the returned data is represented as a short array and should be cast to that type to obtain the elements. If the returned format is 32, the returned data is represented as a long array and should be cast to that type to obtain the elements.
XGetWindowProperty always allocates one extra byte in prop_return (even if the property is zero length) and sets it to zero so that simple properties consisting of characters do not have to be copied into yet another string before use.
If delete is True and bytes_after_return is zero, XGetWindowProperty deletes the property from the window and generates a PropertyNotify event on the window.
The function returns Success if it executes successfully. To free the resulting data, use XFree.
XGetWindowProperty can generate BadAtom, BadValue, and BadWindow errors.
The XListProperties function returns a pointer to an array of atom properties that are defined for the specified window or returns NULL if no properties were found. To free the memory allocated by this function, use XFree.
XListProperties can generate a BadWindow error.
The XChangeProperty function alters the property for the specified window and causes the X server to generate a PropertyNotify event on that window. XChangeProperty performs the following:
If the specified format is 8, the property data must be a char array. If the specified format is 16, the property data must be a short array. If the specified format is 32, the property data must be a long array.
The lifetime of a property is not tied to the storing client. Properties remain until explicitly deleted, until the window is destroyed, or until the server resets. For a discussion of what happens when the connection to the X server is closed, see section 2.6. The maximum size of a property is server dependent and can vary dynamically depending on the amount of memory the server has available. (If there is insufficient space, a BadAlloc error results.)
XChangeProperty can generate BadAlloc, BadAtom, BadMatch, BadValue, and BadWindow errors.
The XRotateWindowProperties function allows you to rotate properties on a window and causes the X server to generate PropertyNotify events. If the property names in the properties array are viewed as being numbered starting from zero and if there are num_prop property names in the list, then the value associated with property name I becomes the value associated with property name (I + npositions) mod N for all I from zero to N - 1. The effect is to rotate the states by npositions places around the virtual ring of property names (right for positive npositions, left for negative npositions). If npositions mod N is nonzero, the X server generates a PropertyNotify event for each property in the order that they are listed in the array. If an atom occurs more than once in the list or no property with that name is defined for the window, a BadMatch error results. If a BadAtom or BadMatch error results, no properties are changed.
XRotateWindowProperties can generate BadAtom, BadMatch, and BadWindow errors.
The XDeleteProperty function deletes the specified property only if the property was defined on the specified window and causes the X server to generate a PropertyNotify event on the window unless the property does not exist.
XDeleteProperty can generate BadAtom and BadWindow errors.