array containing information about the available forms for the clipboard data
function to call to get the actual clipboard data
when the clipboard contents are set again, this function will be called, and @get_func will not be subsequently called.
user data to pass to @get_func and @clear_func.
Return: %TRUE if setting the clipboard data succeeded. If setting the clipboard data failed the provided callback functions will be ignored.
Virtually sets the contents of the specified clipboard by providing a list of supported formats for the clipboard data and a function to call to get the actual data when it is requested.