Window ParametersEverywindow has a
list of parameters, such as background color,
line width, point style, which control its appearance and the way
drawing operations are performed on the window.
See the Manual
Page for Windows for a list of available parameters and their corresponding
types.
Reading and Changing ParametersMost parameters may be retrieved or changed byget() - and
set() -functions. If we use param to denote a window
parameter and param_t to denote its type, the operations are
param_t W.set_param(param_t val); param_t W.get_param(); The Example of How to Use a Window
uses the TipThe fact that theset -operation returns the old value of the parameter
is very convenient when a parameter is to be changed only temporarily.
In order to change, for example, the mouse cursor to a "watch symbol"
during the execution of a time consuming operation one writes
int old_cursor=W.set_cursor(XC_watch); //some time consuming computation W.set_cursor(old_cursor); Remark: There are a few operations for changing parameters that do not follow the scheme described above. See the Manual Page for Windows for details. |
See also:Example of How to Use a Window Manual Pages: |