DOKK / manpages / debian 11 / tk8.6-doc / Tk_UnmaintainGeometry.3tk.en
Tk_MaintainGeometry(3tk) Tk Library Procedures Tk_MaintainGeometry(3tk) 







Tk_MaintainGeometry, Tk_UnmaintainGeometry - maintain geometry of
    one window relative to another








#include <tk.h>

Tk_MaintainGeometry(window, container, x, y, width, height)

Tk_UnmaintainGeometry(window, container)









  
Tk_Window window (in)

  
Window whose geometry is to be controlled.

  
Tk_Window container (in)

  
Window relative to which window's geometry will be controlled.

  
int x (in)

  
Desired x-coordinate of window in container, measured in
      pixels from the inside of container's left border to the outside of
      window's left border.

  
int y (in)

  
Desired y-coordinate of window in container, measured in
      pixels from the inside of container's top border to the outside of
      window's top border.

  
int width (in)

  
Desired width for window, in pixels.

  
int height (in)

  
Desired height for window, in pixels.
    
    

    

  










Tk_MaintainGeometry and Tk_UnmaintainGeometry make
    it easier for geometry managers to deal with windows whose containers are
    not their parents. Three problems arise if the container for a window is not
    its parent:



  
[1]

  
The x- and y-position of the window must be translated from the coordinate
      system of the container to that of the parent before positioning the
      window.

  
[2]

  
If the container window, or any of its ancestors up to the window's
      parent, is moved, then the window must be repositioned within its parent
      in order to maintain the correct position relative to the container.

  
[3]

  
If the container or one of its ancestors is mapped or unmapped, then the
      window must be mapped or unmapped to correspond.




None of these problems is an issue if the parent and container are
    the same. For example, if the container or one of its ancestors is unmapped,
    the window is automatically removed by the screen by X.


Tk_MaintainGeometry deals with these problems for windows
    whose containers are not their parents, as well as handling the simpler case
    of windows whose container are their parents. Tk_MaintainGeometry is
    typically called by a window manager once it has decided where a window
    should be positioned relative to its container. Tk_MaintainGeometry
    translates the coordinates to the coordinate system of window's
    parent and then moves and resizes the window appropriately. Furthermore, it
    remembers the desired position and creates event handlers to monitor the
    container and all of its ancestors up to (but not including) the window's
    parent. If any of these windows is moved, mapped, or unmapped, the window
    will be adjusted so that it is mapped only when the container is mapped and
    its geometry relative to the container remains as specified by x,
    y, width, and height.


When a window manager relinquishes control over a window, or if it
    decides that it does not want the window to appear on the screen under any
    conditions, it calls Tk_UnmaintainGeometry.
    Tk_UnmaintainGeometry unmaps the window and cancels any previous
    calls to Tk_MaintainGeometry for the container-window
    pair, so that the window's geometry and mapped state are no longer
    maintained automatically. Tk_UnmaintainGeometry need not be called by
    a geometry manager if the window, the container, or any of the container's
    ancestors is destroyed: Tk will call it automatically.


If Tk_MaintainGeometry is called repeatedly for the same
    container-window pair, the information from the most recent
    call supersedes any older information. If Tk_UnmaintainGeometry is
    called for a container-window pair that is is not currently
    managed, the call has no effect.








geometry manager, map, container, parent, position, window,
  unmap







  

    4.0
    Tk