common(1)                AfterStep X11 window manager                common(1)



NAME
       common - common functions used in other examples
       libAfterImage/tutorials/common.h

SYNOPSIS
       Generic Xlib related functionality, common for all the tutorials.

SEE ALSO
       libAfterImage,
       ASView, ASScale, ASTile, ASMerge, ASGrad, ASFlip, ASText

NAME_XA_WM_DELETE_WINDOW
SYNOPSIS
       _XA_WM_DELETE_WINDOW - stores value of X Atom "WM_DELETE_WINDOW".

DESCRIPTION
       In X all client's top level windows are managed by window manager.
       That includes moving, resizing, decorating, focusing and closing of
       windows. Interactions between window manager and client window are
       governed by ICCCM specification.
       All the parts of this specification are completely optional, but it
       is recommended that the following minimum set of hints be supplied
       for any client window:
       Window's title(WM_NAME), iconified window title(WM_ICON_NAME), class
       hint (WM_CLASS) and supported protocols (WM_PROTOCOLS). It is
       recommended also that WM_DELETE_WINDOW protocol be supported, as
       otherwise there are no way to safely close client window, but to
       kill it.
       All of the above mentioned hints are identified by atoms that have
       standard preset values, except for WM_DELETE_WINDOW. As the result we
       need to obtain WM_DELETE_WINDOW atoms ID explicitly. We use
       _XA_WM_DELETE_WINDOW to store the ID of that atom, so it is accessible
       anywhere from our application.

SOURCE
       Source :
       Atom _XA_WM_DELETE_WINDOW = None;

NAMEcreate_top_level_window()
SYNOPSIS
       Window create_top_level_window( ASVisual *asv, Window root,
                                       int x, int y,
                                       unsigned int width,
                                       unsigned int height,
                                       unsigned int border_width,
                                       unsigned long attr_mask,
                                       XSetWindowAttributes *attr,
                                       char *app_class );

INPUTS
       asv    - pointer to valid preinitialized ASVisual structure.

       root   - root window of the screen on which to create window.

       x,     y - desired position of the window

       width, height - desired window size.

       border_width
              - desired initial border width of the window (may not have any
              effect due to Window Manager intervention.

       attr_mask
              - mask of the attributes that has to be set on the window

       attr   - values of the attributes to be set.

       app_class
              - title of the application to be used as its window Title and
              resources class.


RETURN VALUE
       ID of the created window.

DESCRIPTION
       create_top_level_window() is autyomating process of creating top
       level application window. It creates window for specified ASVisual,
       and then sets up basic ICCCM hints for that window, such as WM_NAME,
       WM_ICON_NAME, WM_CLASS and WM_PROTOCOLS.

SOURCE
       Source :
       Window
       create_top_level_window( ASVisual *asv, Window root, int x, int y,
                                unsigned int width, unsigned int height,
                                unsigned int border_width,
                                unsigned long attr_mask,
                                XSetWindowAttributes *attr,
                                const char *app_class, const char *app_name )
       {
           Window w = None;
       #ifndef X_DISPLAY_MISSING
           char *tmp ;
           XTextProperty name;
           XClassHint class1;

           w = create_visual_window(asv, root, x, y, width, height, border_width,
                                    InputOutput, attr_mask, attr );

           tmp = (app_name==NULL)?(char*)get_application_name():(char*)app_name;
           XStringListToTextProperty (&tmp, 1, &name);

           class1.res_name = tmp;  /* for future use */
           class1.res_class = (char*)app_class;
           XSetWMProtocols (asv->dpy, w, &_XA_WM_DELETE_WINDOW, 1);
           XSetWMProperties (asv->dpy, w, &name, &name, NULL, 0, NULL, NULL, &class1);
           /* final cleanup */
           XFree ((char *) name.value);

       #endif /* X_DISPLAY_MISSING */
           return w;
       }

NAMEset_window_background_and_free()
SYNOPSIS
       Pixmap set_window_background_and_free( Window w, Pixmap p );

INPUTS
       w      - ID of the window background of which we need to set.

       p      - Pixmap to set background to.


RETURN VALUE
       None on success. Pixmap ID of original Pixmap on failure.

DESCRIPTION
       set_window_background_and_free() will set window's background to
       specified Pixmap, Then refresh window contents so that background
       is drawn by the server, flush all the requests to force it to be sent
       to server to be processed as fast as possible.

NOTES
       After Window's background has been set to Pixmap - X server makes
       hidden copy of this Pixmap for later window refreshing. As the result
       original Pixmap is no longer needed and can be freed to conserve
       resources.

SOURCE
       Source :
       Pixmap
       set_window_background_and_free( Window w, Pixmap p )
       {
       #ifndef X_DISPLAY_MISSING
           if( p != None && w != None )
           {
               Display *dpy = get_default_asvisual()->dpy;

               if (dpy)
               {
                   XSetWindowBackgroundPixmap( dpy, w, p );
                   XClearWindow( dpy, w );
                   XFlush( dpy );
                   XFreePixmap( dpy, p );
                   p = None ;
               }
           }
       #endif /* X_DISPLAY_MISSING */
           return p ;
       }

NAMEwait_closedown()
SYNOPSIS
       void wait_closedown( Window w );

INPUTS
       w      - ID of the window from which to wait for events.


DESCRIPTION
       User action requesting window to be closed is generally received
       first by Window Manager. Window Manager is then handles it down to
       the window by sending it ClientMessage event with first 32 bit word
       of data set to the value of WM_DELETE_WINDOW Atom.
       Accordingly, all client has to do is wait for such event from X server
       and, when received, it should destroy its window and generally exit.

NOTES
       It is recommended that XFlush() is issued right after XDestroyWindow()
       as Window Manager itself may attempt to do something with the window
       until it receives DestroyNotify event.

SEE ALSO
       ICCCM, Window

SOURCE
       Source :
       void
       wait_closedown( Window w )
       {
       #ifndef X_DISPLAY_MISSING
           Display *dpy = get_default_asvisual()->dpy;

           if(dpy)
           {
               if (w)
               {
                   XSelectInput (dpy, w, ( StructureNotifyMask |
                                           ButtonPressMask|
                                           ButtonReleaseMask));

                   while(w != None)
                   {
                       XEvent event ;

                       XNextEvent (dpy, &event);
                       switch(event.type)
                       {
                           case ClientMessage:
                               if ((event.xclient.format != 32) ||
                                   (event.xclient.data.l[0] != _XA_WM_DELETE_WINDOW))
                                   break ;
                           case ButtonPress:
                               XDestroyWindow( dpy, w );
                               XFlush( dpy );
                               w = None ;
                               break ;
                       }
                   }
               }
               XCloseDisplay (dpy);
           }
       #endif
       }



3rd Berkeley Distribution      AfterStep v.2.2.9                     common(1)
