gtkwindow.c

gtk是linux一款强大的夸平台的图形化开发工具

  if (window->handling_resize)
    { 
      GtkAllocation allocation;
      
      /* if we are just responding to a configure event, which
       * might be due to a resize by the window manager, the
       * user, or a response to a resizing request we made
       * earlier, we go ahead, allocate the new size and we're done
       * (see gtk_window_configure_event() for more details).
       */
      
      window->handling_resize = FALSE;
      
      allocation = widget->allocation;
      
      gtk_widget_size_allocate (widget, &allocation);
      gtk_widget_queue_draw (widget);

#ifdef FIXME_ZVT_ME_HARDER
      if ((default_size_changed || hints_changed) && (width != new_width || height != new_height))
	{
	  /* We could be here for two reasons
	   *  1) We coincidentally got a resize while handling
	   *     another resize.
	   *  2) Our computation of default_size_changed was completely
	   *     screwed up, probably because one of our children
	   *     is broken (i.e. changes requisition during
	   *     size allocation). It's probably a zvt widget.
	   *
	   * For 1), we could just go ahead and ask for the
	   * new size right now, but doing that for 2)
	   * might well be fighting the user (and can even
	   * trigger a loop). Since we really don't want to
	   * do that, we requeue a resize in hopes that
	   * by the time it gets handled, the child has seen
	   * the light and is willing to go along with the
	   * new size. (this happens for the zvt widget, since
	   * the size_allocate() above will have stored the
	   * requisition corresponding to the new size in the
	   * zvt widget)
	   *
	   * This doesn't buy us anything for 1), but it shouldn't
	   * hurt us too badly, since it is what would have
	   * happened if we had gotten the configure event before
	   * the new size had been set.
	   */
	  
	  if (x != -1 && y != -1)
	    gdk_window_move (widget->window, x, y);

	  /* we have to preserve the values and flags that are used
	   * for computation of default_size_changed and hints_changed
	   */

	  info->last = saved_last_info;
	  
	  gtk_widget_queue_resize (widget);

	  return;
	}
#endif /* FIXME_ZVT_ME_HARDER */
    }

  /* Now set hints if necessary
   */
  if (hints_changed)
    gdk_window_set_geometry_hints (widget->window,
				   &new_geometry,
				   new_flags);

  if ((default_size_changed || hints_changed) &&
      (width != new_width || height != new_height))
    {
      /* given that (width != new_width || height != new_height), we are in one
       * of the following situations:
       * 
       * default_size_changed
       *   our requisition has changed and we need a different window size,
       *   so we request it from the window manager.
       *
       * !default_size_changed
       *   the window manager wouldn't assign us the size we requested, in this
       *   case we don't try to request a new size with every resize.
       *
       * !default_size_changed && hints_changed
       *   the window manager rejects our size, but we have just changed the
       *   window manager hints, so there's a certain chance our request will
       *   be honoured this time, so we try again.
       */
      
      /* request a new window size */
      if (x != -1 && y != -1)
	gdk_window_move_resize (GTK_WIDGET (window)->window, x, y, new_width, new_height);
      else
	gdk_window_resize (GTK_WIDGET (window)->window, new_width, new_height);
      window->resize_count += 1;
      
      /* we are now awaiting the new configure event in response to our
       * resizing request. the configure event will cause a new resize
       * with ->handling_resize=TRUE.
       * until then, we want to
       * - discard expose events
       * - coalesce resizes for our children
       * - defer any window resizes until the configure event arrived
       * to achive this, we queue a resize for the window, but remove its
       * resizing handler, so resizing will not be handled from the next
       * idle handler but when the configure event arrives.
       *
       * FIXME: we should also dequeue the pending redraws here, since
       * we handle those ourselves in ->handling_resize==TRUE.
       */
      gtk_widget_queue_resize (GTK_WIDGET (container));
      if (container->resize_mode == GTK_RESIZE_QUEUE)
	gtk_container_dequeue_resize_handler (container);
    }
  else
    {
      if (x != -1 && y != -1)
	gdk_window_move (widget->window, x, y);

      if (container->resize_widgets)
	gtk_container_resize_children (GTK_CONTAINER (window));
    }
}

/* Compare two sets of Geometry hints for equality.
 */
static gboolean
gtk_window_compare_hints (GdkGeometry *geometry_a,
			  guint        flags_a,
			  GdkGeometry *geometry_b,
			  guint        flags_b)
{
  if (flags_a != flags_b)
    return FALSE;
  
  if ((flags_a & GDK_HINT_MIN_SIZE) &&
      (geometry_a->min_width != geometry_b->min_width ||
       geometry_a->min_height != geometry_b->min_height))
    return FALSE;

  if ((flags_a & GDK_HINT_MAX_SIZE) &&
      (geometry_a->max_width != geometry_b->max_width ||
       geometry_a->max_height != geometry_b->max_height))
    return FALSE;

  if ((flags_a & GDK_HINT_BASE_SIZE) &&
      (geometry_a->base_width != geometry_b->base_width ||
       geometry_a->base_height != geometry_b->base_height))
    return FALSE;

  if ((flags_a & GDK_HINT_ASPECT) &&
      (geometry_a->min_aspect != geometry_b->min_aspect ||
       geometry_a->max_aspect != geometry_b->max_aspect))
    return FALSE;

  if ((flags_a & GDK_HINT_RESIZE_INC) &&
      (geometry_a->width_inc != geometry_b->width_inc ||
       geometry_a->height_inc != geometry_b->height_inc))
    return FALSE;

  return TRUE;
}

/* Compute the default_size for a window. The result will
 * be stored in *width and *height. The default size is
 * the size the window should have when initially mapped.
 * This routine does not attempt to constrain the size
 * to obey the geometry hints - that must be done elsewhere.
 */
static void 
gtk_window_compute_default_size (GtkWindow       *window,
				 guint           *width,
				 guint           *height)
{
  GtkRequisition requisition;
  GtkWindowGeometryInfo *info;
  
  gtk_widget_get_child_requisition (GTK_WIDGET (window), &requisition);
  *width = requisition.width;
  *height = requisition.height;

  info = gtk_window_get_geometry_info (window, FALSE);
  
  if (*width == 0 && *height == 0)
    {
      /* empty window */
      *width = 200;
      *height = 200;
    }
  
  if (info)
    {
      *width = info->width > 0 ? info->width : *width;
      *height = info->height > 0 ? info->height : *height;
    }
}

/* Constrain a window size to obey the hints passed in geometry
 * and flags. The result will be stored in *new_width and *new_height
 *
 * This routine is partially borrowed from fvwm.
 *
 * Copyright 1993, Robert Nation
 *     You may use this code for any purpose, as long as the original
 *     copyright remains in the source code and all documentation
 *
 * which in turn borrows parts of the algorithm from uwm
 */
static void 
gtk_window_constrain_size (GtkWindow   *window,
			   GdkGeometry *geometry,
			   guint        flags,
			   gint         width,
			   gint         height,
			   gint        *new_width,
			   gint        *new_height)
{
  gint min_width = 0;
  gint min_height = 0;
  gint base_width = 0;
  gint base_height = 0;
  gint xinc = 1;
  gint yinc = 1;
  gint max_width = G_MAXINT;
  gint max_height = G_MAXINT;
  
#define FLOOR(value, base)	( ((gint) ((value) / (base))) * (base) )

  if ((flags & GDK_HINT_BASE_SIZE) && (flags & GDK_HINT_MIN_SIZE))
    {
      base_width = geometry->base_width;
      base_height = geometry->base_height;
      min_width = geometry->min_width;
      min_height = geometry->min_height;
    }
  else if (flags & GDK_HINT_BASE_SIZE)
    {
      base_width = geometry->base_width;
      base_height = geometry->base_height;
      min_width = geometry->base_width;
      min_height = geometry->base_height;
    }
  else if (flags & GDK_HINT_MIN_SIZE)
    {
      base_width = geometry->min_width;
      base_height = geometry->min_height;
      min_width = geometry->min_width;
      min_height = geometry->min_height;
    }

  if (flags & GDK_HINT_MAX_SIZE)
    {
      max_width = geometry->max_width ;
      max_height = geometry->max_height;
    }

  if (flags & GDK_HINT_RESIZE_INC)
    {
      xinc = MAX (xinc, geometry->width_inc);
      yinc = MAX (yinc, geometry->height_inc);
    }
  
  /* clamp width and height to min and max values
   */
  width = CLAMP (width, min_width, max_width);
  height = CLAMP (height, min_height, max_height);
  
  /* shrink to base + N * inc
   */
  width = base_width + FLOOR (width - base_width, xinc);
  height = base_height + FLOOR (height - base_height, yinc);

  /* constrain aspect ratio, according to:
   *
   *                width     
   * min_aspect <= -------- <= max_aspect
   *                height    
   */
  
  if (flags & GDK_HINT_ASPECT &&
      geometry->min_aspect > 0 &&
      geometry->max_aspect > 0)
    {
      gint delta;

      if (geometry->min_aspect * height > width)
	{
	  delta = FLOOR (height - width * geometry->min_aspect, yinc);
	  if (height - delta >= min_height)
	    height -= delta;
	  else
	    { 
	      delta = FLOOR (height * geometry->min_aspect - width, xinc);
	      if (width + delta <= max_width) 
		width += delta;
	    }
	}
      
      if (geometry->max_aspect * height < width)
	{
	  delta = FLOOR (width - height * geometry->max_aspect, xinc);
	  if (width - delta >= min_width) 
	    width -= delta;
	  else
	    {
	      delta = FLOOR (width / geometry->max_aspect - height, yinc);
	      if (height + delta <= max_height)
		height += delta;
	    }
	}
    }

#undef FLOOR
  
  *new_width = width;
  *new_height = height;
}

/* Compute the set of geometry hints and flags for a window
 * based on the application set geometry, and requisiition
 * of the window. gtk_widget_size_request() must have been
 * called first.
 */
static void
gtk_window_compute_hints (GtkWindow   *window,
			  GdkGeometry *new_geometry,
			  guint       *new_flags)
{
  GtkWidget *widget;
  GtkWidgetAuxInfo *aux_info;
  gint ux, uy;
  gint extra_width = 0;
  gint extra_height = 0;
  GtkWindowGeometryInfo *geometry_info;
  GtkRequisition requisition;

  g_return_if_fail (GTK_IS_WINDOW (window));

  widget = GTK_WIDGET (window);
  
  gtk_widget_get_child_requisition (widget, &requisition);
  geometry_info = gtk_window_get_geometry_info (GTK_WINDOW (widget), FALSE);

  g_return_if_fail (geometry_info != NULL);
  
  *new_flags = geometry_info->mask;
  *new_geometry = geometry_info->geometry;
  
  if (geometry_info->widget)
    {
      extra_width = widget->requisition.width - geometry_info->widget->requisition.width;
      extra_height = widget->requisition.height - geometry_info->widget->requisition.height;
    }
  
  ux = 0;
  uy = 0;
  
  aux_info = gtk_object_get_data (GTK_OBJECT (widget), "gtk-aux-info");
  if (aux_info && (aux_info->x != -1) && (aux_info->y != -1))
    {
      ux = aux_info->x;
      uy = aux_info->y;
      *new_flags |= GDK_HINT_POS;
    }
  
  if (*new_flags & GDK_HINT_BASE_SIZE)
    {
      new_geometry->base_width += extra_width;
      new_geometry->base_height += extra_height;
    }
  else if (!(*new_flags & GDK_HINT_MIN_SIZE) &&
	   (*new_flags & GDK_HINT_RESIZE_INC) &&
	   ((extra_width != 0) || (extra_height != 0)))
    {
      *new_flags |= GDK_HINT_BASE_SIZE;
      
      new_geometry->base_width = extra_width;
      new_geometry->base_height = extra_height;
    }
  
  if (*new_flags & GDK_HINT_MIN_SIZE)
    {
      new_geometry->min_width += extra_width;
      new_geometry->min_height += extra_height;
    }
  else if (!window->allow_shrink)
    {
      *new_flags |= GDK_HINT_MIN_SIZE;
      
      new_geometry->min_width = requisition.width;
      new_geometry->min_height = requisition.height;
    }
  
  if (*new_flags & GDK_HINT_MAX_SIZE)
    {
      new_geometry->max_width += extra_width;
      new_geometry->max_height += extra_height;
    }
  else if (!window->allow_grow)
    {
      *new_flags |= GDK_HINT_MAX_SIZE;
      
      new_geometry->max_width = requisition.width;
      new_geometry->max_height = requisition.height;
    }
}

/* Compute a new position for the window based on a new
 * size. *x and *y will be set to the new coordinates, or to -1 if the
 * window does not need to be moved
 */
static void 
gtk_window_compute_reposition (GtkWindow  *window,
			       gint        new_width,
			       gint        new_height,
			       gint       *x,
			       gint       *y)
{
  GtkWidget *widget;

  widget = GTK_WIDGET (window);

  *x = -1;
  *y = -1;
  
  switch (window->position)
    {
    case GTK_WIN_POS_CENTER:
    case GTK_WIN_POS_CENTER_ALWAYS:
      if (window->use_uposition)
	{
	  gint screen_width = gdk_screen_width ();
	  gint screen_height = gdk_screen_height ();
	  
	  *x = (screen_width - new_width) / 2;
	  *y = (screen_height - new_height) / 2;
	}
      break;
    case GTK_WIN_POS_MOUSE:
      if (window->use_uposition)
	{
	  gint screen_width = gdk_screen_width ();
	  gint screen_height = gdk_screen_height ();
	  
	  gdk_window_get_pointer (NULL, x, y, NULL);
	  *x -= new_width / 2;
	  *y -= new_height / 2;
	  *x = CLAMP (*x, 0, screen_width - new_width);
	  *y = CLAMP (*y, 0, screen_height - new_height);
	}
      break;
    default:
      if (window->use_uposition)
	{
	  GtkWidgetAuxInfo *aux_info;
	  
	  aux_info = gtk_object_get_data (GTK_OBJECT (window), "gtk-aux-info");
	  if (aux_info &&
	      aux_info->x != -1 && aux_info->y != -1 &&
	      aux_info->x != -2 && aux_info->y != -2)
	    {
	      *x = aux_info->x;
	      *y = aux_info->y;
	    }
	}
      break;
    }

  if (*x != -1 && *y != -1)
    {
      GtkWidgetAuxInfo *aux_info;
      
      /* we handle necessary window positioning by hand here,
       * so we can coalesce the window movement with possible
       * resizes to get only one configure event.
       * keep this in sync with gtk_widget_set_uposition()
       * and gtk_window_reposition().
       */
      gtk_widget_set_uposition (widget, -1, -1); /* ensure we have aux_info */
      
      aux_info = gtk_object_get_data (GTK_OBJECT (widget), "gtk-aux-info");
      aux_info->x = *x;
      aux_info->y = *y;

      window->use_uposition = FALSE;
    }
}

/***********************
 * Redrawing functions *
 ***********************/

static void
gtk_window_paint (GtkWidget     *widget,
		  GdkRectangle *area)
{
  gtk_paint_flat_box (widget->style, widget->window, GTK_STATE_NORMAL, 
		      GTK_SHADOW_NONE, area, widget, "base", 0, 0, -1, -1);
}

static gint
gtk_window_expose (GtkWidget      *widget,
		   GdkEventExpose *event)
{
  g_return_val_if_fail (widget != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_WINDOW (widget), FALSE);
  g_return_val_if_fail (event != NULL, FALSE);

  if (!GTK_WIDGET_APP_PAINTABLE (widget))
    gtk_window_paint (widget, &event->area);
  
  if (GTK_WIDGET_CLASS (parent_class)->expose_event)
    return GTK_WIDGET_CLASS (parent_class)->expose_event (widget, event);

  return TRUE;
}

static void
gtk_window_draw (GtkWidget    *widget,
		 GdkRectangle *area)
{
  if (!GTK_WIDGET_APP_PAINTABLE (widget))
    gtk_window_paint (widget, area);
  
  if (GTK_WIDGET_CLASS (parent_class)->draw)
    (* GTK_WIDGET_CLASS (parent_class)->draw) (widget, area);
}