gtkimcontextxim.c

linux下电话本所依赖的一些图形库

  if (!context_xim->ic)
    {
      const char *name1 = NULL;
      XVaNestedList list1 = NULL;
      const char *name2 = NULL;
      XVaNestedList list2 = NULL;
      XIMStyle im_style = 0;
      XIC xic = NULL;

      if (context_xim->use_preedit &&
	  (context_xim->im_info->style & PREEDIT_MASK) == XIMPreeditCallbacks)
	{
	  im_style |= XIMPreeditCallbacks;
	  name1 = XNPreeditAttributes;
	  list1 = set_preedit_callback (context_xim);
	}
      else if ((context_xim->im_info->style & PREEDIT_MASK) == XIMPreeditNone)
	im_style |= XIMPreeditNone;
      else
	im_style |= XIMPreeditNothing;

      if ((context_xim->im_info->style & STATUS_MASK) == XIMStatusCallbacks)
	{
	  im_style |= XIMStatusCallbacks;
	  if (name1 == NULL)
	    {
	      name1 = XNStatusAttributes;
	      list1 = set_status_callback (context_xim);
	    }
	  else
	    {
	      name2 = XNStatusAttributes;
	      list2 = set_status_callback (context_xim);
	    }
	}
      else if ((context_xim->im_info->style & STATUS_MASK) == XIMStatusNone)
	im_style |= XIMStatusNone;
      else
	im_style |= XIMStatusNothing;

      xic = XCreateIC (context_xim->im_info->im,
		       XNInputStyle, im_style,
		       XNClientWindow, GDK_DRAWABLE_XID (context_xim->client_window),
		       name1, list1,
		       name2, list2,
		       NULL);
      if (list1)
	XFree (list1);
      if (list2)
	XFree (list2);

      if (xic)
	{
	  /* Don't filter key released events with XFilterEvents unless
	   * input methods ask for. This is a workaround for Solaris input
	   * method bug in C and European locales. It doubles each key
	   * stroke if both key pressed and released events are filtered.
	   * (bugzilla #81759)
	   */
	  gulong mask = 0xaaaaaaaa;
	  XGetICValues (xic,
			XNFilterEvents, &mask,
			NULL);
	  context_xim->filter_key_release = (mask & KeyReleaseMask) != 0;
	  set_string_conversion_callback (context_xim, xic);
	}
      
      context_xim->ic = xic;

      update_status_window (context_xim);
      
      if (xic && context_xim->has_focus)
	XSetICFocus (xic);
    }
  return context_xim->ic;
}

/*****************************************************************
 * Status Window handling
 *
 * A status window is a small window attached to the toplevel
 * that is used to display information to the user about the
 * current input operation.
 *
 * We claim the toplevel's status window for an input context if:
 *
 * A) The input context has a toplevel
 * B) The input context has the focus
 * C) The input context has an XIC associated with it
 *
 * Tracking A) and C) is pretty reliable since we
 * compute A) and create the XIC for C) ourselves.
 * For B) we basically have to depend on our callers
 * calling ::focus-in and ::focus-out at the right time.
 *
 * The toplevel is computed by walking up the GdkWindow
 * hierarchy from context->client_window until we find a
 * window that is owned by some widget, and then calling
 * gtk_widget_get_toplevel() on that widget. This should
 * handle both cases where we might have GdkWindows without widgets,
 * and cases where GtkWidgets have strange window hierarchies
 * (like a torn off GtkHandleBox.)
 *
 * The status window is visible if and only if there is text
 * for it; whenever a new GtkIMContextXIM claims the status
 * window, we blank out any existing text. We actually only
 * create a GtkWindow for the status window the first time
 * it is shown; this is an important optimization when we are
 * using XIM with something like a simple compose-key input
 * method that never needs a status window.
 *****************************************************************/

/* Called when we no longer need a status window
*/
static void
disclaim_status_window (GtkIMContextXIM *context_xim)
{
  if (context_xim->status_window)
    {
      g_assert (context_xim->status_window->context == context_xim);

      status_window_set_text (context_xim->status_window, "");
      
      context_xim->status_window->context = NULL;
      context_xim->status_window = NULL;
    }
}

/* Called when we need a status window
 */
static void
claim_status_window (GtkIMContextXIM *context_xim)
{
  if (!context_xim->status_window && context_xim->client_widget)
    {
      GtkWidget *toplevel = gtk_widget_get_toplevel (context_xim->client_widget);
      if (toplevel && GTK_WIDGET_TOPLEVEL (toplevel))
	{
	  StatusWindow *status_window = status_window_get (toplevel);

	  if (status_window->context)
	    disclaim_status_window (status_window->context);

	  status_window->context = context_xim;
	  context_xim->status_window = status_window;
	}
    }
}

/* Basic call made whenever something changed that might cause
 * us to need, or not to need a status window.
 */
static void
update_status_window (GtkIMContextXIM *context_xim)
{
  if (context_xim->ic && context_xim->in_toplevel && context_xim->has_focus)
    claim_status_window (context_xim);
  else
    disclaim_status_window (context_xim);
}

/* Updates the in_toplevel flag for @context_xim
 */
static void
update_in_toplevel (GtkIMContextXIM *context_xim)
{
  if (context_xim->client_widget)
    {
      GtkWidget *toplevel = gtk_widget_get_toplevel (context_xim->client_widget);
      
      context_xim->in_toplevel = (toplevel && GTK_WIDGET_TOPLEVEL (toplevel));
    }
  else
    context_xim->in_toplevel = FALSE;

  /* Some paranoia, in case we don't get a focus out */
  if (!context_xim->in_toplevel)
    context_xim->has_focus = FALSE;
  
  update_status_window (context_xim);
}

/* Callback when @widget's toplevel changes. It will always
 * change from NULL to a window, or a window to NULL;
 * we use that intermediate NULL state to make sure
 * that we disclaim the toplevel status window for the old
 * window.
 */
static void
on_client_widget_hierarchy_changed (GtkWidget       *widget,
				    GtkWidget       *old_toplevel,
				    GtkIMContextXIM *context_xim)
{
  update_in_toplevel (context_xim);
}

/* Finds the GtkWidget that owns the window, or if none, the
 * widget owning the nearest parent that has a widget.
 */
static GtkWidget *
widget_for_window (GdkWindow *window)
{
  while (window)
    {
      gpointer user_data;
      gdk_window_get_user_data (window, &user_data);
      if (user_data)
	return user_data;

      window = gdk_window_get_parent (window);
    }

  return NULL;
}

/* Called when context_xim->client_window changes; takes care of
 * removing and/or setting up our watches for the toplevel
 */
static void
update_client_widget (GtkIMContextXIM *context_xim)
{
  GtkWidget *new_client_widget = widget_for_window (context_xim->client_window);

  if (new_client_widget != context_xim->client_widget)
    {
      if (context_xim->client_widget)
	{
	  g_signal_handlers_disconnect_by_func (context_xim->client_widget,
						G_CALLBACK (on_client_widget_hierarchy_changed),
						context_xim);
	}
      context_xim->client_widget = new_client_widget;
      if (context_xim->client_widget)
	{
	  g_signal_connect (context_xim->client_widget, "hierarchy-changed",
			    G_CALLBACK (on_client_widget_hierarchy_changed),
			    context_xim);
	}

      update_in_toplevel (context_xim);
    }
}

/* Called when the toplevel is destroyed; frees the status window
 */
static void
on_status_toplevel_destroy (GtkWidget    *toplevel,
			    StatusWindow *status_window)
{
  status_window_free (status_window);
}

/* Called when the screen for the toplevel changes; updates the
 * screen for the status window to match.
 */
static void
on_status_toplevel_notify_screen (GtkWindow    *toplevel,
				  GParamSpec   *pspec,
				  StatusWindow *status_window)
{
  if (status_window->window)
    gtk_window_set_screen (GTK_WINDOW (status_window->window),
			   gtk_widget_get_screen (GTK_WIDGET (toplevel)));
}

/* Called when the toplevel window is moved; updates the position of
 * the status window to follow it.
 */
static gboolean
on_status_toplevel_configure (GtkWidget         *toplevel,
			      GdkEventConfigure *event,
			      StatusWindow      *status_window)
{
  GdkRectangle rect;
  GtkRequisition requisition;
  gint y;
  gint height;

  if (status_window->window)
    {
      height = gdk_screen_get_height (gtk_widget_get_screen (toplevel));
  
      gdk_window_get_frame_extents (toplevel->window, &rect);
      gtk_widget_size_request (status_window->window, &requisition);
      
      if (rect.y + rect.height + requisition.height < height)
	y = rect.y + rect.height;
      else
	y = height - requisition.height;
      
      gtk_window_move (GTK_WINDOW (status_window->window), rect.x, y);
    }

  return FALSE;
}

/* Frees a status window and removes its link from the status_windows list
 */
static void
status_window_free (StatusWindow *status_window)
{
  status_windows = g_slist_remove (status_windows, status_window);

  if (status_window->context)
    status_window->context->status_window = NULL;
 
  g_signal_handlers_disconnect_by_func (status_window->toplevel,
					G_CALLBACK (on_status_toplevel_destroy),
					status_window);
  g_signal_handlers_disconnect_by_func (status_window->toplevel,
					G_CALLBACK (on_status_toplevel_notify_screen),
					status_window);
  g_signal_handlers_disconnect_by_func (status_window->toplevel,
					G_CALLBACK (on_status_toplevel_configure),
					status_window);

  if (status_window->window)
    gtk_widget_destroy (status_window->window);
  
  g_object_set_data (G_OBJECT (status_window->toplevel), "gtk-im-xim-status-window", NULL);
 
  g_free (status_window);
}

/* Finds the status window object for a toplevel, creating it if necessary.
 */
static StatusWindow *
status_window_get (GtkWidget *toplevel)
{
  StatusWindow *status_window;

  status_window = g_object_get_data (G_OBJECT (toplevel), "gtk-im-xim-status-window");
  if (status_window)
    return status_window;
  
  status_window = g_new0 (StatusWindow, 1);
  status_window->toplevel = toplevel;

  status_windows = g_slist_prepend (status_windows, status_window);

  g_signal_connect (toplevel, "destroy",
		    G_CALLBACK (on_status_toplevel_destroy),
		    status_window);
  g_signal_connect (toplevel, "configure_event",
		    G_CALLBACK (on_status_toplevel_configure),
		    status_window);
  g_signal_connect (toplevel, "notify::screen",
		    G_CALLBACK (on_status_toplevel_notify_screen),
		    status_window);
  
  g_object_set_data (G_OBJECT (toplevel), "gtk-im-xim-status-window", status_window);

  return status_window;
}

/* Draw the background (normally white) and border for the status window
 */
static gboolean
on_status_window_expose_event (GtkWidget      *widget,
			       GdkEventExpose *event)
{
  gdk_draw_rectangle (widget->window,
		      widget->style->base_gc [GTK_STATE_NORMAL],
		      TRUE,
		      0, 0,
		      widget->allocation.width, widget->allocation.height);
  gdk_draw_rectangle (widget->window,
		      widget->style->text_gc [GTK_STATE_NORMAL],
		      FALSE,
		      0, 0,
		      widget->allocation.width - 1, widget->allocation.height - 1);

  return FALSE;
}

/* We watch the ::style-set signal for our label widget
 * and use that to change it's foreground color to match
 * the 'text' color of the toplevel window. The text/base
 * pair of colors might be reversed from the fg/bg pair
 * that are normally used for labels.
 */
static void
on_status_window_style_set (GtkWidget *toplevel,
			    GtkStyle  *previous_style,
			    GtkWidget *label)
{
  gint i;
  
  for (i = 0; i < 5; i++)
    gtk_widget_modify_fg (label, i, &toplevel->style->text[i]);
}

/* Creates the widgets for the status window; called when we
 * first need to show text for the status window.
 */
static void
status_window_make_window (StatusWindow *status_window)
{
  GtkWidget *window;
  GtkWidget *status_label;
  
  status_window->window = gtk_window_new (GTK_WINDOW_POPUP);
  window = status_window->window;

  gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
  gtk_widget_set_app_paintable (window, TRUE);

  status_label = gtk_label_new ("");
  gtk_misc_set_padding (GTK_MISC (status_label), 1, 1);
  gtk_widget_show (status_label);
  
  g_signal_connect (window, "style_set",
		    G_CALLBACK (on_status_window_style_set), status_label);
  gtk_container_add (GTK_CONTAINER (window), status_label);
  
  g_signal_connect (window, "expose_event",
		    G_CALLBACK (on_status_window_expose_event), NULL);
  
  gtk_window_set_screen (GTK_WINDOW (status_window->window),
			 gtk_widget_get_screen (status_window->toplevel));

  on_status_toplevel_configure (status_window->toplevel, NULL, status_window);
}

/* Updates the text in the status window, hiding or
 * showing the window as necessary.
 */
static void
status_window_set_text (StatusWindow *status_window,
			const gchar  *text)
{
  if (text[0])
    {
      GtkWidget *label;
      
      if (!status_window->window)
	status_window_make_window (status_window);
      
      label = GTK_BIN (status_window->window)->child;
      gtk_label_set_text (GTK_LABEL (label), text);
  
      gtk_widget_show (status_window->window);
    }
  else
    {
      if (status_window->window)
	gtk_widget_hide (status_window->window);
    }
}

/**
 * gtk_im_context_xim_shutdown:
 * 
 * Destroys all the status windows that are kept by the XIM contexts.  This
 * function should only be called by the XIM module exit routine.
 **/
void
gtk_im_context_xim_shutdown (void)
{
  while (status_windows)
    status_window_free (status_windows->data);
}