gdkevents.c

gtk是linux一款强大的夸平台的图形化开发工具

/* GDK - The GIMP Drawing Kit
 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
 */

#include "gdk.h"
#include "gdkx.h"
#include "gdkprivate.h"
#include "gdkkeysyms.h"

#if HAVE_CONFIG_H
#  include <config.h>
#  if STDC_HEADERS
#    include <string.h>
#  endif
#endif

#include "gdkinput.h"

typedef struct _GdkIOClosure GdkIOClosure;
typedef struct _GdkEventPrivate GdkEventPrivate;

#define DOUBLE_CLICK_TIME      250
#define TRIPLE_CLICK_TIME      500
#define DOUBLE_CLICK_DIST      5
#define TRIPLE_CLICK_DIST      5

typedef enum
{
  /* Following flag is set for events on the event queue during
   * translation and cleared afterwards.
   */
  GDK_EVENT_PENDING = 1 << 0
} GdkEventFlags;

struct _GdkIOClosure
{
  GdkInputFunction function;
  GdkInputCondition condition;
  GdkDestroyNotify notify;
  gpointer data;
};

struct _GdkEventPrivate
{
  GdkEvent event;
  guint    flags;
};

/* 
 * Private function declarations
 */

static GdkEvent *gdk_event_new		(void);
static gint	 gdk_event_apply_filters (XEvent   *xevent,
					  GdkEvent *event,
					  GList    *filters);
static gint	 gdk_event_translate	 (GdkEvent *event, 
					  XEvent   *xevent);
#if 0
static Bool	 gdk_event_get_type	(Display   *display, 
					 XEvent	   *xevent, 
					 XPointer   arg);
#endif
static void      gdk_events_queue       (void);
static GdkEvent* gdk_event_unqueue      (void);

static gboolean  gdk_event_prepare      (gpointer   source_data, 
				 	 GTimeVal  *current_time,
					 gint      *timeout,
					 gpointer   user_data);
static gboolean  gdk_event_check        (gpointer   source_data,
				 	 GTimeVal  *current_time,
					 gpointer   user_data);
static gboolean  gdk_event_dispatch     (gpointer   source_data,
					 GTimeVal  *current_time,
					 gpointer   user_data);

static void	 gdk_synthesize_click	(GdkEvent  *event, 
					 gint	    nclicks);

GdkFilterReturn gdk_wm_protocols_filter (GdkXEvent *xev,
					 GdkEvent  *event,
					 gpointer   data);

/* Private variable declarations
 */

static int connection_number = 0;	    /* The file descriptor number of our
					     *	connection to the X server. This
					     *	is used so that we may determine
					     *	when events are pending by using
					     *	the "select" system call.
					     */
static guint32 button_click_time[2];	    /* The last 2 button click times. Used
					     *	to determine if the latest button click
					     *	is part of a double or triple click.
					     */
static GdkWindow *button_window[2];	    /* The last 2 windows to receive button presses.
					     *	Also used to determine if the latest button
					     *	click is part of a double or triple click.
					     */
static guint button_number[2];		    /* The last 2 buttons to be pressed.
					     */
static GdkEventFunc   event_func = NULL;    /* Callback for events */
static gpointer       event_data = NULL;
static GDestroyNotify event_notify = NULL;

static GList *client_filters;	            /* Filters for client messages */

/* FIFO's for event queue, and for events put back using
 * gdk_event_put().
 */
static GList *queued_events = NULL;
static GList *queued_tail = NULL;

static GSourceFuncs event_funcs = {
  gdk_event_prepare,
  gdk_event_check,
  gdk_event_dispatch,
  (GDestroyNotify)g_free
};

GPollFD event_poll_fd;

/*********************************************
 * Functions for maintaining the event queue *
 *********************************************/

/*************************************************************
 * gdk_event_queue_find_first:
 *     Find the first event on the queue that is not still
 *     being filled in.
 *   arguments:
 *     
 *   results:
 *     Pointer to the list node for that event, or NULL
 *************************************************************/

static GList*
gdk_event_queue_find_first (void)
{
  GList *tmp_list = queued_events;

  while (tmp_list)
    {
      GdkEventPrivate *event = tmp_list->data;
      if (!(event->flags & GDK_EVENT_PENDING))
	return tmp_list;

      tmp_list = g_list_next (tmp_list);
    }

  return NULL;
}

/*************************************************************
 * gdk_event_queue_remove_link:
 *     Remove a specified list node from the event queue.
 *   arguments:
 *     node: Node to remove.
 *   results:
 *************************************************************/

static void
gdk_event_queue_remove_link (GList *node)
{
  if (node->prev)
    node->prev->next = node->next;
  else
    queued_events = node->next;
  
  if (node->next)
    node->next->prev = node->prev;
  else
    queued_tail = node->prev;
  
}

/*************************************************************
 * gdk_event_queue_append:
 *     Append an event onto the tail of the event queue.
 *   arguments:
 *     event: Event to append.
 *   results:
 *************************************************************/

static void
gdk_event_queue_append (GdkEvent *event)
{
  queued_tail = g_list_append (queued_tail, event);
  
  if (!queued_events)
    queued_events = queued_tail;
  else
    queued_tail = queued_tail->next;
}

void 
gdk_events_init (void)
{
  connection_number = ConnectionNumber (gdk_display);
  GDK_NOTE (MISC,
	    g_message ("connection number: %d", connection_number));

  g_source_add (GDK_PRIORITY_EVENTS, TRUE, &event_funcs, NULL, NULL, NULL);

  event_poll_fd.fd = connection_number;
  event_poll_fd.events = G_IO_IN;
  
  g_main_add_poll (&event_poll_fd, GDK_PRIORITY_EVENTS);

  button_click_time[0] = 0;
  button_click_time[1] = 0;
  button_window[0] = NULL;
  button_window[1] = NULL;
  button_number[0] = -1;
  button_number[1] = -1;

  gdk_add_client_message_filter (gdk_wm_protocols, 
				 gdk_wm_protocols_filter, NULL);
}

/*
 *--------------------------------------------------------------
 * gdk_events_pending
 *
 *   Returns if events are pending on the queue.
 *
 * Arguments:
 *
 * Results:
 *   Returns TRUE if events are pending
 *
 * Side effects:
 *
 *--------------------------------------------------------------
 */

gboolean
gdk_events_pending (void)
{
  return (gdk_event_queue_find_first() || XPending (gdk_display));
}

/*
 *--------------------------------------------------------------
 * gdk_event_get_graphics_expose
 *
 *   Waits for a GraphicsExpose or NoExpose event
 *
 * Arguments:
 *
 * Results: 
 *   For GraphicsExpose events, returns a pointer to the event
 *   converted into a GdkEvent Otherwise, returns NULL.
 *
 * Side effects:
 *
 *-------------------------------------------------------------- */

static Bool
graphics_expose_predicate (Display  *display,
			   XEvent   *xevent,
			   XPointer  arg)
{
  GdkWindowPrivate *private = (GdkWindowPrivate*) arg;
  
  g_return_val_if_fail (private != NULL, False);
  
  if (xevent->xany.window == private->xwindow &&
      (xevent->xany.type == GraphicsExpose ||
       xevent->xany.type == NoExpose))
    return True;
  else
    return False;
}

GdkEvent*
gdk_event_get_graphics_expose (GdkWindow *window)
{
  XEvent xevent;
  GdkEvent *event;
  
  g_return_val_if_fail (window != NULL, NULL);
  
  XIfEvent (gdk_display, &xevent, graphics_expose_predicate, (XPointer) window);
  
  if (xevent.xany.type == GraphicsExpose)
    {
      event = gdk_event_new ();
      
      if (gdk_event_translate (event, &xevent))
	return event;
      else
	gdk_event_free (event);
    }
  
  return NULL;	
}

/************************
 * Exposure compression *
 ************************/

/*
 * The following implements simple exposure compression. It is
 * modelled after the way Xt does exposure compression - in
 * particular compress_expose = XtExposeCompressMultiple.
 * It compress consecutive sequences of exposure events,
 * but not sequences that cross other events. (This is because
 * if it crosses a ConfigureNotify, we could screw up and
 * mistakenly compress the exposures generated for the new
 * size - could we just check for ConfigureNotify?)
 *
 * Xt compresses to a region / bounding rectangle, we compress
 * to two rectangles, and try find the two rectangles of minimal
 * area for this - this is supposed to handle the typical
 * L-shaped regions generated by OpaqueMove.
 */

/* Given three rectangles, find the two rectangles that cover
 * them with the smallest area.
 */
static void
gdk_add_rect_to_rects (GdkRectangle *rect1,
		       GdkRectangle *rect2, 
		       GdkRectangle *new_rect)
{
  GdkRectangle t1, t2, t3;
  gint size1, size2, size3;

  gdk_rectangle_union (rect1, rect2, &t1);
  gdk_rectangle_union (rect1, new_rect, &t2);
  gdk_rectangle_union (rect2, new_rect, &t3);

  size1 = t1.width * t1.height + new_rect->width * new_rect->height;
  size2 = t2.width * t2.height + rect2->width * rect2->height;
  size3 = t1.width * t1.height + rect1->width * rect1->height;

  if (size1 < size2)
    {
      if (size1 < size3)
	{
	  *rect1 = t1;
	  *rect2 = *new_rect;
	}
      else
	*rect2 = t3;
    }
  else
    {
      if (size2 < size3)
	*rect1 = t2;
      else
	*rect2 = t3;
    }
}

typedef struct _GdkExposeInfo GdkExposeInfo;

struct _GdkExposeInfo
{
  Window window;
  gboolean seen_nonmatching;
};

static Bool
expose_predicate (Display *display,
		  XEvent  *xevent,
		  XPointer arg)
{
  GdkExposeInfo *info = (GdkExposeInfo*) arg;

  /* Compressing across GravityNotify events is safe, because
   * we completely ignore them, so they can't change what
   * we are going to draw. Compressing across GravityNotify
   * events is necessay because during window-unshading animation
   * we'll get a whole bunch of them interspersed with
   * expose events.
   */
  if (xevent->xany.type != Expose && 
      xevent->xany.type != GravityNotify)
    {
      info->seen_nonmatching = TRUE;
    }

  if (info->seen_nonmatching ||
      xevent->xany.type != Expose ||
      xevent->xany.window != info->window)
    return FALSE;
  else
    return TRUE;
}

void
gdk_compress_exposures (XEvent    *xevent,
			GdkWindow *window)
{
  gint nrects = 1;
  gint count = 0;
  GdkRectangle rect1;
  GdkRectangle rect2;
  GdkRectangle tmp_rect;
  XEvent tmp_event;
  GdkFilterReturn result;
  GdkExposeInfo info;
  GdkEvent event;

  info.window = xevent->xany.window;
  info.seen_nonmatching = FALSE;
  
  rect1.x = xevent->xexpose.x;
  rect1.y = xevent->xexpose.y;
  rect1.width = xevent->xexpose.width;
  rect1.height = xevent->xexpose.height;

  event.any.type = GDK_EXPOSE;
  event.any.window = None;
  event.any.send_event = FALSE;
  
  while (1)
    {
      if (count == 0)
	{
	  if (!XCheckIfEvent (gdk_display, 
			      &tmp_event, 
			      expose_predicate, 
			      (XPointer)&info))
	    break;
	}
      else
	XIfEvent (gdk_display, 
		  &tmp_event, 
		  expose_predicate, 
		  (XPointer)&info);

      event.any.window = window;
      
      /* We apply filters here, and if it was filtered, completely
       * ignore the return
       */
      result = gdk_event_apply_filters (xevent, &event,
					window ? 
					  ((GdkWindowPrivate *)window)->filters
					  : gdk_default_filters);
      
      if (result != GDK_FILTER_CONTINUE)
	{
	  if (result == GDK_FILTER_TRANSLATE)
	    gdk_event_put (&event);
	  continue;
	}

      if (nrects == 1)
	{
	  rect2.x = tmp_event.xexpose.x;
	  rect2.y = tmp_event.xexpose.y;
	  rect2.width = tmp_event.xexpose.width;
	  rect2.height = tmp_event.xexpose.height;

	  nrects++;
	}
      else
	{
	  tmp_rect.x = tmp_event.xexpose.x;
	  tmp_rect.y = tmp_event.xexpose.y;
	  tmp_rect.width = tmp_event.xexpose.width;
	  tmp_rect.height = tmp_event.xexpose.height;

	  gdk_add_rect_to_rects (&rect1, &rect2, &tmp_rect);
	}

      count = tmp_event.xexpose.count;
    }

  if (nrects == 2)
    {
      gdk_rectangle_union (&rect1, &rect2, &tmp_rect);

      if ((tmp_rect.width * tmp_rect.height) <
	  2 * (rect1.height * rect1.width +
	       rect2.height * rect2.width))
	{
	  rect1 = tmp_rect;
	  nrects = 1;
	}
    }

  if (nrects == 2)
    {
      event.expose.type = GDK_EXPOSE;
      event.expose.window = window;
      event.expose.area.x = rect2.x;
      event.expose.area.y = rect2.y;
      event.expose.area.width = rect2.width;
      event.expose.area.height = rect2.height;
      event.expose.count = 0;

      gdk_event_put (&event);
    }

  xevent->xexpose.count = nrects - 1;
  xevent->xexpose.x = rect1.x;
  xevent->xexpose.y = rect1.y;
  xevent->xexpose.width = rect1.width;
  xevent->xexpose.height = rect1.height;
}

/*************************************************************
 * gdk_event_handler_set:
 *     
 *   arguments:
 *     func: Callback function to be called for each event.
 *     data: Data supplied to the function
 *     notify: function called when function is no longer needed
 * 
 *   results:
 *************************************************************/

void 
gdk_event_handler_set (GdkEventFunc   func,
		       gpointer       data,
		       GDestroyNotify notify)
{
  if (event_notify)
    (*event_notify) (event_data);

  event_func = func;
  event_data = data;
  event_notify = notify;
}

/*
 *--------------------------------------------------------------
 * gdk_event_get
 *
 *   Gets the next event.
 *
 * Arguments:
 *
 * Results:
 *   If an event is waiting that we care about, returns 
 *   a pointer to that event, to be freed with gdk_event_free.
 *   Otherwise, returns NULL.
 *
 * Side effects:
 *
 *--------------------------------------------------------------
 */