gtkdnd.c

gtk是linux一款强大的夸平台的图形化开发工具

/* GTK - The GIMP Toolkit
 * Copyright (C) 1995-1999 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/gdkx.h"
#include "gdk/gdkkeysyms.h"

#include "gtkdnd.h"
#include "gtkinvisible.h"
#include "gtkmain.h"
#include "gtksignal.h"
#include "gtkwindow.h"

static GSList *drag_widgets = NULL;
static GSList *source_widgets = NULL;

typedef struct _GtkDragSourceSite GtkDragSourceSite;
typedef struct _GtkDragSourceInfo GtkDragSourceInfo;
typedef struct _GtkDragDestSite GtkDragDestSite;
typedef struct _GtkDragDestInfo GtkDragDestInfo;
typedef struct _GtkDragAnim GtkDragAnim;
typedef struct _GtkDragFindData GtkDragFindData;


typedef enum 
{
  GTK_DRAG_STATUS_DRAG,
  GTK_DRAG_STATUS_WAIT,
  GTK_DRAG_STATUS_DROP
} GtkDragStatus;

struct _GtkDragSourceSite 
{
  GdkModifierType    start_button_mask;
  GtkTargetList     *target_list;        /* Targets for drag data */
  GdkDragAction      actions;            /* Possible actions */
  GdkColormap       *colormap;	         /* Colormap for drag icon */
  GdkPixmap         *pixmap;             /* Icon for drag data */
  GdkBitmap         *mask;

  /* Stored button press information to detect drag beginning */
  gint               state;
  gint               x, y;
};
  
struct _GtkDragSourceInfo 
{
  GtkWidget         *widget;
  GtkTargetList     *target_list; /* Targets for drag data */
  GdkDragAction      possible_actions; /* Actions allowed by source */
  GdkDragContext    *context;	  /* drag context */
  GtkWidget         *icon_window; /* Window for drag */
  GtkWidget         *ipc_widget;  /* GtkInvisible for grab, message passing */
  GdkCursor         *cursor;	  /* Cursor for drag */
  gint hot_x, hot_y;		  /* Hot spot for drag */
  gint button;			  /* mouse button starting drag */

  GtkDragStatus      status;	  /* drag status */
  GdkEvent          *last_event;  /* motion event waiting for response */

  gint               start_x, start_y; /* Initial position */
  gint               cur_x, cur_y;     /* Current Position */

  GList             *selections;  /* selections we've claimed */
  
  GtkDragDestInfo   *proxy_dest;  /* Set if this is a proxy drag */

  guint              drop_timeout;     /* Timeout for aborting drop */
  guint              destroy_icon : 1; /* If true, destroy icon_window
					*/
};

struct _GtkDragDestSite 
{
  GtkDestDefaults    flags;
  GtkTargetList     *target_list;
  GdkDragAction      actions;
  GdkWindow         *proxy_window;
  GdkDragProtocol    proxy_protocol;
  gboolean           do_proxy : 1;
  gboolean           proxy_coords : 1;
  gboolean           have_drag : 1;
};
  
struct _GtkDragDestInfo 
{
  GtkWidget         *widget;	   /* Widget in which drag is in */
  GdkDragContext    *context;	   /* Drag context */
  GtkDragSourceInfo *proxy_source; /* Set if this is a proxy drag */
  GtkSelectionData  *proxy_data;   /* Set while retrieving proxied data */
  gboolean           dropped : 1;     /* Set after we receive a drop */
  guint32            proxy_drop_time; /* Timestamp for proxied drop */
  gboolean           proxy_drop_wait : 1; /* Set if we are waiting for a
					   * status reply before sending
					   * a proxied drop on.
					   */
  gint               drop_x, drop_y; /* Position of drop */
};

#define DROP_ABORT_TIME 300000

#define ANIM_STEP_TIME 50
#define ANIM_STEP_LENGTH 50
#define ANIM_MIN_STEPS 5
#define ANIM_MAX_STEPS 10

struct _GtkDragAnim 
{
  GtkDragSourceInfo *info;
  gint step;
  gint n_steps;
};

struct _GtkDragFindData 
{
  gint x;
  gint y;
  GdkDragContext *context;
  GtkDragDestInfo *info;
  gboolean found;
  gboolean toplevel;
  gboolean (*callback) (GtkWidget *widget, GdkDragContext *context,
			gint x, gint y, guint32 time);
  guint32 time;
};

/* Enumeration for some targets we handle internally */

enum {
  TARGET_MOTIF_SUCCESS = 0x40000000,
  TARGET_MOTIF_FAILURE,
  TARGET_DELETE
};

/* Drag icons */

static GdkPixmap   *default_icon_pixmap = NULL;
static GdkPixmap   *default_icon_mask = NULL;
static GdkColormap *default_icon_colormap = NULL;
static gint         default_icon_hot_x;
static gint         default_icon_hot_y;

/* Forward declarations */
static void          gtk_drag_get_event_actions (GdkEvent        *event, 
					         gint             button,
					         GdkDragAction    actions,
					         GdkDragAction   *suggested_action,
					         GdkDragAction   *possible_actions);
static GdkCursor *   gtk_drag_get_cursor         (GdkDragAction action);
static GtkWidget    *gtk_drag_get_ipc_widget     (void);
static void          gtk_drag_release_ipc_widget (GtkWidget      *widget);

static void          gtk_drag_highlight_paint    (GtkWidget      *widget);
static gboolean      gtk_drag_highlight_expose   (GtkWidget      *widget,
					  	  GdkEventExpose *event,
						  gpointer        data);


static GdkAtom   gtk_drag_dest_find_target    (GtkWidget          *widget,
					       GtkDragDestSite    *site,
			                       GdkDragContext     *context);
static void      gtk_drag_selection_received  (GtkWidget          *widget,
					       GtkSelectionData   *selection_data,
					       guint32             time,
					       gpointer            data);
static void      gtk_drag_find_widget         (GtkWidget          *widget,
					       GtkDragFindData    *data);
static void      gtk_drag_proxy_begin         (GtkWidget          *widget,
					       GtkDragDestInfo    *dest_info);
static void      gtk_drag_dest_info_destroy   (gpointer            data);
static void      gtk_drag_dest_realized       (GtkWidget          *widget);
static void      gtk_drag_dest_site_destroy   (gpointer            data);
static void      gtk_drag_dest_leave          (GtkWidget          *widget,
					       GdkDragContext     *context,
					       guint               time);
static gboolean  gtk_drag_dest_motion         (GtkWidget	  *widget,
				               GdkDragContext     *context,
					       gint                x,
					       gint                y,
					       guint               time);
static gboolean  gtk_drag_dest_drop           (GtkWidget	  *widget,
					       GdkDragContext     *context,
					       gint                x,
					       gint                y,
					       guint               time);

static void gtk_drag_source_check_selection    (GtkDragSourceInfo *info, 
					        GdkAtom            selection,
					        guint32            time);
static void gtk_drag_source_release_selections (GtkDragSourceInfo *info,
						guint32            time);
static void gtk_drag_drop                      (GtkDragSourceInfo *info,
						guint32            time);
static void gtk_drag_drop_finished             (GtkDragSourceInfo *info,
						gboolean           success,
						guint              time);

static gint gtk_drag_source_event_cb           (GtkWidget         *widget,
						GdkEvent          *event,
						gpointer           data);
static void gtk_drag_source_site_destroy       (gpointer           data);
static void gtk_drag_selection_get             (GtkWidget         *widget, 
						GtkSelectionData  *selection_data,
						guint              sel_info,
						guint32            time,
						gpointer           data);
static gint gtk_drag_anim_timeout              (gpointer           data);
static void gtk_drag_remove_icon               (GtkDragSourceInfo *info);
static void gtk_drag_source_info_destroy       (gpointer           data);
static void gtk_drag_update                    (GtkDragSourceInfo *info,
						gint               x_root,
						gint               y_root,
						GdkEvent          *event);
static gint gtk_drag_motion_cb                 (GtkWidget         *widget, 
					        GdkEventMotion    *event, 
					        gpointer           data);
static gint gtk_drag_key_cb                    (GtkWidget         *widget, 
					        GdkEventKey       *event, 
					        gpointer           data);
static gint gtk_drag_button_release_cb         (GtkWidget         *widget, 
					        GdkEventButton    *event, 
					        gpointer           data);
static gint gtk_drag_abort_timeout             (gpointer           data);

/************************
 * Cursor and Icon data *
 ************************/

#define action_ask_width 16
#define action_ask_height 16
static const guchar action_ask_bits[] = {
  0x00, 0x00, 0xfe, 0x7f, 0xfe, 0x1f, 0x06, 0xc0, 0x76, 0xf8, 0xb6, 0xf7, 
  0xd6, 0xec, 0x66, 0xdb, 0x66, 0xdb, 0x96, 0xec, 0x76, 0xf7, 0x76, 0xfb, 
  0xf6, 0xfc, 0x72, 0xfb, 0x7a, 0xfb, 0xf8, 0xfc, };

#define action_ask_mask_width 16
#define action_ask_mask_height 16
static const guchar action_ask_mask_bits[] = {
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0x8f, 0x07, 0xcf, 0x0f, 
  0xef, 0x1f, 0xff, 0x3c, 0xff, 0x3c, 0x6f, 0x1f, 0x8f, 0x0f, 0x8f, 0x07, 
  0x0f, 0x03, 0x8f, 0x07, 0x87, 0x07, 0x07, 0x03, };

#define action_copy_width 16
#define action_copy_height 16
static const guchar action_copy_bits[] = {
  0x00, 0x00, 0xfe, 0x7f, 0xfe, 0x1f, 0x06, 0xc0, 0x76, 0xfb, 0x76, 0xfb, 
  0x76, 0xfb, 0x06, 0x83, 0xf6, 0xbf, 0xf6, 0xbf, 0x06, 0x83, 0x76, 0xfb, 
  0x76, 0xfb, 0x72, 0xfb, 0x7a, 0xf8, 0xf8, 0xff, };

#define action_copy_mask_width 16
#define action_copy_mask_height 16
static const guchar action_copy_mask_bits[] = {
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0x8f, 0x07, 0x8f, 0x07, 
  0x8f, 0x07, 0xff, 0x7f, 0xff, 0x7f, 0xff, 0x7f, 0xff, 0x7f, 0x8f, 0x07, 
  0x8f, 0x07, 0x8f, 0x07, 0x87, 0x07, 0x07, 0x00, };

#define action_move_width 16
#define action_move_height 16
static const guchar action_move_bits[] = {
  0x00, 0x00, 0xfe, 0x7f, 0xfe, 0x1f, 0x06, 0xc0, 0x96, 0xff, 0x26, 0xff, 
  0xc6, 0xf8, 0xd6, 0xe3, 0x96, 0x8f, 0xb6, 0xbf, 0x36, 0xc3, 0x76, 0xfb, 
  0x76, 0xfa, 0xf2, 0xfa, 0xfa, 0xf8, 0xf8, 0xff, };

#define action_move_mask_width 16
#define action_move_mask_height 16
static const guchar action_move_mask_bits[] = {
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0x6f, 0x00, 0xff, 0x00, 
  0xff, 0x07, 0xef, 0x1f, 0xef, 0x7f, 0xcf, 0x7f, 0xcf, 0x3f, 0x8f, 0x07, 
  0x8f, 0x07, 0x0f, 0x07, 0x07, 0x07, 0x07, 0x00, };

#define action_link_width 16
#define action_link_height 16
static const guchar action_link_bits[] = {
  0x00, 0x00, 0xfe, 0x7f, 0xfe, 0x1f, 0x06, 0xc0, 0x36, 0xf8, 0xd6, 0xf7, 
  0x66, 0xec, 0xa6, 0xe8, 0x26, 0xdf, 0xe6, 0xbd, 0xd6, 0xa7, 0xb6, 0xa8, 
  0xb6, 0xb1, 0x72, 0xdf, 0xfa, 0xe0, 0xf8, 0xff, };

#define action_link_mask_width 16
#define action_link_mask_height 16
static const guchar action_link_mask_bits[] = {
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xcf, 0x07, 0xef, 0x0f, 
  0xff, 0x1f, 0x7f, 0x1f, 0xff, 0x3f, 0xff, 0x7f, 0xef, 0x7f, 0xcf, 0x77, 
  0xcf, 0x7f, 0x8f, 0x3f, 0x07, 0x1f, 0x07, 0x00, };

#define action_none_width 16
#define action_none_height 16
static const guchar action_none_bits[] = {
  0x00, 0x00, 0xfe, 0x7f, 0xfe, 0x1f, 0x06, 0xc0, 0xf6, 0xff, 0xf6, 0xff, 
  0xf6, 0xff, 0xf6, 0xff, 0xf6, 0xff, 0xf6, 0xff, 0xf6, 0xff, 0xf6, 0xff, 
  0xf6, 0xff, 0xf2, 0xff, 0xfa, 0xff, 0xf8, 0xff, };

#define action_none_mask_width 16
#define action_none_mask_height 16
static const guchar action_none_mask_bits[] = {
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0x0f, 0x00, 0x0f, 0x00, 
  0x0f, 0x00, 0x0f, 0x00, 0x0f, 0x00, 0x0f, 0x00, 0x0f, 0x00, 0x0f, 0x00, 
  0x0f, 0x00, 0x0f, 0x00, 0x07, 0x00, 0x07, 0x00, };

#define CURSOR_WIDTH 16
#define CURSOR_HEIGHT 16

static struct {
  GdkDragAction action;
  const char *bits;
  const char *mask;
  GdkCursor    *cursor;
} drag_cursors[] = {
  { GDK_ACTION_DEFAULT, 0 },
  { GDK_ACTION_ASK,   action_ask_bits,  action_ask_mask_bits,  NULL },
  { GDK_ACTION_COPY,  action_copy_bits, action_copy_mask_bits, NULL },
  { GDK_ACTION_MOVE,  action_move_bits, action_move_mask_bits, NULL },
  { GDK_ACTION_LINK,  action_link_bits, action_link_mask_bits, NULL },
  { 0              ,  action_none_bits, action_none_mask_bits, NULL },
};

static const gint n_drag_cursors = sizeof (drag_cursors) / sizeof (drag_cursors[0]);

/* XPM */
static const char *drag_default_xpm[] = {
"32 32 3 1",
" 	c None",
".	c #000000",
"+	c #FFFFFF",
"                                ",
"                                ",
"                ..              ",
"              ..+.              ",
"             ..++..             ",
"           ...++++.             ",
"         ...++++++..            ",
"       ...+++++++++.            ",
"     ...+++++++++++..           ",
"    ..+.++++++++++++..          ",
"     .++.++++++++++++..         ",
"     .+++.++++++++++++..        ",
"     .++++.++++++++++++.        ",
"     .+++.+++++++++++++..       ",
"     .++.+++++++++++++++..      ",
"     .+.+++++++++++++++++..     ",
"     ..+++++++++++++++++++..    ",
"     ..++++++++++++++++++++.    ",
"     .++++++++++++++++++++..    ",
"     ..+++++++++++++++++..      ",
"      .++++++++++++++++..       ",
"      ..+++++++++++++...        ",
"       .++++++++++++..          ",
"       ..+++++++++..            ",
"        .++++++++..             ",
"        ..++++++..              ",
"         .+++++..               ",
"          .++..                 ",
"           ...                  ",
"           ..                   ",
"                                ",
"                                "};

/*********************
 * Utility functions *
 *********************/

/*************************************************************
 * gtk_drag_get_ipc_widget:
 *     Return a invisible, off-screen, override-redirect
 *     widget for IPC.
 *   arguments:
 *     
 *   results:
 *************************************************************/

static GtkWidget *
gtk_drag_get_ipc_widget (void)
{
  GtkWidget *result;
  
  if (drag_widgets)
    {
      GSList *tmp = drag_widgets;
      result = drag_widgets->data;
      drag_widgets = drag_widgets->next;
      g_slist_free_1 (tmp);
    }
  else
    {
      result = gtk_invisible_new ();
      gtk_widget_show (result);
    }

  return result;
}

/***************************************************************
 * gtk_drag_release_ipc_widget:
 *     Releases widget retrieved with gtk_drag_get_ipc_widget ()
 *   arguments:
 *     widget: the widget to release.
 *   results:
 ***************************************************************/

static void
gtk_drag_release_ipc_widget (GtkWidget *widget)
{
  drag_widgets = g_slist_prepend (drag_widgets, widget);
}

static guint32
gtk_drag_get_event_time (GdkEvent *event)
{
  guint32 tm = GDK_CURRENT_TIME;
  
  if (event)
    switch (event->type)
      {
      case GDK_MOTION_NOTIFY:
	tm = event->motion.time; break;
      case GDK_BUTTON_PRESS:
      case GDK_2BUTTON_PRESS:
      case GDK_3BUTTON_PRESS:
      case GDK_BUTTON_RELEASE:
	tm = event->button.time; break;
      case GDK_KEY_PRESS:
      case GDK_KEY_RELEASE:
	tm = event->key.time; break;
      case GDK_ENTER_NOTIFY:
      case GDK_LEAVE_NOTIFY:
	tm = event->crossing.time; break;
      case GDK_PROPERTY_NOTIFY:
	tm = event->property.time; break;
      case GDK_SELECTION_CLEAR:
      case GDK_SELECTION_REQUEST:
      case GDK_SELECTION_NOTIFY:
	tm = event->selection.time; break;
      case GDK_PROXIMITY_IN:
      case GDK_PROXIMITY_OUT:
	tm = event->proximity.time; break;
      default:			/* use current time */
	break;
      }
  
  return tm;
}

static void
gtk_drag_get_event_actions (GdkEvent *event, 
			    gint button, 
			    GdkDragAction  actions,
			    GdkDragAction *suggested_action,
			    GdkDragAction *possible_actions)
{
  *suggested_action = 0;
  *possible_actions = 0;

  if (event)