Pileus Git - ~andy/gtk/blob - gtk/gtkclipboard.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 2000 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  *
  19  * Global clipboard abstraction.
  20  */
  21
  22 #include <string.h>
  23
  24 #include "gtkclipboard.h"
  25 #include "gtkinvisible.h"
  26 #include "gtkmain.h"
  27 #include "gtksignal.h"
  28
  29 #ifdef GDK_WINDOWING_X11
  30 #include "x11/gdkx.h"
  31 #endif
  32
  33 #ifdef GDK_WINDOWING_WIN32
  34 #include "win32/gdkwin32.h"
  35 #endif
  36
  37 typedef struct _RequestContentsInfo RequestContentsInfo;
  38 typedef struct _RequestTextInfo RequestTextInfo;
  39
  40 struct _GtkClipboard
  41 {
  42   GdkAtom selection;
  43
  44   GtkClipboardGetFunc get_func;
  45   GtkClipboardClearFunc clear_func;
  46   gpointer user_data;
  47   gboolean have_owner;
  48
  49   guint32 timestamp;
  50
  51   gboolean have_selection;
  52 };
  53
  54 struct _RequestContentsInfo
  55 {
  56   GtkClipboardReceivedFunc callback;
  57   gpointer user_data;
  58 };
  59
  60 struct _RequestTextInfo
  61 {
  62   GtkClipboardTextReceivedFunc callback;
  63   gpointer user_data;
  64 };
  65
  66 static void clipboard_unset    (GtkClipboard     *clipboard);
  67 static void selection_received (GtkWidget        *widget,
  68                                 GtkSelectionData *selection_data,
  69                                 guint             time);
  70
  71 static GSList *clipboards;
  72 static GtkWidget *clipboard_widget;
  73
  74 enum {
  75   TARGET_STRING,
  76   TARGET_TEXT,
  77   TARGET_COMPOUND_TEXT,
  78   TARGET_UTF8_STRING
  79 };
  80
  81 static const gchar *request_contents_key = "gtk-request-contents";
  82 static GQuark request_contents_key_id = 0;
  83
  84 static const gchar *clipboards_owned_key = "gtk-clipboards-owned";
  85 static GQuark clipboards_owned_key_id = 0;
  86
  87
  88 /**
  89  * gtk_clipboard_get:
  90  * @selection: a #GdkAtom which identifies the clipboard
  91  *             to use. A value of GDK_NONE here is the
  92  *             same as gdk_atom_intern ("CLIPBOARD", FALSE),
  93  *             and provides the default clipboard. Another
  94  *             common value is GDK_SELECTION_PRIMARY, which
  95  *             identifies the primary X selection.
  96  *
  97  * Returns the clipboard object for the given selection.
  98  *
  99  * Return value: the appropriate clipboard object. If no
 100  *             clipboard already exists, a new one will
 101  *             be created. Once a clipboard object has
 102  *             been created, it is persistant for all time.
 103  **/
 104 GtkClipboard *
 105 gtk_clipboard_get (GdkAtom selection)
 106 {
 107   GtkClipboard *clipboard = NULL;
 108   GSList *tmp_list;
 109
 110   if (selection == GDK_NONE)
 111     selection = gdk_atom_intern ("CLIPBOARD", FALSE);
 112
 113   tmp_list = clipboards;
 114   while (tmp_list)
 115     {
 116       clipboard = tmp_list->data;
 117       if (clipboard->selection == selection)
 118         break;
 119
 120       tmp_list = tmp_list->next;
 121     }
 122
 123   if (!tmp_list)
 124     {
 125       clipboard = g_new0 (GtkClipboard, 1);
 126       clipboard->selection = selection;
 127       clipboards = g_slist_prepend (clipboards, clipboard);
 128     }
 129
 130   return clipboard;
 131 }
 132
 133 static void
 134 selection_get_cb (GtkWidget          *widget,
 135                   GtkSelectionData   *selection_data,
 136                   guint               time,
 137                   guint               info)
 138 {
 139   GtkClipboard *clipboard = gtk_clipboard_get (selection_data->selection);
 140
 141   if (clipboard && clipboard->get_func)
 142     clipboard->get_func (clipboard, selection_data, info, clipboard->user_data);
 143 }
 144
 145 static gboolean
 146 selection_clear_event_cb (GtkWidget         *widget,
 147                           GdkEventSelection *event)
 148 {
 149   GtkClipboard *clipboard = gtk_clipboard_get (event->selection);
 150
 151   if (clipboard)
 152     {
 153       clipboard_unset (clipboard);
 154       return TRUE;
 155     }
 156
 157   return FALSE;
 158 }
 159
 160 static GtkWidget *
 161 make_clipboard_widget (gboolean provider)
 162 {
 163   GtkWidget *widget = gtk_invisible_new ();
 164
 165   gtk_signal_connect (GTK_OBJECT (widget), "selection_received",
 166                       GTK_SIGNAL_FUNC (selection_received), NULL);
 167
 168   if (provider)
 169     {
 170       /* We need this for gdk_x11_get_server_time() */
 171       gtk_widget_add_events (widget, GDK_PROPERTY_CHANGE_MASK);
 172
 173       gtk_signal_connect (GTK_OBJECT (widget), "selection_get",
 174                           GTK_SIGNAL_FUNC (selection_get_cb), NULL);
 175       gtk_signal_connect (GTK_OBJECT (widget), "selection_clear_event",
 176                           GTK_SIGNAL_FUNC (selection_clear_event_cb), NULL);
 177     }
 178
 179   return widget;
 180 }
 181
 182
 183 static void
 184 ensure_clipboard_widget ()
 185 {
 186   if (!clipboard_widget)
 187     clipboard_widget = make_clipboard_widget (TRUE);
 188 }
 189
 190 /* This function makes a very good guess at what the correct
 191  * timestamp for a selection request should be. If there is
 192  * a currently processed event, it uses the timestamp for that
 193  * event, otherwise it uses the current server time. However,
 194  * if the time resulting from that is older than the time used
 195  * last time, it uses the time used last time instead.
 196  *
 197  * In order implement this correctly, we never use CurrentTime,
 198  * but actually retrieve the actual timestamp from the server.
 199  * This is a little slower but allows us to make the guarantee
 200  * that the times used by this application will always ascend
 201  * and we won't get selections being rejected just because
 202  * we are using a correct timestamp from an event, but used
 203  * CurrentTime previously.
 204  */
 205 static guint32
 206 clipboard_get_timestamp (GtkClipboard *clipboard)
 207 {
 208   guint32 timestamp = gtk_get_current_event_time ();
 209
 210   ensure_clipboard_widget ();
 211
 212   if (timestamp == GDK_CURRENT_TIME)
 213     {
 214 #ifdef GDK_WINDOWING_X11
 215       timestamp = gdk_x11_get_server_time (clipboard_widget->window);
 216 #elif defined GDK_WINDOWING_WIN32
 217       timestamp = GetMessageTime ();
 218 #endif
 219     }
 220   else
 221     {
 222       if (clipboard->timestamp != GDK_CURRENT_TIME)
 223         {
 224           /* Check to see if clipboard->timestamp is newer than
 225            * timestamp, accounting for wraparound.
 226            */
 227
 228           guint32 max = timestamp + 0x80000000;
 229
 230           if ((max > timestamp &&
 231                (clipboard->timestamp > timestamp &&
 232                 clipboard->timestamp <= max)) ||
 233               (max <= timestamp &&
 234                (clipboard->timestamp > timestamp ||
 235                 clipboard->timestamp <= max)))
 236             {
 237               timestamp = clipboard->timestamp;
 238             }
 239         }
 240     }
 241
 242   clipboard->timestamp = timestamp;
 243
 244   return timestamp;
 245 }
 246
 247 static void
 248 clipboard_owner_destroyed (gpointer data)
 249 {
 250   GSList *clipboards = data;
 251   GSList *tmp_list;
 252
 253   tmp_list = clipboards;
 254   while (tmp_list)
 255     {
 256       GtkClipboard *clipboard = tmp_list->data;
 257
 258       clipboard->get_func = NULL;
 259       clipboard->clear_func = NULL;
 260       clipboard->user_data = NULL;
 261       clipboard->have_owner = FALSE;
 262
 263       gtk_clipboard_clear (clipboard);
 264
 265       tmp_list = tmp_list->next;
 266     }
 267
 268   g_slist_free (clipboards);
 269 }
 270
 271 static void
 272 clipboard_add_owner_notify (GtkClipboard *clipboard)
 273 {
 274   if (!clipboards_owned_key_id)
 275     clipboards_owned_key_id = g_quark_from_static_string (clipboards_owned_key);
 276
 277   if (clipboard->have_owner)
 278     g_object_set_qdata_full (clipboard->user_data, clipboards_owned_key_id,
 279                              g_slist_prepend (g_object_steal_qdata (clipboard->user_data,
 280                                                                     clipboards_owned_key_id),
 281                                               clipboard),
 282                              clipboard_owner_destroyed);
 283 }
 284
 285 static void
 286 clipboard_remove_owner_notify (GtkClipboard *clipboard)
 287 {
 288   if (clipboard->have_owner)
 289      g_object_set_qdata_full (clipboard->user_data, clipboards_owned_key_id,
 290                               g_slist_remove (g_object_steal_qdata (clipboard->user_data,
 291                                                                     clipboards_owned_key_id),
 292                                               clipboard),
 293                               clipboard_owner_destroyed);
 294 }
 295
 296 static gboolean
 297 gtk_clipboard_set_contents (GtkClipboard         *clipboard,
 298                             const GtkTargetEntry *targets,
 299                             guint                 n_targets,
 300                             GtkClipboardGetFunc   get_func,
 301                             GtkClipboardClearFunc clear_func,
 302                             gpointer              user_data,
 303                             gboolean              have_owner)
 304 {
 305   ensure_clipboard_widget ();
 306
 307   if (gtk_selection_owner_set (clipboard_widget, clipboard->selection,
 308                                clipboard_get_timestamp (clipboard)))
 309     {
 310       clipboard->have_selection = TRUE;
 311
 312       if (!(clipboard->have_owner && have_owner) ||
 313           clipboard->user_data != user_data)
 314         {
 315           clipboard_unset (clipboard);
 316
 317           if (clipboard->get_func)
 318             {
 319               /* Calling unset() caused the clipboard contents to be reset!
 320                * Avoid leaking and return
 321                */
 322               if (!(clipboard->have_owner && have_owner) ||
 323                   clipboard->user_data != user_data)
 324                 {
 325                   (*clear_func) (clipboard, user_data);
 326                   return FALSE;
 327                 }
 328               else
 329                 return TRUE;
 330             }
 331           else
 332             {
 333               clipboard->user_data = user_data;
 334               clipboard->have_owner = have_owner;
 335               if (have_owner)
 336                 clipboard_add_owner_notify (clipboard);
 337             }
 338
 339         }
 340
 341       clipboard->get_func = get_func;
 342       clipboard->clear_func = clear_func;
 343
 344       gtk_selection_clear_targets (clipboard_widget, clipboard->selection);
 345       gtk_selection_add_targets (clipboard_widget, clipboard->selection,
 346                                  targets, n_targets);
 347
 348       return TRUE;
 349     }
 350   else
 351     return FALSE;
 352 }
 353
 354 /**
 355  * gtk_clipboard_set_with_data:
 356  * @clipboard:  a #GtkClipboard
 357  * @targets:    array containing information about the available forms for the
 358  *              clipboard data
 359  * @n_targets:  number of elements in @targets
 360  * @get_func:   function to call to get the actual clipboard data
 361  * @clear_func: when the clipboard contents are set again, this function will
 362  *              be called, and get_func will not be subsequently called.
 363  * @user_data:  user data to pass to @get_func and @clear_func.
 364  *
 365  * Virtually set the contents of the specified clipboard by providing
 366  * a list of supported formats for the clipboard data and a function
 367  * to call to get the actual data when it is requested.
 368  *
 369  * Return value: %TRUE if setting the clipboard data succeeded. If setting
 370  *               the clipboard data failed the provided callback functions
 371  *               will be ignored.
 372  **/
 373 gboolean
 374 gtk_clipboard_set_with_data (GtkClipboard          *clipboard,
 375                              const GtkTargetEntry  *targets,
 376                              guint                  n_targets,
 377                              GtkClipboardGetFunc    get_func,
 378                              GtkClipboardClearFunc  clear_func,
 379                              gpointer               user_data)
 380 {
 381   g_return_val_if_fail (clipboard != NULL, FALSE);
 382   g_return_val_if_fail (targets != NULL, FALSE);
 383   g_return_val_if_fail (get_func != NULL, FALSE);
 384
 385   return gtk_clipboard_set_contents (clipboard, targets, n_targets,
 386                                      get_func, clear_func, user_data,
 387                                      FALSE);
 388 }
 389
 390 /**
 391  * gtk_clipboard_set_with_owner:
 392  * @clipboard:  a #GtkClipboard
 393  * @targets:    array containing information about the available forms for the
 394  *              clipboard data
 395  * @n_targets:  number of elements in @targets
 396  * @get_func:   function to call to get the actual clipboard data
 397  * @clear_func: when the clipboard contents are set again, this function will
 398  *              be called, and get_func will not be subsequently called.
 399  * @owner:      an object that "owns" the data. This object will be passed
 400  *              to the callbacks when called.
 401  *
 402  * Virtually set the contents of the specified clipboard by providing
 403  * a list of supported formats for the clipboard data and a function
 404  * to call to get the actual data when it is requested.
 405  *
 406  * The difference between this function and gtk_clipboard_set_with_data
 407  * is that instead of an generic @user_data pointer, a #GObject is passed
 408  * in. Because of this,
 409  *
 410  * Return value: %TRUE if setting the clipboard data succeeded. If setting
 411  *               the clipboard data failed the provided callback functions
 412  *               will be ignored.
 413  **/
 414 gboolean
 415 gtk_clipboard_set_with_owner (GtkClipboard          *clipboard,
 416                               const GtkTargetEntry  *targets,
 417                               guint                  n_targets,
 418                               GtkClipboardGetFunc    get_func,
 419                               GtkClipboardClearFunc  clear_func,
 420                               GObject               *owner)
 421 {
 422   g_return_val_if_fail (clipboard != NULL, FALSE);
 423   g_return_val_if_fail (targets != NULL, FALSE);
 424   g_return_val_if_fail (get_func != NULL, FALSE);
 425   g_return_val_if_fail (G_IS_OBJECT (owner), FALSE);
 426
 427   return gtk_clipboard_set_contents (clipboard, targets, n_targets,
 428                                      get_func, clear_func, owner,
 429                                      TRUE);
 430 }
 431
 432 /**
 433  * gtk_clipboard_get_owner:
 434  * @clipboard: a #GtkClipboard
 435  *
 436  * If the clipboard contents callbacks were set with gtk_clipboard_set_owner(),
 437  * and the gtk_clipboard_set_with_data() or gtk_clipboard_clear() has not
 438  * subsequently called, returns the @owner set by gtk_clipboard_set_owner().
 439  *
 440  * Return value: the owner of the clipboard, if any; otherwise %NULL.
 441  **/
 442 GObject *
 443 gtk_clipboard_get_owner (GtkClipboard *clipboard)
 444 {
 445   g_return_val_if_fail (clipboard != NULL, NULL);
 446
 447   if (clipboard->have_owner)
 448     return clipboard->user_data;
 449   else
 450     return NULL;
 451 }
 452
 453 static void
 454 clipboard_unset (GtkClipboard *clipboard)
 455 {
 456   GtkClipboardClearFunc old_clear_func;
 457   gpointer old_data;
 458
 459   old_clear_func = clipboard->clear_func;
 460   old_data = clipboard->user_data;
 461
 462   if (clipboard->have_owner)
 463     {
 464       clipboard_remove_owner_notify (clipboard);
 465       clipboard->have_owner = FALSE;
 466     }
 467
 468   clipboard->get_func = NULL;
 469   clipboard->clear_func = NULL;
 470   clipboard->user_data = NULL;
 471
 472   if (old_clear_func)
 473     old_clear_func (clipboard, old_data);
 474 }
 475
 476 /**
 477  * gtk_clipboard_clear:
 478  * @clipboard:  a #GtkClipboard
 479  *
 480  * Clear the contents of the clipboard. Generally this should only
 481  * be called between the time you call gtk_clipboard_set_contents(),
 482  * and when the @clear_func you supplied is called. Otherwise, the
 483  * clipboard may be owned by someone else.
 484  **/
 485 void
 486 gtk_clipboard_clear (GtkClipboard *clipboard)
 487 {
 488   g_return_if_fail (clipboard != NULL);
 489
 490   if (clipboard->have_selection)
 491     gtk_selection_owner_set (NULL, clipboard->selection,
 492                              clipboard_get_timestamp (clipboard));
 493 }
 494
 495 static void
 496 text_get_func (GtkClipboard     *clipboard,
 497                GtkSelectionData *selection_data,
 498                guint             info,
 499                gpointer          data)
 500 {
 501   gtk_selection_data_set_text (selection_data, data);
 502 }
 503
 504 static void
 505 text_clear_func (GtkClipboard *clipboard,
 506                  gpointer      data)
 507 {
 508   g_free (data);
 509 }
 510
 511 /**
 512  * gtk_clipboard_set_text:
 513  * @clipboard: a #GtkClipboard object
 514  * @text:      a UTF-8 string.
 515  * @len:       length of @text, in bytes, or -1, in which case
 516  *             the length will be determined with strlen().
 517  *
 518  * Set the contents of the clipboard to the given UTF-8 string. GTK+ will
 519  * make a copy of the text and take responsibility for responding
 520  * for requests for the text, and for converting the text into
 521  * the requested format.
 522  **/
 523 void
 524 gtk_clipboard_set_text (GtkClipboard *clipboard,
 525                         const gchar  *text,
 526                         gint          len)
 527 {
 528   static const GtkTargetEntry targets[] = {
 529     { "STRING", 0, TARGET_STRING },
 530     { "TEXT",   0, TARGET_TEXT },
 531     { "COMPOUND_TEXT", 0, TARGET_COMPOUND_TEXT },
 532     { "UTF8_STRING", 0, TARGET_UTF8_STRING }
 533   };
 534
 535   g_return_if_fail (clipboard != NULL);
 536   g_return_if_fail (text != NULL);
 537
 538   if (len < 0)
 539     len = strlen (text);
 540
 541   gtk_clipboard_set_with_data (clipboard,
 542                                targets, G_N_ELEMENTS (targets),
 543                                text_get_func, text_clear_func,
 544                                g_strndup (text, len));
 545 }
 546
 547 static void
 548 set_request_contents_info (GtkWidget           *widget,
 549                            RequestContentsInfo *info)
 550 {
 551   if (!request_contents_key_id)
 552     request_contents_key_id = g_quark_from_static_string (request_contents_key);
 553
 554   gtk_object_set_data_by_id (GTK_OBJECT (widget),
 555                              request_contents_key_id,
 556                              info);
 557 }
 558
 559 static RequestContentsInfo *
 560 get_request_contents_info (GtkWidget *widget)
 561 {
 562   if (!request_contents_key_id)
 563     return NULL;
 564   else
 565     return gtk_object_get_data_by_id (GTK_OBJECT (widget),
 566                                       request_contents_key_id);
 567 }
 568
 569 static void
 570 selection_received (GtkWidget            *widget,
 571                     GtkSelectionData     *selection_data,
 572                     guint                 time)
 573 {
 574   RequestContentsInfo *request_info = get_request_contents_info (widget);
 575   set_request_contents_info (widget, NULL);
 576
 577   request_info->callback (gtk_clipboard_get (selection_data->selection),
 578                           selection_data,
 579                           request_info->user_data);
 580
 581   g_free (request_info);
 582
 583   if (widget != clipboard_widget)
 584     gtk_widget_destroy (widget);
 585 }
 586
 587 /**
 588  * gtk_clipboard_request_contents:
 589  * @clipboard: a #GtkClipboard
 590  * @target:    an atom representing the form into which the clipboard
 591  *             owner should convert the selection.
 592  * @callback:  A function to call when the results are received
 593  *             (or the retrieval fails.) If the retrieval fails
 594  *             the length field of @selection_data will be
 595  *             negative.
 596  * @user_data: user data to pass to @callback
 597  *
 598  * Requests the contents of clipboard as the given target.
 599  * When the results of the result are later received the supplied callback
 600  * will be called.
 601  **/
 602 void
 603 gtk_clipboard_request_contents (GtkClipboard            *clipboard,
 604                                 GdkAtom                  target,
 605                                 GtkClipboardReceivedFunc callback,
 606                                 gpointer                 user_data)
 607 {
 608   RequestContentsInfo *info;
 609   GtkWidget *widget;
 610
 611   g_return_if_fail (clipboard != NULL);
 612   g_return_if_fail (target != GDK_NONE);
 613   g_return_if_fail (callback != NULL);
 614
 615   ensure_clipboard_widget ();
 616
 617   if (get_request_contents_info (clipboard_widget))
 618     widget = make_clipboard_widget (FALSE);
 619   else
 620     widget = clipboard_widget;
 621
 622   info = g_new (RequestContentsInfo, 1);
 623   info->callback = callback;
 624   info->user_data = user_data;
 625
 626   set_request_contents_info (widget, info);
 627
 628   gtk_selection_convert (widget, clipboard->selection, target,
 629                          clipboard_get_timestamp (clipboard));
 630 }
 631
 632 static void
 633 request_text_received_func (GtkClipboard     *clipboard,
 634                             GtkSelectionData *selection_data,
 635                             gpointer          data)
 636 {
 637   RequestTextInfo *info = data;
 638   gchar *result = NULL;
 639
 640   result = gtk_selection_data_get_text (selection_data);
 641
 642   if (!result)
 643     {
 644       /* If we asked for UTF8 and didn't get it, try text; if we asked
 645        * for text and didn't get it, try string.  If we asked for
 646        * anything else and didn't get it, give up.
 647        */
 648       if (selection_data->target == gdk_atom_intern ("UTF8_STRING", FALSE))
 649         {
 650           gtk_clipboard_request_contents (clipboard,
 651                                           gdk_atom_intern ("TEXT", FALSE),
 652                                           request_text_received_func, info);
 653           return;
 654         }
 655       else if (selection_data->target == gdk_atom_intern ("TEXT", FALSE))
 656         {
 657           gtk_clipboard_request_contents (clipboard,
 658                                           GDK_TARGET_STRING,
 659                                           request_text_received_func, info);
 660           return;
 661         }
 662     }
 663
 664   info->callback (clipboard, result, info->user_data);
 665   g_free (info);
 666   g_free (result);
 667 }
 668
 669 /**
 670  * gtk_clipboard_request_text:
 671  * @clipboard: a #GtkClipboard
 672  * @callback:  a function to call when the text is received,
 673  *             or the retrieval fails. (It will always be called
 674  *             one way or the other.)
 675  * @user_data: user data to pass to @callback.
 676  *
 677  * Requests the contents of the clipboard as text. When the text is
 678  * later received, it will be converted to UTF-8 if necessary, and
 679  * @callback will be called.
 680  *
 681  * The @text parameter to @callback will contain the resulting text if
 682  * the request succeeded, or %NULL if it failed. This could happen for
 683  * various reasons, in particular if the clipboard was empty or if the
 684  * contents of the clipboard could not be converted into text form.
 685  **/
 686 void
 687 gtk_clipboard_request_text (GtkClipboard                *clipboard,
 688                             GtkClipboardTextReceivedFunc callback,
 689                             gpointer                     user_data)
 690 {
 691   RequestTextInfo *info;
 692
 693   g_return_if_fail (clipboard != NULL);
 694   g_return_if_fail (callback != NULL);
 695
 696   info = g_new (RequestTextInfo, 1);
 697   info->callback = callback;
 698   info->user_data = user_data;
 699
 700   gtk_clipboard_request_contents (clipboard, gdk_atom_intern ("UTF8_STRING", FALSE),
 701                                   request_text_received_func,
 702                                   info);
 703 }
 704
 705
 706 typedef struct
 707 {
 708   GMainLoop *loop;
 709   gpointer data;
 710 } WaitResults;
 711
 712 static void
 713 clipboard_received_func (GtkClipboard     *clipboard,
 714                          GtkSelectionData *selection_data,
 715                          gpointer          data)
 716 {
 717   WaitResults *results = data;
 718
 719   if (selection_data->length >= 0)
 720     results->data = gtk_selection_data_copy (selection_data);
 721
 722   g_main_quit (results->loop);
 723 }
 724
 725 /**
 726  * gtk_clipboard_wait_for_contents:
 727  * @clipboard: a #GtkClipboard
 728  * @target: an atom representing the form into which the clipboard
 729  *          owner should convert the selection.
 730  *
 731  * Requests the contents of the clipboard using the given target.
 732  * This function waits for the data to be received using the main
 733  * loop, so events, timeouts, etc, may be dispatched during the wait.
 734  *
 735  * Return value: a newly allocated #GtkSelectionData object or %NULL
 736  *               if retrieving the given target failed. If non-%NULL,
 737  *               this value freed with gtk_selection_data_free() when
 738  *               you are finished with it.
 739  **/
 740 GtkSelectionData *
 741 gtk_clipboard_wait_for_contents (GtkClipboard *clipboard,
 742                                  GdkAtom       target)
 743 {
 744   WaitResults results;
 745
 746   g_return_val_if_fail (clipboard != NULL, NULL);
 747   g_return_val_if_fail (target != GDK_NONE, NULL);
 748
 749   results.data = NULL;
 750   results.loop = g_main_new (TRUE);
 751
 752   gtk_clipboard_request_contents (clipboard, target,
 753                                   clipboard_received_func,
 754                                   &results);
 755
 756   if (g_main_is_running (results.loop))
 757     {
 758       GDK_THREADS_LEAVE ();
 759       g_main_run (results.loop);
 760       GDK_THREADS_ENTER ();
 761     }
 762
 763   g_main_destroy (results.loop);
 764
 765   return results.data;
 766 }
 767
 768 static void
 769 clipboard_text_received_func (GtkClipboard *clipboard,
 770                               const gchar  *text,
 771                               gpointer      data)
 772 {
 773   WaitResults *results = data;
 774
 775   results->data = g_strdup (text);
 776   g_main_quit (results->loop);
 777 }
 778
 779
 780 /**
 781  * gtk_clipboard_wait_for_text:
 782  * @clipboard: a #GtkClipboard
 783  *
 784  * Requests the contents of the clipboard as text and converts
 785  * the result to UTF-8 if necessary. This function waits for
 786  * the data to be received using the main loop, so events,
 787  * timeouts, etc, may be dispatched during the wait.
 788  *
 789  * Return value: a newly allocated UTF-8 string which must
 790  *               be freed with g_free(), or %NULL if retrieving
 791  *               the selection data failed. (This could happen
 792  *               for various reasons, in particular if the
 793  *               clipboard was empty or if the contents of the
 794  *               clipboard could not be converted into text form.)
 795  **/
 796 gchar *
 797 gtk_clipboard_wait_for_text (GtkClipboard *clipboard)
 798 {
 799   WaitResults results;
 800
 801   g_return_val_if_fail (clipboard != NULL, NULL);
 802   g_return_val_if_fail (clipboard != NULL, NULL);
 803
 804   results.data = NULL;
 805   results.loop = g_main_new (TRUE);
 806
 807   gtk_clipboard_request_text (clipboard,
 808                               clipboard_text_received_func,
 809                               &results);
 810
 811   if (g_main_is_running (results.loop))
 812     {
 813       GDK_THREADS_LEAVE ();
 814       g_main_run (results.loop);
 815       GDK_THREADS_ENTER ();
 816     }
 817
 818   g_main_destroy (results.loop);
 819
 820   return results.data;
 821 }
 822