1 /* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
2 
3 /* nemo-clipboard.c
4  *
5  * Nemo Clipboard support.  For now, routines to support component cut
6  * and paste.
7  *
8  * Copyright (C) 1999, 2000  Free Software Foundaton
9  * Copyright (C) 2000, 2001  Eazel, Inc.
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Library General Public License as
13  * published by the Free Software Foundation; either version 2 of the
14  * License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * Library General Public License for more details.
20  *
21  * You should have received a copy of the GNU Library General Public
22  * License along with this program; if not, write to the
23  * Free Software Foundation, Inc., 51 Franklin Street - Suite 500,
24  * Boston, MA 02110-1335, USA.
25  *
26  * Authors: Rebecca Schulman <rebecka@eazel.com>,
27  *          Darin Adler <darin@bentspoon.com>
28  */
29 
30 #include <config.h>
31 #include "nemo-clipboard.h"
32 #include "nemo-file-utilities.h"
33 
34 #include <glib/gi18n.h>
35 #include <gtk/gtk.h>
36 #include <string.h>
37 
38 typedef struct _TargetCallbackData TargetCallbackData;
39 
40 typedef void (* SelectAllCallback)    (gpointer target);
41 typedef void (* ConnectCallbacksFunc) (GObject            *object,
42 				       TargetCallbackData *target_data);
43 
44 static void selection_changed_callback            (GtkWidget *widget,
45 						   gpointer callback_data);
46 static void owner_change_callback (GtkClipboard        *clipboard,
47 				   GdkEventOwnerChange *event,
48 				   gpointer callback_data);
49 struct _TargetCallbackData {
50 	GtkUIManager *ui_manager;
51 	GtkActionGroup *action_group;
52 	gboolean shares_selection_changes;
53 
54 	SelectAllCallback select_all_callback;
55 
56 	ConnectCallbacksFunc connect_callbacks;
57 	ConnectCallbacksFunc disconnect_callbacks;
58 };
59 
60 static void
cut_callback(gpointer target)61 cut_callback (gpointer target)
62 {
63 	g_assert (target != NULL);
64 
65 	g_signal_emit_by_name (target, "cut-clipboard");
66 }
67 
68 static void
copy_callback(gpointer target)69 copy_callback (gpointer target)
70 {
71 	g_assert (target != NULL);
72 
73 	g_signal_emit_by_name (target, "copy-clipboard");
74 }
75 
76 static void
paste_callback(gpointer target)77 paste_callback (gpointer target)
78 {
79 	g_assert (target != NULL);
80 
81 	g_signal_emit_by_name (target, "paste-clipboard");
82 }
83 
84 static void
editable_select_all_callback(gpointer target)85 editable_select_all_callback (gpointer target)
86 {
87 	GtkEditable *editable;
88 
89 	editable = GTK_EDITABLE (target);
90 	g_assert (editable != NULL);
91 
92 	gtk_editable_set_position (editable, -1);
93 	gtk_editable_select_region (editable, 0, -1);
94 }
95 
96 static void
text_view_select_all_callback(gpointer target)97 text_view_select_all_callback (gpointer target)
98 {
99 	g_assert (GTK_IS_TEXT_VIEW (target));
100 
101 	g_signal_emit_by_name (target, "select-all", TRUE);
102 }
103 
104 static void
action_cut_callback(GtkAction * action,gpointer callback_data)105 action_cut_callback (GtkAction *action,
106 		     gpointer callback_data)
107 {
108 	cut_callback (callback_data);
109 }
110 
111 static void
action_copy_callback(GtkAction * action,gpointer callback_data)112 action_copy_callback (GtkAction *action,
113 		      gpointer callback_data)
114 {
115 	copy_callback (callback_data);
116 }
117 
118 static void
action_paste_callback(GtkAction * action,gpointer callback_data)119 action_paste_callback (GtkAction *action,
120 		       gpointer callback_data)
121 {
122 	paste_callback (callback_data);
123 }
124 
125 static void
action_select_all_callback(GtkAction * action,gpointer callback_data)126 action_select_all_callback (GtkAction *action,
127 			    gpointer callback_data)
128 {
129 	TargetCallbackData *target_data;
130 
131 	g_assert (callback_data != NULL);
132 
133 	target_data = g_object_get_data (callback_data, "Nemo:clipboard_target_data");
134 	g_assert (target_data != NULL);
135 
136 	target_data->select_all_callback (callback_data);
137 }
138 
139 static void
received_clipboard_contents(GtkClipboard * clipboard,GtkSelectionData * selection_data,gpointer data)140 received_clipboard_contents (GtkClipboard     *clipboard,
141 			     GtkSelectionData *selection_data,
142 			     gpointer          data)
143 {
144 	GtkActionGroup *action_group;
145 	GtkAction *action;
146 
147 	action_group = data;
148 
149 	action = gtk_action_group_get_action (action_group,
150 					      "Paste");
151 	if (action != NULL) {
152 		gtk_action_set_sensitive (action,
153 					  gtk_selection_data_targets_include_text (selection_data));
154 	}
155 
156 	g_object_unref (action_group);
157 }
158 
159 
160 static void
set_paste_sensitive_if_clipboard_contains_data(GtkActionGroup * action_group)161 set_paste_sensitive_if_clipboard_contains_data (GtkActionGroup *action_group)
162 {
163 	GtkAction *action;
164 	if (gdk_display_supports_selection_notification (gdk_display_get_default ())) {
165 		gtk_clipboard_request_contents (gtk_clipboard_get (GDK_SELECTION_CLIPBOARD),
166 						gdk_atom_intern ("TARGETS", FALSE),
167 						received_clipboard_contents,
168 						g_object_ref (action_group));
169 	} else {
170 		/* If selection notification isn't supported, always activate Paste */
171 		action = gtk_action_group_get_action (action_group,
172 						      "Paste");
173 		gtk_action_set_sensitive (action, TRUE);
174 	}
175 }
176 
177 static void
set_clipboard_menu_items_sensitive(GtkActionGroup * action_group)178 set_clipboard_menu_items_sensitive (GtkActionGroup *action_group)
179 {
180 	GtkAction *action;
181 
182 	action = gtk_action_group_get_action (action_group,
183 					      "Cut");
184 	gtk_action_set_sensitive (action, TRUE);
185 	action = gtk_action_group_get_action (action_group,
186 					      "Copy");
187 	gtk_action_set_sensitive (action, TRUE);
188 }
189 
190 static void
set_clipboard_menu_items_insensitive(GtkActionGroup * action_group)191 set_clipboard_menu_items_insensitive (GtkActionGroup *action_group)
192 {
193 	GtkAction *action;
194 
195 	action = gtk_action_group_get_action (action_group,
196 					      "Cut");
197 	gtk_action_set_sensitive (action, FALSE);
198 	action = gtk_action_group_get_action (action_group,
199 					      "Copy");
200 	gtk_action_set_sensitive (action, FALSE);
201 }
202 
203 static gboolean
clipboard_items_are_merged_in(GtkWidget * widget)204 clipboard_items_are_merged_in (GtkWidget *widget)
205 {
206 	return GPOINTER_TO_INT (g_object_get_data (G_OBJECT (widget),
207 						   "Nemo:clipboard_menu_items_merged"));
208 }
209 
210 static void
set_clipboard_items_are_merged_in(GObject * widget_as_object,gboolean merged_in)211 set_clipboard_items_are_merged_in (GObject *widget_as_object,
212 				   gboolean merged_in)
213 {
214 	g_object_set_data (widget_as_object,
215 			   "Nemo:clipboard_menu_items_merged",
216 			   GINT_TO_POINTER (merged_in));
217 }
218 
219 static void
editable_connect_callbacks(GObject * object,TargetCallbackData * target_data)220 editable_connect_callbacks (GObject *object,
221 			    TargetCallbackData *target_data)
222 {
223 	g_signal_connect_after (object, "selection_changed",
224 				G_CALLBACK (selection_changed_callback), target_data);
225 	selection_changed_callback (GTK_WIDGET (object),
226 				    target_data);
227 }
228 
229 static void
editable_disconnect_callbacks(GObject * object,TargetCallbackData * target_data)230 editable_disconnect_callbacks (GObject *object,
231 			       TargetCallbackData *target_data)
232 {
233 	g_signal_handlers_disconnect_matched (object,
234 					      G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
235 					      0, 0, NULL,
236 					      G_CALLBACK (selection_changed_callback),
237 					      target_data);
238 }
239 
240 static void
text_buffer_update_sensitivity(GtkTextBuffer * buffer,TargetCallbackData * target_data)241 text_buffer_update_sensitivity (GtkTextBuffer *buffer,
242 				TargetCallbackData *target_data)
243 {
244 	g_assert (GTK_IS_TEXT_BUFFER (buffer));
245 	g_assert (target_data != NULL);
246 
247 	if (gtk_text_buffer_get_selection_bounds (buffer, NULL, NULL)) {
248 		set_clipboard_menu_items_sensitive (target_data->action_group);
249 	} else {
250 		set_clipboard_menu_items_insensitive (target_data->action_group);
251 	}
252 }
253 
254 static void
text_buffer_delete_range(GtkTextBuffer * buffer,GtkTextIter * iter1,GtkTextIter * iter2,TargetCallbackData * target_data)255 text_buffer_delete_range (GtkTextBuffer *buffer,
256 			  GtkTextIter   *iter1,
257 			  GtkTextIter   *iter2,
258 			  TargetCallbackData *target_data)
259 {
260 	text_buffer_update_sensitivity (buffer, target_data);
261 }
262 
263 static void
text_buffer_mark_set(GtkTextBuffer * buffer,GtkTextIter * iter,GtkTextMark * mark,TargetCallbackData * target_data)264 text_buffer_mark_set (GtkTextBuffer *buffer,
265 		      GtkTextIter *iter,
266 		      GtkTextMark *mark,
267 		      TargetCallbackData *target_data)
268 {
269 	/* anonymous marks with NULL names refer to cursor moves */
270 	if (gtk_text_mark_get_name (mark) != NULL) {
271 		text_buffer_update_sensitivity (buffer, target_data);
272 	}
273 }
274 
275 static void
text_view_connect_callbacks(GObject * object,TargetCallbackData * target_data)276 text_view_connect_callbacks (GObject *object,
277 			     TargetCallbackData *target_data)
278 {
279 	GtkTextBuffer *buffer;
280 
281 	buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (object));
282 	g_assert (buffer);
283 
284 	g_signal_connect_after (buffer, "mark-set",
285 				G_CALLBACK (text_buffer_mark_set), target_data);
286 	g_signal_connect_after (buffer, "delete-range",
287 				G_CALLBACK (text_buffer_delete_range), target_data);
288 	text_buffer_update_sensitivity (buffer, target_data);
289 }
290 
291 static void
text_view_disconnect_callbacks(GObject * object,TargetCallbackData * target_data)292 text_view_disconnect_callbacks (GObject *object,
293 				TargetCallbackData *target_data)
294 {
295 	GtkTextBuffer *buffer;
296 
297 	buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (object));
298 	g_assert (buffer);
299 
300 	g_signal_handlers_disconnect_matched (buffer,
301 					      G_SIGNAL_MATCH_DATA,
302 					      0, 0, NULL, NULL,
303 					      target_data);
304 }
305 
306 static void
merge_in_clipboard_menu_items(GObject * widget_as_object,TargetCallbackData * target_data)307 merge_in_clipboard_menu_items (GObject *widget_as_object,
308 			       TargetCallbackData *target_data)
309 {
310 	gboolean add_selection_callback;
311 
312 	g_assert (target_data != NULL);
313 
314 	add_selection_callback = target_data->shares_selection_changes;
315 
316 	gtk_ui_manager_insert_action_group (target_data->ui_manager,
317 					    target_data->action_group, 0);
318 
319 	set_paste_sensitive_if_clipboard_contains_data (target_data->action_group);
320 
321 	g_signal_connect (gtk_clipboard_get (GDK_SELECTION_CLIPBOARD), "owner_change",
322 			  G_CALLBACK (owner_change_callback), target_data);
323 
324 	if (add_selection_callback) {
325 		target_data->connect_callbacks (widget_as_object, target_data);
326 	} else {
327 		/* If we don't use sensitivity, everything should be on */
328 		set_clipboard_menu_items_sensitive (target_data->action_group);
329 	}
330 	set_clipboard_items_are_merged_in (widget_as_object, TRUE);
331 }
332 
333 static void
merge_out_clipboard_menu_items(GObject * widget_as_object,TargetCallbackData * target_data)334 merge_out_clipboard_menu_items (GObject *widget_as_object,
335 				TargetCallbackData *target_data)
336 
337 {
338 	gboolean selection_callback_was_added;
339 
340 	g_assert (target_data != NULL);
341 
342 	gtk_ui_manager_remove_action_group (target_data->ui_manager,
343 					    target_data->action_group);
344 
345 	g_signal_handlers_disconnect_matched (gtk_clipboard_get (GDK_SELECTION_CLIPBOARD),
346 					      G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
347 					      0, 0, NULL,
348 					      G_CALLBACK (owner_change_callback),
349 					      target_data);
350 
351 	selection_callback_was_added = target_data->shares_selection_changes;
352 
353 	if (selection_callback_was_added) {
354 		target_data->disconnect_callbacks (widget_as_object, target_data);
355 	}
356 	set_clipboard_items_are_merged_in (widget_as_object, FALSE);
357 }
358 
359 static gboolean
focus_changed_callback(GtkWidget * widget,GdkEventAny * event,gpointer callback_data)360 focus_changed_callback (GtkWidget *widget,
361 			GdkEventAny *event,
362 			gpointer callback_data)
363 {
364 	/* Connect the component to the container if the widget has focus. */
365 	if (gtk_widget_has_focus (widget)) {
366 		if (!clipboard_items_are_merged_in (widget)) {
367 			merge_in_clipboard_menu_items (G_OBJECT (widget), callback_data);
368 		}
369 	} else {
370 		if (clipboard_items_are_merged_in (widget)) {
371 			merge_out_clipboard_menu_items (G_OBJECT (widget), callback_data);
372 		}
373 	}
374 
375 	return FALSE;
376 }
377 
378 static void
selection_changed_callback(GtkWidget * widget,gpointer callback_data)379 selection_changed_callback (GtkWidget *widget,
380 			    gpointer callback_data)
381 {
382 	TargetCallbackData *target_data;
383 	GtkEditable *editable;
384 	int start, end;
385 
386 	target_data = (TargetCallbackData *) callback_data;
387 	g_assert (target_data != NULL);
388 
389 	editable = GTK_EDITABLE (widget);
390 	g_assert (editable != NULL);
391 
392 	if (gtk_editable_get_selection_bounds (editable, &start, &end) && start != end) {
393 		set_clipboard_menu_items_sensitive (target_data->action_group);
394 	} else {
395 		set_clipboard_menu_items_insensitive (target_data->action_group);
396 	}
397 }
398 
399 static void
owner_change_callback(GtkClipboard * clipboard,GdkEventOwnerChange * event,gpointer callback_data)400 owner_change_callback (GtkClipboard        *clipboard,
401 		       GdkEventOwnerChange *event,
402 		       gpointer callback_data)
403 {
404 	TargetCallbackData *target_data;
405 
406 	g_assert (callback_data != NULL);
407 	target_data = callback_data;
408 
409 	set_paste_sensitive_if_clipboard_contains_data (target_data->action_group);
410 }
411 
412 static void
target_destroy_callback(GtkWidget * object,gpointer callback_data)413 target_destroy_callback (GtkWidget *object,
414 			 gpointer callback_data)
415 {
416 	g_assert (callback_data != NULL);
417 
418 	if (clipboard_items_are_merged_in (object)) {
419 		merge_out_clipboard_menu_items (G_OBJECT (object), callback_data);
420 	}
421 }
422 
423 static void
target_data_free(TargetCallbackData * target_data)424 target_data_free (TargetCallbackData *target_data)
425 {
426 	g_object_unref (target_data->action_group);
427 	g_free (target_data);
428 }
429 
430 static const GtkActionEntry clipboard_entries[] = {
431   /* name, stock id */      { "Cut", GTK_STOCK_CUT,
432   /* label, accelerator */    NULL, NULL,
433   /* tooltip */               N_("Cut the selected text to the clipboard"),
434                               G_CALLBACK (action_cut_callback) },
435   /* name, stock id */      { "Copy", GTK_STOCK_COPY,
436   /* label, accelerator */    NULL, NULL,
437   /* tooltip */               N_("Copy the selected text to the clipboard"),
438                               G_CALLBACK (action_copy_callback) },
439   /* name, stock id */      { "Paste", GTK_STOCK_PASTE,
440   /* label, accelerator */    NULL, NULL,
441   /* tooltip */               N_("Paste the text stored on the clipboard"),
442                               G_CALLBACK (action_paste_callback) },
443   /* name, stock id */      { "Select All", NULL,
444   /* label, accelerator */    N_("Select _All"), "<control>A",
445   /* tooltip */               N_("Select all the text in a text field"),
446                               G_CALLBACK (action_select_all_callback) },
447 };
448 
449 static TargetCallbackData *
initialize_clipboard_component_with_callback_data(GtkEditable * target,GtkUIManager * ui_manager,gboolean shares_selection_changes,SelectAllCallback select_all_callback,ConnectCallbacksFunc connect_callbacks,ConnectCallbacksFunc disconnect_callbacks)450 initialize_clipboard_component_with_callback_data (GtkEditable *target,
451 						   GtkUIManager *ui_manager,
452 						   gboolean shares_selection_changes,
453 						   SelectAllCallback select_all_callback,
454 						   ConnectCallbacksFunc connect_callbacks,
455 						   ConnectCallbacksFunc disconnect_callbacks)
456 {
457 	GtkActionGroup *action_group;
458 	TargetCallbackData *target_data;
459 
460 	action_group = gtk_action_group_new ("ClipboardActions");
461 	gtk_action_group_set_translation_domain (action_group, GETTEXT_PACKAGE);
462 	gtk_action_group_add_actions (action_group,
463 				      clipboard_entries, G_N_ELEMENTS (clipboard_entries),
464 				      target);
465 
466 	/* Do the actual connection of the UI to the container at
467 	 * focus time, and disconnect at both focus and destroy
468 	 * time.
469 	 */
470 	target_data = g_new (TargetCallbackData, 1);
471 	target_data->ui_manager = ui_manager;
472 	target_data->action_group = action_group;
473 	target_data->shares_selection_changes = shares_selection_changes;
474 	target_data->select_all_callback = select_all_callback;
475 	target_data->connect_callbacks = connect_callbacks;
476 	target_data->disconnect_callbacks = disconnect_callbacks;
477 
478 	return target_data;
479 }
480 
481 static void
nemo_clipboard_real_set_up(gpointer target,GtkUIManager * ui_manager,gboolean shares_selection_changes,SelectAllCallback select_all_callback,ConnectCallbacksFunc connect_callbacks,ConnectCallbacksFunc disconnect_callbacks)482 nemo_clipboard_real_set_up (gpointer target,
483 				GtkUIManager *ui_manager,
484 				gboolean shares_selection_changes,
485 				SelectAllCallback select_all_callback,
486 				ConnectCallbacksFunc connect_callbacks,
487 				ConnectCallbacksFunc disconnect_callbacks)
488 {
489 	TargetCallbackData *target_data;
490 
491 	if (g_object_get_data (G_OBJECT (target), "Nemo:clipboard_target_data") != NULL) {
492 		return;
493 	}
494 
495 	target_data = initialize_clipboard_component_with_callback_data
496 		(target,
497 		 ui_manager,
498 		 shares_selection_changes,
499 		 select_all_callback,
500 		 connect_callbacks,
501 		 disconnect_callbacks);
502 
503 	g_signal_connect (target, "focus_in_event",
504 			  G_CALLBACK (focus_changed_callback), target_data);
505 	g_signal_connect (target, "focus_out_event",
506 			  G_CALLBACK (focus_changed_callback), target_data);
507 	g_signal_connect (target, "destroy",
508 			  G_CALLBACK (target_destroy_callback), target_data);
509 
510 	g_object_set_data_full (G_OBJECT (target), "Nemo:clipboard_target_data",
511 				target_data, (GDestroyNotify) target_data_free);
512 
513 	/* Call the focus changed callback once to merge if the window is
514 	 * already in focus.
515 	 */
516 	focus_changed_callback (GTK_WIDGET (target), NULL, target_data);
517 }
518 
519 void
nemo_clipboard_set_up_editable(GtkEditable * target,GtkUIManager * ui_manager,gboolean shares_selection_changes)520 nemo_clipboard_set_up_editable (GtkEditable *target,
521 				    GtkUIManager *ui_manager,
522 				    gboolean shares_selection_changes)
523 {
524 	g_return_if_fail (GTK_IS_EDITABLE (target));
525 	g_return_if_fail (GTK_IS_UI_MANAGER (ui_manager));
526 
527 	nemo_clipboard_real_set_up (target, ui_manager,
528 					shares_selection_changes,
529 					editable_select_all_callback,
530 					editable_connect_callbacks,
531 					editable_disconnect_callbacks);
532 }
533 
534 void
nemo_clipboard_set_up_text_view(GtkTextView * target,GtkUIManager * ui_manager)535 nemo_clipboard_set_up_text_view (GtkTextView *target,
536 				     GtkUIManager *ui_manager)
537 {
538 	g_return_if_fail (GTK_IS_TEXT_VIEW (target));
539 	g_return_if_fail (GTK_IS_UI_MANAGER (ui_manager));
540 
541 	nemo_clipboard_real_set_up (target, ui_manager, TRUE,
542 					text_view_select_all_callback,
543 					text_view_connect_callbacks,
544 					text_view_disconnect_callbacks);
545 }
546 
547 static GList *
convert_lines_to_str_list(char ** lines,gboolean * cut)548 convert_lines_to_str_list (char **lines, gboolean *cut)
549 {
550 	int i;
551 	GList *result;
552 
553 	if (cut) {
554 		*cut = FALSE;
555 	}
556 
557 	if (lines[0] == NULL) {
558 		return NULL;
559 	}
560 
561 	if (strcmp (lines[0], "cut") == 0) {
562 		if (cut) {
563 			*cut = TRUE;
564 		}
565 	} else if (strcmp (lines[0], "copy") != 0) {
566 		return NULL;
567 	}
568 
569 	result = NULL;
570 	for (i = 1; lines[i] != NULL; i++) {
571 		result = g_list_prepend (result, g_strdup (lines[i]));
572 	}
573 	return g_list_reverse (result);
574 }
575 
576 GList*
nemo_clipboard_get_uri_list_from_selection_data(GtkSelectionData * selection_data,gboolean * cut,GdkAtom copied_files_atom)577 nemo_clipboard_get_uri_list_from_selection_data (GtkSelectionData *selection_data,
578 						     gboolean *cut,
579 						     GdkAtom copied_files_atom)
580 {
581 	GList *items;
582 	char **lines;
583 
584 	if (gtk_selection_data_get_data_type (selection_data) != copied_files_atom
585 	    || gtk_selection_data_get_length (selection_data) <= 0) {
586 		items = NULL;
587 	} else {
588 		gchar *data;
589 		/* Not sure why it's legal to assume there's an extra byte
590 		 * past the end of the selection data that it's safe to write
591 		 * to. But gtk_editable_selection_received does this, so I
592 		 * think it is OK.
593 		 */
594 		data = (gchar *) gtk_selection_data_get_data (selection_data);
595 		data[gtk_selection_data_get_length (selection_data)] = '\0';
596 		lines = g_strsplit (data, "\n", 0);
597 		items = convert_lines_to_str_list (lines, cut);
598 		g_strfreev (lines);
599 	}
600 
601 	return items;
602 }
603 
604 GtkClipboard *
nemo_clipboard_get(GtkWidget * widget)605 nemo_clipboard_get (GtkWidget *widget)
606 {
607 	return gtk_clipboard_get_for_display (gtk_widget_get_display (GTK_WIDGET (widget)),
608 					      GDK_SELECTION_CLIPBOARD);
609 }
610 
611 void
nemo_clipboard_clear_if_colliding_uris(GtkWidget * widget,const GList * item_uris,GdkAtom copied_files_atom)612 nemo_clipboard_clear_if_colliding_uris (GtkWidget *widget,
613 					    const GList *item_uris,
614 					    GdkAtom copied_files_atom)
615 {
616 	GtkSelectionData *data;
617 	GList *clipboard_item_uris, *l;
618 	gboolean collision;
619 
620 	collision = FALSE;
621 	data = gtk_clipboard_wait_for_contents (nemo_clipboard_get (widget),
622 						copied_files_atom);
623 	if (data == NULL) {
624 		return;
625 	}
626 
627 	clipboard_item_uris = nemo_clipboard_get_uri_list_from_selection_data (data, NULL,
628 										   copied_files_atom);
629 
630 	for (l = (GList *) item_uris; l; l = l->next) {
631 		if (g_list_find_custom ((GList *) item_uris, l->data,
632 					(GCompareFunc) g_strcmp0)) {
633 			collision = TRUE;
634 			break;
635 		}
636 	}
637 
638 	if (collision) {
639 		gtk_clipboard_clear (nemo_clipboard_get (widget));
640 	}
641 
642 	if (clipboard_item_uris) {
643 		g_list_free_full (clipboard_item_uris, g_free);
644 	}
645 }
646