Initial commit for sylpheed 3.7.0

1 files changed, 673 insertions, 0 deletions

diff --git a/src/undo.c b/src/undo.c
new file mode 100644
index 0000000..122afc6
--- /dev/null
+++ b/src/undo.c
@@ -0,0 +1,673 @@
+/*
+ * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
+ * Copyright (C) 1999-2011 Hiroyuki Yamamoto
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* code ported from gedit */
+/* This is for my patient girlfirend Regina */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <glib.h>
+#include <gtk/gtktextview.h>
+
+#include "undo.h"
+#include "utils.h"
+#include "prefs_common.h"
+
+typedef struct _UndoInfo UndoInfo;
+
+struct _UndoInfo 
+{
+        UndoAction action;
+        gchar *text;
+        gint start_pos;
+        gint end_pos;
+        gfloat window_position;
+        gint mergeable;
+};
+
+/* #define UNDO_DEBUG   1 */
+#ifdef UNDO_DEBUG
+#  define undo_debug    debug_print
+#else
+#  define undo_debug    1 ? (void)0 : debug_print
+#endif
+
+static void undo_free_list      (GList         **list_pointer);
+static void undo_check_size     (UndoMain       *undostruct);
+static gint undo_merge          (GList          *list,
+                                 guint           start_pos,
+                                 guint           end_pos,
+                                 gint            action,
+                                 const gchar    *text);
+static void undo_add            (const gchar    *text,
+                                 gint            start_pos,
+                                 gint            end_pos,
+                                 UndoAction      action,
+                                 UndoMain       *undostruct);
+static gint undo_get_selection  (GtkTextView    *textview,
+                                 guint          *start,
+                                 guint          *end);
+static void undo_insert_text_cb (GtkTextBuffer  *textbuf,
+                                 GtkTextIter    *iter,
+                                 gchar          *new_text,
+                                 gint            new_text_length,
+                                 UndoMain       *undostruct);
+static void undo_delete_text_cb (GtkTextBuffer  *textbuf,
+                                 GtkTextIter    *start,
+                                 GtkTextIter    *end,
+                                 UndoMain       *undostruct);
+
+static void undo_paste_clipboard_cb     (GtkTextView    *textview,
+                                         UndoMain       *undostruct);
+
+void undo_undo                  (UndoMain       *undostruct);
+void undo_redo                  (UndoMain       *undostruct);
+
+
+UndoMain *undo_init(GtkWidget *text) 
+{
+        UndoMain *undostruct;
+        GtkTextView *textview = GTK_TEXT_VIEW(text);
+        GtkTextBuffer *textbuf;
+
+        g_return_val_if_fail(text != NULL, NULL);
+
+        textbuf = gtk_text_view_get_buffer(textview);
+
+        undostruct = g_new(UndoMain, 1);
+        undostruct->textview = textview;
+        undostruct->undo = NULL;
+        undostruct->redo = NULL;
+        undostruct->paste = 0;
+        undostruct->undo_state = FALSE;
+        undostruct->redo_state = FALSE;
+
+        g_signal_connect(G_OBJECT(textbuf), "insert-text",
+                         G_CALLBACK(undo_insert_text_cb), undostruct);
+        g_signal_connect(G_OBJECT(textbuf), "delete-range",
+                         G_CALLBACK(undo_delete_text_cb), undostruct);
+        g_signal_connect(G_OBJECT(textview), "paste-clipboard",
+                         G_CALLBACK(undo_paste_clipboard_cb), undostruct);
+
+        return undostruct;
+}
+
+void undo_destroy (UndoMain *undostruct) 
+{
+        undo_free_list(&undostruct->undo);
+        undo_free_list(&undostruct->redo);
+        g_free(undostruct);
+}
+
+static UndoInfo *undo_object_new(gchar *text, gint start_pos, gint end_pos, 
+                                 UndoAction action, gfloat window_position) 
+{
+        UndoInfo *undoinfo;
+        undoinfo = g_new (UndoInfo, 1);
+        undoinfo->text      = text;
+        undoinfo->start_pos = start_pos;
+        undoinfo->end_pos   = end_pos;
+        undoinfo->action    = action;
+        undoinfo->window_position = window_position;
+        return undoinfo;
+}
+
+static void undo_object_free(UndoInfo *undo) 
+{
+        g_free (undo->text);
+        g_free (undo);
+}
+
+/**
+ * undo_free_list:
+ * @list_pointer: list to be freed
+ *
+ * frees and undo structure list
+ **/
+static void undo_free_list(GList **list_pointer) 
+{
+        UndoInfo *undo;
+        GList *cur, *list = *list_pointer;
+
+        if (list == NULL) return;
+
+        for (cur = list; cur != NULL; cur = cur->next) {
+                undo = (UndoInfo *)cur->data;
+                undo_object_free(undo);
+        }
+
+        g_list_free(list);
+        *list_pointer = NULL;
+}
+
+void undo_set_change_state_func(UndoMain *undostruct, UndoChangeStateFunc func,
+                                gpointer data)
+{
+        g_return_if_fail(undostruct != NULL);
+
+        undostruct->change_state_func = func;
+        undostruct->change_state_data = data;
+}
+
+/**
+ * undo_check_size:
+ * @compose: document to check
+ *
+ * Checks that the size of compose->undo does not excede settings->undo_levels and
+ * frees any undo level above sett->undo_level.
+ *
+ **/
+static void undo_check_size(UndoMain *undostruct) 
+{
+        UndoInfo *last_undo;
+        guint length;
+
+        if (prefs_common.undolevels < 1) return;
+
+        /* No need to check for the redo list size since the undo
+           list gets freed on any call to compose_undo_add */
+        length = g_list_length(undostruct->undo);
+        if (length >= prefs_common.undolevels && prefs_common.undolevels > 0) {
+                last_undo = (UndoInfo *)g_list_last(undostruct->undo)->data;
+                undostruct->undo = g_list_remove(undostruct->undo, last_undo);
+                undo_object_free(last_undo);
+        }
+}
+
+/**
+ * undo_merge:
+ * @last_undo:
+ * @start_pos:
+ * @end_pos:
+ * @action:
+ *
+ * This function tries to merge the undo object at the top of
+ * the stack with a new set of data. So when we undo for example
+ * typing, we can undo the whole word and not each letter by itself
+ *
+ * Return Value: TRUE is merge was sucessful, FALSE otherwise
+ **/
+static gint undo_merge(GList *list, guint start_pos, guint end_pos,
+                       gint action, const gchar *text) 
+{
+        gchar *temp_string;
+        UndoInfo *last_undo;
+
+        undo_debug("undo_merge: %d: %d: text: %s\n", action, start_pos, text);
+
+        /* This are the cases in which we will NOT merge :
+           1. if (last_undo->mergeable == FALSE)
+           [mergeable = FALSE when the size of the undo data was not 1.
+           or if the data was size = 1 but = '\n' or if the undo object
+           has been "undone" already ]
+           2. The size of text is not 1
+           3. If the new merging data is a '\n'
+           4. If the last char of the undo_last data is a space/tab
+           and the new char is not a space/tab ( so that we undo
+           words and not chars )
+           5. If the type (action) of undo is different from the last one
+           Chema */
+
+        if (list == NULL) return FALSE;
+
+        last_undo = list->data;
+
+        if (!last_undo->mergeable) return FALSE;
+
+        if (end_pos - start_pos != 1 ||
+            text[0] == '\n' ||
+            action != last_undo->action ||
+            action == UNDO_ACTION_REPLACE_INSERT ||
+            action == UNDO_ACTION_REPLACE_DELETE) {
+                last_undo->mergeable = FALSE;
+                return FALSE;
+        }
+
+        if (action == UNDO_ACTION_DELETE) {
+                gboolean checkit = TRUE;
+
+                if (last_undo->start_pos != end_pos &&
+                    last_undo->start_pos != start_pos) {
+                        last_undo->mergeable = FALSE;
+                        return FALSE;
+                } else if (last_undo->start_pos == start_pos) {
+                        /* Deleted with the delete key */
+                        undo_debug("undo_merge: deleted with the delete key\n");
+                        if (text[0] != ' ' && text[0] != '\t' &&
+                            (last_undo->text[last_undo->end_pos - last_undo->start_pos - 1] == ' ' ||
+                             last_undo->text[last_undo->end_pos - last_undo->start_pos - 1] == '\t'))
+                                checkit = FALSE;
+                        else {
+                                temp_string = g_strdup_printf("%s%s", last_undo->text, text);
+                                last_undo->end_pos++;
+                                g_free(last_undo->text);
+                                last_undo->text = temp_string;
+                        }
+                } else {
+                        /* Deleted with the backspace key */
+                        undo_debug("undo_merge: deleted with the backspace key\n");
+                        if (text[0] != ' ' && text[0] != '\t' &&
+                            (last_undo->text[0] == ' ' ||
+                             last_undo->text[0] == '\t'))
+                                checkit = FALSE;
+                        else {
+                                temp_string = g_strdup_printf("%s%s", text, last_undo->text);
+                                last_undo->start_pos = start_pos;
+                                g_free(last_undo->text);
+                                last_undo->text = temp_string;
+                        }
+                }
+
+                if (!checkit) {
+                        undo_debug("undo_merge: checkit = FALSE\n");
+                        last_undo->mergeable = FALSE;
+                        return FALSE;
+                }
+        } else if (action == UNDO_ACTION_INSERT) {
+                if (last_undo->end_pos != start_pos) {
+                        last_undo->mergeable = FALSE;
+                        return FALSE;
+                } else {
+                        temp_string = g_strdup_printf("%s%s", last_undo->text, text);
+                        g_free(last_undo->text);
+                        last_undo->end_pos = end_pos;
+                        last_undo->text = temp_string;
+                }
+        } else
+                undo_debug("Unknown action [%i] inside undo merge encountered", action);
+
+        undo_debug("undo_merge: merged: %d: text: %s\n", last_undo->start_pos, last_undo->text);
+        return TRUE;
+}
+
+/**
+ * undo_add:
+ * @text:
+ * @start_pos:
+ * @end_pos:
+ * @action: either UNDO_ACTION_INSERT or UNDO_ACTION_DELETE
+ *
+ * Adds text to the undo stack. It also performs test to limit the number
+ * of undo levels and deltes the redo list
+ **/
+
+static void undo_add(const gchar *text, 
+                     gint start_pos, gint end_pos,
+                     UndoAction action, UndoMain *undostruct) 
+{
+        UndoInfo *undoinfo;
+        GtkAdjustment *vadj;
+
+        g_return_if_fail(text != NULL);
+        g_return_if_fail(end_pos >= start_pos);
+
+        undo_debug("undo_add: %d: %d: %s\n", action, start_pos, text);
+
+        undo_free_list(&undostruct->redo);
+
+        /* Set the redo sensitivity */
+        undostruct->change_state_func(undostruct,
+                                      UNDO_STATE_UNCHANGED, UNDO_STATE_FALSE,
+                                      undostruct->change_state_data);
+
+        if (undostruct->paste != 0) {
+                if (action == UNDO_ACTION_INSERT) 
+                        action = UNDO_ACTION_REPLACE_INSERT;
+                else 
+                        action = UNDO_ACTION_REPLACE_DELETE;
+                undostruct->paste = undostruct->paste + 1;
+                if (undostruct->paste == 3) 
+                        undostruct->paste = 0;
+        }
+
+        if (undo_merge(undostruct->undo, start_pos, end_pos, action, text))
+                return;
+
+        undo_check_size(undostruct);
+
+        vadj = GTK_ADJUSTMENT(GTK_TEXT_VIEW(undostruct->textview)->vadjustment);
+        undoinfo = undo_object_new(g_strdup(text), start_pos, end_pos, action,
+                                   vadj->value);
+
+        if (end_pos - start_pos != 1 || text[0] == '\n')
+                undoinfo->mergeable = FALSE;
+        else
+                undoinfo->mergeable = TRUE;
+
+        undostruct->undo = g_list_prepend(undostruct->undo, undoinfo);
+
+        undostruct->change_state_func(undostruct,
+                                      UNDO_STATE_TRUE, UNDO_STATE_UNCHANGED,
+                                      undostruct->change_state_data);
+}
+
+/**
+ * undo_undo:
+ * @w: not used
+ * @data: not used
+ *
+ * Executes an undo request on the current document
+ **/
+void undo_undo(UndoMain *undostruct) 
+{
+        UndoInfo *undoinfo;
+        GtkTextView *textview;
+        GtkTextBuffer *buffer;
+        GtkTextIter iter, start_iter, end_iter;
+        GtkTextMark *mark;
+
+        g_return_if_fail(undostruct != NULL);
+
+        if (undostruct->undo == NULL) return;
+
+        /* The undo data we need is always at the top op the
+           stack. So, therefore, the first one */
+        undoinfo = (UndoInfo *)undostruct->undo->data;
+        g_return_if_fail(undoinfo != NULL);
+        undoinfo->mergeable = FALSE;
+        undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
+        undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
+
+        textview = undostruct->textview;
+        buffer = gtk_text_view_get_buffer(textview);
+
+        undo_block(undostruct);
+
+        /* Check if there is a selection active */
+        mark = gtk_text_buffer_get_insert(buffer);
+        gtk_text_buffer_get_iter_at_mark(buffer, &iter, mark);
+        gtk_text_buffer_place_cursor(buffer, &iter);
+
+        /* Move the view (scrollbars) to the correct position */
+        gtk_adjustment_set_value(GTK_ADJUSTMENT(textview->vadjustment),
+                                 undoinfo->window_position);
+
+        switch (undoinfo->action) {
+        case UNDO_ACTION_DELETE:
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &iter, undoinfo->start_pos);
+                gtk_text_buffer_insert(buffer, &iter, undoinfo->text, -1);
+                undo_debug("undo: UNDO_ACTION_DELETE: %d: %s\n",
+                           undoinfo->start_pos, undoinfo->text);
+                break;
+        case UNDO_ACTION_INSERT:
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &start_iter, undoinfo->start_pos);
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &end_iter, undoinfo->end_pos);
+                gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
+                undo_debug("undo: UNDO_ACTION_INSERT: %d: delete %d chars\n",
+                           undoinfo->start_pos,
+                           undoinfo->end_pos - undoinfo->start_pos);
+                break;
+        case UNDO_ACTION_REPLACE_INSERT:
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &start_iter, undoinfo->start_pos);
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &end_iter, undoinfo->end_pos);
+                undo_debug("undo: UNDO_ACTION_REPLACE: %d: %s\n",
+                           undoinfo->start_pos, undoinfo->text);
+                /* "pull" another data structure from the list */
+                undoinfo = (UndoInfo *)undostruct->undo->data;
+                g_return_if_fail(undoinfo != NULL);
+                undostruct->redo = g_list_prepend(undostruct->redo, undoinfo);
+                undostruct->undo = g_list_remove(undostruct->undo, undoinfo);
+                g_return_if_fail(undoinfo->action == UNDO_ACTION_REPLACE_DELETE);
+                gtk_text_buffer_insert(buffer, &start_iter, undoinfo->text, -1);
+                undo_debug("undo: UNDO_ACTION_REPLACE: %d: %s\n",
+                           undoinfo->start_pos, undoinfo->text);
+                break;
+        case UNDO_ACTION_REPLACE_DELETE:
+                g_warning("undo: this should not happen: UNDO_REPLACE_DELETE");
+                break;
+        default:
+                g_assert_not_reached();
+                break;
+        }
+
+        gtk_widget_queue_draw(GTK_WIDGET(textview));
+
+        undostruct->change_state_func(undostruct,
+                                      UNDO_STATE_UNCHANGED, UNDO_STATE_TRUE,
+                                      undostruct->change_state_data);
+
+        if (undostruct->undo == NULL)
+                undostruct->change_state_func(undostruct,
+                                              UNDO_STATE_FALSE,
+                                              UNDO_STATE_UNCHANGED,
+                                              undostruct->change_state_data);
+
+        undo_unblock(undostruct);
+}
+
+/**
+ * undo_redo:
+ * @w: not used
+ * @data: not used
+ *
+ * executes a redo request on the current document
+ **/
+void undo_redo(UndoMain *undostruct) 
+{
+        UndoInfo *redoinfo;
+        GtkTextView *textview;
+        GtkTextBuffer *buffer;
+        GtkTextIter iter, start_iter, end_iter;
+        GtkTextMark *mark;
+
+        g_return_if_fail(undostruct != NULL);
+
+        if (undostruct->redo == NULL) return;
+
+        redoinfo = (UndoInfo *)undostruct->redo->data;
+        g_return_if_fail (redoinfo != NULL);
+        undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
+        undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
+
+        textview = undostruct->textview;
+        buffer = gtk_text_view_get_buffer(textview);
+
+        undo_block(undostruct);
+
+        /* Check if there is a selection active */
+        mark = gtk_text_buffer_get_insert(buffer);
+        gtk_text_buffer_get_iter_at_mark(buffer, &iter, mark);
+        gtk_text_buffer_place_cursor(buffer, &iter);
+
+        /* Move the view to the right position. */
+        gtk_adjustment_set_value(textview->vadjustment, 
+                                 redoinfo->window_position);
+
+        switch (redoinfo->action) {
+        case UNDO_ACTION_INSERT:
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &iter, redoinfo->start_pos);
+                gtk_text_buffer_insert(buffer, &iter, redoinfo->text, -1);
+                undo_debug("redo: UNDO_ACTION_DELETE: %d: %s\n",
+                           redoinfo->start_pos, redoinfo->text);
+                break;
+        case UNDO_ACTION_DELETE:
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &start_iter, redoinfo->start_pos);
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &end_iter, redoinfo->end_pos);
+                gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
+                undo_debug("redo: UNDO_ACTION_INSERT: %d: delete %d chars\n", 
+                           redoinfo->start_pos,
+                           redoinfo->end_pos - redoinfo->start_pos);
+                break;
+        case UNDO_ACTION_REPLACE_DELETE:
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &start_iter, redoinfo->start_pos);
+                gtk_text_buffer_get_iter_at_offset
+                        (buffer, &end_iter, redoinfo->end_pos);
+                gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
+                undo_debug("redo: UNDO_ACTION_REPLACE: %d: %s\n",
+                           redoinfo->start_pos, redoinfo->text);
+                /* "pull" another data structure from the list */
+                redoinfo = (UndoInfo *)undostruct->redo->data;
+                g_return_if_fail(redoinfo != NULL);
+                undostruct->undo = g_list_prepend(undostruct->undo, redoinfo);
+                undostruct->redo = g_list_remove(undostruct->redo, redoinfo);
+                g_return_if_fail(redoinfo->action == UNDO_ACTION_REPLACE_INSERT);
+                gtk_text_buffer_insert(buffer, &start_iter, redoinfo->text, -1);
+                undo_debug("redo: UNDO_ACTION_REPLACE: %d: %s\n",
+                           redoinfo->start_pos, redoinfo->text);
+                break;
+        case UNDO_ACTION_REPLACE_INSERT:
+                g_warning("redo: this should not happen: UNDO_REPLACE_INSERT");
+                break;
+        default:
+                g_assert_not_reached();
+                break;
+        }
+
+        gtk_widget_queue_draw(GTK_WIDGET(textview));
+
+        undostruct->change_state_func(undostruct,
+                                      UNDO_STATE_TRUE, UNDO_STATE_UNCHANGED, 
+                                      undostruct->change_state_data);
+
+        if (undostruct->redo == NULL)
+                undostruct->change_state_func(undostruct,
+                                              UNDO_STATE_UNCHANGED,
+                                              UNDO_STATE_FALSE,
+                                              undostruct->change_state_data);
+
+        undo_unblock(undostruct);
+}
+
+void undo_block(UndoMain *undostruct)
+{
+        GtkTextBuffer *buffer;
+
+        g_return_if_fail(GTK_IS_TEXT_VIEW(undostruct->textview));
+
+        buffer = gtk_text_view_get_buffer(undostruct->textview);
+        g_signal_handlers_block_by_func
+                (buffer, undo_insert_text_cb, undostruct);
+        g_signal_handlers_block_by_func
+                (buffer, undo_delete_text_cb, undostruct);
+        g_signal_handlers_block_by_func
+                (buffer, undo_paste_clipboard_cb, undostruct);
+}
+
+void undo_unblock(UndoMain *undostruct)
+{
+        GtkTextBuffer *buffer;
+
+        g_return_if_fail(GTK_IS_TEXT_VIEW(undostruct->textview));
+
+        buffer = gtk_text_view_get_buffer(undostruct->textview);
+        g_signal_handlers_unblock_by_func
+                (buffer, undo_insert_text_cb, undostruct);
+        g_signal_handlers_unblock_by_func
+                (buffer, undo_delete_text_cb, undostruct);
+        g_signal_handlers_unblock_by_func
+                (buffer, undo_paste_clipboard_cb, undostruct);
+}
+
+void undo_insert_text_cb(GtkTextBuffer *textbuf, GtkTextIter *iter,
+                         gchar *new_text, gint new_text_length,
+                         UndoMain *undostruct) 
+{
+        gchar *text_to_insert;
+        gint pos;
+
+        if (prefs_common.undolevels <= 0) return;
+
+        pos = gtk_text_iter_get_offset(iter);
+
+        text_to_insert = g_strndup(new_text, new_text_length);
+        undo_add(text_to_insert, pos, pos + g_utf8_strlen(text_to_insert, -1),
+                 UNDO_ACTION_INSERT, undostruct);
+        g_free(text_to_insert);
+}
+
+void undo_delete_text_cb(GtkTextBuffer *textbuf, GtkTextIter *start,
+                         GtkTextIter *end, UndoMain *undostruct) 
+{
+        gchar *text_to_delete;
+        gint start_pos, end_pos;
+
+        if (prefs_common.undolevels <= 0) return;
+
+        text_to_delete = gtk_text_buffer_get_text(textbuf, start, end, FALSE);
+        if (!text_to_delete || !*text_to_delete) return;
+
+        start_pos = gtk_text_iter_get_offset(start);
+        end_pos   = gtk_text_iter_get_offset(end);
+
+        undo_add(text_to_delete, start_pos, end_pos, UNDO_ACTION_DELETE,
+                 undostruct);
+        g_free(text_to_delete);
+}
+
+void undo_paste_clipboard_cb(GtkTextView *textview, UndoMain *undostruct)
+{
+        undo_debug("before Paste: %d\n", undostruct->paste);
+        if (prefs_common.undolevels > 0)
+                if (undo_get_selection(textview, NULL, NULL))
+                        undostruct->paste = TRUE;
+        undo_debug("after Paste: %d\n", undostruct->paste);
+}
+
+/**
+ * undo_get_selection:
+ * @text: Text to get the selection from
+ * @start: return here the start position of the selection
+ * @end: return here the end position of the selection
+ *
+ * Gets the current selection for View
+ *
+ * Return Value: TRUE if there is a selection active, FALSE if not
+ **/
+static gint undo_get_selection(GtkTextView *textview, guint *start, guint *end) 
+{
+        GtkTextBuffer *buffer;
+        GtkTextIter start_iter, end_iter;
+        guint start_pos, end_pos;
+
+        buffer = gtk_text_view_get_buffer(textview);
+        gtk_text_buffer_get_selection_bounds(buffer, &start_iter, &end_iter);
+
+        start_pos = gtk_text_iter_get_offset(&start_iter);
+        end_pos   = gtk_text_iter_get_offset(&end_iter);
+
+        /* The user can select from end to start too. If so, swap it*/
+        if (end_pos < start_pos) {
+                guint swap_pos;
+                swap_pos  = end_pos;
+                end_pos   = start_pos;
+                start_pos = swap_pos;
+        }
+
+        if (start != NULL)
+                *start = start_pos;
+                
+        if (end != NULL)
+                *end = end_pos;
+
+        if ((start_pos > 0 || end_pos > 0) && (start_pos != end_pos))
+                return TRUE;
+        else
+                return FALSE;
+}