[gnome-builder] gedit: add some gedit text utilities for line deletion

[Christian Hergert <chergert src gnome org>]

commit a5a5ff870c28ec186d8814e152c7891831afe58a
Author: Christian Hergert <christian hergert me>
Date:   Sat Sep 12 17:08:59 2015 -0700

    gedit: add some gedit text utilities for line deletion
    
    This comes from gedit-view.c, where in gedit overrides the
    'delete-from-cursor' interaction from GtkTextView. This is very much
    a worth while thing to maybe even have in GtkSourceView.
    
    For now, we'll copy it in.

 libide/Makefile.am          |    2 +
 libide/util/ide-text-util.c |  123 +++++++++++++++++++++++++++++++++++++++++++
 libide/util/ide-text-util.h |   31 +++++++++++
 3 files changed, 156 insertions(+), 0 deletions(-)
---
diff --git a/libide/Makefile.am b/libide/Makefile.am
index e415634..95671f0 100644
--- a/libide/Makefile.am
+++ b/libide/Makefile.am
@@ -236,6 +236,8 @@ libide_1_0_la_SOURCES = \
        util/ide-pango.h \
        util/ide-rgba.c \
        util/ide-rgba.h \
+       util/ide-text-util.c \
+       util/ide-text-util.h \
        $(NULL)
 
 libide_1_0_la_includes = \
diff --git a/libide/util/ide-text-util.c b/libide/util/ide-text-util.c
new file mode 100644
index 0000000..111decc
--- /dev/null
+++ b/libide/util/ide-text-util.c
@@ -0,0 +1,123 @@
+/*
+ * gedit-view.c
+ * This file is part of gedit
+ *
+ * Copyright (C) 1998, 1999 Alex Roberts, Evan Lawrence
+ * Copyright (C) 2000, 2002 Chema Celorio, Paolo Maggi
+ * Copyright (C) 2003-2005 Paolo Maggi
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ide-text-util.h"
+
+void
+ide_text_util_delete_line (GtkTextView *text_view,
+                           gint         count)
+{
+       GtkTextIter start;
+       GtkTextIter end;
+       GtkTextBuffer *buffer;
+
+       buffer = gtk_text_view_get_buffer (text_view);
+
+       gtk_text_view_reset_im_context (text_view);
+
+       /* If there is a selection delete the selected lines and ignore count. */
+       if (gtk_text_buffer_get_selection_bounds (buffer, &start, &end))
+       {
+               gtk_text_iter_order (&start, &end);
+
+               if (gtk_text_iter_starts_line (&end))
+               {
+                       /* Do not delete the line with the cursor if the cursor
+                        * is at the beginning of the line.
+                        */
+                       count = 0;
+               }
+               else
+               {
+                       count = 1;
+               }
+       }
+
+       gtk_text_iter_set_line_offset (&start, 0);
+
+       if (count > 0)
+       {
+               gtk_text_iter_forward_lines (&end, count);
+
+               if (gtk_text_iter_is_end (&end))
+               {
+                       if (gtk_text_iter_backward_line (&start) &&
+                           !gtk_text_iter_ends_line (&start))
+                       {
+                               gtk_text_iter_forward_to_line_end (&start);
+                       }
+               }
+       }
+       else if (count < 0)
+       {
+               if (!gtk_text_iter_ends_line (&end))
+               {
+                       gtk_text_iter_forward_to_line_end (&end);
+               }
+
+               while (count < 0)
+               {
+                       if (!gtk_text_iter_backward_line (&start))
+                       {
+                               break;
+                       }
+
+                       count++;
+               }
+
+               if (count == 0)
+               {
+                       if (!gtk_text_iter_ends_line (&start))
+                       {
+                               gtk_text_iter_forward_to_line_end (&start);
+                       }
+               }
+               else
+               {
+                       gtk_text_iter_forward_line (&end);
+               }
+       }
+
+       if (!gtk_text_iter_equal (&start, &end))
+       {
+               GtkTextIter cur = start;
+               gtk_text_iter_set_line_offset (&cur, 0);
+
+               gtk_text_buffer_begin_user_action (buffer);
+
+               gtk_text_buffer_place_cursor (buffer, &cur);
+
+               gtk_text_buffer_delete_interactive (buffer,
+                                                   &start,
+                                                   &end,
+                                                   gtk_text_view_get_editable (text_view));
+
+               gtk_text_buffer_end_user_action (buffer);
+
+               gtk_text_view_scroll_mark_onscreen (text_view,
+                                                   gtk_text_buffer_get_insert (buffer));
+       }
+       else
+       {
+               gtk_widget_error_bell (GTK_WIDGET (text_view));
+       }
+}
diff --git a/libide/util/ide-text-util.h b/libide/util/ide-text-util.h
new file mode 100644
index 0000000..40d2fd4
--- /dev/null
+++ b/libide/util/ide-text-util.h
@@ -0,0 +1,31 @@
+/* ide-text-util.h
+ *
+ * Copyright (C) 2015 Christian Hergert <christian hergert me>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef IDE_TEXT_UTIL_H
+#define IDE_TEXT_UTIL_H
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+void ide_text_util_delete_line (GtkTextView *text_view,
+                                gint         count);
+
+G_END_DECLS
+
+#endif /* IDE_TEXT_UTIL_H */