[gnome-builder] source-view: improve handling of Control+BackSpace

[Christian Hergert <chergert src gnome org>]

commit 7657001a178a68dab5e194cbf6fac5e1f2960861
Author: Christian Hergert <christian hergert me>
Date:   Fri May 8 12:19:45 2015 -0700

    source-view: improve handling of Control+BackSpace
    
    GtkTextView universally sucks at handling Control+BackSpace. It is
    non-obvious where the backspace will end and often jumps multiple lines.
    
    As such, we will override that behavior when smart-backspace is emabled.
    
    If you are at the beginning of a line, ctrl+backspace will simply move
    you to the end of the previous line. I believe this is the right
    behavior because anything else would require you to be cross-eyed and
    looking at the start and end of the line at the same time. Non-obvious.
    
    When there is only whitespace between the insertion cursor and the
    beginning of the line, we will remove that space and leave the insert
    mark at line offset 0.

 libide/ide-source-view.c |   37 ++++++++++++++++++++++++++++++++++---
 1 files changed, 34 insertions(+), 3 deletions(-)
---
diff --git a/libide/ide-source-view.c b/libide/ide-source-view.c
index 2077b0e..2e000dc 100644
--- a/libide/ide-source-view.c
+++ b/libide/ide-source-view.c
@@ -1915,15 +1915,33 @@ ide_source_view_do_smart_backspace (IdeSourceView *self,
   g_assert (event);
   g_assert (event->type == GDK_KEY_PRESS);
 
-#define GET_VISUAL_COLUMN(iter) gtk_source_view_get_visual_column(GTK_SOURCE_VIEW(self),iter)
-
   buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (self));
 
-  gtk_text_buffer_get_selection_bounds (buffer, &insert, &end);
+  ide_buffer_get_selection_bounds (IDE_BUFFER (buffer), &insert, &end);
 
   if (!gtk_text_iter_equal (&insert, &end))
     IDE_RETURN (FALSE);
 
+  if ((event->state & GDK_CONTROL_MASK) != 0)
+    {
+      /*
+       * A <Control>BackSpace at the beginning of the line should only move us to the
+       * end of the previous line. Anything more than that is non-obvious because it requires
+       * looking in a position other than where the cursor is.
+       */
+      if ((gtk_text_iter_get_line_offset (&insert) == 0) && (gtk_text_iter_get_line (&insert) > 0))
+        {
+          gtk_text_buffer_begin_user_action (buffer);
+          gtk_text_iter_backward_char (&insert);
+          gtk_text_buffer_delete (buffer, &insert, &end);
+          gtk_text_buffer_end_user_action (buffer);
+
+          IDE_RETURN (TRUE);
+        }
+    }
+
+#define GET_VISUAL_COLUMN(iter) gtk_source_view_get_visual_column(GTK_SOURCE_VIEW(self),iter)
+
   /* if the line isn't empty up to our cursor, ignore */
   tmp = insert;
   while (TRUE)
@@ -1941,6 +1959,19 @@ ide_source_view_do_smart_backspace (IdeSourceView *self,
       gtk_text_iter_backward_char (&tmp);
     }
 
+  /*
+   * If <Control>BackSpace was specified, delete up to the zero position.
+   */
+  if ((event->state & GDK_CONTROL_MASK) != 0)
+    {
+      gtk_text_buffer_begin_user_action (buffer);
+      gtk_text_iter_set_line_offset (&insert, 0);
+      gtk_text_buffer_delete (buffer, &insert, &end);
+      gtk_text_buffer_end_user_action (buffer);
+
+      IDE_RETURN (TRUE);
+    }
+
   visual_column = GET_VISUAL_COLUMN (&insert);
   indent_width = gtk_source_view_get_indent_width (GTK_SOURCE_VIEW (self));
   tab_width = gtk_source_view_get_tab_width (GTK_SOURCE_VIEW (self));