[gtksourceview] view: always do ctrl+backspace behavior for leading spaces

[Sébastien Wilmet <swilmet src gnome org>]

commit f5fa1340e69973f04080d919c5e2c7e862bb7b44
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Aug 16 18:57:13 2015 +0200

    view: always do ctrl+backspace behavior for leading spaces
    
    The ctrl+backspace deletes all the leading spaces, if only leading
    spaces are on the left of the cursor. This was tight to the
    smart-backspace property, but the smart-backspace is more about removing
    one indentation level when spaces are used for the indentation.
    
    So it's better to always handle the ctrl+backspace behavior, outside of
    the smart-backspace property.
    
    The behavior of ctrl+backspace in GtkTextView is to remove the previous
    word. But the previous word can be on a previous line, so it's not a
    great default behavior.

 gtksourceview/gtksourceview.c |  106 +++++++++++++++++++++++++----------------
 1 files changed, 64 insertions(+), 42 deletions(-)
---
diff --git a/gtksourceview/gtksourceview.c b/gtksourceview/gtksourceview.c
index 4bc24f0..ba41043 100644
--- a/gtksourceview/gtksourceview.c
+++ b/gtksourceview/gtksourceview.c
@@ -4062,18 +4062,18 @@ gtk_source_view_move_lines (GtkSourceView *view,
 }
 
 static gboolean
-gtk_source_view_do_smart_backspace (GtkSourceView *view,
-                                    guint          modifiers)
+do_smart_backspace (GtkSourceView *view)
 {
        GtkTextBuffer *buffer;
        gboolean default_editable;
        GtkTextIter insert;
        GtkTextIter end;
-       GtkTextIter iter;
+       GtkTextIter leading;
+       GtkTextIter trailing;
        guint visual_column;
        gint indent_width;
 
-       buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
+       buffer = GTK_TEXT_BUFFER (view->priv->source_buffer);
        default_editable = gtk_text_view_get_editable (GTK_TEXT_VIEW (view));
 
        if (gtk_text_buffer_get_selection_bounds (buffer, &insert, &end))
@@ -4081,43 +4081,11 @@ gtk_source_view_do_smart_backspace (GtkSourceView *view,
                return FALSE;
        }
 
-       if ((modifiers & 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_iter_backward_cursor_position (&insert);
-                       gtk_text_buffer_delete_interactive (buffer, &insert, &end, default_editable);
-                       return TRUE;
-               }
-       }
-
        /* If the line isn't empty up to our cursor, ignore. */
-       iter = insert;
-       gtk_text_iter_set_line_offset (&iter, 0);
-       while (gtk_text_iter_compare (&iter, &insert) < 0)
+       get_leading_trailing (&insert, &leading, &trailing);
+       if (gtk_text_iter_compare (&leading, &insert) < 0)
        {
-               gunichar ch = gtk_text_iter_get_char (&iter);
-
-               if (!g_unichar_isspace (ch))
-               {
-                       return FALSE;
-               }
-
-               gtk_text_iter_forward_char (&iter);
-       }
-
-       /* If <Control>BackSpace was specified, delete up to the zero position. */
-       if ((modifiers & GDK_CONTROL_MASK) != 0)
-       {
-               gtk_text_iter_set_line_offset (&insert, 0);
-               gtk_text_buffer_delete_interactive (buffer, &insert, &end, default_editable);
-               return TRUE;
+               return FALSE;
        }
 
        visual_column = gtk_source_view_get_visual_column (view, &insert);
@@ -4180,6 +4148,50 @@ gtk_source_view_do_smart_backspace (GtkSourceView *view,
 }
 
 static gboolean
+do_ctrl_backspace (GtkSourceView *view)
+{
+       GtkTextBuffer *buffer;
+       GtkTextIter insert;
+       GtkTextIter end;
+       GtkTextIter leading;
+       GtkTextIter trailing;
+       gboolean default_editable;
+
+       buffer = GTK_TEXT_BUFFER (view->priv->source_buffer);
+       default_editable = gtk_text_view_get_editable (GTK_TEXT_VIEW (view));
+
+       if (gtk_text_buffer_get_selection_bounds (buffer, &insert, &end))
+       {
+               return FALSE;
+       }
+
+       /* 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_iter_backward_cursor_position (&insert);
+               gtk_text_buffer_delete_interactive (buffer, &insert, &end, default_editable);
+               return TRUE;
+       }
+
+       /* If only leading whitespaces are on the left of the cursor, delete up
+        * to the zero position.
+        */
+       get_leading_trailing (&insert, &leading, &trailing);
+       if (gtk_text_iter_compare (&insert, &leading) <= 0)
+       {
+               gtk_text_iter_set_line_offset (&insert, 0);
+               gtk_text_buffer_delete_interactive (buffer, &insert, &end, default_editable);
+               return TRUE;
+       }
+
+       return FALSE;
+}
+
+static gboolean
 gtk_source_view_key_press_event (GtkWidget   *widget,
                                 GdkEventKey *event)
 {
@@ -4289,11 +4301,21 @@ gtk_source_view_key_press_event (GtkWidget   *widget,
                return GDK_EVENT_STOP;
        }
 
-       if ((key == GDK_KEY_BackSpace) && view->priv->smart_backspace)
+       if (key == GDK_KEY_BackSpace)
        {
-               if (gtk_source_view_do_smart_backspace (view, (event->state & modifiers)))
+               if ((event->state & modifiers) == 0)
                {
-                       return GDK_EVENT_STOP;
+                       if (view->priv->smart_backspace && do_smart_backspace (view))
+                       {
+                               return GDK_EVENT_STOP;
+                       }
+               }
+               else if ((event->state & modifiers) == GDK_CONTROL_MASK)
+               {
+                       if (do_ctrl_backspace (view))
+                       {
+                               return GDK_EVENT_STOP;
+                       }
                }
        }