[gnome-builder/wip/libide] libide: add IdeSourceView::auto-indent gsignalaction

[Christian Hergert <chergert src gnome org>]

commit 7c51b781d32cad501ea299788fbbbdd6a81938fb
Author: Christian Hergert <christian hergert me>
Date:   Fri Mar 6 12:04:13 2015 -0800

    libide: add IdeSourceView::auto-indent gsignalaction
    
    This action can be useful when you need to prime the indenter with the
    character just before the current insert mark. This will delete that
    character and reinsert it using a synthesized keypress.

 libide/ide-source-view.c |   79 ++++++++++++++++++++++++++++++++++++++++++++++
 libide/ide-source-view.h |    1 +
 2 files changed, 80 insertions(+), 0 deletions(-)
---
diff --git a/libide/ide-source-view.c b/libide/ide-source-view.c
index 0dbbb53..3fe65c5 100644
--- a/libide/ide-source-view.c
+++ b/libide/ide-source-view.c
@@ -112,6 +112,7 @@ enum {
 enum {
   ACTION,
   APPEND_TO_COUNT,
+  AUTO_INDENT,
   CHANGE_CASE,
   CLEAR_SELECTION,
   CYCLE_COMPLETION,
@@ -1549,6 +1550,64 @@ ide_source_view_real_append_to_count (IdeSourceView *self,
 }
 
 static void
+ide_source_view_real_auto_indent (IdeSourceView *self)
+{
+  GtkTextView *text_view = (GtkTextView *)self;
+  GtkTextBuffer *buffer;
+  GtkTextMark *insert;
+  GtkTextIter iter;
+
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (self));
+  insert = gtk_text_buffer_get_insert (buffer);
+  gtk_text_buffer_get_iter_at_mark (buffer, &iter, insert);
+
+  if (!gtk_text_iter_is_start (&iter))
+    {
+      GdkEvent fake_event = { 0 };
+      GtkTextIter copy;
+      gchar str[8] = { 0 };
+      gunichar ch;
+
+      copy = iter;
+
+      gtk_text_iter_backward_char (&copy);
+      ch = gtk_text_iter_get_char (&copy);
+      g_unichar_to_utf8 (ch, str);
+
+      /*
+       * Now delete the character since the indenter will take care of
+       * reinserting it based on the GdkEventKey.
+       */
+      gtk_text_buffer_delete (buffer, &copy, &iter);
+
+      /*
+       * Now insert the last character (presumably something like \n) with a
+       * synthesized event that the indenter can deal with.
+       */
+      fake_event.key.type = GDK_KEY_PRESS;
+      fake_event.key.window = gtk_text_view_get_window (text_view, GTK_TEXT_WINDOW_TEXT);
+      fake_event.key.send_event = FALSE;
+      fake_event.key.time = GDK_CURRENT_TIME;
+      fake_event.key.state = 0;
+      fake_event.key.length = 1;
+      fake_event.key.string = str;
+      fake_event.key.hardware_keycode = 0;
+      fake_event.key.group = 0;
+      fake_event.key.is_modifier = 0;
+
+      /* Be nice during the common case */
+      if (*str == '\n')
+        fake_event.key.keyval = GDK_KEY_KP_Enter;
+      else
+        fake_event.key.keyval = gdk_unicode_to_keyval (ch);
+
+      ide_source_view_do_indent (self, &fake_event.key);
+    }
+}
+
+static void
 ide_source_view_real_change_case (IdeSourceView           *self,
                                   GtkSourceChangeCaseType  type)
 {
@@ -2334,6 +2393,7 @@ ide_source_view_class_init (IdeSourceViewClass *klass)
 
   klass->action = ide_source_view_real_action;
   klass->append_to_count = ide_source_view_real_append_to_count;
+  klass->auto_indent = ide_source_view_real_auto_indent;
   klass->change_case = ide_source_view_real_change_case;
   klass->clear_selection = ide_source_view_real_clear_selection;
   klass->cycle_completion = ide_source_view_real_cycle_completion;
@@ -2452,6 +2512,25 @@ ide_source_view_class_init (IdeSourceViewClass *klass)
                   1,
                   G_TYPE_INT);
 
+  /**
+   * IdeSourceView::auto-indent:
+   *
+   * Requests that the auto-indenter perform an indent request using the last
+   * inserted character. For example, if on the first character of a line, the
+   * last inserted character would be a newline and therefore "\n".
+   *
+   * If on the first character of the buffer, this signal will do nothing.
+   */
+  gSignals [AUTO_INDENT] =
+    g_signal_new ("auto-indent",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+                  G_STRUCT_OFFSET (IdeSourceViewClass, auto_indent),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE,
+                  0);
+
   gSignals [CHANGE_CASE] =
     g_signal_new ("change-case",
                   G_TYPE_FROM_CLASS (klass),
diff --git a/libide/ide-source-view.h b/libide/ide-source-view.h
index 0e63cf1..849f6a5 100644
--- a/libide/ide-source-view.h
+++ b/libide/ide-source-view.h
@@ -192,6 +192,7 @@ struct _IdeSourceViewClass
                                        const gchar             *param);
   void (*append_to_count)             (IdeSourceView           *self,
                                        gint                     digit);
+  void (*auto_indent)                 (IdeSourceView           *self);
   void (*change_case)                 (IdeSourceView           *self,
                                        GtkSourceChangeCaseType  type);
   void (*clear_selection)             (IdeSourceView           *self);