[gnome-builder/wip/libide] libide: add IdeSourceView::capture-modifier and ::clear-modifier

[Christian Hergert <chergert src gnome org>]

commit 1fa117a3c43c59a48a58cb227ae2a29713339e36
Author: Christian Hergert <christian hergert me>
Date:   Tue Mar 10 20:37:02 2015 -0700

    libide: add IdeSourceView::capture-modifier and ::clear-modifier
    
    These signals help in the process of waiting for a modifier key. This can
    be used to pass to movements that require additional input.
    
    The capture-modifier signal will block the main loop (similar to that of
    gtk_dialog_run() until the key as been pressed or focus leaves). After
    which, the signal bindings can continue.

 libide/ide-source-view-movements.c |    3 +
 libide/ide-source-view-movements.h |    1 +
 libide/ide-source-view.c           |   96 +++++++++++++++++++++++++++++++++++-
 libide/ide-source-view.h           |    2 +
 4 files changed, 101 insertions(+), 1 deletions(-)
---
diff --git a/libide/ide-source-view-movements.c b/libide/ide-source-view-movements.c
index fe9ef6f..9495812 100644
--- a/libide/ide-source-view-movements.c
+++ b/libide/ide-source-view-movements.c
@@ -44,6 +44,7 @@ typedef struct
   GtkTextIter            insert;                      /* Current insert cursor location */
   GtkTextIter            selection;                   /* Current selection cursor location */
   gint                   count;                       /* Repeat count for movement */
+  gunichar               modifier;                    /* For forward/backward char search */
   guint                  extend_selection : 1;        /* If selection should be extended */
   guint                  exclusive : 1;               /* See ":help exclusive" in vim */
   guint                  ignore_select : 1;           /* Don't update selection after movement */
@@ -1184,6 +1185,7 @@ _ide_source_view_apply_movement (IdeSourceView         *self,
                                  gboolean               extend_selection,
                                  gboolean               exclusive,
                                  guint                  count,
+                                 gunichar               modifier,
                                  gint                  *target_offset)
 {
   Movement mv = { 0 };
@@ -1219,6 +1221,7 @@ _ide_source_view_apply_movement (IdeSourceView         *self,
   mv.count = count;
   mv.ignore_select = FALSE;
   mv.ignore_target_offset = FALSE;
+  mv.modifier = modifier;
 
   ide_source_view_movements_get_selection (&mv);
 
diff --git a/libide/ide-source-view-movements.h b/libide/ide-source-view-movements.h
index 4f17fee..0cfcb7b 100644
--- a/libide/ide-source-view-movements.h
+++ b/libide/ide-source-view-movements.h
@@ -28,6 +28,7 @@ void _ide_source_view_apply_movement (IdeSourceView         *source_view,
                                       gboolean               extend_selection,
                                       gboolean               exclusive,
                                       guint                  count,
+                                      gunichar               modifier,
                                       gint                  *target_offset);
 
 G_END_DECLS
diff --git a/libide/ide-source-view.c b/libide/ide-source-view.c
index f3316a0..eb6cea4 100644
--- a/libide/ide-source-view.c
+++ b/libide/ide-source-view.c
@@ -110,6 +110,7 @@ typedef struct
   guint                        change_sequence;
 
   gint                         target_line_offset;
+  gunichar                     modifier;
   guint                        count;
 
   guint                        scroll_offset;
@@ -127,6 +128,7 @@ typedef struct
   guint                        show_grid_lines : 1;
   guint                        show_line_changes : 1;
   guint                        snippet_completion : 1;
+  guint                        waiting_for_capture : 1;
 } IdeSourceViewPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (IdeSourceView, ide_source_view, GTK_SOURCE_TYPE_VIEW)
@@ -151,8 +153,10 @@ enum {
   ACTION,
   APPEND_TO_COUNT,
   AUTO_INDENT,
+  CAPTURE_MODIFIER,
   CHANGE_CASE,
   CLEAR_COUNT,
+  CLEAR_MODIFIER,
   CLEAR_SELECTION,
   CLEAR_SNIPPETS,
   CYCLE_COMPLETION,
@@ -1618,6 +1622,33 @@ ide_source_view_do_mode (IdeSourceView *self,
 }
 
 static gboolean
+is_modifier_key (GdkEventKey *event)
+{
+  static const guint modifier_keyvals[] = {
+    GDK_KEY_Shift_L, GDK_KEY_Shift_R, GDK_KEY_Shift_Lock,
+    GDK_KEY_Caps_Lock, GDK_KEY_ISO_Lock, GDK_KEY_Control_L,
+    GDK_KEY_Control_R, GDK_KEY_Meta_L, GDK_KEY_Meta_R,
+    GDK_KEY_Alt_L, GDK_KEY_Alt_R, GDK_KEY_Super_L, GDK_KEY_Super_R,
+    GDK_KEY_Hyper_L, GDK_KEY_Hyper_R, GDK_KEY_ISO_Level3_Shift,
+    GDK_KEY_ISO_Next_Group, GDK_KEY_ISO_Prev_Group,
+    GDK_KEY_ISO_First_Group, GDK_KEY_ISO_Last_Group,
+    GDK_KEY_Mode_switch, GDK_KEY_Num_Lock, GDK_KEY_Multi_key,
+    GDK_KEY_Scroll_Lock,
+    0
+  };
+  const guint *ac_val;
+
+  ac_val = modifier_keyvals;
+  while (*ac_val)
+    {
+      if (event->keyval == *ac_val++)
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+static gboolean
 ide_source_view_key_press_event (GtkWidget   *widget,
                                  GdkEventKey *event)
 {
@@ -1631,6 +1662,13 @@ ide_source_view_key_press_event (GtkWidget   *widget,
 
   g_assert (IDE_IS_SOURCE_VIEW (self));
 
+  if (priv->waiting_for_capture)
+    {
+      if (!is_modifier_key (event))
+        priv->modifier = gdk_keyval_to_unicode (event->keyval);
+      return TRUE;
+    }
+
   buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (self));
   insert = gtk_text_buffer_get_insert (buffer);
 
@@ -1886,6 +1924,19 @@ ide_source_view_real_auto_indent (IdeSourceView *self)
 }
 
 static void
+ide_source_view_real_capture_modifier (IdeSourceView *self)
+{
+  IdeSourceViewPrivate *priv = ide_source_view_get_instance_private (self);
+
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  priv->waiting_for_capture = TRUE;
+  while ((priv->modifier == 0) && gtk_widget_has_focus (GTK_WIDGET (self)))
+    gtk_main_iteration ();
+  priv->waiting_for_capture = FALSE;
+}
+
+static void
 ide_source_view_real_change_case (IdeSourceView           *self,
                                   GtkSourceChangeCaseType  type)
 {
@@ -1913,6 +1964,16 @@ ide_source_view_real_clear_count (IdeSourceView *self)
 }
 
 static void
+ide_source_view_real_clear_modifier (IdeSourceView *self)
+{
+  IdeSourceViewPrivate *priv = ide_source_view_get_instance_private (self);
+
+  g_assert (IDE_IS_SOURCE_VIEW (self));
+
+  priv->modifier = 0;
+}
+
+static void
 ide_source_view_real_clear_selection (IdeSourceView *self)
 {
   GtkTextView *text_view = (GtkTextView *)self;
@@ -2437,7 +2498,7 @@ ide_source_view_real_movement (IdeSourceView         *self,
     count = priv->count;
 
   _ide_source_view_apply_movement (self, movement, extend_selection, exclusive,
-                                   count, &priv->target_line_offset);
+                                   count, priv->modifier, &priv->target_line_offset);
 }
 
 static void
@@ -3210,8 +3271,10 @@ 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->capture_modifier = ide_source_view_real_capture_modifier;
   klass->change_case = ide_source_view_real_change_case;
   klass->clear_count = ide_source_view_real_clear_count;
+  klass->clear_modifier = ide_source_view_real_clear_modifier;
   klass->clear_snippets = ide_source_view_clear_snippets;
   klass->clear_selection = ide_source_view_real_clear_selection;
   klass->cycle_completion = ide_source_view_real_cycle_completion;
@@ -3361,6 +3424,27 @@ ide_source_view_class_init (IdeSourceViewClass *klass)
                   G_TYPE_NONE,
                   0);
 
+  /**
+   * IdeSourceView::capture-modifier:
+   *
+   * This signal will block the main loop in a similar fashion to how
+   * gtk_dialog_run() performs until a key-press has occurred that can be
+   * captured for use in movements.
+   *
+   * Pressing Escape or unfocusing the widget will break from this loop.
+   *
+   * Use of this signal is not recommended except in very specific cases.
+   */
+  gSignals [CAPTURE_MODIFIER] =
+    g_signal_new ("capture-modifier",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+                  G_STRUCT_OFFSET (IdeSourceViewClass, capture_modifier),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE,
+                  0);
+
   gSignals [CHANGE_CASE] =
     g_signal_new ("change-case",
                   G_TYPE_FROM_CLASS (klass),
@@ -3382,6 +3466,16 @@ ide_source_view_class_init (IdeSourceViewClass *klass)
                   G_TYPE_NONE,
                   0);
 
+  gSignals [CLEAR_MODIFIER] =
+    g_signal_new ("clear-modifier",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+                  G_STRUCT_OFFSET (IdeSourceViewClass, clear_modifier),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__VOID,
+                  G_TYPE_NONE,
+                  0);
+
   gSignals [CLEAR_SELECTION] =
     g_signal_new ("clear-selection",
                   G_TYPE_FROM_CLASS (klass),
diff --git a/libide/ide-source-view.h b/libide/ide-source-view.h
index d8fddfa..ababfda 100644
--- a/libide/ide-source-view.h
+++ b/libide/ide-source-view.h
@@ -206,9 +206,11 @@ struct _IdeSourceViewClass
   void (*append_to_count)             (IdeSourceView           *self,
                                        gint                     digit);
   void (*auto_indent)                 (IdeSourceView           *self);
+  void (*capture_modifier)            (IdeSourceView           *self);
   void (*change_case)                 (IdeSourceView           *self,
                                        GtkSourceChangeCaseType  type);
   void (*clear_count)                 (IdeSourceView           *self);
+  void (*clear_modifier)              (IdeSourceView           *self);
   void (*clear_selection)             (IdeSourceView           *self);
   void (*clear_snippets)              (IdeSourceView           *self);
   void (*cycle_completion)            (IdeSourceView           *self,