[gimp] app: add "selection-changed" signal to GimpCruveView

[Ell <ell src gnome org>]

commit 91ecca7e10c0bcc18479984c91a190c1e08e49f9
Author: Ell <ell_se yahoo com>
Date:   Fri Apr 19 07:29:40 2019 -0400

    app: add "selection-changed" signal to GimpCruveView
    
    ... which gets emitted when the selected point changes.

 app/widgets/gimpcurveview.c | 31 +++++++++++++++++++++++++++++--
 app/widgets/gimpcurveview.h | 11 ++++++++---
 2 files changed, 37 insertions(+), 5 deletions(-)
---
diff --git a/app/widgets/gimpcurveview.c b/app/widgets/gimpcurveview.c
index f4322777c3..bd6c46df10 100644
--- a/app/widgets/gimpcurveview.c
+++ b/app/widgets/gimpcurveview.c
@@ -56,6 +56,7 @@ enum
 
 enum
 {
+  SELECTION_CHANGED,
   CUT_CLIPBOARD,
   COPY_CLIPBOARD,
   PASTE_CLIPBOARD,
@@ -140,6 +141,7 @@ gimp_curve_view_class_init (GimpCurveViewClass *klass)
   widget_class->leave_notify_event   = gimp_curve_view_leave_notify;
   widget_class->key_press_event      = gimp_curve_view_key_press;
 
+  klass->selection_changed           = NULL;
   klass->cut_clipboard               = gimp_curve_view_cut_clipboard;
   klass->copy_clipboard              = gimp_curve_view_copy_clipboard;
   klass->paste_clipboard             = gimp_curve_view_paste_clipboard;
@@ -179,6 +181,15 @@ gimp_curve_view_class_init (GimpCurveViewClass *klass)
                                                         NULL,
                                                         GIMP_PARAM_READWRITE));
 
+  curve_view_signals[SELECTION_CHANGED] =
+    g_signal_new ("selection-changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_FIRST,
+                  G_STRUCT_OFFSET (GimpCurveViewClass, selection_changed),
+                  NULL, NULL,
+                  gimp_marshal_VOID__VOID,
+                  G_TYPE_NONE, 0);
+
   curve_view_signals[CUT_CLIPBOARD] =
     g_signal_new ("cut-clipboard",
                   G_TYPE_FROM_CLASS (klass),
@@ -1389,9 +1400,25 @@ gimp_curve_view_set_selected (GimpCurveView *view,
 {
   g_return_if_fail (GIMP_IS_CURVE_VIEW (view));
 
-  view->selected = selected;
+  if (selected != view->selected)
+    {
+      view->selected = selected;
 
-  gtk_widget_queue_draw (GTK_WIDGET (view));
+      g_signal_emit (view, curve_view_signals[SELECTION_CHANGED], 0);
+
+      gtk_widget_queue_draw (GTK_WIDGET (view));
+    }
+}
+
+gint
+gimp_curve_view_get_selected (GimpCurveView *view)
+{
+  g_return_val_if_fail (GIMP_IS_CURVE_VIEW (view), -1);
+
+  if (view->curve && view->selected < gimp_curve_get_n_points (view->curve))
+    return view->selected;
+  else
+    return -1;
 }
 
 void
diff --git a/app/widgets/gimpcurveview.h b/app/widgets/gimpcurveview.h
index b41358441e..903c8ec393 100644
--- a/app/widgets/gimpcurveview.h
+++ b/app/widgets/gimpcurveview.h
@@ -81,9 +81,12 @@ struct _GimpCurveViewClass
 {
   GimpHistogramViewClass  parent_class;
 
-  void (* cut_clipboard)   (GimpCurveView *view);
-  void (* copy_clipboard)  (GimpCurveView *view);
-  void (* paste_clipboard) (GimpCurveView *view);
+  /* signals */
+  void (* selection_changed) (GimpCurveView *view);
+
+  void (* cut_clipboard)     (GimpCurveView *view);
+  void (* copy_clipboard)    (GimpCurveView *view);
+  void (* paste_clipboard)   (GimpCurveView *view);
 };
 
 
@@ -106,6 +109,8 @@ void   gimp_curve_view_remove_all_backgrounds (GimpCurveView *view);
 
 void        gimp_curve_view_set_selected      (GimpCurveView *view,
                                                gint           selected);
+gint        gimp_curve_view_get_selected      (GimpCurveView *view);
+
 void        gimp_curve_view_set_range_x       (GimpCurveView *view,
                                                gdouble        min,
                                                gdouble        max);