add optional arg to Editor::ensure_time_axis_view_is_visible() to "force" "make it visible as the top track" behaviour

4 files changed, 20 insertions, 8 deletions

diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 3bc094d165..e93afebea3 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -178,6 +178,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void set_internal_edit (bool yn);
 	bool toggle_internal_editing_from_double_click (GdkEvent*);
 
+        void _ensure_time_axis_view_is_visible (const TimeAxisView& tav, bool at_top);
 	void foreach_time_axis_view (sigc::slot<void,TimeAxisView&>);
 	void add_to_idle_resize (TimeAxisView*, int32_t);
 
@@ -350,7 +351,6 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 
 	void show_window ();
 
-	void ensure_time_axis_view_is_visible (const TimeAxisView& tav);
 	void scroll_tracks_down_line ();
 	void scroll_tracks_up_line ();
         bool scroll_up_one_track ();
diff --git a/gtk2_ardour/editor_canvas.cc b/gtk2_ardour/editor_canvas.cc
index 2303f50ece..4c0ca25eb5 100644
--- a/gtk2_ardour/editor_canvas.cc
+++ b/gtk2_ardour/editor_canvas.cc
@@ -731,19 +731,26 @@ Editor::entered_track_canvas (GdkEventCrossing */*ev*/)
 }
 
 void
-Editor::ensure_time_axis_view_is_visible (const TimeAxisView& tav)
+Editor::_ensure_time_axis_view_is_visible (const TimeAxisView& tav, bool at_top)
 {
 	double begin = tav.y_position();
-
 	double v = vertical_adjustment.get_value ();
 
-	if (begin < v || begin + tav.current_height() > v + _visible_canvas_height) {
+	if (!at_top && (begin < v || begin + tav.current_height() > v + _visible_canvas_height)) {
 		/* try to put the TimeAxisView roughly central */
 		if (begin >= _visible_canvas_height/2.0) {
 			begin -= _visible_canvas_height/2.0;
 		}
-		vertical_adjustment.set_value (begin);
 	}
+
+	/* Clamp the y pos so that we do not extend beyond the canvas full
+	 * height. 
+	 */
+	if (_full_canvas_height - begin < _visible_canvas_height){
+		begin = _full_canvas_height - _visible_canvas_height;
+	}
+
+	vertical_adjustment.set_value (begin);
 }
 
 /** Called when the main vertical_adjustment has changed */
diff --git a/gtk2_ardour/editor_routes.cc b/gtk2_ardour/editor_routes.cc
index c9514e81c3..38706a6525 100644
--- a/gtk2_ardour/editor_routes.cc
+++ b/gtk2_ardour/editor_routes.cc
@@ -1293,7 +1293,7 @@ EditorRoutes::button_press (GdkEventButton* ev)
 		TimeAxisView *tv = row[_columns.tv];
 
 		if (tv) {
-			_editor->ensure_time_axis_view_is_visible (*tv);
+			_editor->ensure_time_axis_view_is_visible (*tv, true);
 		}
 	}
 
@@ -1322,7 +1322,7 @@ EditorRoutes::selection_changed ()
 		}
 
 		_editor->get_selection().set (selected);
-		_editor->ensure_time_axis_view_is_visible (*(selected.front()));
+		_editor->ensure_time_axis_view_is_visible (*(selected.front()), true);
 
 	} else {
 		_editor->get_selection().clear_tracks ();
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index 47d08af7f1..66f8ca9aa0 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -267,7 +267,9 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible, publi
 	virtual framecnt_t current_page_samples() const = 0;
 	virtual double visible_canvas_height () const = 0;
 	virtual void temporal_zoom_step (bool coarser) = 0;
-	virtual void ensure_time_axis_view_is_visible (const TimeAxisView& tav) = 0;
+        virtual void ensure_time_axis_view_is_visible (const TimeAxisView& tav, bool at_top = false) { 
+	    _ensure_time_axis_view_is_visible (tav, at_top);
+	}
 	virtual void scroll_tracks_down_line () = 0;
 	virtual void scroll_tracks_up_line () = 0;
         virtual bool scroll_down_one_track () = 0;
@@ -409,6 +411,9 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible, publi
 
 	PBD::Signal0<void> SnapChanged;
 	PBD::Signal0<void> MouseModeChanged;
+
+  protected:
+       virtual void _ensure_time_axis_view_is_visible (const TimeAxisView& tav, bool at_top) = 0;
 };
 
 #endif // __gtk_ardour_public_editor_h__