add ctrl-drag on tempo bar/ruler to adjust tempo more directly

gtk2_ardour/editor.h

@@ -2493,6 +2493,7 @@ private:
 	friend class BBTRulerDrag;
 	friend class MeterMarkerDrag;
 	friend class TempoMarkerDrag;
+	friend class TempoCurveDrag;
 	friend class TempoTwistDrag;
 	friend class TempoEndDrag;
 	friend class CursorDrag;

gtk2_ardour/editor_drag.cc

@@ -3530,6 +3530,83 @@ MeterMarkerDrag::aborted (bool moved)
 
 }
 
+TempoCurveDrag::TempoCurveDrag (Editor* e, ArdourCanvas::Item* i)
+	: Drag (e, i, Temporal::BeatTime)
+{
+}
+
+void
+TempoCurveDrag::start_grab (GdkEvent* event, Gdk::Cursor* cursor)
+{
+	Drag::start_grab (event, cursor);
+	/* setup thread-local tempo map ptr as a writable copy */
+	map = _editor->begin_tempo_map_edit ();
+	TempoCurve* tc = reinterpret_cast<TempoCurve*> (_item->get_data (X_("tempo curve")));
+	if (!tc) {
+		point = const_cast<TempoPoint*> (&map->tempo_at (raw_grab_time()));
+	} else {
+		point = const_cast<TempoPoint*> (&tc->tempo());
+	}
+	initial_bpm = point->note_types_per_minute();
+}
+
+void
+TempoCurveDrag::motion (GdkEvent* event, bool first_move)
+{
+	if (first_move) {
+		/* get current state */
+		_before_state = &map->get_state();
+		_editor->begin_reversible_command (_("change tempo"));
+	}
+
+	double new_bpm = std::max (1.5, initial_bpm - ((current_pointer_x() - grab_x()) / 5.0));
+	stringstream strs;
+	Temporal::Tempo new_tempo (new_bpm, point->note_type());
+	map->change_tempo (*point, new_tempo);
+	strs << "Tempo: " << fixed << setprecision(3) << new_bpm;
+	show_verbose_cursor_text (strs.str());
+
+	_editor->mid_tempo_change ();
+}
+
+
+void
+TempoCurveDrag::finished (GdkEvent* event, bool movement_occurred)
+{
+	if (!movement_occurred) {
+		/* reset the per-thread tempo map ptr back to the current
+		 * official version
+		 */
+
+		_editor->abort_tempo_map_edit ();
+
+		if (was_double_click()) {
+			// XXX would be nice to do this
+			// _editor->edit_tempo_marker (*_marker);
+		}
+
+		return;
+	}
+
+	/* push the current state of our writable map copy */
+
+	TempoMap::update (map);
+	XMLNode &after = map->get_state();
+
+	_editor->session()->add_command (new Temporal::TempoCommand (_("change tempo"), _before_state, &after));
+	_editor->commit_reversible_command ();
+}
+
+void
+TempoCurveDrag::aborted (bool moved)
+{
+	/* reset the per-thread tempo map ptr back to the current
+	 * official version
+	 */
+
+	_editor->abort_tempo_map_edit ();
+}
+
 TempoMarkerDrag::TempoMarkerDrag (Editor* e, ArdourCanvas::Item* i)
 	: Drag (e, i, Temporal::BeatTime)
 	, _grab_bpm (120.0, 4.0)

gtk2_ardour/editor_drag.h

@@ -76,6 +76,7 @@ class MidiRegionView;
 class MeterMarker;
 class ArdourMarker;
 class TempoMarker;
+class TempoCurve;
 class ControlPoint;
 class AudioRegionView;
 class AutomationLine;
@@ -860,6 +861,24 @@ private:
 	XMLNode* before_state;
 };
 
+/** Tempo curve drag */
+class TempoCurveDrag : public Drag
+{
+public:
+	TempoCurveDrag (Editor*, ArdourCanvas::Item*);
+
+	void start_grab (GdkEvent *, Gdk::Cursor* c = 0);
+	void motion (GdkEvent *, bool);
+	void finished (GdkEvent *, bool);
+	void aborted (bool);
+
+private:
+	Temporal::TempoPoint* point;
+	double initial_bpm;
+	Temporal::TempoMap::WritableSharedPtr map;
+	XMLNode* _before_state;
+};
+
 /** Tempo marker drag */
 class TempoMarkerDrag : public Drag
 {

gtk2_ardour/editor_mouse.cc

@@ -816,9 +816,14 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 		return true;
 		break;
 
-	case MarkerBarItem:
 	case TempoBarItem:
 	case TempoCurveItem:
+		if (Keyboard::modifier_state_equals (event->button.state, Keyboard::PrimaryModifier)) {
+			_drags->set (new TempoCurveDrag (this, item), event);
+			return true;
+		}
+		/* fallthru */
+	case MarkerBarItem:
 	case MeterBarItem:
 	case TimecodeRulerItem:
 	case SamplesRulerItem:

gtk2_ardour/tempo_curve.cc

@@ -99,13 +99,14 @@ TempoCurve::TempoCurve (PublicEditor& ed, ArdourCanvas::Item& parent, guint32 rg
 	 * make sure they can both be used to lookup this object.
 	 */
 
-	_curve->set_data ("tempo curve", this);
+	_curve->set_data (X_("tempo curve"), this);
 
 	if (handle_events) {
-		//group->Event.connect (sigc::bind (sigc::mem_fun (editor, &PublicEditor::canvas_marker_event), group, this));
+		// group->Event.connect (sigc::bind (sigc::mem_fun (editor, &PublicEditor::canvas_marker_event), group, this));
 	}
 
 	group->Event.connect (sigc::bind (sigc::mem_fun (editor, &PublicEditor::canvas_tempo_curve_event), _curve, this));
+	_curve->Event.connect (sigc::bind (sigc::mem_fun (editor, &PublicEditor::canvas_tempo_curve_event), _curve, this));
 
 }