change metric-scale on the sides of meterbridge when scrolling

gtk2_ardour/meter_strip.cc

@@ -474,7 +474,12 @@ MeterStrip::meter_metrics_expose (GdkEventExpose *ev)
 void
 MeterStrip::set_metric_mode (int metricmode, ARDOUR::MeterType mt)
 {
+	if (metric_type == mt && _metricmode == metricmode) {
+		return;
+	}
 	metric_type = mt;
+	_metricmode = metricmode;
+
 	_types.clear ();
 	switch(metricmode) {
 		case 0:

gtk2_ardour/meter_strip.h

@@ -65,6 +65,7 @@ class MeterStrip : public Gtk::VBox, public RouteUI
 	void set_meter_type_multi (int, ARDOUR::RouteGroup*, ARDOUR::MeterType);
 
 	void set_metric_mode (int, ARDOUR::MeterType);
+	int  get_metric_mode() { return _metricmode; }
 	void set_tick_bar (int);
 	int  get_tick_bar() { return _tick_bar; }
 	bool has_midi() { return _has_midi; }
@@ -121,6 +122,7 @@ class MeterStrip : public Gtk::VBox, public RouteUI
 	bool _has_midi;
 	int _tick_bar;
 	int _strip_type;
+	int _metricmode;
 
 	LevelMeterHBox *level_meter;
 

gtk2_ardour/meterbridge.cc

@@ -376,6 +376,10 @@ Meterbridge::on_size_allocate (Gtk::Allocation& a)
 	const Gtk::Scrollbar * hsc = scroller.get_hscrollbar();
 
 	if (scroller.get_hscrollbar_visible() && hsc) {
+		if (!scroll_connection.connected()) {
+			scroll_connection = scroller.get_hscrollbar()->get_adjustment()->signal_value_changed().connect(sigc::mem_fun (*this, &Meterbridge::on_scroll));
+			scroller.get_hscrollbar()->get_adjustment()->signal_changed().connect(sigc::mem_fun (*this, &Meterbridge::on_scroll));
+		}
 		gint scrollbar_spacing;
 		gtk_widget_style_get (GTK_WIDGET (scroller.gobj()),
 				"scrollbar-spacing", &scrollbar_spacing, NULL);
@@ -389,6 +393,41 @@ Meterbridge::on_size_allocate (Gtk::Allocation& a)
 	Gtk::Window::on_size_allocate(a);
 }
 
+void
+Meterbridge::on_scroll()
+{
+	if (!scroller.get_hscrollbar()) return;
+
+	Adjustment* adj = scroller.get_hscrollbar()->get_adjustment();
+	int leftend = adj->get_value();
+	int rightend = scroller.get_width() + leftend;
+
+	int mm_left = _mm_left;
+	int mm_right = _mm_right;
+	ARDOUR::MeterType mt_left = _mt_left;
+	ARDOUR::MeterType mt_right = _mt_right;
+
+	for (unsigned int i = 0; i < _metrics.size(); ++i) {
+		int sx, dx, dy;
+		int mm = _metrics[i]->get_metric_mode();
+		sx = (mm & 2) ? _metrics[i]->get_width() : 0;
+
+		_metrics[i]->translate_coordinates(meterarea, sx, 0, dx, dy);
+
+		if (dx < leftend && !(mm&2)) {
+			mm_left = mm;
+			mt_left = _metrics[i]->meter_type();
+		}
+		if (dx > rightend && (mm&2)) {
+			mm_right = mm;
+			mt_right = _metrics[i]->meter_type();
+			break;
+		}
+	}
+	metrics_left.set_metric_mode(mm_left, mt_left);
+	metrics_right.set_metric_mode(mm_right, mt_right);
+}
+
 void
 Meterbridge::set_session (Session* s)
 {
@@ -722,6 +761,13 @@ Meterbridge::sync_order_keys (RouteSortOrderKey)
 		delete (_metrics.back());
 		_metrics.pop_back();
 	}
+
+	_mm_left = metrics_left.get_metric_mode();
+	_mt_left = metrics_left.meter_type();
+	_mm_right = metrics_right.get_metric_mode();
+	_mt_right = metrics_right.meter_type();
+
+	on_scroll();
 	queue_resize();
 }
 

gtk2_ardour/meterbridge.h

@@ -147,6 +147,12 @@ class Meterbridge :
 
 	void parameter_changed (std::string const & p);
 	void on_theme_changed ();
+
+	void on_scroll ();
+	sigc::connection scroll_connection;
+
+	int _mm_left, _mm_right;
+	ARDOUR::MeterType _mt_left, _mt_right;
 };
 
 #endif