Bug #6722, Add UI config option to always use mouse position as zoom focus on scroll

This means that mouse zoom scrolling behaviour is consistent on the ruler
canvas area and track canvas area.

The config option defaults to true so this means the behaviour of Mixbus will
be unchanged but in Ardour the ruler area will now follow the option so by
default will use the mouse position as zoom focus when zooming rather than the
zoom focus setting.

3 files changed, 21 insertions, 8 deletions

diff --git a/gtk2_ardour/editor_canvas_events.cc b/gtk2_ardour/editor_canvas_events.cc
index e821254c9b..58e3dda285 100644
--- a/gtk2_ardour/editor_canvas_events.cc
+++ b/gtk2_ardour/editor_canvas_events.cc
@@ -75,8 +75,11 @@ Editor::track_canvas_scroll (GdkEventScroll* ev)
 	switch (direction) {
 	case GDK_SCROLL_UP:
 		if (Keyboard::modifier_state_equals (ev->state, Keyboard::ScrollZoomHorizontalModifier)) {
-			//for mouse-wheel zoom, force zoom-focus to mouse
-			temporal_zoom_step_mouse_focus (false);
+			if (UIConfiguration::instance().get_use_mouse_position_as_zoom_focus_on_scroll()) {
+				temporal_zoom_step_mouse_focus (false);
+			} else {
+				temporal_zoom_step (false);
+			}
 			return true;
 		} else if (Keyboard::modifier_state_equals (ev->state, Keyboard::ScrollHorizontalModifier)) {
 			scroll_left_step ();
@@ -101,8 +104,11 @@ Editor::track_canvas_scroll (GdkEventScroll* ev)
 
 	case GDK_SCROLL_DOWN:
 		if (Keyboard::modifier_state_equals (ev->state, Keyboard::ScrollZoomHorizontalModifier)) {
-			//for mouse-wheel zoom, force zoom-focus to mouse
-			temporal_zoom_step_mouse_focus (true);
+			if (UIConfiguration::instance().get_use_mouse_position_as_zoom_focus_on_scroll()) {
+				temporal_zoom_step_mouse_focus (true);
+			} else {
+				temporal_zoom_step (true);
+			}
 			return true;
 		} else if (Keyboard::modifier_state_equals (ev->state, Keyboard::ScrollHorizontalModifier)) {
 			scroll_right_step ();
@@ -1025,8 +1031,7 @@ Editor::canvas_ruler_event (GdkEvent *event, ArdourCanvas::Item* item, ItemType
 			if (Keyboard::modifier_state_equals(event->scroll.state,
 			                                    Keyboard::ScrollHorizontalModifier)) {
 				scroll_left_half_page ();
-			} else if (Profile->get_mixbus()) {
-				//for mouse-wheel zoom, force zoom-focus to mouse
+			} else if (UIConfiguration::instance().get_use_mouse_position_as_zoom_focus_on_scroll()) {
 				temporal_zoom_step_mouse_focus (false);
 			} else {
 				temporal_zoom_step (false);
@@ -1038,8 +1043,7 @@ Editor::canvas_ruler_event (GdkEvent *event, ArdourCanvas::Item* item, ItemType
 			if (Keyboard::modifier_state_equals(event->scroll.state,
 			                                    Keyboard::ScrollHorizontalModifier)) {
 				scroll_right_half_page ();
-			} else if (Profile->get_mixbus()) {
-				//for mouse-wheel zoom, force zoom-focus to mouse
+			} else if (UIConfiguration::instance().get_use_mouse_position_as_zoom_focus_on_scroll()) {
 				temporal_zoom_step_mouse_focus (true);
 			} else {
 				temporal_zoom_step (true);
diff --git a/gtk2_ardour/rc_option_editor.cc b/gtk2_ardour/rc_option_editor.cc
index fc904b2109..421e4c56c2 100644
--- a/gtk2_ardour/rc_option_editor.cc
+++ b/gtk2_ardour/rc_option_editor.cc
@@ -2108,6 +2108,14 @@ if (!Profile->get_mixbus()) {
 			    sigc::mem_fun (UIConfiguration::instance(), &UIConfiguration::get_show_zoom_tools),
 			    sigc::mem_fun (UIConfiguration::instance(), &UIConfiguration::set_show_zoom_tools)
 			    ));
+
+	add_option (_("Editor"),
+		    new BoolOption (
+			    "use-mouse-position-as-zoom-focus-on-scroll",
+			    _("Always use mouse cursor position as zoom focus when zooming using mouse scroll wheel"),
+			    sigc::mem_fun (UIConfiguration::instance(), &UIConfiguration::get_use_mouse_position_as_zoom_focus_on_scroll),
+			    sigc::mem_fun (UIConfiguration::instance(), &UIConfiguration::set_use_mouse_position_as_zoom_focus_on_scroll)
+			    ));
 }  // !mixbus
 
 	add_option (_("Editor"),
diff --git a/gtk2_ardour/ui_config_vars.h b/gtk2_ardour/ui_config_vars.h
index 2cf2855390..e512fe397b 100644
--- a/gtk2_ardour/ui_config_vars.h
+++ b/gtk2_ardour/ui_config_vars.h
@@ -49,6 +49,7 @@ UI_CONFIG_VARIABLE (bool, never_display_periodic_midi, "never-display-periodic-m
 UI_CONFIG_VARIABLE (bool, sound_midi_notes, "sound-midi-notes", false)
 UI_CONFIG_VARIABLE (bool, show_plugin_scan_window, "show-plugin-scan-window", false)
 UI_CONFIG_VARIABLE (bool, show_zoom_tools, "show-zoom-tools", true)
+UI_CONFIG_VARIABLE (bool, use_mouse_position_as_zoom_focus_on_scroll, "use-mouse-position-as-zoom-focus-on-scroll", true)
 UI_CONFIG_VARIABLE (bool, widget_prelight, "widget-prelight", true)
 UI_CONFIG_VARIABLE (bool, use_tooltips, "use-tooltips", true)
 UI_CONFIG_VARIABLE (std::string, mixer_strip_visibility, "mixer-element-visibility", "Input,PhaseInvert,RecMon,SoloIsoLock,Output,Comments")