Add settings to pan canvas editor with scrolling

This feature is mainly designed for developers who uses touchpad instead of mouse, and want to scroll instead of zoom. Every macOS developers will like it since it feels intuitive.

2 new settings are added to “editors/2d”:

scroll_to_pan: turn on to use mouse/touchpad scroll to pan canvas item editor view instead of zoom
pan_speed: use this value to change scroll speed

2 files changed, 50 insertions, 20 deletions

diff --git a/editor/editor_settings.cpp b/editor/editor_settings.cpp
index 3dab1707a1..ec7e7597d5 100644
--- a/editor/editor_settings.cpp
+++ b/editor/editor_settings.cpp
@@ -614,6 +614,8 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 	set("editors/2d/bone_ik_color", Color(0.9, 0.9, 0.45, 0.9));
 	set("editors/2d/keep_margins_when_changing_anchors", false);
 	set("editors/2d/warped_mouse_panning", true);
+	set("editors/2d/scroll_to_pan", false);
+	set("editors/2d/pan_speed", 20);
 
 	set("editors/poly_editor/point_grab_radius", 8);
 
diff --git a/editor/plugins/canvas_item_editor_plugin.cpp b/editor/plugins/canvas_item_editor_plugin.cpp
index e6c08a9009..803e59469c 100644
--- a/editor/plugins/canvas_item_editor_plugin.cpp
+++ b/editor/plugins/canvas_item_editor_plugin.cpp
@@ -1010,8 +1010,7 @@ void CanvasItemEditor::_list_select(const Ref<InputEventMouseButton> &b) {
 			selection_menu->add_item(item->get_name());
 			selection_menu->set_item_icon(i, icon);
 			selection_menu->set_item_metadata(i, node_path);
-			selection_menu->set_item_tooltip(i, String(item->get_name()) +
-														"\nType: " + item->get_class() + "\nPath: " + node_path);
+			selection_menu->set_item_tooltip(i, String(item->get_name()) + "\nType: " + item->get_class() + "\nPath: " + node_path);
 		}
 
 		additive_selection = b->get_shift();
@@ -1047,17 +1046,25 @@ void CanvasItemEditor::_viewport_gui_input(const Ref<InputEvent> &p_event) {
 
 		if (b->get_button_index() == BUTTON_WHEEL_DOWN) {
 
-			if (zoom < MIN_ZOOM)
-				return;
+			if (bool(EditorSettings::get_singleton()->get("editors/2d/scroll_to_pan"))) {
+
+				v_scroll->set_value(v_scroll->get_value() + int(EditorSettings::get_singleton()->get("editors/2d/pan_speed")) / zoom * b->get_factor());
+
+			} else {
+
+				if (zoom < MIN_ZOOM)
+					return;
 
-			float prev_zoom = zoom;
-			zoom = zoom * (1 - (0.05 * b->get_factor()));
-			{
-				Point2 ofs = b->get_position();
-				ofs = ofs / prev_zoom - ofs / zoom;
-				h_scroll->set_value(h_scroll->get_value() + ofs.x);
-				v_scroll->set_value(v_scroll->get_value() + ofs.y);
+				float prev_zoom = zoom;
+				zoom = zoom * (1 - (0.05 * b->get_factor()));
+				{
+					Point2 ofs = b->get_position();
+					ofs = ofs / prev_zoom - ofs / zoom;
+					h_scroll->set_value(h_scroll->get_value() + ofs.x);
+					v_scroll->set_value(v_scroll->get_value() + ofs.y);
+				}
 			}
+
 			_update_scroll(0);
 			viewport->update();
 			return;
@@ -1065,16 +1072,21 @@ void CanvasItemEditor::_viewport_gui_input(const Ref<InputEvent> &p_event) {
 
 		if (b->get_button_index() == BUTTON_WHEEL_UP) {
 
-			if (zoom > MAX_ZOOM)
-				return;
+			if (bool(EditorSettings::get_singleton()->get("editors/2d/scroll_to_pan"))) {
+
+				v_scroll->set_value(v_scroll->get_value() - int(EditorSettings::get_singleton()->get("editors/2d/pan_speed")) / zoom * b->get_factor());
 
-			float prev_zoom = zoom;
-			zoom = zoom * ((0.95 + (0.05 * b->get_factor())) / 0.95);
-			{
-				Point2 ofs = b->get_position();
-				ofs = ofs / prev_zoom - ofs / zoom;
-				h_scroll->set_value(h_scroll->get_value() + ofs.x);
-				v_scroll->set_value(v_scroll->get_value() + ofs.y);
+			} else {
+				if (zoom > MAX_ZOOM) return;
+
+				float prev_zoom = zoom;
+				zoom = zoom * ((0.95 + (0.05 * b->get_factor())) / 0.95);
+				{
+					Point2 ofs = b->get_position();
+					ofs = ofs / prev_zoom - ofs / zoom;
+					h_scroll->set_value(h_scroll->get_value() + ofs.x);
+					v_scroll->set_value(v_scroll->get_value() + ofs.y);
+				}
 			}
 
 			_update_scroll(0);
@@ -1082,6 +1094,22 @@ void CanvasItemEditor::_viewport_gui_input(const Ref<InputEvent> &p_event) {
 			return;
 		}
 
+		if (b->get_button_index() == BUTTON_WHEEL_LEFT) {
+
+			if (bool(EditorSettings::get_singleton()->get("editors/2d/scroll_to_pan"))) {
+
+				h_scroll->set_value(h_scroll->get_value() - int(EditorSettings::get_singleton()->get("editors/2d/pan_speed")) / zoom * b->get_factor());
+			}
+		}
+
+		if (b->get_button_index() == BUTTON_WHEEL_RIGHT) {
+
+			if (bool(EditorSettings::get_singleton()->get("editors/2d/scroll_to_pan"))) {
+
+				h_scroll->set_value(h_scroll->get_value() + int(EditorSettings::get_singleton()->get("editors/2d/pan_speed")) / zoom * b->get_factor());
+			}
+		}
+
 		if (b->get_button_index() == BUTTON_RIGHT) {
 
 			if (b->is_pressed() && (tool == TOOL_SELECT && b->get_alt())) {