From d10a5b2928175b313baf709b480620d755983f36 Mon Sep 17 00:00:00 2001
From: Hugo Locurcio <hugo.locurcio@hugo.pro>
Date: Sat, 30 May 2020 12:29:53 +0200
Subject: [PATCH] Allow mouse zooming without hovering the texture in the
 TileSet editor

This partially addresses
https://github.com/godotengine/godot-proposals/issues/968.
---
 editor/plugins/tile_set_editor_plugin.cpp | 33 ++++++++++++++++-------
 editor/plugins/tile_set_editor_plugin.h   |  1 +
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/editor/plugins/tile_set_editor_plugin.cpp b/editor/plugins/tile_set_editor_plugin.cpp
index 644facd5bd4..b3d4b391d3a 100644
--- a/editor/plugins/tile_set_editor_plugin.cpp
+++ b/editor/plugins/tile_set_editor_plugin.cpp
@@ -569,6 +569,7 @@ TileSetEditor::TileSetEditor(EditorNode *p_editor) {
 	scroll = memnew(ScrollContainer);
 	main_vb->add_child(scroll);
 	scroll->set_v_size_flags(SIZE_EXPAND_FILL);
+	scroll->connect("gui_input", callable_mp(this, &TileSetEditor::_on_scroll_container_input));
 	scroll->set_clip_contents(true);
 
 	empty_message = memnew(Label);
@@ -1198,6 +1199,27 @@ bool TileSetEditor::is_within_grabbing_distance_of_first_point(const Vector2 &p_
 	return distance < p_grab_threshold;
 }
 
+void TileSetEditor::_on_scroll_container_input(const Ref<InputEvent> &p_event) {
+	const Ref<InputEventMouseButton> mb = p_event;
+
+	if (mb.is_valid()) {
+		// Zoom in/out using Ctrl + mouse wheel. This is done on the ScrollContainer
+		// to allow performing this action anywhere, even if the cursor isn't
+		// hovering the texture in the workspace.
+		if (mb->get_button_index() == BUTTON_WHEEL_UP && mb->is_pressed() && mb->get_control()) {
+			print_line("zooming in");
+			_zoom_in();
+			// Don't scroll up after zooming in.
+			accept_event();
+		} else if (mb->get_button_index() == BUTTON_WHEEL_DOWN && mb->is_pressed() && mb->get_control()) {
+			print_line("zooming out");
+			_zoom_out();
+			// Don't scroll down after zooming out.
+			accept_event();
+		}
+	}
+}
+
 void TileSetEditor::_on_workspace_input(const Ref<InputEvent> &p_ie) {
 	if (tileset.is_null() || !get_current_texture().is_valid()) {
 		return;
@@ -1214,8 +1236,8 @@ void TileSetEditor::_on_workspace_input(const Ref<InputEvent> &p_ie) {
 	}
 	current_tile_region.position += WORKSPACE_MARGIN;
 
-	Ref<InputEventMouseButton> mb = p_ie;
-	Ref<InputEventMouseMotion> mm = p_ie;
+	const Ref<InputEventMouseButton> mb = p_ie;
+	const Ref<InputEventMouseMotion> mm = p_ie;
 
 	if (mb.is_valid()) {
 		if (mb->is_pressed() && mb->get_button_index() == BUTTON_LEFT && !creating_shape) {
@@ -1239,13 +1261,6 @@ void TileSetEditor::_on_workspace_input(const Ref<InputEvent> &p_ie) {
 				delete tiles;
 			}
 		}
-
-		// Mouse Wheel Event
-		if (mb->get_button_index() == BUTTON_WHEEL_UP && mb->is_pressed() && mb->get_control()) {
-			_zoom_in();
-		} else if (mb->get_button_index() == BUTTON_WHEEL_DOWN && mb->is_pressed() && mb->get_control()) {
-			_zoom_out();
-		}
 	}
 	// Drag Middle Mouse
 	if (mm.is_valid()) {
diff --git a/editor/plugins/tile_set_editor_plugin.h b/editor/plugins/tile_set_editor_plugin.h
index 827325cfd7b..2955dda2449 100644
--- a/editor/plugins/tile_set_editor_plugin.h
+++ b/editor/plugins/tile_set_editor_plugin.h
@@ -200,6 +200,7 @@ private:
 	void _on_workspace_overlay_draw();
 	void _on_workspace_draw();
 	void _on_workspace_process();
+	void _on_scroll_container_input(const Ref<InputEvent> &p_event);
 	void _on_workspace_input(const Ref<InputEvent> &p_ie);
 	void _on_tool_clicked(int p_tool);
 	void _on_priority_changed(float val);