It's better if mouse wheel doesn't center the scroll on zoom-in/out

src/app/ui/editor/editor.cpp

@@ -1120,14 +1120,26 @@ bool Editor::isInsideSelection()
     m_document->getMask()->containsPoint(x, y);
 }
 
-void Editor::setZoomAndCenterInMouse(int zoom, int mouse_x, int mouse_y)
+void Editor::setZoomAndCenterInMouse(int zoom, int mouse_x, int mouse_y, ZoomBehavior zoomBehavior)
 {
   View* view = View::getView(this);
   Rect vp = view->getViewportBounds();
   int x, y;
-  bool centerMouse = get_config_bool("Editor", "CenterMouseInZoom", true);
+  bool centerMouse;
   int mx, my;
 
+  switch (zoomBehavior) {
+    case kCofiguredZoomBehavior:
+      centerMouse = get_config_bool("Editor", "CenterMouseInZoom", true);
+      break;
+    case kCenterOnZoom:
+      centerMouse = true;
+      break;
+    case kDontCenterOnZoom:
+      centerMouse = false;
+      break;
+  }
+
   hideDrawingCursor();
   screenToEditor(mouse_x, mouse_y, &x, &y);
 

src/app/ui/editor/editor.h

@@ -70,6 +70,12 @@ namespace app {
       kDefaultEditorFlags = kShowGridFlag | kShowMaskFlag,
     };
 
+    enum ZoomBehavior {
+      kCofiguredZoomBehavior,
+      kCenterOnZoom,
+      kDontCenterOnZoom,
+    };
+
     Editor(Document* document, EditorFlags flags = kDefaultEditorFlags);
     ~Editor();
 
@@ -157,7 +163,7 @@ namespace app {
     // Returns true if the cursor is inside the active mask/selection.
     bool isInsideSelection();
 
-    void setZoomAndCenterInMouse(int zoom, int mouse_x, int mouse_y);
+    void setZoomAndCenterInMouse(int zoom, int mouse_x, int mouse_y, ZoomBehavior zoomBehavior);
 
     bool processKeysToSetZoom(ui::KeyMessage* msg);
 

src/app/ui/editor/keys.cpp

@@ -62,7 +62,8 @@ bool Editor::processKeysToSetZoom(KeyMessage* msg)
 
     // Change zoom
     if (zoom >= 0) {
-      setZoomAndCenterInMouse(zoom, jmouse_x(0), jmouse_y(0));
+      setZoomAndCenterInMouse(zoom, jmouse_x(0), jmouse_y(0),
+        Editor::kCofiguredZoomBehavior);
       return true;
     }
   }

src/app/ui/editor/standby_state.cpp

@@ -356,7 +356,9 @@ bool StandbyState::onMouseWheel(Editor* editor, MouseMessage* msg)
       MouseMessage* mouseMsg = static_cast<MouseMessage*>(msg);
       int zoom = MID(MIN_ZOOM, editor->getZoom()-dz, MAX_ZOOM);
       if (editor->getZoom() != zoom)
-        editor->setZoomAndCenterInMouse(zoom, mouseMsg->position().x, mouseMsg->position().y);
+        editor->setZoomAndCenterInMouse(zoom,
+          mouseMsg->position().x, mouseMsg->position().y,
+          Editor::kDontCenterOnZoom);
       break;
     }
 

src/app/ui/editor/zooming_state.cpp

@@ -60,7 +60,8 @@ bool ZoomingState::onMouseUp(Editor* editor, MouseMessage* msg)
   else if (msg->right() && zoom > 0)
     --zoom;
 
-  editor->setZoomAndCenterInMouse(zoom, msg->position().x, msg->position().y);
+  editor->setZoomAndCenterInMouse(zoom, msg->position().x, msg->position().y,
+    Editor::kCofiguredZoomBehavior);
 
   editor->backToPreviousState();
   editor->releaseMouse();