In RackWidget::setModulePosForce(), if module old position is to the left of the new position, shove other modules to the left instead of the right.

src/app/RackWidget.cpp

@@ -696,30 +696,31 @@ void RackWidget::setModulePosNearest(ModuleWidget* mw, math::Vec pos) {
 }
 
 void RackWidget::setModulePosForce(ModuleWidget* mw, math::Vec pos) {
-	mw->setPosition(pos.div(RACK_GRID_SIZE).round().mult(RACK_GRID_SIZE));
+	math::Rect newBox = mw->box;
+	newBox.pos = (pos / RACK_GRID_SIZE).round() * RACK_GRID_SIZE;
 
 	// Comparison of X coordinates
 	auto cmp = [&](const widget::Widget* a, const widget::Widget* b) {
 		return a->box.pos.x < b->box.pos.x;
 	};
 
-	// Collect modules to the left and right of `mw`
+	// Collect modules to the left and right of pos
 	std::set<widget::Widget*, decltype(cmp)> leftModules(cmp);
 	std::set<widget::Widget*, decltype(cmp)> rightModules(cmp);
 	for (widget::Widget* w2 : internal->moduleContainer->children) {
-		// Skip this module
-		if (w2 == mw)
-			continue;
-		// Reset position to old position
+		// Reset position to old position, including this module
 		auto it = internal->moduleOldPositions.find(w2);
 		if (it != internal->moduleOldPositions.end()) {
 			w2->box.pos = it->second;
 		}
-		// Modules must be on the same row as `mw`
-		if (w2->box.getTop() != mw->box.getTop())
+		// Skip this module
+		if (w2 == mw)
+			continue;
+		// Modules must be on the same row as pos
+		if (w2->box.getTop() != newBox.getTop())
 			continue;
 		// Insert into leftModules or rightModules
-		if (w2->box.getCenter().x < mw->box.getCenter().x)
+		if (w2->box.getCenter().x < newBox.getCenter().x)
 			leftModules.insert(w2);
 		else
 			rightModules.insert(w2);
@@ -729,35 +730,52 @@ void RackWidget::setModulePosForce(ModuleWidget* mw, math::Vec pos) {
 	widget::Widget* rightModule = rightModules.empty() ? NULL : *rightModules.begin();
 
 	if (leftModule) {
-		if (leftModule->box.getRight() > mw->box.getLeft()) {
-			mw->box.pos.x = leftModule->box.getRight();
+		// Place right of leftModule
+		if (leftModule->box.getRight() > newBox.getLeft()) {
+			newBox.pos.x = leftModule->box.getRight();
 		}
 	}
 	if (rightModule) {
-		if (mw->box.getRight() > rightModule->box.getLeft()) {
-			mw->box.pos.x = rightModule->box.getLeft() - mw->box.size.x;
+		// Place left of rightModule
+		if (newBox.getRight() > rightModule->box.getLeft()) {
+			newBox.pos.x = rightModule->box.getLeft() - newBox.size.x;
 		}
 	}
 	if (leftModule && rightModule) {
 		// If there isn't enough space between the last leftModule and first rightModule, place module to the right of the leftModule.
-		if (leftModule->box.getRight() + mw->box.getWidth() > rightModule->box.getLeft()) {
-			mw->box.pos.x = leftModule->box.getRight();
-
-			// Shove right modules
-			float xLimit = mw->box.getRight();
-			for (auto it = rightModules.begin(); it != rightModules.end(); it++) {
-				widget::Widget* w2 = *it;
-				math::Vec newPos = w2->box.pos;
-				newPos.x = xLimit;
-				newPos.x = std::round(newPos.x / RACK_GRID_WIDTH) * RACK_GRID_WIDTH;
-				if (w2->box.pos.x > newPos.x)
-					break;
-				w2->box.pos = newPos;
-				xLimit = w2->box.getRight();
+		if (leftModule->box.getRight() + newBox.getWidth() > rightModule->box.getLeft()) {
+			// If module old position is to the left of the new position, shove other modules to the left instead of the right.
+			if (mw->box.getTop() == newBox.getTop() && mw->box.getLeft() < newBox.getLeft()) {
+				newBox.pos.x = rightModule->box.getLeft() - newBox.size.x;
+
+				// Shove left modules
+				float xLeft = newBox.getLeft();
+				for (auto it = leftModules.rbegin(); it != leftModules.rend(); it++) {
+					widget::Widget* w2 = *it;
+					if (w2->box.getRight() <= xLeft)
+						break;
+					w2->box.pos.x = std::round((xLeft - w2->box.size.x) / RACK_GRID_WIDTH) * RACK_GRID_WIDTH;
+					xLeft = w2->box.getLeft();
+				}
+			}
+			else {
+				newBox.pos.x = leftModule->box.getRight();
+
+				// Shove right modules
+				float xRight = newBox.getRight();
+				for (auto it = rightModules.begin(); it != rightModules.end(); it++) {
+					widget::Widget* w2 = *it;
+					if (w2->box.getLeft() >= xRight)
+						break;
+					w2->box.pos.x = std::round(xRight / RACK_GRID_WIDTH) * RACK_GRID_WIDTH;
+					xRight = w2->box.getRight();
+				}
 			}
 		}
 	}
 
+	mw->box.pos = (newBox.pos / RACK_GRID_SIZE).round() * RACK_GRID_SIZE;
+
 	updateExpanders();
 }