When cloning, pasting, or importing module selection, place modules nearest to center of rack viewport.

include/ui/ScrollWidget.hpp

@@ -23,6 +23,9 @@ struct ScrollWidget : widget::OpaqueWidget {
 
 	ScrollWidget();
 	~ScrollWidget();
+	math::Vec getScrollOffset() {
+		return offset;
+	}
 	void scrollTo(math::Rect r);
 	/** Returns the bound of allowed `offset` values in pixels. */
 	math::Rect getContainerOffsetBound();

include/widget/Widget.hpp

@@ -85,7 +85,7 @@ struct Widget : WeakBase {
 	}
 	/** Returns a subset of the given Rect bounded by the box of this widget and all ancestors.
 	*/
-	virtual math::Rect getViewport(math::Rect r);
+	virtual math::Rect getViewport(math::Rect r = math::Rect::inf());
 
 	template <class T>
 	T* getAncestorOfType() {

src/app/RackWidget.cpp

@@ -401,6 +401,8 @@ static PasteJsonResult RackWidget_pasteJson(RackWidget* that, json_t* rootJ, his
 	that->deselectAll();
 
 	std::map<int64_t, ModuleWidget*> newModules;
+	math::Vec posMin(INFINITY, INFINITY);
+	math::Vec posMax(-INFINITY, -INFINITY);
 
 	// modules
 	json_t* modulesJ = json_object_get(rootJ, "modules");
@@ -435,8 +437,9 @@ static PasteJsonResult RackWidget_pasteJson(RackWidget* that, json_t* rootJ, his
 		double x = 0.0, y = 0.0;
 		json_unpack(posJ, "[F, F]", &x, &y);
 		math::Vec pos = math::Vec(x, y);
-		pos = pos.mult(RACK_GRID_SIZE);
-		mw->box.pos = pos.plus(RACK_OFFSET);
+		mw->box.pos = pos * RACK_GRID_SIZE + RACK_OFFSET;
+		posMin = posMin.min(mw->box.getTopLeft());
+		posMax = posMax.max(mw->box.getBottomRight());
 
 		that->internal->moduleContainer->addChild(mw);
 		that->select(mw);
@@ -444,6 +447,16 @@ static PasteJsonResult RackWidget_pasteJson(RackWidget* that, json_t* rootJ, his
 		newModules[id] = mw;
 	}
 
+	// Adjust center of selection to appear at center of rack view
+	math::Vec posCenter = (posMin + posMax) / 2;
+	math::Vec rackCenter = APP->scene->rack->getViewport().getCenter();
+	math::Vec posDelta = ((rackCenter - posCenter) / RACK_GRID_SIZE).round() * RACK_GRID_SIZE;
+
+	for (auto pair : newModules) {
+		ModuleWidget* mw = pair.second;
+		mw->box.pos += posDelta;
+	}
+
 	// This calls updateExpanders()
 	that->setSelectionPosNearest(math::Vec(0, 0));