centered layout: propagate dimension constraints from view

src/vs/base/browser/ui/centered/centeredViewLayout.ts

@@ -32,9 +32,9 @@ function createEmptyView() {
 function toSplitViewView(view: IView, getHeight: () => number): ISplitViewView {
 	return {
 		element: view.element,
-		maximumSize: view.maximumWidth,
-		minimumSize: view.minimumWidth,
-		onDidChange: mapEvent(view.onDidChange, widthAndHeight => widthAndHeight && widthAndHeight.width),
+		get maximumSize() { return view.maximumWidth; },
+		get minimumSize() { return view.minimumWidth; },
+		onDidChange: mapEvent(view.onDidChange, e => e && e.width),
 		layout: size => view.layout(size, getHeight())
 	};
 }

src/vs/base/browser/ui/splitview/splitview.ts

@@ -425,8 +425,17 @@ export class SplitView implements IDisposable {
 
 		size = typeof size === 'number' ? size : item.size;
 		size = clamp(size, item.view.minimumSize, item.view.maximumSize);
-		item.size = size;
-		this.relayout(index);
+
+		if (this.inverseAltBehavior && index > 0) {
+			// In this case, we want the view to grow or shrink both sides equally
+			// so we just resize the "left" side by half and let `resize` do the clamping magic
+			this.resize(index - 1, Math.floor((item.size - size) / 2));
+			this.distributeEmptySpace();
+			this.layoutViews();
+		} else {
+			item.size = size;
+			this.relayout(index, undefined);
+		}
 	}
 
 	resizeView(index: number, size: number): void {