Improve efficiency when validating an ALM layout.

src/libs/alm/ALMLayout.cpp

@@ -1016,12 +1016,6 @@ BALMLayout::UpdateConstraints(BLayoutContext* context)
 	for (int i = 0; i < CountItems(); i++)
 		AreaFor(ItemAt(i))->InvalidateSizeConstraints();
 	fRowColumnManager->UpdateConstraints();
-
-	if (context) {
-		BSize size(LayoutArea().Size());
-		Right()->SetRange(size.width, size.width);
-		Bottom()->SetRange(size.height, size.height);
-	}
 }
 
 

src/libs/alm/SharedSolver.cpp

@@ -194,11 +194,17 @@ SharedSolver::ValidateLayout(BLayoutContext* context)
 	if (fLayoutValid && fLayoutContext == context)
 		return;
 
-	fConstraintsValid = false;
 	_SetContext(context);
 	_ValidateConstraints();
-	fLayoutResult = fLinearSpec.Solve();
 
+	for (int32 i = fLayouts.CountItems() - 1; i >= 0; i--) {
+		BALMLayout* layout = fLayouts.ItemAt(i);
+		BSize size(layout->LayoutArea().Size());
+		layout->Right()->SetRange(size.width, size.width);
+		layout->Bottom()->SetRange(size.height, size.height);
+	}
+
+	fLayoutResult = fLinearSpec.Solve();
 	fLayoutValid = true;
 }