From 09117c4f6d2820883b02a4ef63e455565c186cb0 Mon Sep 17 00:00:00 2001
From: Uwe Rathmann <Uwe.Rathmann@tigertal.de>
Date: Sat, 18 Apr 2020 11:50:44 +0200
Subject: [PATCH] avoid useless constraints

---
 playground/anchors/AnchorBox.cpp | 15 ++++++++-------
 playground/anchors/AnchorBox.h   |  4 ++--
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/playground/anchors/AnchorBox.cpp b/playground/anchors/AnchorBox.cpp
index 5cba5761..5b6ebd68 100644
--- a/playground/anchors/AnchorBox.cpp
+++ b/playground/anchors/AnchorBox.cpp
@@ -229,8 +229,8 @@ void AnchorBox::updateHints()
 
     Solver solver;
 
-    setupAnchorConstraints( solver );
-    setupSizeConstraints( solver );
+    setupAnchorConstraints( false, solver );
+    setupSizeConstraints( true, solver );
 
     {
         solver.updateVariables();
@@ -305,8 +305,8 @@ void AnchorBox::updateVariables( qreal width, qreal height )
 
     if ( !solver.hasConstraints() )
     {
-        setupAnchorConstraints( solver );
-        setupSizeConstraints( solver );
+        setupAnchorConstraints( true, solver );
+        setupSizeConstraints( true, solver );
 
         const double strength = 0.9 * Strength::required;
 
@@ -320,7 +320,7 @@ void AnchorBox::updateVariables( qreal width, qreal height )
     solver.updateVariables();
 }
 
-void AnchorBox::setupAnchorConstraints( Solver& solver )
+void AnchorBox::setupAnchorConstraints( bool layoutChildren, Solver& solver )
 {
     auto& geometries = m_data->geometries;
 
@@ -367,7 +367,7 @@ void AnchorBox::setupAnchorConstraints( Solver& solver )
         solver.addConstraint( expr1 == expr2 );
 
 #if 1
-        if ( anchor.item2 != this )
+        if ( layoutChildren && anchor.item2 != this )
         {
             const auto o = qskOrientation( anchor.edge1 );
 
@@ -386,7 +386,7 @@ void AnchorBox::setupAnchorConstraints( Solver& solver )
     }
 }
 
-void AnchorBox::setupSizeConstraints( Solver& solver )
+void AnchorBox::setupSizeConstraints( bool layoutChildren, Solver& solver )
 {
     auto& geometries = m_data->geometries;
 
@@ -409,6 +409,7 @@ void AnchorBox::setupSizeConstraints( Solver& solver )
                 solver.addConstraint( r.height() >= minSize.height() );
         }
 
+        if ( layoutChildren )
         {
             // preferred size
             const auto prefSize = qskSizeConstraint( item, Qt::PreferredSize );
diff --git a/playground/anchors/AnchorBox.h b/playground/anchors/AnchorBox.h
index 73a6a7ce..57fe526d 100644
--- a/playground/anchors/AnchorBox.h
+++ b/playground/anchors/AnchorBox.h
@@ -40,8 +40,8 @@ class AnchorBox : public QskControl
   private:
     void updateHints();
     void updateVariables( qreal width, qreal height );
-    void setupAnchorConstraints( Solver& );
-    void setupSizeConstraints( Solver& );
+    void setupAnchorConstraints( bool layoutChildren, Solver& );
+    void setupSizeConstraints( bool layoutChildren, Solver& );
 
     class PrivateData;
     std::unique_ptr< PrivateData > m_data;