Merge pull request #759 from fluentribbon/issues/#746

Fixes #746
fluentribbon · Dec 1, 2019 · 1a41dc3 · 1a41dc3
2 parents e0fcbfd + 7f1fe2d
commit 1a41dc3
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diff --git a/Changelog.md b/Changelog.md
@@ -1,5 +1,9 @@
 # Changelog for Fluent.Ribbon
 
+## 7.0.1
+- ### Bug fixes
+  - [#746](../../issues/746) -  NullReferenceException after upgrading to 7.0.0
+
 ## 7.0.0
 - ### Breaking changes
   - [#471](../../issues/471) - **Drop support for .Net 4.0**

diff --git a/Fluent.Ribbon/Controls/RibbonGroupBox.cs b/Fluent.Ribbon/Controls/RibbonGroupBox.cs
@@ -135,7 +135,7 @@ private void UpdateChildSizes()
             {
                 var element = this.ItemContainerGenerator.ContainerFromItem(item);
 
-                if (element == null)
+                if (element is null)
                 {
                     continue;
                 }
@@ -174,24 +174,63 @@ internal int Scale
                 {
                     if (difference > 0)
                     {
-                        this.IncreaseScalableElement();
+                        this.EnlargeScalableItems();
                     }
                     else
                     {
-                        this.DecreaseScalableElement();
+                        this.ReduceScalableItems();
                     }
                 }
             }
         }
 
-        // Finds and increase size of all scalable elements in the given group box
-        private void IncreaseScalableElement()
+        private enum ScaleDirection
+        {
+            Enlarge,
+            Reduce
+        }
+
+        // Finds and increases size of all scalable elements in this group box
+        private void EnlargeScalableItems()
+        {
+            this.ScaleScaleableItems(ScaleDirection.Enlarge);
+        }
+
+        // Finds and decreases size of all scalable elements in this group box
+        private void ReduceScalableItems()
+        {
+            this.ScaleScaleableItems(ScaleDirection.Reduce);
+        }
+
+        private void ScaleScaleableItems(ScaleDirection scaleDirection)
         {
             foreach (var item in this.Items)
             {
-                var scalableRibbonControl = item as IScalableRibbonControl;
+                var element = this.ItemContainerGenerator.ContainerFromItem(item);
+
+                if (element is null
+                    || (element is UIElement uiElement && uiElement.Visibility != Visibility.Visible))
+                {
+                    continue;
+                }
+
+                var scalableRibbonControl = element as IScalableRibbonControl;
 
-                scalableRibbonControl?.Enlarge();
+                if (scalableRibbonControl is null)
+                {
+                    continue;
+                }
+
+                switch (scaleDirection)
+                {
+                    case ScaleDirection.Enlarge:
+                        scalableRibbonControl.Enlarge();
+                        break;
+
+                    case ScaleDirection.Reduce:
+                        scalableRibbonControl.Reduce();
+                        break;
+                }
             }
         }
 
@@ -205,26 +244,19 @@ private void OnScalableControlScaled(object sender, EventArgs e)
         /// </summary>
         internal bool SuppressCacheReseting { get; set; }
 
-        // Finds and decrease size of all scalable elements in the given group box
-        private void DecreaseScalableElement()
+        private void UpdateScalableControlSubscritions(bool registerEvents)
         {
             foreach (var item in this.Items)
             {
-                var scalableRibbonControl = item as IScalableRibbonControl;
+                var element = this.ItemContainerGenerator.ContainerFromItem(item);
 
-                scalableRibbonControl?.Reduce();
-            }
-        }
+                var scalableRibbonControl = element as IScalableRibbonControl;
 
-        private void UpdateScalableControlSubscribing()
-        {
-            this.UpdateScalableControlSubscribing(true);
-        }
+                if (scalableRibbonControl is null)
+                {
+                    continue;
+                }
 
-        private void UpdateScalableControlSubscribing(bool registerEvents)
-        {
-            foreach (var scalableRibbonControl in this.Items.OfType<IScalableRibbonControl>())
-            {
                 // Always unregister first to ensure that we don't subscribe twice
                 scalableRibbonControl.Scaled -= this.OnScalableControlScaled;
 
@@ -638,7 +670,7 @@ private void SubscribeEvents()
             // Always unsubscribe events to ensure we don't subscribe twice
             this.UnSubscribeEvents();
 
-            this.UpdateScalableControlSubscribing();
+            this.UpdateScalableControlSubscritions(true);
 
             if (this.LauncherButton != null)
             {
@@ -654,7 +686,7 @@ private void SubscribeEvents()
 
         private void UnSubscribeEvents()
         {
-            this.UpdateScalableControlSubscribing(false);
+            this.UpdateScalableControlSubscritions(false);
 
             if (this.LauncherButton != null)
             {
@@ -793,7 +825,7 @@ internal Size DesiredSizeIntermediate
                     var contentHeight = UIHelper.GetParent<RibbonTabControl>(this)?.ContentHeight ?? RibbonTabControl.DefaultContentHeight;
 
                     this.SuppressCacheReseting = true;
-                    this.UpdateScalableControlSubscribing();
+                    this.UpdateScalableControlSubscritions(true);
 
                     // Get desired size for these values
                     var backupState = this.State;
@@ -845,7 +877,7 @@ internal void InvalidateLayout()
 
         private static void InvalidateMeasureRecursive(UIElement element)
         {
-            if (element == null)
+            if (element is null)
             {
                 return;
             }
@@ -856,7 +888,7 @@ private static void InvalidateMeasureRecursive(UIElement element)
             {
                 var child = VisualTreeHelper.GetChild(element, i) as UIElement;
 
-                if (child == null)
+                if (child is null)
                 {
                     continue;
                 }
@@ -911,7 +943,7 @@ private void OnPopupClosed(object sender, EventArgs e)
         protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
         {
             if (ReferenceEquals(e.Source, this) == false
-                || this.DropDownPopup == null)
+                || this.DropDownPopup is null)
             {
                 return;
             }
@@ -1065,7 +1097,7 @@ private void OnQuickAccessOpened(object sender, EventArgs e)
                 // Save state
                 this.IsSnapped = true;
 
-                if (this.ItemsSource == null)
+                if (this.ItemsSource is null)
                 {
                     for (var i = 0; i < this.Items.Count; i++)
                     {
@@ -1082,7 +1114,7 @@ private void OnQuickAccessClosed(object sender, EventArgs e)
         {
             var groupBox = (RibbonGroupBox)sender;
 
-            if (this.ItemsSource == null)
+            if (this.ItemsSource is null)
             {
                 for (var i = 0; i < groupBox.Items.Count; i++)
                 {

diff --git a/Fluent.Ribbon/Metro/Behaviours/StylizedBehaviors.cs b/Fluent.Ribbon/Metro/Behaviours/StylizedBehaviors.cs
@@ -163,7 +163,7 @@ private static readonly DependencyProperty OriginalBehaviorProperty
 
         private static Behavior GetOriginalBehavior(DependencyObject obj)
         {
-            return obj.GetValue(OriginalBehaviorProperty) as Behavior;
+            return (Behavior)obj.GetValue(OriginalBehaviorProperty);
         }
 
         private static void SetOriginalBehavior(DependencyObject obj, Behavior value)