Refactor SupplementaryItemsControl to improve performance, not rely on parents and not force the parent element to be HorizonAlignment="stretch"

src/Calculator/Calculator.vcxproj

@@ -257,6 +257,7 @@
     <ClInclude Include="Converters\ItemSizeToVisibilityConverter.h" />
     <ClInclude Include="Converters\RadixToStringConverter.h" />
     <ClInclude Include="Converters\VisibilityNegationConverter.h" />
+    <ClInclude Include="Controls\HorizontalNoOverflowStackPanel.h" />
     <ClInclude Include="pch.h" />
     <ClInclude Include="App.xaml.h">
       <DependentUpon>App.xaml</DependentUpon>
@@ -390,6 +391,7 @@
     <ClCompile Include="Converters\ItemSizeToVisibilityConverter.cpp" />
     <ClCompile Include="Converters\RadixToStringConverter.cpp" />
     <ClCompile Include="Converters\VisibilityNegationConverter.cpp" />
+    <ClCompile Include="Controls\HorizontalNoOverflowStackPanel.cpp" />
     <ClCompile Include="pch.cpp">
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Create</PrecompiledHeader>
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">Create</PrecompiledHeader>

src/Calculator/Controls/HorizontalNoOverflowStackPanel.cpp

@@ -0,0 +1,66 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+//
+// HorizontalNoOverflowStackPanel.xaml.cpp
+// Implementation of the HorizontalNoOverflowStackPanel class
+//
+
+#include "pch.h"
+#include "HorizontalNoOverflowStackPanel.h"
+
+using namespace std;
+using namespace CalculatorApp::Controls;
+using namespace Windows::Foundation;
+
+Size HorizontalNoOverflowStackPanel::MeasureOverride(Size availableSize)
+{
+    float maxHeight = 0;
+    float width = 0;
+    for (auto child : Children)
+    {
+        child->Measure(Size(numeric_limits<float>::infinity(), numeric_limits<float>::infinity()));
+        maxHeight = max(maxHeight, child->DesiredSize.Height);
+        width += child->DesiredSize.Width;
+    }
+    return Size(min(width, availableSize.Width), min(availableSize.Height, maxHeight));
+}
+
+bool HorizontalNoOverflowStackPanel::ShouldPrioritizeLastItem()
+{
+    return false;
+}
+
+Size HorizontalNoOverflowStackPanel::ArrangeOverride(Size finalSize)
+{
+    float posX = 0;
+    if (Children->Size == 0)
+        return finalSize;
+
+    auto lastChild = Children->GetAt(Children->Size - 1);
+    float lastChildWidth = 0;
+    if (Children->Size > 2 && ShouldPrioritizeLastItem())
+        lastChildWidth = lastChild->DesiredSize.Width;
+    for (auto item : Children)
+    {
+        auto widthAvailable = finalSize.Width - posX;
+        if (item != lastChild)
+        {
+            widthAvailable -= lastChildWidth;
+        }
+        float itemWidth = item->DesiredSize.Width;
+        if (widthAvailable > 0 && itemWidth <= widthAvailable)
+        {
+            //stack the items horizontally (left to right)
+            item->Arrange(Rect(posX, 0, itemWidth, finalSize.Height));
+            posX += item->DesiredSize.Width;
+        }
+        else
+        {
+            //Not display the item
+            item->Arrange(Rect(0, 0, 0, 0));
+        }
+    }
+    return finalSize;
+}
+

src/Calculator/Controls/HorizontalNoOverflowStackPanel.h

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+//
+// HorizontalNoOverflowStackPanel.h
+// Declaration of the HorizontalNoOverflowStackPanel class
+//
+
+#pragma once
+#include "CalcViewModel/Common/Utils.h"
+
+namespace CalculatorApp
+{
+    namespace Controls
+    {
+        public ref class HorizontalNoOverflowStackPanel : public Windows::UI::Xaml::Controls::Panel
+        {
+            DEPENDENCY_PROPERTY_OWNER(HorizontalNoOverflowStackPanel);
+            //Prioritize the last item over all other items (except the first one)
+        internal:
+            HorizontalNoOverflowStackPanel() {}
+        protected:
+            virtual Windows::Foundation::Size MeasureOverride(Windows::Foundation::Size availableSize) override;
+            virtual Windows::Foundation::Size ArrangeOverride(Windows::Foundation::Size finalSize) override;
+            virtual bool ShouldPrioritizeLastItem();
+        };
+    }
+}

src/Calculator/Controls/SupplementaryItemsControl.cpp

@@ -38,5 +38,3 @@ void SupplementaryItemsControl::PrepareContainerForItemOverride(DependencyObject
  {
      return ref new SupplementaryContentPresenterAP(this);
  }
-
-

src/Calculator/Views/SupplementaryResults.xaml

@@ -80,7 +80,7 @@
             <Setter Property="ItemsPanel">
                 <Setter.Value>
                     <ItemsPanelTemplate>
-                        <StackPanel Orientation="Horizontal"/>
+                        <local:SupplementaryResultNoOverflowStackPanel/>
                     </ItemsPanelTemplate>
                 </Setter.Value>
             </Setter>
@@ -102,6 +102,6 @@
                                             Style="{ThemeResource SupplementaryValuesStyle}"
                                             IsTextScaleFactorEnabled="False"
                                             ItemTemplateSelector="{StaticResource ResultTemplateSelector}"
-                                            LayoutUpdated="OnSupplementaryValuesLayoutUpdated"/>
+                                            ItemsSource="{x:Bind Results, Mode=OneWay}"/>
     </StackPanel>
 </UserControl>

src/Calculator/Views/SupplementaryResults.xaml.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 //
@@ -27,6 +27,8 @@ using namespace Windows::UI::Xaml::Navigation;
 
 // The User Control item template is documented at https://go.microsoft.com/fwlink/?LinkId=234236
 
+DEPENDENCY_PROPERTY_INITIALIZATION(SupplementaryResults, Results);
+
 Object^ DelighterUnitToStyleConverter::Convert(Object^ value, TypeName /*targetType*/, Object^ /*parameter*/, String^ /*language*/)
 {
     Unit^ unit = safe_cast<Unit^>(value);
@@ -66,70 +68,17 @@ SupplementaryResults::SupplementaryResults() :
     m_data(ref new Vector<SupplementaryResult^>)
 {
     InitializeComponent();
-
-    this->Loaded += ref new RoutedEventHandler(this, &SupplementaryResults::OnLoaded);
 }
 
-void SupplementaryResults::RefreshData()
+bool SupplementaryResultNoOverflowStackPanel::ShouldPrioritizeLastItem()
 {
-    // Copy the list so that when we chop stuff off, we don't modify the original
-    // complete list.
-    m_data->Clear();
-    for(SupplementaryResult^ sr : safe_cast<UnitConverterViewModel^>(this->DataContext)->SupplementaryResults)
-    {
-        m_data->Append(sr);
-    }
-
-    // Set as source
-    SupplementaryValues->ItemsSource = m_data;
-}
-
-void SupplementaryResults::OnLoaded(Object^ sender, RoutedEventArgs^ e)
-{
-    UnitConverterViewModel^ vm = safe_cast<UnitConverterViewModel^>(this->DataContext);
-    vm->PropertyChanged += ref new PropertyChangedEventHandler(this, &SupplementaryResults::OnConverterPropertyChanged);
-    Window::Current->SizeChanged += ref new WindowSizeChangedEventHandler(this, &SupplementaryResults::OnWindowSizeChanged);
-    // We may be loaded into a state where we need to render (like rehydrate), so prepare data
-    RefreshData();
-}
-
-void SupplementaryResults::OnConverterPropertyChanged(Object^ /*sender*/, PropertyChangedEventArgs^ e)
-{
-    if (e->PropertyName == UnitConverterViewModelProperties::SupplementaryResults)
-    {
-        RefreshData();
-    }
-}
-
-void SupplementaryResults::OnWindowSizeChanged(Platform::Object^ sender, Windows::UI::Core::WindowSizeChangedEventArgs^ e)
-{
-    // to reload supplementary results every time the window is resized
-    RefreshData();
-}
-
-void SupplementaryResults::OnSupplementaryValuesLayoutUpdated(Platform::Object^ sender, Platform::Object^ e)
-{
-    // This means we overflowed and are cutting off, or in a very rare case we fit exactly. Unfortunately
-    // the fitting exactly case will still have an item removed, as there is no other way for us to
-    // detect that we need to trim.
-    Grid^ parentGrid = dynamic_cast<Grid^>(VisualTreeHelper::GetParent(this));
-    if (parentGrid != nullptr)
-    {
-        double parentWidth = parentGrid->ActualWidth;
-        if (SupplementaryValues && SupplementaryValues->ActualWidth >= parentWidth)
-        {
-            if (m_data->Size > 0)
-            {
-                SupplementaryResult^ last = m_data->GetAt(m_data->Size - 1);
-                if (!last->IsWhimsical() || m_data->Size <= 2)
-                {
-                    m_data->RemoveAtEnd();
-                }
-                else
-                {
-                    m_data->RemoveAt(m_data->Size - 2);
-                }
-            }
-        }
-    }
+    if (Children->Size == 0)
+        return false;
+    auto lastChild = dynamic_cast<FrameworkElement^>(Children->GetAt(Children->Size - 1));
+    if (lastChild == nullptr)
+        return false;
+    auto suppResult = dynamic_cast<SupplementaryResult^>(lastChild->DataContext);
+    if (suppResult == nullptr)
+        return false;
+    return suppResult->IsWhimsical();
 }

src/Calculator/Views/SupplementaryResults.xaml.h

@@ -12,6 +12,7 @@
 #include "Controls/SupplementaryItemsControl.h"
 #include "Controls/OperandTextBox.h"
 #include "Controls/OperatorTextBox.h"
+#include "Controls/HorizontalNoOverflowStackPanel.h"
 #include "CalcViewModel/UnitConverterViewModel.h"
 
 namespace CalculatorApp
@@ -58,18 +59,23 @@ namespace CalculatorApp
         Windows::UI::Xaml::DataTemplate^ m_delighterTemplate;
     };
 
+    public ref class SupplementaryResultNoOverflowStackPanel sealed: public CalculatorApp::Controls::HorizontalNoOverflowStackPanel
+    {
+    protected:
+        virtual bool ShouldPrioritizeLastItem() override;
+    };
+
     [Windows::Foundation::Metadata::WebHostHidden]
     public ref class SupplementaryResults sealed
     {
     public:
         SupplementaryResults();
-
+        DEPENDENCY_PROPERTY_OWNER(SupplementaryResults);
+        DEPENDENCY_PROPERTY_WITH_DEFAULT(Windows::Foundation::Collections::IIterable<ViewModel::SupplementaryResult^>^, Results, nullptr);
     private:
         void RefreshData();
         void OnLoaded(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
         void OnConverterPropertyChanged(Platform::Object^ sender, Windows::UI::Xaml::Data::PropertyChangedEventArgs^ e);
-        void OnSupplementaryValuesLayoutUpdated(Platform::Object^ sender, Platform::Object^ e);
-        void OnWindowSizeChanged(Platform::Object^ sender, Windows::UI::Core::WindowSizeChangedEventArgs^ e);
         Windows::Foundation::Collections::IObservableVector<ViewModel::SupplementaryResult^>^ m_data;
     };
 }

src/Calculator/Views/UnitConverter.xaml

@@ -599,6 +599,7 @@
             <local:SupplementaryResults x:Name="SupplementaryResults"
                                         HorizontalAlignment="Left"
                                         VerticalAlignment="Center"
+                                        Results="{x:Bind Model.SupplementaryResults, Mode=OneWay}"
                                         Visibility="{x:Bind Model.SupplementaryVisibility, Mode=OneWay}"/>
             <StackPanel Visibility="{x:Bind Model.IsCurrencyCurrentCategory, Mode=OneWay, Converter={StaticResource BooleanToVisibilityConverter}}">
                 <!-- Currency Ratio Equality -->