From b2dd55a64f6f62abadf6d5d9eaf0e420bb04cb3b Mon Sep 17 00:00:00 2001
From: Pepe Rivera <joseartrivera@gmail.com>
Date: Mon, 23 Sep 2019 11:51:08 -0700
Subject: [PATCH] Switch to RichEdit math mode in EquationTextBox (#672)

* Use RichEdit Math Mode

* Add comment

Co-Authored-By: Stephanie Anderl <46726333+sanderl@users.noreply.github.com>
---
 src/CalcManager/CalcManager.vcxproj           |   2 +-
 src/CalcViewModel/CalcViewModel.vcxproj       |   2 +-
 src/Calculator/App.xaml                       |   3 +-
 src/Calculator/Calculator.vcxproj             |   2 +-
 src/Calculator/Controls/EquationTextBox.cpp   | 123 ++++++++++++------
 src/Calculator/Controls/EquationTextBox.h     |   7 +-
 .../GraphingCalculator/EquationInputArea.xaml |   2 +-
 .../EquationInputArea.xaml.cpp                |  17 +--
 .../EquationInputArea.xaml.h                  |   2 +-
 .../CalculatorUnitTests.vcxproj               |   2 +-
 .../NavCategoryUnitTests.cpp                  |   2 +-
 src/GraphControl/Control/Equation.cpp         |  22 +++-
 src/GraphControl/Control/Grapher.cpp          |   8 +-
 src/GraphControl/GraphControl.vcxproj         |   2 +-
 src/MockGraphingImpl/MockGraphingImpl.vcxproj |   2 +-
 15 files changed, 126 insertions(+), 72 deletions(-)

diff --git a/src/CalcManager/CalcManager.vcxproj b/src/CalcManager/CalcManager.vcxproj
index 7022cd3..00803dc 100644
--- a/src/CalcManager/CalcManager.vcxproj
+++ b/src/CalcManager/CalcManager.vcxproj
@@ -45,7 +45,7 @@
     <AppContainerApplication>true</AppContainerApplication>
     <ApplicationType>Windows Store</ApplicationType>
     <ApplicationTypeRevision>10.0</ApplicationTypeRevision>
-    <WindowsTargetPlatformVersion Condition="'$(WindowsTargetPlatformVersion)' == ''">10.0.18362.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion Condition="'$(WindowsTargetPlatformVersion)' == ''">10.0.18970.0</WindowsTargetPlatformVersion>
     <WindowsTargetPlatformMinVersion>10.0.17134.0</WindowsTargetPlatformMinVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
diff --git a/src/CalcViewModel/CalcViewModel.vcxproj b/src/CalcViewModel/CalcViewModel.vcxproj
index f5085a2..5ca5e03 100644
--- a/src/CalcViewModel/CalcViewModel.vcxproj
+++ b/src/CalcViewModel/CalcViewModel.vcxproj
@@ -42,7 +42,7 @@
     <MinimumVisualStudioVersion>14.0</MinimumVisualStudioVersion>
     <AppContainerApplication>true</AppContainerApplication>
     <ApplicationType>Windows Store</ApplicationType>
-    <WindowsTargetPlatformVersion>10.0.18362.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion>10.0.18970.0</WindowsTargetPlatformVersion>
     <WindowsTargetPlatformMinVersion>10.0.17134.0</WindowsTargetPlatformMinVersion>
     <ApplicationTypeRevision>10.0</ApplicationTypeRevision>
   </PropertyGroup>
diff --git a/src/Calculator/App.xaml b/src/Calculator/App.xaml
index cff324d..6f25c2b 100644
--- a/src/Calculator/App.xaml
+++ b/src/Calculator/App.xaml
@@ -1628,6 +1628,7 @@
                                 <Button x:Name="EquationButton"
                                         MinWidth="44"
                                         MinHeight="44"
+                                        VerticalAlignment="Stretch"
                                         Background="{TemplateBinding EquationColor}"
                                         Foreground="{StaticResource SystemChromeWhiteColor}"
                                         Content="ƒₓ">
@@ -1651,7 +1652,7 @@
                                             <ColumnDefinition Width="Auto"/>
                                         </Grid.ColumnDefinitions>
                                         <RichEditBox x:Name="EquationTextBox"
-                                                     MinHeight="42"
+                                                     MinHeight="44"
                                                      Padding="{TemplateBinding Padding}"
                                                      VerticalAlignment="Stretch"
                                                      Style="{StaticResource EquationTextBoxStyle}"
diff --git a/src/Calculator/Calculator.vcxproj b/src/Calculator/Calculator.vcxproj
index 7e70004..468d397 100644
--- a/src/Calculator/Calculator.vcxproj
+++ b/src/Calculator/Calculator.vcxproj
@@ -8,7 +8,7 @@
     <MinimumVisualStudioVersion>15.0</MinimumVisualStudioVersion>
     <AppContainerApplication>true</AppContainerApplication>
     <ApplicationType>Windows Store</ApplicationType>
-    <WindowsTargetPlatformVersion Condition="'$(WindowsTargetPlatformVersion)' == ''">10.0.18362.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion Condition="'$(WindowsTargetPlatformVersion)' == ''">10.0.18970.0</WindowsTargetPlatformVersion>
     <WindowsTargetPlatformMinVersion>10.0.18362.0</WindowsTargetPlatformMinVersion>
     <!-- We want to manually control the MinVersion/MaxVersionTested in the manifest so turn of the replacement. -->
     <AppxOSMinVersionReplaceManifestVersion>false</AppxOSMinVersionReplaceManifestVersion>
diff --git a/src/Calculator/Controls/EquationTextBox.cpp b/src/Calculator/Controls/EquationTextBox.cpp
index 6416bcc..e3429bd 100644
--- a/src/Calculator/Controls/EquationTextBox.cpp
+++ b/src/Calculator/Controls/EquationTextBox.cpp
@@ -11,12 +11,14 @@ using namespace CalculatorApp;
 using namespace CalculatorApp::Common;
 using namespace CalculatorApp::Controls;
 using namespace CalculatorApp::ViewModel;
+using namespace Windows::System;
 using namespace Windows::Foundation;
+using namespace Windows::ApplicationModel;
+using namespace Windows::UI::Text;
 using namespace Windows::UI::Xaml;
 using namespace Windows::UI::Xaml::Controls;
 using namespace Windows::UI::Xaml::Input;
 using namespace Windows::UI::Xaml::Controls::Primitives;
-using namespace Windows::UI::Text;
 
 DEPENDENCY_PROPERTY_INITIALIZATION(EquationTextBox, EquationColor);
 DEPENDENCY_PROPERTY_INITIALIZATION(EquationTextBox, KeyGraphFeaturesContent);
@@ -24,18 +26,20 @@ DEPENDENCY_PROPERTY_INITIALIZATION(EquationTextBox, ColorChooserFlyout);
 
 void EquationTextBox::OnApplyTemplate()
 {
-    m_equationButton = dynamic_cast<Button^>(GetTemplateChild("EquationButton"));
-    m_richEditBox = dynamic_cast<RichEditBox^>(GetTemplateChild("EquationTextBox"));
-    m_deleteButton = dynamic_cast<Button^>(GetTemplateChild("DeleteButton"));
-    m_removeButton = dynamic_cast<Button^>(GetTemplateChild("RemoveButton"));
-    m_functionButton = dynamic_cast<Button^>(GetTemplateChild("FunctionButton"));
-    m_colorChooserButton = dynamic_cast<ToggleButton^>(GetTemplateChild("ColorChooserButton"));
+    m_equationButton = dynamic_cast<Button ^>(GetTemplateChild("EquationButton"));
+    m_richEditBox = dynamic_cast<RichEditBox ^>(GetTemplateChild("EquationTextBox"));
+    m_deleteButton = dynamic_cast<Button ^>(GetTemplateChild("DeleteButton"));
+    m_removeButton = dynamic_cast<Button ^>(GetTemplateChild("RemoveButton"));
+    m_functionButton = dynamic_cast<Button ^>(GetTemplateChild("FunctionButton"));
+    m_colorChooserButton = dynamic_cast<ToggleButton ^>(GetTemplateChild("ColorChooserButton"));
 
     if (m_richEditBox != nullptr)
     {
+        m_richEditBox->Loaded += ref new RoutedEventHandler(this, &EquationTextBox::OnRichEditBoxLoaded);
         m_richEditBox->GotFocus += ref new RoutedEventHandler(this, &EquationTextBox::OnRichEditBoxGotFocus);
         m_richEditBox->LostFocus += ref new RoutedEventHandler(this, &EquationTextBox::OnRichEditBoxLostFocus);
         m_richEditBox->TextChanged += ref new RoutedEventHandler(this, &EquationTextBox::OnRichEditBoxTextChanged);
+        m_richEditBox->SelectionFlyout = nullptr;
     }
 
     if (m_equationButton != nullptr)
@@ -65,86 +69,113 @@ void EquationTextBox::OnApplyTemplate()
 
     if (ColorChooserFlyout != nullptr)
     {
-        ColorChooserFlyout->Opened += ref new EventHandler<Object^>(this, &EquationTextBox::OnColorFlyoutOpened);
-        ColorChooserFlyout->Closed += ref new EventHandler<Object^>(this, &EquationTextBox::OnColorFlyoutClosed);
+        ColorChooserFlyout->Opened += ref new EventHandler<Object ^>(this, &EquationTextBox::OnColorFlyoutOpened);
+        ColorChooserFlyout->Closed += ref new EventHandler<Object ^>(this, &EquationTextBox::OnColorFlyoutClosed);
     }
 }
 
-void EquationTextBox::OnPointerEntered(PointerRoutedEventArgs^ e)
+void EquationTextBox::OnPointerEntered(PointerRoutedEventArgs ^ e)
 {
     m_isPointerOver = true;
     UpdateCommonVisualState();
 }
 
-void EquationTextBox::OnPointerExited(PointerRoutedEventArgs^ e)
+void EquationTextBox::OnPointerExited(PointerRoutedEventArgs ^ e)
 {
     m_isPointerOver = false;
     UpdateCommonVisualState();
 }
 
-void EquationTextBox::OnPointerCanceled(PointerRoutedEventArgs^ e)
+void EquationTextBox::OnPointerCanceled(PointerRoutedEventArgs ^ e)
 {
     m_isPointerOver = false;
     UpdateCommonVisualState();
 }
 
-void EquationTextBox::OnPointerCaptureLost(PointerRoutedEventArgs^ e)
+void EquationTextBox::OnPointerCaptureLost(PointerRoutedEventArgs ^ e)
 {
     m_isPointerOver = false;
     UpdateCommonVisualState();
 }
 
-void EquationTextBox::OnColorFlyoutOpened(Object^ sender, Object^ e)
+void EquationTextBox::OnKeyDown(KeyRoutedEventArgs ^ e)
+{
+    if (e->Key == VirtualKey::Enter)
+    {
+        EquationSubmitted(this, ref new RoutedEventArgs());
+    }
+}
+
+void EquationTextBox::OnLostFocus(RoutedEventArgs ^ e)
+{
+    if (!m_richEditBox->ContextFlyout->IsOpen)
+    {
+        EquationSubmitted(this, ref new RoutedEventArgs());
+    }
+}
+
+void EquationTextBox::OnColorFlyoutOpened(Object ^ sender, Object ^ e)
 {
     m_isColorChooserFlyoutOpen = true;
     UpdateCommonVisualState();
 }
 
-void EquationTextBox::OnColorFlyoutClosed(Object^ sender, Object^ e)
+void EquationTextBox::OnColorFlyoutClosed(Object ^ sender, Object ^ e)
 {
     m_colorChooserButton->IsChecked = false;
     m_isColorChooserFlyoutOpen = false;
     UpdateCommonVisualState();
 }
 
-void EquationTextBox::OnRichEditBoxTextChanged(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnRichEditBoxLoaded(Object ^ sender, RoutedEventArgs ^ e)
+{
+    LimitedAccessFeatures::TryUnlockFeature(
+        "com.microsoft.windows.richeditmath",
+        "H6wflFFz3gkOsAHtG/D9Tg==",
+        "8wekyb3d8bbwe has registered their use of com.microsoft.windows.richeditmath with Microsoft and agrees to the terms of use.");
+    m_richEditBox->TextDocument->SetMathMode(::RichEditMathMode::MathOnly);
+}
+
+void EquationTextBox::OnRichEditBoxTextChanged(Object ^ sender, RoutedEventArgs ^ e)
 {
     UpdateDeleteButtonVisualState();
 }
 
-void EquationTextBox::OnRichEditBoxGotFocus(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnRichEditBoxGotFocus(Object ^ sender, RoutedEventArgs ^ e)
 {
     m_isFocused = true;
     UpdateCommonVisualState();
     UpdateDeleteButtonVisualState();
 }
 
-void EquationTextBox::OnRichEditBoxLostFocus(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnRichEditBoxLostFocus(Object ^ sender, RoutedEventArgs ^ e)
 {
-    m_isFocused = false;
+    if (!m_richEditBox->ContextFlyout->IsOpen)
+    {
+        m_isFocused = false;
+    }
     UpdateCommonVisualState();
     UpdateDeleteButtonVisualState();
 }
 
-void EquationTextBox::OnDeleteButtonClicked(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnDeleteButtonClicked(Object ^ sender, RoutedEventArgs ^ e)
 {
     if (m_richEditBox != nullptr)
     {
-        m_richEditBox->TextDocument->SetText(::TextSetOptions::None, L"");
+        m_richEditBox->TextDocument->SetMath(L"");
     }
 }
 
-void EquationTextBox::OnEquationButtonClicked(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnEquationButtonClicked(Object ^ sender, RoutedEventArgs ^ e)
 {
-
 }
 
-void EquationTextBox::OnRemoveButtonClicked(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnRemoveButtonClicked(Object ^ sender, RoutedEventArgs ^ e)
 {
     RemoveButtonClicked(this, ref new RoutedEventArgs());
 }
 
-void EquationTextBox::OnColorChooserButtonClicked(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnColorChooserButtonClicked(Object ^ sender, RoutedEventArgs ^ e)
 {
     if (ColorChooserFlyout != nullptr && m_richEditBox != nullptr)
     {
@@ -152,16 +183,17 @@ void EquationTextBox::OnColorChooserButtonClicked(Object^ sender, RoutedEventArg
     }
 }
 
-void EquationTextBox::OnFunctionButtonClicked(Object^ sender, RoutedEventArgs^ e)
+void EquationTextBox::OnFunctionButtonClicked(Object ^ sender, RoutedEventArgs ^ e)
 {
-    auto equationViewModel = static_cast<EquationViewModel^>(DataContext);
-    equationViewModel->KeyGraphFeaturesVisibility = (equationViewModel->KeyGraphFeaturesVisibility == ::Visibility::Collapsed) ? ::Visibility::Visible : ::Visibility::Collapsed;
+    auto equationViewModel = static_cast<EquationViewModel ^>(DataContext);
+    equationViewModel->KeyGraphFeaturesVisibility =
+        (equationViewModel->KeyGraphFeaturesVisibility == ::Visibility::Collapsed) ? ::Visibility::Visible : ::Visibility::Collapsed;
     UpdateCommonVisualState();
 }
 
 void EquationTextBox::UpdateDeleteButtonVisualState()
 {
-    String^ state;
+    String ^ state;
 
     if (ShouldDeleteButtonBeVisible())
     {
@@ -177,7 +209,7 @@ void EquationTextBox::UpdateDeleteButtonVisualState()
 
 void EquationTextBox::UpdateCommonVisualState()
 {
-    String^ state = "Normal";
+    String ^ state = "Normal";
 
     if (m_isFocused)
     {
@@ -191,30 +223,43 @@ void EquationTextBox::UpdateCommonVisualState()
     VisualStateManager::GoToState(this, state, true);
 }
 
-
-Platform::String^ EquationTextBox::GetEquationText()
+Platform::String ^ EquationTextBox::GetEquationText()
 {
-    String^ text;
-
+    String ^ text;
     if (m_richEditBox != nullptr)
     {
-        m_richEditBox->TextDocument->GetText(::TextGetOptions::NoHidden, &text);
+        // Clear formatting since the graph control doesn't work with bold/italic/underlines
+        ITextRange ^ range = m_richEditBox->TextDocument->GetRange(0, m_richEditBox->TextDocument->Selection->EndPosition);
+
+        if (range != nullptr)
+        {
+            range->CharacterFormat->Bold = FormatEffect::Off;
+            range->CharacterFormat->Italic = FormatEffect::Off;
+            range->CharacterFormat->Underline = UnderlineType::None;
+        }
+
+        m_richEditBox->TextDocument->GetMath(&text);
     }
 
     return text;
 }
 
-void EquationTextBox::SetEquationText(Platform::String^ equationText)
+void EquationTextBox::SetEquationText(Platform::String ^ equationText)
 {
     if (m_richEditBox != nullptr)
     {
-        m_richEditBox->TextDocument->SetText(::TextSetOptions::None, equationText);
+        m_richEditBox->TextDocument->SetMath(equationText);
     }
 }
 
-
 bool EquationTextBox::ShouldDeleteButtonBeVisible()
 {
-    return (!GetEquationText()->IsEmpty() && m_isFocused);
+    String ^ text;
 
+    if (m_richEditBox != nullptr)
+    {
+        m_richEditBox->TextDocument->GetMath(&text);
+    }
+
+    return (!text->IsEmpty() && m_isFocused);
 }
diff --git a/src/Calculator/Controls/EquationTextBox.h b/src/Calculator/Controls/EquationTextBox.h
index f5e5238..48bac1d 100644
--- a/src/Calculator/Controls/EquationTextBox.h
+++ b/src/Calculator/Controls/EquationTextBox.h
@@ -21,7 +21,8 @@ namespace CalculatorApp
             DEPENDENCY_PROPERTY(Windows::UI::Xaml::UIElement^, KeyGraphFeaturesContent);
             DEPENDENCY_PROPERTY(Windows::UI::Xaml::Controls::Flyout^, ColorChooserFlyout);
 
-            event Windows::UI::Xaml::RoutedEventHandler^ RemoveButtonClicked;
+            event Windows::UI::Xaml::RoutedEventHandler ^ RemoveButtonClicked;
+            event Windows::UI::Xaml::RoutedEventHandler ^ EquationSubmitted;
 
             Platform::String^ GetEquationText();
             void SetEquationText(Platform::String^ equationText);
@@ -32,14 +33,18 @@ namespace CalculatorApp
             virtual void OnPointerExited(Windows::UI::Xaml::Input::PointerRoutedEventArgs^ e) override;
             virtual void OnPointerCanceled(Windows::UI::Xaml::Input::PointerRoutedEventArgs^ e) override;
             virtual void OnPointerCaptureLost(Windows::UI::Xaml::Input::PointerRoutedEventArgs^ e) override;
+            virtual void OnKeyDown(Windows::UI::Xaml::Input::KeyRoutedEventArgs^ e) override;
+            virtual void OnLostFocus(Windows::UI::Xaml::RoutedEventArgs^ e) override;
 
         private:
             void UpdateCommonVisualState();
             void UpdateDeleteButtonVisualState();
             bool ShouldDeleteButtonBeVisible();
 
+            void OnRichEditBoxLoaded(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
             void OnRichEditBoxGotFocus(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
             void OnRichEditBoxLostFocus(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
+            void OnRichEditBoxLosingFocus(Windows::UI::Xaml::UIElement ^ sender, Windows::UI::Xaml::Input::LosingFocusEventArgs ^ e);
             void OnRichEditBoxTextChanged(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
 
             void OnDeleteButtonClicked(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
diff --git a/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml b/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml
index 1c09527..a8e74b9 100644
--- a/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml
+++ b/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml
@@ -45,8 +45,8 @@
                                                   Grid.Column="1"
                                                   Margin="0,0,3,0"
                                                   Style="{StaticResource EquationTextBoxStyle}"
+                                                  EquationSubmitted="InputTextBox_Submitted"
                                                   GotFocus="InputTextBox_GotFocus"
-                                                  KeyUp="InputTextBox_KeyUp"
                                                   LostFocus="InputTextBox_LostFocus"
                                                   RemoveButtonClicked="EquationTextBox_RemoveButtonClicked">
                             <controls:EquationTextBox.EquationColor>
diff --git a/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.cpp b/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.cpp
index 72bc0d9..3d993d3 100644
--- a/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.cpp
+++ b/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.cpp
@@ -78,22 +78,13 @@ void EquationInputArea::InputTextBox_GotFocus(Object^ sender, RoutedEventArgs^ e
 void EquationInputArea::InputTextBox_LostFocus(Object^ sender, RoutedEventArgs^ e)
 {
     KeyboardShortcutManager::HonorShortcuts(true);
-    
-    auto tb = static_cast<EquationTextBox^>(sender);
-    auto eq = static_cast<EquationViewModel^>(tb->DataContext);
-    tb->SetEquationText(eq->Expression);
 }
 
-void EquationInputArea::InputTextBox_KeyUp(Object^ sender, KeyRoutedEventArgs^ e)
+void EquationInputArea::InputTextBox_Submitted(Object ^ sender, RoutedEventArgs ^ e)
 {
-    if (e->Key == VirtualKey::Enter)
-    {
-        auto tb = static_cast<EquationTextBox^>(sender);
-        auto eq = static_cast<EquationViewModel^>(tb->DataContext);
-        eq->Expression = tb->GetEquationText();
-
-        e->Handled = true;
-    }
+    auto tb = static_cast<EquationTextBox^>(sender);
+    auto eq = static_cast<EquationViewModel^>(tb->DataContext);
+    eq->Expression = tb->GetEquationText();
 }
 
 Color EquationInputArea::GetNextLineColor()
diff --git a/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.h b/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.h
index ef7a471..2da5170 100644
--- a/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.h
+++ b/src/Calculator/Views/GraphingCalculator/EquationInputArea.xaml.h
@@ -23,7 +23,7 @@ namespace CalculatorApp
 
         void InputTextBox_GotFocus(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
         void InputTextBox_LostFocus(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
-        void InputTextBox_KeyUp(Platform::Object^ sender, Windows::UI::Xaml::Input::KeyRoutedEventArgs^ e);
+        void InputTextBox_Submitted(Platform::Object ^ sender, Windows::UI::Xaml::RoutedEventArgs ^ e);
 
         Windows::UI::Color GetNextLineColor();
 
diff --git a/src/CalculatorUnitTests/CalculatorUnitTests.vcxproj b/src/CalculatorUnitTests/CalculatorUnitTests.vcxproj
index da2eac3..676fbf0 100644
--- a/src/CalculatorUnitTests/CalculatorUnitTests.vcxproj
+++ b/src/CalculatorUnitTests/CalculatorUnitTests.vcxproj
@@ -7,7 +7,7 @@
     <MinimumVisualStudioVersion>15.0</MinimumVisualStudioVersion>
     <AppContainerApplication>true</AppContainerApplication>
     <ApplicationType>Windows Store</ApplicationType>
-    <WindowsTargetPlatformVersion Condition=" '$(WindowsTargetPlatformVersion)' == '' ">10.0.18362.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion Condition=" '$(WindowsTargetPlatformVersion)' == '' ">10.0.18970.0</WindowsTargetPlatformVersion>
     <WindowsTargetPlatformMinVersion>10.0.17134.0</WindowsTargetPlatformMinVersion>
     <ApplicationTypeRevision>10.0</ApplicationTypeRevision>
     <UnitTestPlatformVersion Condition="'$(UnitTestPlatformVersion)' == ''">15.0</UnitTestPlatformVersion>
diff --git a/src/CalculatorUnitTests/NavCategoryUnitTests.cpp b/src/CalculatorUnitTests/NavCategoryUnitTests.cpp
index 11a4eee..fe583b7 100644
--- a/src/CalculatorUnitTests/NavCategoryUnitTests.cpp
+++ b/src/CalculatorUnitTests/NavCategoryUnitTests.cpp
@@ -274,7 +274,7 @@ namespace CalculatorUnitTests
     void NavCategoryUnitTests::GetPosition()
     {
         // Position is the 1-based ordering of modes
-        vector<ViewMode> orderedModes = { ViewMode::Standard, ViewMode::Scientific, ViewMode::Programmer, ViewMode::Date,     ViewMode::Graphing
+        vector<ViewMode> orderedModes = { ViewMode::Standard, ViewMode::Scientific, ViewMode::Programmer, ViewMode::Date,     ViewMode::Graphing,
                                           ViewMode::Currency, ViewMode::Volume,   ViewMode::Length,     ViewMode::Weight,     ViewMode::Temperature,
                                           ViewMode::Energy,   ViewMode::Area,     ViewMode::Speed,      ViewMode::Time,       ViewMode::Power,
                                           ViewMode::Data,     ViewMode::Pressure, ViewMode::Angle };
diff --git a/src/GraphControl/Control/Equation.cpp b/src/GraphControl/Control/Equation.cpp
index 9371064..959543c 100644
--- a/src/GraphControl/Control/Equation.cpp
+++ b/src/GraphControl/Control/Equation.cpp
@@ -9,6 +9,9 @@ using namespace Windows::UI::Xaml;
 
 namespace GraphControl
 {
+    // Remove mml: formatting specific to RichEditBox control, which is not understood by the graph engine.
+    static constexpr wstring_view s_mathPrefix = L"mml:";
+
     DependencyProperty^ Equation::s_expressionProperty;
     static constexpr auto s_propertyName_Expression = L"Expression";
 
@@ -74,7 +77,7 @@ namespace GraphControl
         ss  << GetRequestHeader()
             << GetExpression()
             << GetLineColor()
-            << L")";
+            << L"</mfenced></mrow>";
 
         return ss.str();
     }
@@ -82,19 +85,28 @@ namespace GraphControl
     wstring Equation::GetRequestHeader()
     {
         wstring expr{ Expression->Data() };
-        if (expr.find(L"=") != wstring::npos)
+        if (expr.find(L">=<") != wstring::npos)
         {
-            return L"plotEq2d("s;
+            return L"<mrow><mi>plotEq2d</mi><mfenced separators=\"\">"s;
         }
         else
         {
-            return L"plot2d("s;
+            return L"<mrow><mi>plot2d</mi><mfenced separators=\"\">"s;
         }
     }
 
     wstring Equation::GetExpression()
     {
-        return Expression->Data();
+        wstring mathML = Expression->Data();
+
+        size_t mathPrefix = 0;
+        while ((mathPrefix = mathML.find(s_mathPrefix, mathPrefix)) != std::string::npos)
+        {
+            mathML.replace(mathPrefix, s_mathPrefix.length(), L"");
+            mathPrefix += s_mathPrefix.length();
+        }
+
+        return mathML;
     }
 
     wstring Equation::GetLineColor()
diff --git a/src/GraphControl/Control/Grapher.cpp b/src/GraphControl/Control/Grapher.cpp
index 3fb3890..814a2c7 100644
--- a/src/GraphControl/Control/Grapher.cpp
+++ b/src/GraphControl/Control/Grapher.cpp
@@ -55,7 +55,7 @@ namespace GraphControl
         : m_solver{ IMathSolver::CreateMathSolver() }
         , m_graph{ m_solver->CreateGrapher() }
     {
-        m_solver->ParsingOptions().SetFormatType(FormatType::Linear);
+        m_solver->ParsingOptions().SetFormatType(FormatType::MathML);
 
         DefaultStyleKey = StringReference(s_defaultStyleKey);
 
@@ -365,20 +365,20 @@ namespace GraphControl
             if (!validEqs.empty())
             {
                 wstringstream ss{};
-                ss << L"show2d(";
+                ss << L"<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>show2d</mi><mfenced separators=\"\">";
 
                 int numValidEquations = 0;
                 for (Equation^ eq : validEqs)
                 {
                     if (numValidEquations++ > 0)
                     {
-                        ss << L",";
+                        ss << L"<mo>,</mo>";
                     }
 
                     ss << eq->GetRequest();
                 }
 
-                ss << L")";
+                ss << L"</mfenced></mrow></math>";
 
                 wstring request = ss.str();
                 unique_ptr<IExpression> graphExpression;
diff --git a/src/GraphControl/GraphControl.vcxproj b/src/GraphControl/GraphControl.vcxproj
index 054f859..e8c423c 100644
--- a/src/GraphControl/GraphControl.vcxproj
+++ b/src/GraphControl/GraphControl.vcxproj
@@ -42,7 +42,7 @@
     <MinimumVisualStudioVersion>14.0</MinimumVisualStudioVersion>
     <AppContainerApplication>true</AppContainerApplication>
     <ApplicationType>Windows Store</ApplicationType>
-    <WindowsTargetPlatformVersion Condition="'$(WindowsTargetPlatformVersion)' == ''">10.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion Condition="'$(WindowsTargetPlatformVersion)' == ''">10.0.18970.0</WindowsTargetPlatformVersion>
     <WindowsTargetPlatformMinVersion>10.0.18362.0</WindowsTargetPlatformMinVersion>
     <ApplicationTypeRevision>10.0</ApplicationTypeRevision>
   </PropertyGroup>
diff --git a/src/MockGraphingImpl/MockGraphingImpl.vcxproj b/src/MockGraphingImpl/MockGraphingImpl.vcxproj
index 81d2476..3387a92 100644
--- a/src/MockGraphingImpl/MockGraphingImpl.vcxproj
+++ b/src/MockGraphingImpl/MockGraphingImpl.vcxproj
@@ -42,7 +42,7 @@
     <MinimumVisualStudioVersion>14.0</MinimumVisualStudioVersion>
     <AppContainerApplication>true</AppContainerApplication>
     <ApplicationType>Windows Store</ApplicationType>
-    <WindowsTargetPlatformVersion>10.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion>10.0.18970.0</WindowsTargetPlatformVersion>
     <WindowsTargetPlatformMinVersion>10.0.18362.0</WindowsTargetPlatformMinVersion>
     <ApplicationTypeRevision>10.0</ApplicationTypeRevision>
   </PropertyGroup>