Change active tracing to use correct glyph instead of dot (#890)

* Change active tracing to use correct glyph instead of dot

* make the pointer on the glyph line up correctly

src/Calculator/Views/GraphingCalculator/GraphingCalculator.xaml

@@ -424,6 +424,18 @@
                     </Button>
                 </StackPanel>
             </Border>
+            <Border x:Name="TracePointer"
+                    Width="16"
+                    Height="18"
+                    Margin="48,50,0,0"
+                    HorizontalAlignment="Left"
+                    VerticalAlignment="Top"
+                    Visibility="Collapsed">
+                <FontIcon Foreground="Red"
+                          FontFamily="{StaticResource CalculatorFontFamily}"
+                          FontSize="18"
+                          Glyph="&#xE3B3;"/>
+            </Border>
             <Border MinWidth="36"
                     Margin="0,0,12,12"
                     HorizontalAlignment="Right"

src/Calculator/Views/GraphingCalculator/GraphingCalculator.xaml.cpp

@@ -67,6 +67,9 @@ GraphingCalculator::GraphingCalculator()
     // And when the actual trace value changes
     GraphingControl->TracingValueChangedEvent += ref new TracingValueChangedEventHandler(this, &GraphingCalculator::OnTracePointChanged);
 
+    // Update where the pointer value is (ie: where the user cursor from keyboard inputs moves the point to)
+    GraphingControl->PointerValueChangedEvent += ref new PointerValueChangedEventHandler(this, &GraphingCalculator::OnPointerPointChanged);
+
     // OemMinus and OemAdd aren't declared in the VirtualKey enum, we can't add this accelerator XAML-side
     auto virtualKey = ref new KeyboardAccelerator();
     virtualKey->Key = (VirtualKey)187; //OemMinus key
@@ -177,6 +180,13 @@ void GraphingCalculator::OnTracePointChanged(Windows::Foundation::Point newPoint
     PositionGraphPopup();
 }
 
+void CalculatorApp::GraphingCalculator::OnPointerPointChanged(Windows::Foundation::Point newPoint)
+{
+    // Move the pointer glyph to where it is supposed to be.
+    // because the glyph is centered and has some spacing, to get the point to properly line up with the glyph, move the x point over 2 px
+    TracePointer->Margin = Thickness(newPoint.X - 2, newPoint.Y, 0, 0);
+}
+
 GraphingCalculatorViewModel ^ GraphingCalculator::ViewModel::get()
 {
     return m_viewModel;
@@ -479,6 +489,8 @@ void CalculatorApp::GraphingCalculator::ActiveTracing_Checked(Platform::Object ^
             this, &CalculatorApp::GraphingCalculator::ActiveTracing_KeyUp);
 
     KeyboardShortcutManager::IgnoreEscape(false);
+
+    TracePointer->Visibility = ::Visibility::Visible;
 }
 
 void CalculatorApp::GraphingCalculator::ActiveTracing_Unchecked(Platform::Object ^ sender, Windows::UI::Xaml::RoutedEventArgs ^ e)
@@ -495,6 +507,8 @@ void CalculatorApp::GraphingCalculator::ActiveTracing_Unchecked(Platform::Object
         m_activeTracingKeyUpToken.Value = 0;
     }
     KeyboardShortcutManager::HonorEscape();
+
+    TracePointer->Visibility = ::Visibility::Collapsed;
 }
 
 void CalculatorApp::GraphingCalculator::ActiveTracing_KeyUp(Windows::UI::Core::CoreWindow ^ sender, Windows::UI::Core::KeyEventArgs ^ args)

src/Calculator/Views/GraphingCalculator/GraphingCalculator.xaml.h

@@ -55,6 +55,7 @@ public ref class GraphingCalculator sealed : public Windows::UI::Xaml::Data::INo
 
         void OnShowTracePopupChanged(bool newValue);
         void OnTracePointChanged(Windows::Foundation::Point newPoint);
+        void OnPointerPointChanged(Windows::Foundation::Point newPoint);
     private:
         void OnDataRequested(
             Windows::ApplicationModel::DataTransfer::DataTransferManager ^ sender,