ProgressBar: Update indicator size when Padding changes. (#2418)

* ProgressBar: Update indicator size when Padding changes.

* Update DP changed handler name.

Co-authored-by: Stephen Peters <stpete@microsoft.com>

dev/ProgressBar/ProgressBar.cpp

@@ -18,9 +18,10 @@ ProgressBar::ProgressBar()
 
     // NOTE: This is necessary only because Value isn't one of OUR properties, it's implemented in RangeBase.
     // If it was one of ProgressBar's properties, defined in the IDL, you'd do it differently (see IsIndeterminate).
-    RegisterPropertyChangedCallback(winrt::RangeBase::ValueProperty(), { this, &ProgressBar::OnRangeBasePropertyChanged });
-    RegisterPropertyChangedCallback(winrt::RangeBase::MinimumProperty(), { this, &ProgressBar::OnRangeBasePropertyChanged });
-    RegisterPropertyChangedCallback(winrt::RangeBase::MaximumProperty(), { this, &ProgressBar::OnRangeBasePropertyChanged });
+    RegisterPropertyChangedCallback(winrt::RangeBase::ValueProperty(), { this, &ProgressBar::OnIndicatorWidthComponentChanged });
+    RegisterPropertyChangedCallback(winrt::RangeBase::MinimumProperty(), { this, &ProgressBar::OnIndicatorWidthComponentChanged });
+    RegisterPropertyChangedCallback(winrt::RangeBase::MaximumProperty(), { this, &ProgressBar::OnIndicatorWidthComponentChanged });
+    RegisterPropertyChangedCallback(winrt::Control::PaddingProperty(), { this, &ProgressBar::OnIndicatorWidthComponentChanged });
 
     SetValue(s_TemplateSettingsProperty, winrt::make<::ProgressBarTemplateSettings>());
 }
@@ -52,7 +53,7 @@ void ProgressBar::OnSizeChanged(const winrt::IInspectable&, const winrt::IInspec
     UpdateWidthBasedTemplateSettings();
 }
 
-void ProgressBar::OnRangeBasePropertyChanged(const winrt::DependencyObject& sender, const winrt::DependencyProperty& args)
+void ProgressBar::OnIndicatorWidthComponentChanged(const winrt::DependencyObject& sender, const winrt::DependencyProperty& args)
 {
     // NOTE: This hits when the Value property changes, because we called RegisterPropertyChangedCallback.
     SetProgressBarIndicatorWidth();
@@ -62,7 +63,7 @@ void ProgressBar::OnIsIndeterminatePropertyChanged(const winrt::DependencyProper
 {
     // NOTE: This hits when IsIndeterminate changes because we set MUX_PROPERTY_CHANGED_CALLBACK to true in the idl.
     SetProgressBarIndicatorWidth();
-    UpdateStates(); 
+    UpdateStates();
 }
 
 void ProgressBar::OnShowPausedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& args)
@@ -120,7 +121,7 @@ void ProgressBar::SetProgressBarIndicatorWidth()
 
             // Adds "Updating" state in between to trigger RepositionThemeAnimation Visual Transition
             // in ProgressBar.xaml when reverting back to previous state
-            winrt::VisualStateManager::GoToState(*this, s_UpdatingStateName, true); 
+            winrt::VisualStateManager::GoToState(*this, s_UpdatingStateName, true);
 
             if (IsIndeterminate())
             {
@@ -149,7 +150,7 @@ void ProgressBar::SetProgressBarIndicatorWidth()
             {
                 determinateProgressBarIndicator.Width(0); // Error
             }
-           
+
             UpdateStates(); // Reverts back to previous state
         }
     }

dev/ProgressBar/ProgressBar.h

@@ -29,7 +29,7 @@ class ProgressBar :
     void OnShowPausedPropertyChanged(const winrt::DependencyPropertyChangedEventArgs& args);
 
 private:
-    void OnRangeBasePropertyChanged(const winrt::DependencyObject& sender, const winrt::DependencyProperty& args);
+    void OnIndicatorWidthComponentChanged(const winrt::DependencyObject& sender, const winrt::DependencyProperty& args);
 
     void SetProgressBarIndicatorWidth();
     void UpdateStates();