Add tab color indicator for tab switch menu (CTRL+Tab) (#17820)

Added tab color indicator for the tab switch menu. Tab color indicators
have the same color as the background color of the tabs. If a tab has
the default background color, the indicator is not shown in the tab
switch menu.

Closes #17465

(cherry picked from commit 544452d)
Service-Card-Id: PVTI_lADOAF3p4s4AmhmQzgS0CZA
Service-Version: 1.22

Author: nukoseer

src/cascadia/TerminalApp/CommandPalette.xaml

@@ -205,6 +205,13 @@
                                   Visibility="{x:Bind Item.(local:TabPaletteItem.TabStatus).IsInputBroadcastActive, Mode=OneWay}" />
 
                     </StackPanel>
+
+                    <Ellipse Grid.Column="4"
+                             Width="8"
+                             Height="8"
+                             HorizontalAlignment="Center"
+                             VerticalAlignment="Center"
+                             Fill="{x:Bind mtu:Converters.ColorToBrush(Item.(local:TabPaletteItem.TabStatus).TabColorIndicator), Mode=OneWay}" />
                 </Grid>
             </DataTemplate>
 

src/cascadia/TerminalApp/TerminalTab.cpp

@@ -976,6 +976,7 @@ namespace winrt::TerminalApp::implementation
                     // active control in this tab. We'll just recalculate the
                     // current color anyways.
                     tab->_RecalculateAndApplyTabColor();
+                    tab->_tabStatus.TabColorIndicator(tab->GetTabColor().value_or(Windows::UI::Colors::Transparent()));
                 }
             });
 
@@ -1617,6 +1618,7 @@ namespace winrt::TerminalApp::implementation
 
         _runtimeTabColor.emplace(color);
         _RecalculateAndApplyTabColor();
+        _tabStatus.TabColorIndicator(color);
     }
 
     // Method Description:
@@ -1633,6 +1635,7 @@ namespace winrt::TerminalApp::implementation
 
         _runtimeTabColor.reset();
         _RecalculateAndApplyTabColor();
+        _tabStatus.TabColorIndicator(GetTabColor().value_or(Windows::UI::Colors::Transparent()));
     }
 
     winrt::Windows::UI::Xaml::Media::Brush TerminalTab::_BackgroundBrush()

src/cascadia/TerminalApp/TerminalTabStatus.h

@@ -20,6 +20,7 @@ namespace winrt::TerminalApp::implementation
         WINRT_OBSERVABLE_PROPERTY(bool, IsReadOnlyActive, PropertyChanged.raise);
         WINRT_OBSERVABLE_PROPERTY(uint32_t, ProgressValue, PropertyChanged.raise);
         WINRT_OBSERVABLE_PROPERTY(bool, IsInputBroadcastActive, PropertyChanged.raise);
+        WINRT_OBSERVABLE_PROPERTY(winrt::Windows::UI::Color, TabColorIndicator, PropertyChanged.raise);
     };
 }
 

src/cascadia/TerminalApp/TerminalTabStatus.idl

@@ -15,5 +15,6 @@ namespace TerminalApp
         UInt32 ProgressValue { get; set; };
         Boolean IsReadOnlyActive { get; set; };
         Boolean IsInputBroadcastActive { get; set; };
+        Windows.UI.Color TabColorIndicator { get; set; };
     }
 }

src/cascadia/TerminalApp/pch.h

@@ -40,6 +40,7 @@
 #include <winrt/Windows.UI.Xaml.Automation.Peers.h>
 #include <winrt/Windows.UI.Xaml.Controls.h>
 #include <winrt/Windows.UI.Xaml.Controls.Primitives.h>
+#include <winrt/Windows.UI.Xaml.Shapes.h>
 #include <winrt/Windows.UI.Xaml.Data.h>
 #include <winrt/Windows.UI.Xaml.Documents.h>
 #include <winrt/Windows.UI.Xaml.Input.h>