Make ITab an unsealed runtimeclass (#8053)

`TerminalTab` and `SettingsTab` share some implementation details. The
close submenu introduced in #7728 is a good example of functionality
that is consistent across all tabs. This PR transforms `ITab` from an
interface, into an [unsealed runtime class] to de-duplicate some
functionality. Most of the logic from `SettingsTab` was moved there
because I expect the default behavior of a tab to resemble the
`SettingsTab` over a `TerminalTab`.

## References
Verified that Close submenu work was transferred over (#7728, #7961, #8010).

## Validation Steps Performed
Check close submenu on first/last tab when multiple tabs are open.

Closes #7969

[unsealed runtime class]: https://docs.microsoft.com/en-us/uwp/midl-3/intro#base-classes

.github/actions/spell-check/dictionary/apis.txt

@@ -46,6 +46,7 @@ oaidl
 ocidl
 otms
 OUTLINETEXTMETRICW
+overridable
 PAGESCROLL
 RETURNCMD
 rfind

src/cascadia/TerminalApp/SettingsTab.cpp

@@ -31,19 +31,6 @@ namespace winrt::TerminalApp::implementation
         _CreateIcon();
     }
 
-    // Method Description:
-    // - Initializes a TabViewItem for this Tab instance.
-    // Arguments:
-    // - <none>
-    // Return Value:
-    // - <none>
-    void SettingsTab::_MakeTabViewItem()
-    {
-        TabViewItem(::winrt::MUX::Controls::TabViewItem{});
-        Title(RS_(L"SettingsTab"));
-        TabViewItem().Header(winrt::box_value(Title()));
-    }
-
     // Method Description:
     // - Focus the settings UI
     // Arguments:
@@ -56,13 +43,21 @@ namespace winrt::TerminalApp::implementation
 
         if (_focusState != FocusState::Unfocused)
         {
-            Content().Focus(focusState);
+            Content().as<WUX::Controls::Page>().Focus(focusState);
         }
     }
 
-    WUX::FocusState SettingsTab::FocusState() const noexcept
+    // Method Description:
+    // - Initializes a TabViewItem for this Tab instance.
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - <none>
+    void SettingsTab::_MakeTabViewItem()
     {
-        return _focusState;
+        TabViewItem(::winrt::MUX::Controls::TabViewItem{});
+        Title(RS_(L"SettingsTab"));
+        TabViewItem().Header(winrt::box_value(Title()));
     }
 
     // Method Description:
@@ -90,117 +85,4 @@ namespace winrt::TerminalApp::implementation
             SwitchToTabCommand().Icon(glyph);
         }
     }
-
-    // Method Description:
-    // - Prepares this tab for being removed from the UI hierarchy
-    void SettingsTab::Shutdown()
-    {
-        // TODO: Does/Will the settings UI need some shutdown procedures?
-        Content(nullptr);
-        _ClosedHandlers(nullptr, nullptr);
-    }
-
-    // Method Description:
-    // - Creates a context menu attached to the tab.
-    // Currently contains elements allowing the user to close the selected tab
-    // Arguments:
-    // - <none>
-    // Return Value:
-    // - <none>
-    void SettingsTab::_CreateContextMenu()
-    {
-        auto weakThis{ get_weak() };
-
-        // Close
-        Controls::MenuFlyoutItem closeTabMenuItem;
-        Controls::FontIcon closeSymbol;
-        closeSymbol.FontFamily(Media::FontFamily{ L"Segoe MDL2 Assets" });
-        closeSymbol.Glyph(L"\xE8BB");
-
-        closeTabMenuItem.Click([weakThis](auto&&, auto&&) {
-            if (auto tab{ weakThis.get() })
-            {
-                tab->_ClosedHandlers(nullptr, nullptr);
-            }
-        });
-        closeTabMenuItem.Text(RS_(L"TabClose"));
-        closeTabMenuItem.Icon(closeSymbol);
-
-        // Build the menu
-        Controls::MenuFlyout newTabFlyout;
-        newTabFlyout.Items().Append(_CreateCloseSubMenu());
-        newTabFlyout.Items().Append(closeTabMenuItem);
-        TabViewItem().ContextFlyout(newTabFlyout);
-    }
-
-    // Method Description:
-    // - Creates a sub-menu containing menu items to close multiple tabs
-    // Arguments:
-    // - <none>
-    // Return Value:
-    // - the created MenuFlyoutSubItem
-    Controls::MenuFlyoutSubItem SettingsTab::_CreateCloseSubMenu()
-    {
-        auto weakThis{ get_weak() };
-
-        // Close tabs after
-        _closeTabsAfterMenuItem.Click([weakThis](auto&&, auto&&) {
-            if (auto tab{ weakThis.get() })
-            {
-                tab->_CloseTabsAfter();
-            }
-        });
-        _closeTabsAfterMenuItem.Text(RS_(L"TabCloseAfter"));
-
-        // Close other tabs
-        _closeOtherTabsMenuItem.Click([weakThis](auto&&, auto&&) {
-            if (auto tab{ weakThis.get() })
-            {
-                tab->_CloseOtherTabs();
-            }
-        });
-        _closeOtherTabsMenuItem.Text(RS_(L"TabCloseOther"));
-
-        Controls::MenuFlyoutSubItem closeSubMenu;
-        closeSubMenu.Text(RS_(L"TabCloseSubMenu"));
-        closeSubMenu.Items().Append(_closeTabsAfterMenuItem);
-        closeSubMenu.Items().Append(_closeOtherTabsMenuItem);
-
-        return closeSubMenu;
-    }
-
-    // Method Description:
-    // - Enable the Close menu items based on tab index and total number of tabs
-    // Arguments:
-    // - <none>
-    // Return Value:
-    // - <none>
-    void SettingsTab::_EnableCloseMenuItems()
-    {
-        // close other tabs is enabled only if there are other tabs
-        _closeOtherTabsMenuItem.IsEnabled(TabViewNumTabs() > 1);
-        // close tabs after is enabled only if there are other tabs on the right
-        _closeTabsAfterMenuItem.IsEnabled(TabViewIndex() < TabViewNumTabs() - 1);
-    }
-
-    void SettingsTab::_CloseTabsAfter()
-    {
-        CloseTabsAfterArgs args{ _TabViewIndex };
-        ActionAndArgs closeTabsAfter{ ShortcutAction::CloseTabsAfter, args };
-
-        _dispatch.DoAction(closeTabsAfter);
-    }
-
-    void SettingsTab::_CloseOtherTabs()
-    {
-        CloseOtherTabsArgs args{ _TabViewIndex };
-        ActionAndArgs closeOtherTabs{ ShortcutAction::CloseOtherTabs, args };
-
-        _dispatch.DoAction(closeOtherTabs);
-    }
-
-    void SettingsTab::SetDispatch(const winrt::TerminalApp::ShortcutActionDispatch& dispatch)
-    {
-        _dispatch = dispatch;
-    }
 }

src/cascadia/TerminalApp/SettingsTab.h

@@ -16,50 +16,23 @@ Author(s):
 --*/
 
 #pragma once
+#include "TabBase.h"
 #include "SettingsTab.g.h"
 #include <winrt/TerminalApp.h>
 #include <winrt/Microsoft.Terminal.Settings.Editor.h>
 #include "../../cascadia/inc/cppwinrt_utils.h"
 
 namespace winrt::TerminalApp::implementation
 {
-    struct SettingsTab : SettingsTabT<SettingsTab>
+    struct SettingsTab : SettingsTabT<SettingsTab, TabBase>
     {
     public:
         SettingsTab(winrt::Microsoft::Terminal::Settings::Editor::MainPage settingsUI);
-        void Focus(winrt::Windows::UI::Xaml::FocusState focusState);
-        winrt::Windows::UI::Xaml::FocusState FocusState() const noexcept;
 
-        void Shutdown();
-
-        void SetDispatch(const winrt::TerminalApp::ShortcutActionDispatch& dispatch);
-        WINRT_CALLBACK(Closed, winrt::Windows::Foundation::EventHandler<winrt::Windows::Foundation::IInspectable>);
-        WINRT_CALLBACK(PropertyChanged, Windows::UI::Xaml::Data::PropertyChangedEventHandler);
-
-        GETSET_PROPERTY(winrt::hstring, Title);
-        GETSET_PROPERTY(winrt::hstring, Icon);
-        GETSET_PROPERTY(winrt::Microsoft::Terminal::Settings::Model::Command, SwitchToTabCommand, nullptr);
-        GETSET_PROPERTY(winrt::Microsoft::UI::Xaml::Controls::TabViewItem, TabViewItem, nullptr);
-        GETSET_PROPERTY(winrt::Windows::UI::Xaml::Controls::Page, Content, nullptr);
-
-        // The TabViewIndex is the index this Tab object resides in TerminalPage's _tabs vector.
-        // This is needed since Tab is going to be managing its own SwitchToTab command.
-        OBSERVABLE_GETSET_PROPERTY(uint32_t, TabViewIndex, _PropertyChangedHandlers, 0);
-        // The TabViewNumTabs is the number of Tab objects in TerminalPage's _tabs vector.
-        OBSERVABLE_GETSET_PROPERTY(uint32_t, TabViewNumTabs, _PropertyChangedHandlers, 0);
+        void Focus(winrt::Windows::UI::Xaml::FocusState focusState) override;
 
     private:
-        winrt::Windows::UI::Xaml::FocusState _focusState{ winrt::Windows::UI::Xaml::FocusState::Unfocused };
-        winrt::Windows::UI::Xaml::Controls::MenuFlyoutItem _closeOtherTabsMenuItem{};
-        winrt::Windows::UI::Xaml::Controls::MenuFlyoutItem _closeTabsAfterMenuItem{};
-        winrt::TerminalApp::ShortcutActionDispatch _dispatch;
-
         void _MakeTabViewItem();
-        void _CreateContextMenu();
-        winrt::Windows::UI::Xaml::Controls::MenuFlyoutSubItem _CreateCloseSubMenu();
-        void _EnableCloseMenuItems();
         winrt::fire_and_forget _CreateIcon();
-        void _CloseTabsAfter();
-        void _CloseOtherTabs();
     };
 }

src/cascadia/TerminalApp/SettingsTab.idl

@@ -1,11 +1,11 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 
-import "ITab.idl";
+import "TabBase.idl";
 
 namespace TerminalApp
 {
-    [default_interface] runtimeclass SettingsTab : ITab
+    [default_interface] runtimeclass SettingsTab : TabBase
     {
     }
 }