Add support for changing the active color scheme with an action (#6993)

## Summary of the Pull Request

Adds the `setColorScheme` action, to change the color scheme of the active control to one given by the `name` parameter. `name` is required. If `name` is not the name of a color scheme, the action does nothing.

## References

* Being done as a stepping stone to #6689 

## PR Checklist
* [x] Closes #5401
* [x] I work here
* [ ] Tests added/passed
* [n/a] Requires documentation to be updated

## Detailed Description of the Pull Request / Additional comments

Technically, the action is being done by changing the settings of the current `TerminalSettings` of the `TermControl`. Frankly, it should be operating on a copy of the `TermControl`'s `IControlSettings`, then updating the control's settings, or the Control should just listen for changes to it's setting's properties, and update in real time (without a manual call to `UpdateSettings`. However, both those paths are somewhere unknowable beyond #6904, so we'll just do this for now.

## Validation Steps Performed

* tested manually with a scheme that exists
* tested manually with a scheme that doesn't exist

Author: zadjii-msft

doc/cascadia/profiles.schema.json

@@ -59,6 +59,7 @@
         "toggleAlwaysOnTop",
         "toggleRetroEffect",
         "find",
+        "setColorScheme",
         "setTabColor",
         "openTabColorPicker",
         "renameTab",
@@ -283,6 +284,23 @@
         }
       ]
     },
+    "SetColorSchemeAction": {
+      "description": "Arguments corresponding to a Set Color Scheme Action",
+      "allOf": [
+        { "$ref": "#/definitions/ShortcutAction" },
+        {
+          "properties": {
+            "action": { "type": "string", "pattern": "setColorScheme" },
+            "colorScheme": {
+              "type": "string",
+              "default": "",
+              "description": "the name of the scheme to apply to the active pane"
+            }
+          }
+        }
+      ],
+      "required": [ "name" ]
+    },
     "WtAction": {
       "description": "Arguments corresponding to a wt Action",
       "allOf": [
@@ -350,6 +368,7 @@
               { "$ref": "#/definitions/SplitPaneAction" },
               { "$ref": "#/definitions/OpenSettingsAction" },
               { "$ref": "#/definitions/SetTabColorAction" },
+              { "$ref": "#/definitions/SetColorSchemeAction" },
               { "$ref": "#/definitions/WtAction" },
               { "$ref": "#/definitions/CloseOtherTabsAction" },
               { "$ref": "#/definitions/CloseTabsAfterAction" },

src/cascadia/TerminalApp/ActionAndArgs.cpp

@@ -36,6 +36,7 @@ static constexpr std::string_view ToggleRetroEffectKey{ "toggleRetroEffect" };
 static constexpr std::string_view ToggleFocusModeKey{ "toggleFocusMode" };
 static constexpr std::string_view ToggleFullscreenKey{ "toggleFullscreen" };
 static constexpr std::string_view ToggleAlwaysOnTopKey{ "toggleAlwaysOnTop" };
+static constexpr std::string_view SetColorSchemeKey{ "setColorScheme" };
 static constexpr std::string_view SetTabColorKey{ "setTabColor" };
 static constexpr std::string_view OpenTabColorPickerKey{ "openTabColorPicker" };
 static constexpr std::string_view RenameTabKey{ "renameTab" };
@@ -83,6 +84,7 @@ namespace winrt::TerminalApp::implementation
         { ResizePaneKey, ShortcutAction::ResizePane },
         { MoveFocusKey, ShortcutAction::MoveFocus },
         { OpenSettingsKey, ShortcutAction::OpenSettings },
+        { SetColorSchemeKey, ShortcutAction::SetColorScheme },
         { ToggleRetroEffectKey, ShortcutAction::ToggleRetroEffect },
         { ToggleFocusModeKey, ShortcutAction::ToggleFocusMode },
         { ToggleFullscreenKey, ShortcutAction::ToggleFullscreen },
@@ -125,6 +127,8 @@ namespace winrt::TerminalApp::implementation
 
         { ShortcutAction::OpenSettings, winrt::TerminalApp::implementation::OpenSettingsArgs::FromJson },
 
+        { ShortcutAction::SetColorScheme, winrt::TerminalApp::implementation::SetColorSchemeArgs::FromJson },
+
         { ShortcutAction::SetTabColor, winrt::TerminalApp::implementation::SetTabColorArgs::FromJson },
 
         { ShortcutAction::RenameTab, winrt::TerminalApp::implementation::RenameTabArgs::FromJson },
@@ -280,6 +284,7 @@ namespace winrt::TerminalApp::implementation
                 { ShortcutAction::TogglePaneZoom, RS_(L"TogglePaneZoomCommandKey") },
                 { ShortcutAction::Invalid, L"" },
                 { ShortcutAction::Find, RS_(L"FindCommandKey") },
+                { ShortcutAction::SetColorScheme, L"" },
                 { ShortcutAction::SetTabColor, RS_(L"ResetTabColorCommandKey") },
                 { ShortcutAction::OpenTabColorPicker, RS_(L"OpenTabColorPickerCommandKey") },
                 { ShortcutAction::RenameTab, RS_(L"ResetTabNameCommandKey") },

src/cascadia/TerminalApp/ActionArgs.cpp

@@ -15,6 +15,7 @@
 #include "AdjustFontSizeArgs.g.cpp"
 #include "SplitPaneArgs.g.cpp"
 #include "OpenSettingsArgs.g.cpp"
+#include "SetColorSchemeArgs.g.cpp"
 #include "SetTabColorArgs.g.cpp"
 #include "RenameTabArgs.g.cpp"
 #include "ExecuteCommandlineArgs.g.cpp"
@@ -229,6 +230,19 @@ namespace winrt::TerminalApp::implementation
         }
     }
 
+    winrt::hstring SetColorSchemeArgs::GenerateName() const
+    {
+        // "Set color scheme to "{_SchemeName}""
+        if (!_SchemeName.empty())
+        {
+            return winrt::hstring{
+                fmt::format(std::wstring_view(RS_(L"SetColorSchemeCommandKey")),
+                            _SchemeName.c_str())
+            };
+        }
+        return L"";
+    }
+
     winrt::hstring SetTabColorArgs::GenerateName() const
     {
         // "Set tab color to #RRGGBB"

src/cascadia/TerminalApp/ActionArgs.h

@@ -15,6 +15,7 @@
 #include "AdjustFontSizeArgs.g.h"
 #include "SplitPaneArgs.g.h"
 #include "OpenSettingsArgs.g.h"
+#include "SetColorSchemeArgs.g.h"
 #include "SetTabColorArgs.g.h"
 #include "RenameTabArgs.g.h"
 #include "ExecuteCommandlineArgs.g.h"
@@ -332,6 +333,38 @@ namespace winrt::TerminalApp::implementation
         }
     };
 
+    struct SetColorSchemeArgs : public SetColorSchemeArgsT<SetColorSchemeArgs>
+    {
+        SetColorSchemeArgs() = default;
+        GETSET_PROPERTY(winrt::hstring, SchemeName, L"");
+
+        static constexpr std::string_view NameKey{ "colorScheme" };
+
+    public:
+        hstring GenerateName() const;
+
+        bool Equals(const IActionArgs& other)
+        {
+            auto otherAsUs = other.try_as<SetColorSchemeArgs>();
+            if (otherAsUs)
+            {
+                return otherAsUs->_SchemeName == _SchemeName;
+            }
+            return false;
+        };
+        static FromJsonResult FromJson(const Json::Value& json)
+        {
+            // LOAD BEARING: Not using make_self here _will_ break you in the future!
+            auto args = winrt::make_self<SetColorSchemeArgs>();
+            JsonUtils::GetValueForKey(json, NameKey, args->_SchemeName);
+            if (args->_SchemeName.empty())
+            {
+                return { nullptr, { ::TerminalApp::SettingsLoadWarnings::MissingRequiredParameter } };
+            }
+            return { *args, {} };
+        }
+    };
+
     struct SetTabColorArgs : public SetTabColorArgsT<SetTabColorArgs>
     {
         SetTabColorArgs() = default;

src/cascadia/TerminalApp/ActionArgs.idl

@@ -106,6 +106,11 @@ namespace TerminalApp
         SettingsTarget Target { get; };
     };
 
+    [default_interface] runtimeclass SetColorSchemeArgs : IActionArgs
+    {
+        String SchemeName { get; };
+    };
+
     [default_interface] runtimeclass SetTabColorArgs : IActionArgs
     {
         Windows.Foundation.IReference<UInt32> TabColor { get; };

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -291,6 +291,27 @@ namespace winrt::TerminalApp::implementation
         args.Handled(true);
     }
 
+    void TerminalPage::_HandleSetColorScheme(const IInspectable& /*sender*/,
+                                             const TerminalApp::ActionEventArgs& args)
+    {
+        args.Handled(false);
+        if (const auto& realArgs = args.ActionArgs().try_as<TerminalApp::SetColorSchemeArgs>())
+        {
+            if (auto activeTab = _GetFocusedTab())
+            {
+                if (auto activeControl = activeTab->GetActiveTerminalControl())
+                {
+                    auto controlSettings = activeControl.Settings();
+                    if (_settings->ApplyColorScheme(controlSettings, realArgs.SchemeName()))
+                    {
+                        activeControl.UpdateSettings(controlSettings);
+                        args.Handled(true);
+                    }
+                }
+            }
+        }
+    }
+
     void TerminalPage::_HandleSetTabColor(const IInspectable& /*sender*/,
                                           const TerminalApp::ActionEventArgs& args)
     {

src/cascadia/TerminalApp/CascadiaSettings.cpp

@@ -744,3 +744,26 @@ const ColorScheme* CascadiaSettings::GetColorSchemeForProfile(const GUID profile
         return nullptr;
     }
 }
+
+// Method Description:
+// - Apply the color scheme (provided by name) to the given IControlSettings.
+//   The settings are modified in-place.
+// - If the name doesn't correspond to any of our schemes, this does nothing.
+// Arguments:
+// - settings: the IControlSettings object to modify
+// - name: the name of the scheme to apply
+// Return Value:
+// - true iff we found a matching scheme for the name schemeName
+bool CascadiaSettings::ApplyColorScheme(winrt::Microsoft::Terminal::TerminalControl::IControlSettings& settings,
+                                        std::wstring_view schemeName)
+{
+    std::wstring name{ schemeName };
+    auto schemeAndName = _globals.GetColorSchemes().find(name);
+    if (schemeAndName != _globals.GetColorSchemes().end())
+    {
+        const auto& scheme = schemeAndName->second;
+        scheme.ApplyScheme(settings);
+        return true;
+    }
+    return false;
+}

src/cascadia/TerminalApp/CascadiaSettings.h

@@ -74,6 +74,8 @@ class TerminalApp::CascadiaSettings final
 
     std::vector<TerminalApp::SettingsLoadWarnings>& GetWarnings();
 
+    bool ApplyColorScheme(winrt::Microsoft::Terminal::TerminalControl::IControlSettings& settings, std::wstring_view schemeName);
+
 private:
     GlobalAppSettings _globals;
     std::vector<Profile> _profiles;

src/cascadia/TerminalApp/ColorScheme.cpp

@@ -67,7 +67,7 @@ ColorScheme::~ColorScheme()
 // - terminalSettings: the object to apply our settings to.
 // Return Value:
 // - <none>
-void ColorScheme::ApplyScheme(TerminalSettings terminalSettings) const
+void ColorScheme::ApplyScheme(const winrt::Microsoft::Terminal::TerminalControl::IControlSettings& terminalSettings) const
 {
     terminalSettings.DefaultForeground(static_cast<COLORREF>(_defaultForeground));
     terminalSettings.DefaultBackground(static_cast<COLORREF>(_defaultBackground));

src/cascadia/TerminalApp/ColorScheme.h

@@ -37,7 +37,7 @@ class TerminalApp::ColorScheme
     ColorScheme(std::wstring name, til::color defaultFg, til::color defaultBg, til::color cursorColor);
     ~ColorScheme();
 
-    void ApplyScheme(winrt::TerminalApp::TerminalSettings terminalSettings) const;
+    void ApplyScheme(const winrt::Microsoft::Terminal::TerminalControl::IControlSettings& terminalSettings) const;
 
     static ColorScheme FromJson(const Json::Value& json);
     bool ShouldBeLayered(const Json::Value& json) const;