#459 IME UI does not follow the cursor in Windows Terminal

src/cascadia/TerminalControl/TSFInputControl.cpp

@@ -0,0 +1,350 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+#include "TSFInputControl.h"
+#include "TSFInputControl.g.cpp"
+
+#include <Utils.h>
+
+using namespace winrt::Windows::Foundation;
+using namespace winrt::Windows::Graphics::Display;
+using namespace winrt::Windows::UI::Core;
+using namespace winrt::Windows::UI::Text;
+using namespace winrt::Windows::UI::Text::Core;
+using namespace winrt::Windows::UI::Xaml;
+
+namespace winrt::Microsoft::Terminal::TerminalControl::implementation
+{
+    TSFInputControl::TSFInputControl() :
+        _editContext{ nullptr }
+    {
+        _Create();
+    }
+
+    // Method Description:
+    // - Creates XAML controls for displaying user input and hooks up CoreTextEditContext handlers
+    //   for handling text input from the Text Services Framework.
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_Create()
+    {
+        // TextBlock for user input form TSF
+        _textBlock = Controls::TextBlock();
+        _textBlock.Visibility(Visibility::Collapsed);
+        _textBlock.IsTextSelectionEnabled(false);
+        _textBlock.TextDecorations(TextDecorations::Underline);
+
+        // Canvas for controlling exact position of the TextBlock
+        _canvas = Windows::UI::Xaml::Controls::Canvas();
+        _canvas.Visibility(Visibility::Collapsed);
+
+        // add the Textblock to the Canvas
+        _canvas.Children().Append(_textBlock);
+
+        // set the content of this control to be the Canvas
+        this->Content(_canvas);
+
+        // Create a CoreTextEditingContext for since we are acting like a custom edit control
+        auto manager = Core::CoreTextServicesManager::GetForCurrentView();
+        _editContext = manager.CreateEditContext();
+
+        // sets the Input Pane display policy to Manual for now so that it can manually show the
+        // software keyboard when the control gains focus and dismiss it when the control loses focus.
+        // TODO GitHub #3639: Should Input Pane display policy be Automatic
+        _editContext.InputPaneDisplayPolicy(Core::CoreTextInputPaneDisplayPolicy::Manual);
+
+        // set the input scope to Text because this control is for any text.
+        _editContext.InputScope(Core::CoreTextInputScope::Text);
+
+        _editContext.TextRequested({ this, &TSFInputControl::_textRequestedHandler });
+
+        _editContext.SelectionRequested({ this, &TSFInputControl::_selectionRequestedHandler });
+
+        _editContext.FocusRemoved({ this, &TSFInputControl::_focusRemovedHandler });
+
+        _editContext.TextUpdating({ this, &TSFInputControl::_textUpdatingHandler });
+
+        _editContext.SelectionUpdating({ this, &TSFInputControl::_selectionUpdatingHandler });
+
+        _editContext.FormatUpdating({ this, &TSFInputControl::_formatUpdatingHandler });
+
+        _editContext.LayoutRequested({ this, &TSFInputControl::_layoutRequestedHandler });
+
+        _editContext.CompositionStarted({ this, &TSFInputControl::_compositionStartedHandler });
+
+        _editContext.CompositionCompleted({ this, &TSFInputControl::_compositionCompletedHandler });
+    }
+
+    // Method Description:
+    // - NotifyFocusEnter handler for notifying CoreEditTextContext of focus enter
+    //   when TerminalControl receives focus.
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - <none>
+    void TSFInputControl::NotifyFocusEnter()
+    {
+        if (_editContext != nullptr)
+        {
+            _editContext.NotifyFocusEnter();
+        }
+    }
+
+    // Method Description:
+    // - NotifyFocusEnter handler for notifying CoreEditTextContext of focus leaving.
+    //   when TerminalControl no longer has focus.
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - <none>
+    void TSFInputControl::NotifyFocusLeave()
+    {
+        if (_editContext != nullptr)
+        {
+            // _editContext.NotifyFocusLeave(); TODO GitHub #3645: Enabling causes IME to no longer show up, need to determine if required
+        }
+    }
+
+    // Method Description:
+    // - Handler for LayoutRequested event by CoreEditContext responsible
+    //   for returning the current position the IME should be placed
+    //   in screen coordinates on the screen.  TSFInputControls internal
+    //   XAML controls (TextBlock/Canvas) are also positioned and updated.
+    //   NOTE: documentation says application should handle this event
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request.
+    // - args: CoreTextLayoutRequestedEventArgs to be updated with position information.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_layoutRequestedHandler(CoreTextEditContext sender, CoreTextLayoutRequestedEventArgs const& args)
+    {
+        auto request = args.Request();
+
+        // Get window in screen coordinates, this is the entire window including tabs
+        const auto windowBounds = CoreWindow::GetForCurrentThread().Bounds();
+
+        // Get the cursor position in text buffer position
+        auto cursorArgs = winrt::make_self<CursorPositionEventArgs>();
+        _CurrentCursorPositionHandlers(*this, *cursorArgs);
+        const COORD cursorPos = { gsl::narrow_cast<SHORT>(cursorArgs->CurrentPosition().X), gsl::narrow_cast<SHORT>(cursorArgs->CurrentPosition().Y) };
+
+        // Get Font Info as we use this is the pixel size for characters in the display
+        auto fontArgs = winrt::make_self<FontInfoEventArgs>();
+        _CurrentFontInfoHandlers(*this, *fontArgs);
+
+        const float fontWidth = fontArgs->FontSize().Width;
+        const float fontHeight = fontArgs->FontSize().Height;
+
+        // Convert text buffer cursor position to client coordinate position within the window
+        COORD clientCursorPos;
+        COORD screenCursorPos;
+        THROW_IF_FAILED(ShortMult(cursorPos.X, gsl::narrow<SHORT>(fontWidth), &clientCursorPos.X));
+        THROW_IF_FAILED(ShortMult(cursorPos.Y, gsl::narrow<SHORT>(fontHeight), &clientCursorPos.Y));
+
+        // Convert from client coordinate to screen coordinate by adding window position
+        THROW_IF_FAILED(ShortAdd(clientCursorPos.X, gsl::narrow_cast<SHORT>(windowBounds.X), &screenCursorPos.X));
+        THROW_IF_FAILED(ShortAdd(clientCursorPos.Y, gsl::narrow_cast<SHORT>(windowBounds.Y), &screenCursorPos.Y));
+
+        // get any offset (margin + tabs, etc..) of the control within the window
+        const auto offsetPoint = this->TransformToVisual(nullptr).TransformPoint(winrt::Windows::Foundation::Point(0, 0));
+
+        // add the margin offsets if any
+        const auto currentMargin = this->Margin();
+        THROW_IF_FAILED(ShortAdd(screenCursorPos.X, gsl::narrow_cast<SHORT>(offsetPoint.X), &screenCursorPos.X));
+        THROW_IF_FAILED(ShortAdd(screenCursorPos.Y, gsl::narrow_cast<SHORT>(offsetPoint.Y), &screenCursorPos.Y));
+
+        // Get scale factor for view
+        const double scaleFactor = DisplayInformation::GetForCurrentView().RawPixelsPerViewPixel();
+
+        // Set the selection layout bounds
+        Rect selectionRect = Rect(screenCursorPos.X, screenCursorPos.Y, 0, fontHeight);
+        request.LayoutBounds().TextBounds(ScaleRect(selectionRect, scaleFactor));
+
+        // Set the control bounds of the whole control
+        Rect controlRect = Rect(screenCursorPos.X, screenCursorPos.Y, 0, fontHeight);
+        request.LayoutBounds().ControlBounds(ScaleRect(controlRect, scaleFactor));
+
+        // position textblock to cursor position
+        _canvas.SetLeft(_textBlock, clientCursorPos.X);
+        _canvas.SetTop(_textBlock, static_cast<double>(clientCursorPos.Y));
+
+        // width is cursor to end of canvas
+        _textBlock.Width(200); // TODO GitHub #3640: Determine proper Width
+        _textBlock.Height(fontHeight);
+
+        // calculate FontSize in pixels from DIPs
+        const float logicalDpi = DisplayInformation::GetForCurrentView().LogicalDpi();
+        const double fontSizePx = (fontHeight * 72) / logicalDpi;
+        _textBlock.FontSize(fontSizePx);
+
+        _textBlock.FontFamily(Media::FontFamily(fontArgs->FontFace()));
+    }
+
+    // Method Description:
+    // - Handler for CompositionStarted event by CoreEditContext responsible
+    //   for making internal TSFInputControl controls visisble.
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextCompositionStartedEventArgs. Not used in method.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_compositionStartedHandler(CoreTextEditContext sender, CoreTextCompositionStartedEventArgs const& /*args*/)
+    {
+        _canvas.Visibility(Visibility::Visible);
+        _textBlock.Visibility(Visibility::Visible);
+    }
+
+    // Method Description:
+    // - Handler for CompositionCompleted event by CoreEditContext responsible
+    //   for making internal TSFInputControl controls visisble.
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextCompositionCompletedEventArgs. Not used in method.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_compositionCompletedHandler(CoreTextEditContext sender, CoreTextCompositionCompletedEventArgs const& /*args*/)
+    {
+        // only need to do work if the current buffer has text
+        if (!_inputBuffer.empty())
+        {
+            const auto hstr = to_hstring(_inputBuffer.c_str());
+
+            // call event handler with data handled by parent
+            _compositionCompletedHandlers(hstr);
+
+            // clear the buffer for next round
+            _inputBuffer.clear();
+            _textBlock.Text(L"");
+
+            // tell the input server that we've cleared the buffer
+            CoreTextRange emptyTextRange;
+            emptyTextRange.StartCaretPosition = 0;
+            emptyTextRange.EndCaretPosition = 0;
+
+            // indicate text is now 0
+            _editContext.NotifyTextChanged(emptyTextRange, 0, emptyTextRange);
+            _editContext.NotifySelectionChanged(emptyTextRange);
+
+            // hide the controls until composition starts again
+            _canvas.Visibility(Visibility::Collapsed);
+            _textBlock.Visibility(Visibility::Collapsed);
+        }
+    }
+
+    // Method Description:
+    // - Handler for FocusRemoved event by CoreEditContext responsible
+    //   for removing focus for the TSFInputControl control accordingly
+    //   when focus was forecibly removed from text input control. (TODO GitHub #3644)
+    //   NOTE: Documentation says application should handle this event
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - object: CoreTextCompositionStartedEventArgs. Not used in method.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_focusRemovedHandler(CoreTextEditContext sender, winrt::Windows::Foundation::IInspectable const& /*object*/)
+    {
+    }
+
+    // Method Description:
+    // - Handler for TextRequested event by CoreEditContext responsible
+    //   for returning the range of text requested.
+    //   NOTE: Documentation says application should handle this event
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextTextRequestedEventArgs to be updated with requested range text.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_textRequestedHandler(CoreTextEditContext sender, CoreTextTextRequestedEventArgs const& args)
+    {
+        // the range the TSF wants to know about
+        const auto range = args.Request().Range();
+
+        try
+        {
+            const auto textRequested = _inputBuffer.substr(range.StartCaretPosition, static_cast<size_t>(range.EndCaretPosition) - static_cast<size_t>(range.StartCaretPosition));
+
+            args.Request().Text(winrt::to_hstring(textRequested.c_str()));
+        }
+        CATCH_LOG();
+    }
+
+    // Method Description:
+    // - Handler for SelectionRequested event by CoreEditContext responsible
+    //   for returning the currently selected text.
+    //   TSFInputControl currently doesn't allow selection, so nothing happens.
+    //   NOTE: Documentation says application should handle this event
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextSelectionRequestedEventArgs for providing data for the SelectionRequested event. Not used in method.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_selectionRequestedHandler(CoreTextEditContext sender, CoreTextSelectionRequestedEventArgs const& /*args*/)
+    {
+    }
+
+    // Method Description:
+    // - Handler for SelectionUpdating event by CoreEditContext responsible
+    //   for handling modifications to the range of text currently selected.
+    //   TSFInputControl doesn't currently allow selection, so nothing happens.
+    //   NOTE: Documentation says application should set its selection range accordingly
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextSelectionUpdatingEventArgs for providing data for the SelectionUpdating event. Not used in method.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_selectionUpdatingHandler(CoreTextEditContext sender, CoreTextSelectionUpdatingEventArgs const& /*args*/)
+    {
+    }
+
+    // Method Description:
+    // - Handler for TextUpdating event by CoreEditContext responsible
+    //   for handling text updates.
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextTextUpdatingEventArgs contains new text to update buffer with.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_textUpdatingHandler(CoreTextEditContext sender, CoreTextTextUpdatingEventArgs const& args)
+    {
+        const auto text = args.Text();
+        const auto range = args.Range();
+
+        try
+        {
+            _inputBuffer = _inputBuffer.replace(
+                range.StartCaretPosition,
+                static_cast<size_t>(range.EndCaretPosition) - static_cast<size_t>(range.StartCaretPosition),
+                text.c_str());
+
+            _textBlock.Text(_inputBuffer);
+
+            // Notify the TSF that the update succeeded
+            args.Result(CoreTextTextUpdatingResult::Succeeded);
+        }
+        catch (...)
+        {
+            LOG_CAUGHT_EXCEPTION();
+
+            // indicate updating failed.
+            args.Result(CoreTextTextUpdatingResult::Failed);
+        }
+    }
+
+    // Method Description:
+    // - Handler for FormatUpdating event by CoreEditContext responsible
+    //   for handling different format updates for a particular range of text.
+    //   TSFInputControl doesn't do anything with this event.
+    // Arguments:
+    // - sender: CoreTextEditContext sending the request. Not used in method.
+    // - args: CoreTextFormatUpdatingEventArgs Provides data for the FormatUpdating event. Not used in method.
+    // Return Value:
+    // - <none>
+    void TSFInputControl::_formatUpdatingHandler(CoreTextEditContext sender, CoreTextFormatUpdatingEventArgs const& /*args*/)
+    {
+    }
+
+    DEFINE_EVENT(TSFInputControl, CompositionCompleted, _compositionCompletedHandlers, TerminalControl::CompositionCompletedEventArgs);
+}