void FWindowsTextInputMethodSystem::OnIMEActivationStateChanged(const bool bIsEnabled)
{
if(bIsEnabled)
{
// It seems that switching away from an IMM based IME doesn't generate a deactivation notification
//check(CurrentAPI == EAPI::Unknown);
const HKL KeyboardLayout = ::GetKeyboardLayout(0);
TF_INPUTPROCESSORPROFILE TSFProfile;
if(SUCCEEDED(TSFInputProcessorProfileManager->GetActiveProfile(GUID_TFCAT_TIP_KEYBOARD, &TSFProfile)) && TSFProfile.dwProfileType == TF_PROFILETYPE_INPUTPROCESSOR)
{
CurrentAPI = EAPI::TSF;
}
else if(::ImmGetIMEFileName(KeyboardLayout, nullptr, 0) > 0)
{
CurrentAPI = EAPI::IMM;
UpdateIMMProperty(KeyboardLayout);
}
else
{
CurrentAPI = EAPI::Unknown;
}
}
else
{
// It seems that switching away from an IMM based IME doesn't generate a deactivation notification
//check(CurrentAPI != EAPI::Unknown);
CurrentAPI = EAPI::Unknown;
}
LogActiveIMEInfo();
}
void FWindowsTextInputMethodSystem::OnIMEActivationStateChanged(const bool bIsEnabled)
{
if(bIsEnabled)
{
// It seems that switching away from an IMM based IME doesn't generate a deactivation notification
//check(CurrentAPI == EAPI::Unknown);
FString APIString;
const HKL KeyboardLayout = ::GetKeyboardLayout(0);
if(::ImmGetIMEFileName(KeyboardLayout, nullptr, 0) > 0)
{
CurrentAPI = EAPI::IMM;
UpdateIMMProperty(KeyboardLayout);
APIString = TEXT("IMM");
}
else
{
CurrentAPI = EAPI::TSF;
APIString = TEXT("TSF");
}
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("IME system now activated using %s."), *APIString);
}
else
{
// It seems that switching away from an IMM based IME doesn't generate a deactivation notification
//check(CurrentAPI != EAPI::Unknown);
CurrentAPI = EAPI::Unknown;
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("IME system now deactivated."));
}
}
bool FWindowsTextInputMethodSystem::InitializeIMM()
{
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Initializing IMM..."));
IMMContextId = ::ImmCreateContext();
UpdateIMMProperty(::GetKeyboardLayout(0));
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Initialized IMM!"));
return true;
}
int32 FWindowsTextInputMethodSystem::ProcessMessage(HWND hwnd, uint32 msg, WPARAM wParam, LPARAM lParam)
{
if(CurrentAPI != EAPI::IMM)
{
return DefWindowProc(hwnd, msg, wParam, lParam);
}
switch(msg)
{
case WM_INPUTLANGCHANGEREQUEST:
case WM_INPUTLANGCHANGE:
{
HKL KeyboardLayoutHandle = reinterpret_cast<HKL>(lParam);
UpdateIMMProperty(KeyboardLayoutHandle);
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_SETCONTEXT:
{
if(ActiveContext.IsValid())
{
// Disable showing an IME-implemented composition window if we're going to draw the composition string ourselves.
if(wParam && ShouldDrawIMMCompositionString())
{
lParam &= ~ISC_SHOWUICOMPOSITIONWINDOW;
}
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Setting IMM context."));
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_NOTIFY:
{
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_REQUEST:
{
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_STARTCOMPOSITION:
{
if(ActiveContext.IsValid())
{
BeginIMMComposition();
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Beginning IMM composition."));
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_COMPOSITION:
{
if(ActiveContext.IsValid())
{
FInternalContext& InternalContext = ContextToInternalContextMap[ActiveContext];
check(InternalContext.IMMContext.IsComposing);
HIMC IMMContext = ::ImmGetContext(hwnd);
UpdateIMMWindowPositions(IMMContext);
const bool bHasBeenCanceled = !lParam;
const bool bHasCompositionStringFlag = !!(lParam & GCS_COMPSTR);
const bool bHasResultStringFlag = !!(lParam & GCS_RESULTSTR);
const bool bHasNoMoveCaretFlag = !!(lParam & CS_NOMOVECARET);
const bool bHasCursorPosFlag = !!(lParam & GCS_CURSORPOS);
// Canceled, so remove the compositing string
if(bHasBeenCanceled)
{
CancelIMMComposition();
}
// Check Result
if(bHasResultStringFlag)
{
// If we're being deactivated, so we need to take the current selection so we can restore it properly
// otherwise calling SetTextInRange can cause the cursor/selection to jump around
uint32 SelectionBeginIndex = 0;
uint32 SelectionLength = 0;
ITextInputMethodContext::ECaretPosition SelectionCaretPosition = ITextInputMethodContext::ECaretPosition::Ending;
ActiveContext->GetSelectionRange(SelectionBeginIndex, SelectionLength, SelectionCaretPosition);
const FString ResultString = GetIMMStringAsFString(IMMContext, GCS_RESULTSTR);
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("WM_IME_COMPOSITION Result String: %s"), *ResultString);
// Update Result
ActiveContext->SetTextInRange(InternalContext.IMMContext.CompositionBeginIndex, InternalContext.IMMContext.CompositionLength, ResultString);
if(InternalContext.IMMContext.IsDeactivating)
{
// Restore any previous selection
ActiveContext->SetSelectionRange(SelectionBeginIndex, SelectionLength, SelectionCaretPosition);
}
else
{
// Once we get a result, we're done; set the caret to the end of the result and end the current composition
ActiveContext->SetSelectionRange(InternalContext.IMMContext.CompositionBeginIndex + ResultString.Len(), 0, ITextInputMethodContext::ECaretPosition::Ending);
}
EndIMMComposition();
}
// Check Composition
if(bHasCompositionStringFlag)
{
const FString CompositionString = GetIMMStringAsFString(IMMContext, GCS_COMPSTR);
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("WM_IME_COMPOSITION Composition String: %s"), *CompositionString);
// Not all IMEs send a cancel request when you press escape, but instead just set the string to empty
// We need to cancel out the composition string here to avoid weirdness when you start typing again
// Don't do this if we have a result string, as we'll have already called EndIMMComposition to finish the composition
if(CompositionString.Len() == 0 && !bHasResultStringFlag)
{
CancelIMMComposition();
}
// We've typed a character, so we need to clear out any currently selected text to mimic what happens when you normally type into a text input
uint32 SelectionBeginIndex = 0;
uint32 SelectionLength = 0;
ITextInputMethodContext::ECaretPosition SelectionCaretPosition = ITextInputMethodContext::ECaretPosition::Ending;
ActiveContext->GetSelectionRange(SelectionBeginIndex, SelectionLength, SelectionCaretPosition);
if(SelectionLength)
{
ActiveContext->SetTextInRange(SelectionBeginIndex, SelectionLength, TEXT(""));
}
// If we received a result (handled above) then the previous composition will have been ended, so we need to start a new one now
// This ensures that each composition ends up as its own distinct undo
if(!InternalContext.IMMContext.IsComposing)
{
BeginIMMComposition();
}
const int32 CurrentCompositionBeginIndex = InternalContext.IMMContext.CompositionBeginIndex;
const uint32 CurrentCompositionLength = InternalContext.IMMContext.CompositionLength;
// Update Composition Range
InternalContext.IMMContext.CompositionLength = CompositionString.Len();
ActiveContext->UpdateCompositionRange(InternalContext.IMMContext.CompositionBeginIndex, InternalContext.IMMContext.CompositionLength);
// Update Composition
ActiveContext->SetTextInRange(CurrentCompositionBeginIndex, CurrentCompositionLength, CompositionString);
}
// Check Cursor
if(!bHasNoMoveCaretFlag && bHasCursorPosFlag)
{
const LONG CursorPositionResult = ::ImmGetCompositionString(IMMContext, GCS_CURSORPOS, nullptr, 0);
const int16 CursorPosition = CursorPositionResult & 0xFFFF;
// Update Cursor
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("WM_IME_COMPOSITION Cursor Position: %d"), CursorPosition);
ActiveContext->SetSelectionRange(InternalContext.IMMContext.CompositionBeginIndex + CursorPosition, 0, ITextInputMethodContext::ECaretPosition::Ending);
}
::ImmReleaseContext(hwnd, IMMContext);
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Updating IMM composition."));
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_ENDCOMPOSITION:
{
// On composition end, notify context of the end.
if(ActiveContext.IsValid())
{
EndIMMComposition();
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Ending IMM composition."));
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
case WM_IME_CHAR:
{
// Suppress sending a WM_CHAR for this WM_IME_CHAR - the composition windows messages will have handled this.
UE_LOG(LogWindowsTextInputMethodSystem, Verbose, TEXT("Ignoring WM_IME_CHAR message."));
return 0;
}
break;
default:
{
UE_LOG(LogWindowsTextInputMethodSystem, Warning, TEXT("Unexpected windows message received for processing."));
return DefWindowProc(hwnd, msg, wParam, lParam);
}
break;
}
}
