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#include "qwinrtinputcontext.h"
#include "qwinrtscreen.h"
#include <QtGui/QGuiApplication>
#include <QtGui/QWindow>
#include <private/qeventdispatcher_winrt_p.h>

#include <functional>
#include <wrl.h>
#include <roapi.h>
#include <windows.ui.viewmanagement.h>
#include <windows.ui.core.h>
using namespace Microsoft::WRL;
using namespace Microsoft::WRL::Wrappers;
using namespace ABI::Windows::Foundation;
using namespace ABI::Windows::UI::ViewManagement;
using namespace ABI::Windows::UI::Core;

typedef ITypedEventHandler<InputPane*, InputPaneVisibilityEventArgs*> InputPaneVisibilityHandler;

QT_BEGIN_NAMESPACE

Q_LOGGING_CATEGORY(lcQpaInputMethods, "qt.qpa.input.methods")

inline QRectF getInputPaneRect(ComPtr<IInputPane> pane, qreal scaleFactor)
{
    Rect rect;
    pane->get_OccludedRect(&rect);
    return QRectF(qRound(qreal(rect.X) * scaleFactor), qRound(qreal(rect.Y) * scaleFactor),
                  qRound(qreal(rect.Width) * scaleFactor), qRound(qreal(rect.Height) * scaleFactor));
}

/*!
    \class QWinRTInputContext
    \brief Manages Input Method visibility
    \internal
    \ingroup qt-qpa-winrt

    Listens to the native virtual keyboard for hide/show events and provides
    hints to the OS for showing/hiding. On WinRT, showInputPanel()/hideInputPanel()
    have no effect because WinRT dictates that keyboard presence is user-driven:
    (http://msdn.microsoft.com/en-us/library/windows/apps/hh465404.aspx)
    Windows Phone, however, supports direct hiding/showing of the keyboard.
*/

QWinRTInputContext::QWinRTInputContext(QWinRTScreen *screen)
    : m_screen(screen)
{
    qCDebug(lcQpaInputMethods) << __FUNCTION__ << screen;

    QEventDispatcherWinRT::runOnXamlThread([this]() {
        ComPtr<IInputPaneStatics> statics;
        if (FAILED(GetActivationFactory(HString::MakeReference(RuntimeClass_Windows_UI_ViewManagement_InputPane).Get(),
                                        &statics))) {
            qWarning("failed to retrieve input pane statics.");
            return S_OK;
        }

        ComPtr<IInputPane> inputPane;
        statics->GetForCurrentView(&inputPane);
        if (inputPane) {
            EventRegistrationToken showToken, hideToken;
            inputPane->add_Showing(Callback<InputPaneVisibilityHandler>(
                this, &QWinRTInputContext::onShowing).Get(), &showToken);
            inputPane->add_Hiding(Callback<InputPaneVisibilityHandler>(
                this, &QWinRTInputContext::onHiding).Get(), &hideToken);

            m_keyboardRect = getInputPaneRect(inputPane, m_screen->scaleFactor());
            m_isInputPanelVisible = !m_keyboardRect.isEmpty();
        } else {
            qWarning("failed to retrieve InputPane.");
        }
        return S_OK;
    });

    connect(QGuiApplication::inputMethod(), &QInputMethod::cursorRectangleChanged,
            this, &QWinRTInputContext::updateScreenCursorRect);
}

QRectF QWinRTInputContext::keyboardRect() const
{
    return m_keyboardRect;
}

bool QWinRTInputContext::isInputPanelVisible() const
{
    return m_isInputPanelVisible;
}

void QWinRTInputContext::updateScreenCursorRect()
{
    m_screen->setCursorRect(QGuiApplication::inputMethod()->cursorRectangle());
}

HRESULT QWinRTInputContext::onShowing(IInputPane *pane, IInputPaneVisibilityEventArgs *)
{
    qCDebug(lcQpaInputMethods) << __FUNCTION__ << pane;
    m_isInputPanelVisible = true;
    emitInputPanelVisibleChanged();
    return handleVisibilityChange(pane);
}

HRESULT QWinRTInputContext::onHiding(IInputPane *pane, IInputPaneVisibilityEventArgs *)
{
    qCDebug(lcQpaInputMethods) << __FUNCTION__ << pane;
    m_isInputPanelVisible = false;
    emitInputPanelVisibleChanged();
    return handleVisibilityChange(pane);
}

HRESULT QWinRTInputContext::handleVisibilityChange(IInputPane *pane)
{
    qCDebug(lcQpaInputMethods) << __FUNCTION__ << pane;
    const QRectF keyboardRect = getInputPaneRect(pane, m_screen->scaleFactor());
    if (m_keyboardRect != keyboardRect) {
        m_keyboardRect = keyboardRect;
        m_screen->setKeyboardRect(m_keyboardRect);
        emitKeyboardRectChanged();
    }
    return S_OK;
}

static HRESULT getInputPane(ComPtr<IInputPane2> *inputPane2)
{
    ComPtr<IInputPaneStatics> factory;
    HRESULT hr = GetActivationFactory(HString::MakeReference(RuntimeClass_Windows_UI_ViewManagement_InputPane).Get(),
                                      &factory);
    if (FAILED(hr)) {
        qErrnoWarning(hr, "Failed to get input pane factory.");
        return hr;
    }

    ComPtr<IInputPane> inputPane;
    hr = factory->GetForCurrentView(&inputPane);
    if (FAILED(hr)) {
        qErrnoWarning(hr, "Failed to get input pane.");
        return hr;
    }

    hr = inputPane.As(inputPane2);
    if (FAILED(hr)) {
        qErrnoWarning(hr, "Failed to get extended input pane.");
        return hr;
    }
    return hr;
}

void QWinRTInputContext::showInputPanel()
{
    qCDebug(lcQpaInputMethods) << __FUNCTION__;

    QEventDispatcherWinRT::runOnXamlThread([&]() {
        ComPtr<IInputPane2> inputPane;
        HRESULT hr = getInputPane(&inputPane);
        if (FAILED(hr))
            return S_OK;
        boolean success;
        hr = inputPane->TryShow(&success);
        if (FAILED(hr) || !success)
            qErrnoWarning(hr, "Failed to show input panel.");
        return S_OK;
    });
}

void QWinRTInputContext::hideInputPanel()
{
    qCDebug(lcQpaInputMethods) << __FUNCTION__;
    if (!m_isInputPanelVisible)
        return;

    QEventDispatcherWinRT::runOnXamlThread([&]() {
        ComPtr<IInputPane2> inputPane;
        HRESULT hr = getInputPane(&inputPane);
        if (FAILED(hr))
            return S_OK;
        boolean success;
        hr = inputPane->TryHide(&success);
        if (FAILED(hr) || !success)
            qErrnoWarning(hr, "Failed to hide input panel.");
        return S_OK;
    });
}

QT_END_NAMESPACE