qwasminputcontext.cpp

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// Copyright (C) 2019 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
// Qt-Security score:significant reason:default
 
#include "qwasminputcontext.h"
#include "qwasmwindow.h"
#include "qwasmaccessibility.h"
 
#include <QRectF>
#include <QLoggingCategory>
#include <qguiapplication.h>
#include <qwindow.h>
#include <qpa/qplatforminputcontext.h>
#include <qpa/qwindowsysteminterface.h>
#if QT_CONFIG(clipboard)
#include <QClipboard>
#endif
#include <QtGui/qtextobject.h>
 
QT_BEGIN_NAMESPACE
 
Q_LOGGING_CATEGORY(qLcQpaWasmInputContext, "qt.qpa.wasm.inputcontext")
 
using namespace qstdweb;
 
void QWasmInputContext::inputCallback(emscripten::val event)
{
    emscripten::val inputType = event["inputType"];
    if (inputType.isNull() || inputType.isUndefined())
        return;
    const auto inputTypeString = inputType.as<std::string>();
 
    emscripten::val inputData = event["data"];
    QString inputStr = (!inputData.isNull() && !inputData.isUndefined())
        ? QString::fromEcmaString(inputData) : QString();
 
 
    // also do dataTransfer
    // containing rich text
    emscripten::val dataTr = event["dataTransfer"];
    if (!dataTr.isUndefined() && !dataTr.isNull()) {
        qCDebug(qLcQpaWasmInputContext) << "inputEvent dataTransfer" << inputStr;
        inputStr = QString::fromStdString(dataTr.
                                          call<emscripten::val>("getData",
                                                                std::string("text")).as<std::string>());
    }
 
    if (m_ignoreNextInput) {
        m_ignoreNextInput = false;
        return;
    }
    // There are many inputTypes for InputEvent
    // https://www.w3.org/TR/input-events-1/
    // Some of them should be implemented here later.
 
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << "inputType : " << inputTypeString;
 
    if (!inputTypeString.compare("deleteContentBackward")
            || !inputTypeString.compare("deleteContent")) {
        // deleteContent is direction-agnostic. WebKit emits it for generic
        // editing deletions, and embedded virtual keyboards drive backspace
        // this way, so treat it as a backward delete.
        const ResolvedRange resolved = resolveRange(getFirstRange());
 
        const int deleteFrom = resolved.replaceFrom <= 0 ? resolved.replaceFrom : -1;
        commitText(QString(), deleteFrom, resolved.replaceLength);
    } else if (!inputTypeString.compare("deleteContentForward")) {
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_Delete, Qt::NoModifier);
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyRelease, Qt::Key_Delete, Qt::NoModifier);
    } else if (!inputTypeString.compare("deleteWordBackward")) {
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_Backspace, Qt::ControlModifier);
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyRelease, Qt::Key_Backspace, Qt::ControlModifier);
    } else if (!inputTypeString.compare("deleteWordForward")) {
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_Delete, Qt::ControlModifier);
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyRelease, Qt::Key_Delete, Qt::ControlModifier);
    } else if (!inputTypeString.compare("insertParagraph")) {
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_Return, Qt::NoModifier);
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyRelease, Qt::Key_Return, Qt::NoModifier);
    } else if (!inputTypeString.compare("insertLineBreak")) {
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyPress, Qt::Key_Return, Qt::ShiftModifier);
        QWindowSystemInterface::handleKeyEvent(0, QEvent::KeyRelease, Qt::Key_Return, Qt::ShiftModifier);
    } else if (!inputTypeString.compare("insertCompositionText")) {
 
        qCDebug(qLcQpaWasmInputContext) << "insertCompositionText : " << inputStr;
        if (event["isComposing"].as<bool>()) {
            const CompositionRange range = getFirstRange();
            setPreeditString(inputStr);
            insertPreedit(range.end - range.start);
        }
    } else if (!inputTypeString.compare("insertReplacementText")) {
 
        qCDebug(qLcQpaWasmInputContext) << "insertReplacementText >>>>" << "inputString : " << inputStr;
        const CompositionRange range = getFirstRange();
 
        if (range.isValid) {
            const ResolvedRange resolved = resolveRange(range);
            commitText(inputStr, resolved.replaceFrom, resolved.replaceLength);
        } else {
            QInputMethodQueryEvent queryEvent(Qt::ImQueryAll);
            QCoreApplication::sendEvent(m_focusObject, &queryEvent);
            int qCursorPosition = queryEvent.value(Qt::ImCursorPosition).toInt();
            QString textFieldString = queryEvent.value(Qt::ImTextBeforeCursor).toString();
 
            int spaceIndex = textFieldString.lastIndexOf(' ') + 1;
            int replaceIndex = (qCursorPosition - spaceIndex);
            commitText(inputStr, -replaceIndex, replaceIndex);
        }
    } else if (!inputTypeString.compare("deleteCompositionText")) {
        setPreeditString("");
        insertPreedit();
    } else if (!inputTypeString.compare("insertFromComposition")) {
        setPreeditString(inputStr);
        insertPreedit();
    } else if (!inputTypeString.compare("insertText")) {
        const CompositionRange range = getFirstRange();
 
        if (range.isValid && range.start != range.end) {
            const ResolvedRange resolved = resolveRange(range);
            commitText(inputStr, resolved.replaceFrom, resolved.replaceLength);
        } else {
            commitText(inputStr);
        }
    } else if (!inputTypeString.compare("insertFromPaste")) {
        commitText(inputStr);
    // These can be supported here,
    // But now, keyCallback in QWasmWindow
    // will take them as exceptions.
    //} else if (!inputTypeString.compare("deleteByCut")) {
    } else {
        qCWarning(qLcQpaWasmInputContext) << Q_FUNC_INFO << "inputType \"" <<
            inputType.as<std::string>() << "\" is not supported in Qt yet";
    }
 
    // Prevent the event from propagting to any listeners outside of the Qt window
    event.call<void>("stopPropagation");
 
    // The composition target range set by the preceding "beforeinput" event has
    // been consumed by this input event; clear it so a later input event without
    // a fresh beforeinput cannot reuse a stale range.
    m_compositionRange = emscripten::val::null();
}
 
void QWasmInputContext::compositionEndCallback(emscripten::val event)
{
    const auto inputStr = QString::fromEcmaString(event["data"]);
 
    if (preeditString().isEmpty()) // we get final results from inputCallback
        return;
 
    if (inputStr != preeditString()) {
        qCWarning(qLcQpaWasmInputContext) << Q_FUNC_INFO
                    << "Composition string" << inputStr
                    << "is differ from" << preeditString();
    }
    commitPreeditAndClear();
}
 
void QWasmInputContext::compositionStartCallback(emscripten::val event)
{
     Q_UNUSED(event);
 
    // Do nothing when starting composition
}
 
void QWasmInputContext::compositionUpdateCallback(emscripten::val event)
{
    const auto compositionStr = QString::fromEcmaString(event["data"]);
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << compositionStr;
 
    setPreeditString(compositionStr);
}
 
void QWasmInputContext::beforeInputCallback(emscripten::val event)
{
    m_compositionRange = event.call<emscripten::val>("getTargetRanges");
 
    if (const CompositionRange range = getFirstRange(); range.isValid) {
        qCDebug(qLcQpaWasmInputContext) << "startOffset" << range.start;
        qCDebug(qLcQpaWasmInputContext) << "endOffset" << range.end;
    }
}
 
// Returns the first of the target ranges from the most recent "beforeinput"
// event (InputEvent.getTargetRanges(), a possibly empty list of StaticRanges).
QWasmInputContext::CompositionRange QWasmInputContext::getFirstRange() const
{
    CompositionRange range;
    if (!m_compositionRange.isNull() && !m_compositionRange.isUndefined()
        && m_compositionRange["length"].as<int>() > 0) {
        emscripten::val first = m_compositionRange[0];
        range.start = first["startOffset"].as<int>();
        range.end = first["endOffset"].as<int>();
        range.isValid = true;
    }
    return range;
}
 
// Resolves a composition range against the current input cursor position for 
// the focus object. Returns (replaceFrom, replaceLength) which can be passed
// to QInputMethodEvent, where replaceFrom is an offset from the cursor position.
QWasmInputContext::ResolvedRange QWasmInputContext::resolveRange(const CompositionRange &range) const
{
    QInputMethodQueryEvent queryEvent(Qt::ImQueryAll);
    QCoreApplication::sendEvent(m_focusObject, &queryEvent);
    const int cursorPosition = queryEvent.value(Qt::ImCursorPosition).toInt();
    return { range.start - cursorPosition, range.end - range.start };
}
 
QWasmInputContext::QWasmInputContext()
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO;
}
 
QWasmInputContext::~QWasmInputContext()
{
}
 
void QWasmInputContext::update(Qt::InputMethodQueries queries)
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << queries;
 
    if (m_inputElement.isNull())
        return;
 
    if (queries & Qt::ImInputItemClipRectangle) {
        const QRect inputItemRectangle = QPlatformInputContext::inputItemRectangle().toRect();
        qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << "propagating inputItemRectangle:" << inputItemRectangle;
        m_inputElement["style"].set("left", std::to_string(inputItemRectangle.x()) + "px");
        m_inputElement["style"].set("top", std::to_string(inputItemRectangle.y()) + "px");
        m_inputElement["style"].set("width", "1px"); // "1px" to avoid overflowing window layout FIXME: fix layout
        m_inputElement["style"].set("height", "1px");
    }
}
 
void QWasmInputContext::showInputPanel()
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO;
 
    // Note: showInputPanel not necessarily called, we also
    // need to make sure the input panel is shown in response
    // to setFocusObject()
    if (!m_inputElement.isNull())
        focusOnFocusWindow(QWasmWindow::InputFocus);
}
 
void QWasmInputContext::hideInputPanel()
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO;
 
    // hide only if m_focusObject does not exist
    if (m_focusObject)
        return;
 
    focusOnFocusWindow(QWasmWindow::WindowFocus);
}
 
void QWasmInputContext::setFocusObject(QObject *object)
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << object << inputMethodAccepted();
 
    // Commit the previous composition before change m_focusObject
    if (m_focusObject && !m_preeditString.isEmpty())
        commitPreeditAndClear();
 
    m_focusObject = object;
 
    // Handle the case where the current focus object does not accept input
    // (becuse it is e.g. a button, or is null)
    if (!inputMethodAccepted()) {
        // "park" the input element now that it is unused
        if (!m_inputElement.isNull()) {
            m_inputElement["style"].set("left", "0px");
            m_inputElement["style"].set("top", "0px");
            m_inputElement = emscripten::val::null();
        }
 
        // Set focus to the focus helper for the current focus window. This moves focus
        // away from the input element which will hide virtual keyboards.
        focusOnFocusWindow(QWasmWindow::WindowFocus);
    } else {
        // Make the input element's properties match the current focus obj
        m_inputElement = QWasmWindow::focusedWindowInputElement();
        if (!m_inputElement.isNull()) {
            updateInputElement();
 
            // Set foucs to the input element. This shows (and re-shows) the virtual
            // keyboard on mobile devices.
            focusOnFocusWindow(QWasmWindow::InputFocus);
        }
    }
}
 
void QWasmInputContext::updateInputElement()
{
    if (QWasmAccessibility::isEnabled())
        return;
 
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO;
 
    QInputMethodQueryEvent queryEvent(Qt::ImQueryAll);
    QCoreApplication::sendEvent(m_focusObject, &queryEvent);
 
    qCDebug(qLcQpaWasmInputContext) << "Qt surrounding text: " << queryEvent.value(Qt::ImSurroundingText).toString();
    qCDebug(qLcQpaWasmInputContext) << "Qt current selection: " << queryEvent.value(Qt::ImCurrentSelection).toString();
    qCDebug(qLcQpaWasmInputContext) << "Qt text before cursor: " << queryEvent.value(Qt::ImTextBeforeCursor).toString();
    qCDebug(qLcQpaWasmInputContext) << "Qt text after cursor: " << queryEvent.value(Qt::ImTextAfterCursor).toString();
    qCDebug(qLcQpaWasmInputContext) << "Qt cursor position: " << queryEvent.value(Qt::ImCursorPosition).toInt();
    qCDebug(qLcQpaWasmInputContext) << "Qt anchor position: " << queryEvent.value(Qt::ImAnchorPosition).toInt();
 
    m_inputElement.set("value", queryEvent.value(Qt::ImSurroundingText).toString().toStdString());
    m_inputElement.set("selectionStart", queryEvent.value(Qt::ImAnchorPosition).toUInt());
    m_inputElement.set("selectionEnd", queryEvent.value(Qt::ImCursorPosition).toUInt());
 
    Qt::InputMethodHints imHints = static_cast<Qt::InputMethodHints>(queryEvent.value(Qt::ImHints).toInt());
 
    // Set input mode, use "password" for ImhHiddenText to prevent unwanted interactions with
    // spell checking and auto-complete.
    if (imHints & Qt::ImhHiddenText)
        m_inputElement.set("type", "password");
    else
        m_inputElement.set("type", "text");
 
    // Change inputmode to suit Qt imhints
    std::string inMode = "text";
    if (imHints & Qt::ImhDigitsOnly)
        inMode = "numeric";
    if (imHints & Qt::ImhFormattedNumbersOnly)
        inMode = "decimal";
    if (imHints & Qt::ImhDialableCharactersOnly)
        inMode = "tel";
    if (imHints & Qt::ImhEmailCharactersOnly)
        inMode = "email";
    if (imHints & Qt::ImhUrlCharactersOnly)
        inMode = "url";
    // FIXME: handle search mode?
    m_inputElement.set("inputMode", inMode);
}
 
// Moves native focus to the focus helper (WindowFocus) or the input element
// (InputFocus) of the currently focused window. InputFocus shows the virtual
// keyboard on mobile; WindowFocus moves focus off the input element and hides it.
void QWasmInputContext::focusOnFocusWindow(QWasmWindow::FocusTarget target)
{
    if (QWasmWindow *focusWindow = QWasmWindow::focusWindow())
        focusWindow->focus(target);
}
 
void QWasmInputContext::setPreeditString(QString preeditStr)
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << preeditStr;
    m_preeditString = preeditStr;
}
 
void QWasmInputContext::insertPreedit(int replaceLength)
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << m_preeditString;
    if (replaceLength == 0)
        replaceLength = m_preeditString.length();
 
    QList<QInputMethodEvent::Attribute> attributes;
    {
        QInputMethodEvent::Attribute attr_cursor(QInputMethodEvent::Cursor,
                                                 0,
                                                 1);
        attributes.append(attr_cursor);
 
        QTextCharFormat format;
        format.setFontUnderline(true);
        format.setUnderlineStyle(QTextCharFormat::SingleUnderline);
        QInputMethodEvent::Attribute attr_format(QInputMethodEvent::TextFormat,
                                                0,
                                                replaceLength, format);
        attributes.append(attr_format);
    }
 
    QInputMethodEvent e(m_preeditString, attributes);
    QCoreApplication::sendEvent(m_focusObject, &e);
}
 
void QWasmInputContext::commitPreeditAndClear()
{
    if (m_preeditString.isEmpty())
        return;
    QInputMethodEvent e;
    e.setCommitString(m_preeditString);
    m_preeditString.clear();
    QCoreApplication::sendEvent(m_focusObject, &e);
}
 
// Commits text to the focus object, optionally replacing replaceLength
// characters starting replaceFrom positions relative to the cursor.
void QWasmInputContext::commitText(const QString &text, int replaceFrom, int replaceLength)
{
    qCDebug(qLcQpaWasmInputContext) << Q_FUNC_INFO << text << replaceFrom << replaceLength;
    QInputMethodEvent e;
    e.setCommitString(text, replaceFrom, replaceLength);
    QCoreApplication::sendEvent(m_focusObject, &e);
    m_preeditString.clear();
}
 
QT_END_NAMESPACE