qshortcutmap.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qshortcutmap_p.h"
#include "private/qobject_p.h"
#include "qkeysequence.h"
#include "qdebug.h"
#include "qevent.h"
#include "qlist.h"
#include "qguiapplication.h"
#include "qwindow.h"
#include <private/qkeymapper_p.h>
#include <QtCore/qloggingcategory.h>
#include <QtCore/qscopeguard.h>
 
#include <algorithm>
 
QT_BEGIN_NAMESPACE
 
Q_LOGGING_CATEGORY(lcShortcutMap, "qt.gui.shortcutmap")
 
/* \internal
    Entry data for QShortcutMap
    Contains:
        Keysequence for entry
        Pointer to parent owning the sequence
*/
 
struct QShortcutEntry
{
    QShortcutEntry()
        : keyseq(0), context(Qt::WindowShortcut), enabled(false), autorepeat(1), id(0), owner(nullptr), contextMatcher(nullptr)
    {}
 
    QShortcutEntry(const QKeySequence &k)
        : keyseq(k), context(Qt::WindowShortcut), enabled(false), autorepeat(1), id(0), owner(nullptr), contextMatcher(nullptr)
    {}
 
    QShortcutEntry(QObject *o, const QKeySequence &k, Qt::ShortcutContext c, int i, bool a, QShortcutMap::ContextMatcher m)
        : keyseq(k), context(c), enabled(true), autorepeat(a), id(i), owner(o), contextMatcher(m)
    {}
 
    bool correctContext() const { return contextMatcher(owner, context); }
 
    bool operator<(const QShortcutEntry &f) const
    { return keyseq < f.keyseq; }
 
    QKeySequence keyseq;
    Qt::ShortcutContext context;
    bool enabled : 1;
    bool autorepeat : 1;
    signed int id;
    QObject *owner;
    QShortcutMap::ContextMatcher contextMatcher;
};
Q_DECLARE_TYPEINFO(QShortcutEntry, Q_RELOCATABLE_TYPE);
 
#ifdef Dump_QShortcutMap
static QDebug &operator<<(QDebug &dbg, const QShortcutEntry *se)
{
    QDebugStateSaver saver(dbg);
    if (!se)
        return dbg << "QShortcutEntry(0x0)";
    dbg.nospace()
        << "QShortcutEntry(" << se->keyseq
        << "), id(" << se->id << "), enabled(" << se->enabled << "), autorepeat(" << se->autorepeat
        << "), owner(" << se->owner << ')';
    return dbg;
}
#endif // Dump_QShortcutMap
 
/* \internal
    Private data for QShortcutMap
*/
class QShortcutMapPrivate
{
    Q_DECLARE_PUBLIC(QShortcutMap)
 
public:
    QShortcutMapPrivate(QShortcutMap* parent)
        : q_ptr(parent), currentId(0), ambigCount(0), currentState(QKeySequence::NoMatch)
    {
        identicals.reserve(10);
        currentSequences.reserve(10);
    }
    QShortcutMap *q_ptr;                        // Private's parent
 
    QList<QShortcutEntry> sequences;            // All sequences!
 
    int currentId;                              // Global shortcut ID number
    int ambigCount;                             // Index of last enabled ambiguous dispatch
    QKeySequence::SequenceMatch currentState;
    QList<QKeySequence> currentSequences;       // Sequence for the current state
    QList<QKeySequence> newEntries;
    QKeySequence prevSequence;                  // Sequence for the previous identical match
    QList<const QShortcutEntry*> identicals;    // Last identical matches
};
 
 
QShortcutMap::QShortcutMap()
    : d_ptr(new QShortcutMapPrivate(this))
{
    resetState();
}
 
QShortcutMap::~QShortcutMap()
{
}
 
int QShortcutMap::addShortcut(QObject *owner, const QKeySequence &key, Qt::ShortcutContext context, ContextMatcher matcher)
{
    Q_ASSERT_X(owner, "QShortcutMap::addShortcut", "All shortcuts need an owner");
    Q_ASSERT_X(!key.isEmpty(), "QShortcutMap::addShortcut", "Cannot add keyless shortcuts to map");
    Q_D(QShortcutMap);
 
    QShortcutEntry newEntry(owner, key, context, --(d->currentId), true, matcher);
    const auto it = std::upper_bound(d->sequences.begin(), d->sequences.end(), newEntry);
    d->sequences.insert(it, newEntry); // Insert sorted
    qCDebug(lcShortcutMap).nospace()
        << "QShortcutMap::addShortcut(" << owner << ", "
        << key << ", " << context << ") added shortcut with ID " << d->currentId;
    return d->currentId;
}
 
int QShortcutMap::removeShortcut(int id, QObject *owner, const QKeySequence &key)
{
    Q_D(QShortcutMap);
    int itemsRemoved = 0;
    bool allOwners = (owner == nullptr);
    bool allKeys = key.isEmpty();
    bool allIds = id == 0;
 
    auto debug = qScopeGuard([&](){
        qCDebug(lcShortcutMap).nospace()
            << "QShortcutMap::removeShortcut(" << id << ", " << owner << ", "
            << key << ") removed " << itemsRemoved << " shortcuts(s)";
    });
 
    // Special case, remove everything
    if (allOwners && allKeys && allIds) {
        itemsRemoved = d->sequences.size();
        d->sequences.clear();
        return itemsRemoved;
    }
 
    int i = d->sequences.size()-1;
    while (i>=0)
    {
        const QShortcutEntry &entry = d->sequences.at(i);
        int entryId = entry.id;
        if ((allOwners || entry.owner == owner)
            && (allIds || entry.id == id)
            && (allKeys || entry.keyseq == key)) {
            d->sequences.removeAt(i);
            ++itemsRemoved;
        }
        if (id == entryId)
            return itemsRemoved;
        --i;
    }
    return itemsRemoved;
}
 
int QShortcutMap::setShortcutEnabled(bool enable, int id, QObject *owner, const QKeySequence &key)
{
    Q_D(QShortcutMap);
    int itemsChanged = 0;
    bool allOwners = (owner == nullptr);
    bool allKeys = key.isEmpty();
    bool allIds = id == 0;
 
    int i = d->sequences.size()-1;
    while (i>=0)
    {
        QShortcutEntry entry = d->sequences.at(i);
        if ((allOwners || entry.owner == owner)
            && (allIds || entry.id == id)
            && (allKeys || entry.keyseq == key)) {
            d->sequences[i].enabled = enable;
            ++itemsChanged;
        }
        if (id == entry.id)
            return itemsChanged;
        --i;
    }
    qCDebug(lcShortcutMap).nospace()
        << "QShortcutMap::setShortcutEnabled(" << enable << ", " << id << ", "
        << owner << ", " << key << ") = " << itemsChanged;
    return itemsChanged;
}
 
int QShortcutMap::setShortcutAutoRepeat(bool on, int id, QObject *owner, const QKeySequence &key)
{
    Q_D(QShortcutMap);
    int itemsChanged = 0;
    bool allOwners = (owner == nullptr);
    bool allKeys = key.isEmpty();
    bool allIds = id == 0;
 
    int i = d->sequences.size()-1;
    while (i>=0)
    {
        QShortcutEntry entry = d->sequences.at(i);
        if ((allOwners || entry.owner == owner)
            && (allIds || entry.id == id)
            && (allKeys || entry.keyseq == key)) {
                d->sequences[i].autorepeat = on;
                ++itemsChanged;
        }
        if (id == entry.id)
            return itemsChanged;
        --i;
    }
    qCDebug(lcShortcutMap).nospace()
        << "QShortcutMap::setShortcutAutoRepeat(" << on << ", " << id << ", "
        << owner << ", " << key << ") = " << itemsChanged;
    return itemsChanged;
}
 
void QShortcutMap::resetState()
{
    Q_D(QShortcutMap);
    d->currentState = QKeySequence::NoMatch;
    clearSequence(d->currentSequences);
}
 
QKeySequence::SequenceMatch QShortcutMap::state()
{
    Q_D(QShortcutMap);
    return d->currentState;
}
 
bool QShortcutMap::tryShortcut(QKeyEvent *e)
{
    Q_D(QShortcutMap);
 
    if (e->key() == Qt::Key_unknown)
        return false;
 
    QKeySequence::SequenceMatch previousState = state();
 
    switch (nextState(e)) {
    case QKeySequence::NoMatch:
        // In the case of going from a partial match to no match we handled the
        // event, since we already stated that we did for the partial match. But
        // in the normal case of directly going to no match we say we didn't.
        return previousState == QKeySequence::PartialMatch;
    case QKeySequence::PartialMatch:
        // For a partial match we don't know yet if we will handle the shortcut
        // but we need to say we did, so that we get the follow-up key-presses.
        return true;
    case QKeySequence::ExactMatch: {
        // Save number of identical matches before dispatching
        // to keep QShortcutMap and tryShortcut reentrant.
        const int identicalMatches = d->identicals.size();
        resetState();
        dispatchEvent(e);
        // If there are no identicals we've only found disabled shortcuts, and
        // shouldn't say that we handled the event.
        return identicalMatches > 0;
    }
    }
    Q_UNREACHABLE_RETURN(false);
}
 
QKeySequence::SequenceMatch QShortcutMap::nextState(QKeyEvent *e)
{
    Q_D(QShortcutMap);
    // Modifiers can NOT be shortcuts...
    if (e->key() >= Qt::Key_Shift &&
        e->key() <= Qt::Key_ScrollLock)
        return d->currentState;
 
    QKeySequence::SequenceMatch result = QKeySequence::NoMatch;
 
    // We start fresh each time..
    d->identicals.clear();
 
    result = find(e);
    if (result == QKeySequence::NoMatch && (e->modifiers() & Qt::KeypadModifier)) {
        // Try to find a match without keypad modifier
        result = find(e, Qt::KeypadModifier);
    }
    if (result == QKeySequence::NoMatch && e->modifiers() & Qt::ShiftModifier) {
        // If Shift + Key_Backtab, also try Shift + Qt::Key_Tab
        if (e->key() == Qt::Key_Backtab) {
            QKeyEvent pe = QKeyEvent(e->type(), Qt::Key_Tab, e->modifiers(), e->text());
            result = find(&pe);
        }
    }
 
    // Does the new state require us to clean up?
    if (result == QKeySequence::NoMatch)
        clearSequence(d->currentSequences);
    d->currentState = result;
 
    qCDebug(lcShortcutMap).nospace() << "QShortcutMap::nextState(" << e << ") = " << result;
    return result;
}
 
 
bool QShortcutMap::hasShortcutForKeySequence(const QKeySequence &seq) const
{
    Q_D(const QShortcutMap);
    QShortcutEntry entry(seq); // needed for searching
    const auto itEnd = d->sequences.cend();
    auto it = std::lower_bound(d->sequences.cbegin(), itEnd, entry);
 
    for (;it != itEnd; ++it) {
        if (matches(entry.keyseq, (*it).keyseq) == QKeySequence::ExactMatch && (*it).correctContext() && (*it).enabled) {
            return true;
        }
    }
 
    //end of the loop: we didn't find anything
    return false;
}
 
QKeySequence::SequenceMatch QShortcutMap::find(QKeyEvent *e, int ignoredModifiers)
{
    Q_D(QShortcutMap);
    if (!d->sequences.size())
        return QKeySequence::NoMatch;
 
    createNewSequences(e, d->newEntries, ignoredModifiers);
    qCDebug(lcShortcutMap) << "Possible shortcut key sequences:" << d->newEntries;
 
    // Should never happen
    if (d->newEntries == d->currentSequences) {
        Q_ASSERT_X(e->key() != Qt::Key_unknown || e->text().size(),
                   "QShortcutMap::find", "New sequence to find identical to previous");
        return QKeySequence::NoMatch;
    }
 
    // Looking for new identicals, scrap old
    d->identicals.clear();
 
    bool partialFound = false;
    bool identicalDisabledFound = false;
    QList<QKeySequence> okEntries;
    int result = QKeySequence::NoMatch;
    for (int i = d->newEntries.size()-1; i >= 0 ; --i) {
        QShortcutEntry entry(d->newEntries.at(i)); // needed for searching
        qCDebug(lcShortcutMap) << "- checking entry" << entry.id << entry.keyseq;
        const auto itEnd = d->sequences.constEnd();
        auto it = std::lower_bound(d->sequences.constBegin(), itEnd, entry);
 
        int oneKSResult = QKeySequence::NoMatch;
        int tempRes = QKeySequence::NoMatch;
        do {
            if (it == itEnd)
                break;
            tempRes = matches(entry.keyseq, (*it).keyseq);
            oneKSResult = qMax(oneKSResult, tempRes);
            qCDebug(lcShortcutMap) << "  - matches returned" << tempRes << "for" << entry.keyseq << it->keyseq
                << "- correctContext()?" << it->correctContext();
            if (tempRes != QKeySequence::NoMatch && (*it).correctContext()) {
                if (tempRes == QKeySequence::ExactMatch) {
                    if ((*it).enabled)
                        d->identicals.append(&*it);
                    else
                        identicalDisabledFound = true;
                } else if (tempRes == QKeySequence::PartialMatch) {
                    // We don't need partials, if we have identicals
                    if (d->identicals.size())
                        break;
                    // We only care about enabled partials, so we don't consume
                    // key events when all partials are disabled!
                    partialFound |= (*it).enabled;
                }
            }
            ++it;
            // If we got a valid match on this run, there might still be more keys to check against,
            // so we'll loop once more. If we get NoMatch, there's guaranteed no more possible
            // matches in the shortcutmap.
        } while (tempRes != QKeySequence::NoMatch);
 
        // If the type of match improves (ergo, NoMatch->Partial, or Partial->Exact), clear the
        // previous list. If this match is equal or better than the last match, append to the list
        if (oneKSResult > result) {
            okEntries.clear();
            qCDebug(lcShortcutMap) << "Found better match (" << d->newEntries << "), clearing key sequence list";
        }
        if (oneKSResult && oneKSResult >= result) {
            okEntries << d->newEntries.at(i);
            qCDebug(lcShortcutMap) << "Added ok key sequence" << d->newEntries;
        }
    }
 
    if (d->identicals.size()) {
        result = QKeySequence::ExactMatch;
    } else if (partialFound) {
        result = QKeySequence::PartialMatch;
    } else if (identicalDisabledFound) {
        result = QKeySequence::ExactMatch;
    } else {
        clearSequence(d->currentSequences);
        result = QKeySequence::NoMatch;
    }
    if (result != QKeySequence::NoMatch)
        d->currentSequences = okEntries;
    qCDebug(lcShortcutMap) << "Returning shortcut match == " << result;
    return QKeySequence::SequenceMatch(result);
}
 
void QShortcutMap::clearSequence(QList<QKeySequence> &ksl)
{
    ksl.clear();
    d_func()->newEntries.clear();
}
 
void QShortcutMap::createNewSequences(QKeyEvent *e, QList<QKeySequence> &ksl, int ignoredModifiers)
{
    Q_D(QShortcutMap);
    QList<int> possibleKeys = QKeyMapper::possibleKeys(e);
    qCDebug(lcShortcutMap) << "Creating new sequences for" << e
        << "with ignoredModifiers=" << Qt::KeyboardModifiers(ignoredModifiers);
    int pkTotal = possibleKeys.size();
    if (!pkTotal)
        return;
 
    int ssActual = d->currentSequences.size();
    int ssTotal = qMax(1, ssActual);
    // Resize to possible permutations of the current sequence(s).
    ksl.resize(pkTotal * ssTotal);
 
    int index = ssActual ? d->currentSequences.at(0).count() : 0;
    for (int pkNum = 0; pkNum < pkTotal; ++pkNum) {
        for (int ssNum = 0; ssNum < ssTotal; ++ssNum) {
            int i = (pkNum * ssTotal) + ssNum;
            QKeySequence &curKsl = ksl[i];
            if (ssActual) {
                const QKeySequence &curSeq = d->currentSequences.at(ssNum);
                curKsl.setKey(curSeq[0], 0);
                curKsl.setKey(curSeq[1], 1);
                curKsl.setKey(curSeq[2], 2);
                curKsl.setKey(curSeq[3], 3);
            } else {
                curKsl.setKey(QKeyCombination::fromCombined(0), 0);
                curKsl.setKey(QKeyCombination::fromCombined(0), 1);
                curKsl.setKey(QKeyCombination::fromCombined(0), 2);
                curKsl.setKey(QKeyCombination::fromCombined(0), 3);
            }
            curKsl.setKey(QKeyCombination::fromCombined(possibleKeys.at(pkNum) & ~ignoredModifiers), index);
        }
    }
}
 
QKeySequence::SequenceMatch QShortcutMap::matches(const QKeySequence &seq1,
                                                  const QKeySequence &seq2) const
{
    uint userN = seq1.count(),
        seqN = seq2.count();
 
    if (userN > seqN)
        return QKeySequence::NoMatch;
 
    // If equal in length, we have a potential ExactMatch sequence,
    // else we already know it can only be partial.
    QKeySequence::SequenceMatch match = (userN == seqN
                                            ? QKeySequence::ExactMatch
                                            : QKeySequence::PartialMatch);
 
    for (uint i = 0; i < userN; ++i) {
        int userKey = seq1[i].toCombined(),
            sequenceKey = seq2[i].toCombined();
        if ((userKey & Qt::Key_unknown) == Qt::Key_hyphen)
            userKey = (userKey & Qt::KeyboardModifierMask) | Qt::Key_Minus;
        if ((sequenceKey & Qt::Key_unknown) == Qt::Key_hyphen)
            sequenceKey = (sequenceKey & Qt::KeyboardModifierMask) | Qt::Key_Minus;
        if (userKey != sequenceKey)
            return QKeySequence::NoMatch;
    }
    return match;
}
 
 
int QShortcutMap::translateModifiers(Qt::KeyboardModifiers modifiers)
{
    int result = 0;
    if (modifiers & Qt::ShiftModifier)
        result |= Qt::SHIFT;
    if (modifiers & Qt::ControlModifier)
        result |= Qt::CTRL;
    if (modifiers & Qt::MetaModifier)
        result |= Qt::META;
    if (modifiers & Qt::AltModifier)
        result |= Qt::ALT;
    return result;
}
 
QList<const QShortcutEntry*> QShortcutMap::matches() const
{
    Q_D(const QShortcutMap);
    return d->identicals;
}
 
void QShortcutMap::dispatchEvent(QKeyEvent *e)
{
    Q_D(QShortcutMap);
    if (!d->identicals.size())
        return;
 
    const QKeySequence &curKey = d->identicals.at(0)->keyseq;
    if (d->prevSequence != curKey) {
        d->ambigCount = 0;
        d->prevSequence = curKey;
    }
    // Find next
    const QShortcutEntry *current = nullptr, *next = nullptr;
    int i = 0, enabledShortcuts = 0;
    QList<const QShortcutEntry*> ambiguousShortcuts;
    while(i < d->identicals.size()) {
        current = d->identicals.at(i);
        if (current->enabled || !next){
            ++enabledShortcuts;
            if (lcShortcutMap().isDebugEnabled())
                ambiguousShortcuts.append(current);
            if (enabledShortcuts > d->ambigCount + 1)
                break;
            next = current;
        }
        ++i;
    }
    d->ambigCount = (d->identicals.size() == i ? 0 : d->ambigCount + 1);
    // Don't trigger shortcut if we're autorepeating and the shortcut is
    // grabbed with not accepting autorepeats.
    if (!next || (e->isAutoRepeat() && !next->autorepeat))
        return;
    // Dispatch next enabled
    if (lcShortcutMap().isDebugEnabled()) {
        if (ambiguousShortcuts.size() > 1) {
            qCDebug(lcShortcutMap) << "The following shortcuts are about to be activated ambiguously:";
            for (const QShortcutEntry *entry : std::as_const(ambiguousShortcuts))
                qCDebug(lcShortcutMap).nospace() << "- " << entry->keyseq << " (belonging to " << entry->owner << ")";
        }
 
        qCDebug(lcShortcutMap).nospace()
            << "QShortcutMap::dispatchEvent(): Sending QShortcutEvent(\""
            << next->keyseq.toString() << "\", " << next->id << ", "
            << static_cast<bool>(enabledShortcuts>1) << ") to object(" << next->owner << ')';
    }
    QShortcutEvent se(next->keyseq, next->id, enabledShortcuts>1);
    QCoreApplication::sendEvent(const_cast<QObject *>(next->owner), &se);
}
 
QList<QKeySequence> QShortcutMap::keySequences(bool getAll) const
{
    Q_D(const QShortcutMap);
    QList<QKeySequence> keys;
    for (auto sequence : d->sequences) {
        bool addSequence = false;
        if (sequence.enabled) {
            if (getAll || sequence.context == Qt::ApplicationShortcut ||
                sequence.owner == QGuiApplication::focusObject()) {
                addSequence = true;
            } else {
                QObject *possibleWindow = sequence.owner;
                while (possibleWindow) {
                    if (qobject_cast<QWindow *>(possibleWindow))
                        break;
                    possibleWindow = possibleWindow->parent();
                }
                if (possibleWindow == QGuiApplication::focusWindow()) {
                    if (sequence.context == Qt::WindowShortcut) {
                        addSequence = true;
                    } else if (sequence.context == Qt::WidgetWithChildrenShortcut) {
                        QObject *possibleWidget = QGuiApplication::focusObject();
                        while (possibleWidget->parent()) {
                            possibleWidget = possibleWidget->parent();
                            if (possibleWidget == sequence.owner) {
                                addSequence = true;
                                break;
                            }
                        }
                    }
                }
            }
            if (addSequence)
                keys << sequence.keyseq;
        }
    }
    return keys;
 
}
 
/* \internal
    QShortcutMap dump function, only available when DEBUG_QSHORTCUTMAP is
    defined.
*/
#if defined(Dump_QShortcutMap)
void QShortcutMap::dumpMap() const
{
    Q_D(const QShortcutMap);
    for (int i = 0; i < d->sequences.size(); ++i)
        qDebug().nospace() << &(d->sequences.at(i));
}
#endif
 
QT_END_NAMESPACE