Method processKeystrokeAction

core/document.cpp:4381–4451

}

void Document::processKeystrokeAction(const Action *action, Okular::FormField *ff, const QVariant &newValue, int prevCursorPos, int prevAnchorPos)
{
    if (action->actionType() != Action::Script) {
        qCDebug(OkularCoreDebug) << "Unsupported action type" << action->actionType() << "for keystroke.";
        return;
    }
    // Lookup the page of the FormFieldText
    int foundPage = d->findFieldPageNumber(ff);

    if (foundPage == -1) {
        qCDebug(OkularCoreDebug) << "Could not find page for formfield!";
        return;
    }

    std::shared_ptr<Event> event = Event::createKeystrokeEvent(ff, d->m_pagesVector[foundPage]);

    /* Set the selStart and selEnd event properties

       QString using UTF-16 counts a code point as made up of 1 or 2 16-bit code units.

       When encoded using 2 code units, the units are referred to as surrogate pairs.
       selectionStart() and selectionEnd() methods evaluate prevCursorPos and prevAnchorPos based on code units during selection.

       While this unit-based evaluation is suitable for detecting changes, for providing consistency with Adobe Reader for values of selStart and selEnd,
       it would be best to evaluate in terms of code points rather than the code units.

       To correct the values of selStart and selEnd accordingly, we iterate over the code units. If a surrogate pair is encountered, then selStart and
       selEnd are accordingly decremented.
    */
    int selStart = std::min(prevCursorPos, prevAnchorPos);
    int selEnd = std::max(prevCursorPos, prevAnchorPos);
    int codeUnit;
    int initialSelStart = selStart;
    int initialSelEnd = selEnd;
    QString inputString = ff->value().toString();
    for (codeUnit = 0; codeUnit < initialSelStart && codeUnit < inputString.size(); codeUnit++) {
        if (inputString.at(codeUnit).isHighSurrogate()) {
            // skip the low surrogate and decrement selStart and selEnd
            codeUnit++;
            selStart--;
            selEnd--;
        }
    }
    for (; codeUnit < initialSelEnd && codeUnit < inputString.size(); codeUnit++) {
        if (inputString.at(codeUnit).isHighSurrogate()) {
            // skip the low surrogate and decrement selEnd
            codeUnit++;
            selEnd--;
        }
    }
    std::u32string oldUcs4 = inputString.toStdU32String();
    std::u32string newUcs4 = newValue.toString().toStdU32String();
    // It is necessary to count size in terms of code points rather than code units for deletion.
    if (oldUcs4.size() - newUcs4.size() == 1 && selStart == selEnd) {
        // consider a one character removal as selection of that character and then its removal.
        selStart--;
    }
    event->setSelStart(selStart);