QTextObjectInterface and QQuickTextEdit.



  • I registred handler for simple QTextObjectInterface, that draws just 10x10 red rectangle.
    When i used QTextEdit in normal QWidget app, it worked.
    When i used QQuickTextEdit (TextEdit qml component) in Qt Quick app, it doesn't worked (nothing is drawed, but the rectangle in TextEdit is reserved, because when i change cursor position, i notice that there is something, but just empty space, nothing is drawed.
    The QTextObjectInterface intrinsicSize method is called, but the drawObject isn't.

    I did some research and i found that actually the problem is probably here:

    QQuickTextEdit.cpp from Qt 5.3.0 sources (line 1821)

    @QSGNode *QQuickTextEdit::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *updatePaintNodeData) {
    .
    .
    .
    if (textFrame->firstPosition() > textFrame->lastPosition()
    && textFrame->frameFormat().position() != QTextFrameFormat::InFlow) {
    updateNodeTransform(node, d->document->documentLayout()->frameBoundingRect(textFrame).topLeft());
    const int pos = textFrame->firstPosition() - 1;
    ProtectedLayoutAccessor *a = static_cast<ProtectedLayoutAccessor *>(d->document->documentLayout());
    QTextCharFormat format = a->formatAccessor(pos);
    QTextBlock block = textFrame->firstCursorPosition().block();
    node->m_engine->setCurrentLine(block.layout()->lineForTextPosition(pos - block.position()));
    node->m_engine->addTextObject(QPointF(0, 0), format, QQuickTextNodeEngine::Unselected, d->document,
    pos, textFrame->frameFormat().position());
    nodeStart = pos;
    }
    @
    it never reaches the point where node->m_engine->addTextObject is called. It is because
    this part of if condition textFrame->firstPosition() > textFrame->lastPosition() is evaluated to false.
    I tried std::cout the firstPostion and the lastPosition when i established the context and firstPosition is 0, lastPosition is 1

    @#include <QApplication>
    #include <QQmlApplicationEngine>
    #include <QQmlContext>
    #include <QTextDocument>
    #include <QQuickTextDocument>
    #include <iostream>
    #include <QTextCursor>
    #include <QTextBlock>
    #include <QPainter>
    #include <QAbstractTextDocumentLayout>
    #include <QTextCharFormat>
    #include "qmlcomponentspace.h"
    #include <QTextEdit>

    int main(int argc, char *argv[])
    {
    QApplication app(argc, argv);

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    
    QTextDocument * doc = engine.rootObjects().first()->findChild<QObject *>("editor")->property("textDocument").value<QQuickTextDocument *>()->textDocument();
    
    QTextCursor cur(doc);
    
    int objectType = QTextFormat::UserObject + 1000;
    
    QmlComponentSpace * component = new QmlComponentSpace();
    
    doc->documentLayout()->registerHandler(objectType, component);
    
    QTextCharFormat fmt;
    fmt.setObjectType(objectType);
    fmt.setForeground(Qt::red);
    fmt.setBackground(Qt::red);
    
    cur.movePosition(QTextCursor::End);
    
    cur.insertText(QString(QChar::ObjectReplacementCharacter), fmt);
    
    std::cout << "FIRST:" << doc->rootFrame()->firstPosition() << std::endl;
    std::cout << "END:" << doc->rootFrame()->lastPosition() << std::endl;
    
    return app.exec();
    

    }@

    Could anyone help me with it please?


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