How to set TextFormat of a TextBlock directly

[wang9658]

textDoc = QTextEdit->document;
...

I want to set one line's color, but no effect. I think for the TextBlock of plaintext, block and line are same things.

QTextBlock blk = textDoc->begin(); 
int index = 0; 
while(blk.isValid()){ 
qDebug() << "BLOCK:" << blk.text(); 
index++; 
if(1){//index == 10){ 
QTextCursor cursor(blk); 
QTextCharFormat format; 
format.setForeground(Qt::darkYellow); 
format.setBackground(Qt::gray); 
cursor.setBlockCharFormat(format); 
} 
blk = blk.next(); 
}

QTextBlock blk = textDoc->begin(); 
int index = 0; 
while(blk.isValid()){ 
qDebug() << "BLOCK:" << blk.text(); 
index++; 
if(1){//index == 10){ 
QTextCursor cursor(blk); 
QTextCharFormat format; 
format.setForeground(Qt::darkYellow); 
format.setBackground(Qt::gray); 
cursor.setBlockCharFormat(format); 
} 
blk = blk.next(); 
}

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[ChrisW67]

Do you need to have a selection (i.e. selectionStart() then setPosition() or movePosition()) to apply a format to?

[wang9658]

No selection.
I have a string list, if the lines in QTextEdit same as string in the string list, I'll highlight it. That's my purpose.

[ChrisW67]

The block's character format is used when inserting text into an empty block, something you are not doing. You need to make a selection and then either QTextCursor::setCharFormat() or QTextCursor::mergeCharFormat().

#include <QtGui>
#include <QDebug>
 
int main(int argc, char **argv)
{
    QApplication app(argc, argv);
 
    QTextEdit te;
    te.setText("Line 1\nLine 2\nLine 3");
 
    QTextDocument *textDoc = te.document();
    QTextBlock blk = textDoc->begin();
    int index = 0;
    while (blk.isValid()) {
        qDebug() << blk.text();
        if (index == 1) {
            QTextCursor cursor(blk);
            cursor.movePosition(QTextCursor::EndOfLine, QTextCursor::KeepAnchor);
            QTextCharFormat format; 
            format.setForeground(Qt::darkYellow); 
            format.setBackground(Qt::gray); 
            cursor.setCharFormat(format); 
        }
        ++index;
        blk = blk.next();
    }
 
    te.show();
    return app.exec();
}

#include <QtGui>
#include <QDebug>

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

    QTextEdit te;
    te.setText("Line 1\nLine 2\nLine 3");

    QTextDocument *textDoc = te.document();
    QTextBlock blk = textDoc->begin();
    int index = 0;
    while (blk.isValid()) {
        qDebug() << blk.text();
        if (index == 1) {
            QTextCursor cursor(blk);
            cursor.movePosition(QTextCursor::EndOfLine, QTextCursor::KeepAnchor);
            QTextCharFormat format; 
            format.setForeground(Qt::darkYellow); 
            format.setBackground(Qt::gray); 
            cursor.setCharFormat(format); 
        }
        ++index;
        blk = blk.next();
    }

    te.show();
    return app.exec();
}

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[wang9658]

You are right, if make a selection, it works.
I tried your code. For plaintext, it should be

cursor.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);

cursor.movePosition(QTextCursor::EndOfBlock, QTextCursor::KeepAnchor);

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Thank you again.