QTextEdit and custom paint event

  • I have the following code snippet in a TextEdit paint event.

    void TextEdit::paintEvent(QPaintEvent *e)
    QPainter painter(viewport());

    QAbstractTextDocumentLayout::Selection selection;
    selection.cursor = textCursor();
    selection.format = currentCharFormat();
    QAbstractTextDocumentLayout::PaintContext ctx;
    ctx.cursorPosition = textCursor().position();


    There are two problems I am looking to fix. The first problem is when I select text you do not see it as select. Second, the cursor is drawn but does not blink. Any suggestions?

  • I assume this isn't a QTextEdit subclass, right?
    (If not, why isn't this a qtextedit? it looks very much like one ;)

    In QTextEdit the cursor blinking is done by a timer (see QTextControlPrivate::setBlinkingCursorEnabled) which calls update() on the right rectangle (see QTextControlPrivate::repaintCursor); you might have to do this by yourself if this isn't a QTextEdit.

    For the selections, you need to give them a background color, currentCharFormat() will be "black on white" so basically it doesn't look different from when it's not selected. Looking at QTextControl::getPaintContext I'd say you need to do something like

    QPalette::ColorGroup cg = d->hasFocus ? QPalette::Active : QPalette::Inactive;
    selection.format.setBackground(ctx.palette.brush(cg, QPalette::Highlight));
    selection.format.setForeground(ctx.palette.brush(cg, QPalette::HighlightedText));

  • hi dfaure, pls markup the code

  • Yes this is a subclass of QTextEdit. I do see that I have to do all the blinky cursor stuff myself. QPlainTextEdit has a really nice convenience function called getPaintContext that handles the state of the cursor for you, wish they had the same call in QTextEdit. oh well.

Log in to reply

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.