Tabbed QPlainTextEdit

[Durkin]

Hello,

I 'm looking to create a QPlainTextEdit with multiple tabs, like notepad++ or gedit. It would seem that using multiple QPlainTextEdits with a QTabbedWidget is an easy way to accomplish this. However, I 'm wondering how 'heavy' QPlainTextEdit is? Do I really need to have multiple of those, when I basically just need multiple documents?
I looked to QPlainTextEdit::setDocument though and it suggets that setting another doc would delete the current (if it's not owned by something else). I 'm assuming I would need something to contain and own the documents then.
Which of the two approaches makes the most sense?

Also, I was playing around with the syntax highlighter, while most features work fine on QTextcharFormat

setFontCapitalization(QFont::AllUppercase)

setFontCapitalization(QFont::AllUppercase)

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does nothing. Any clues what I 'm missing? Thanks.

[Lykurg]

notepad++ or gedit are open source. Go and look how they have done it. For a Qt related project look for kate. (second approach sound better to me.)

For the last question: do you have a minimal example reproducing the problem?

[Durkin]

Minimal example:

#include <QApplication>
#include <QPlainTextEdit>
#include <QSyntaxHighlighter>
 
class dummyHighlighter : public QSyntaxHighlighter{
public:
    dummyHighlighter(QTextDocument *parent):
        QSyntaxHighlighter(parent)
    {
 
    }
 
    void highlightBlock(const QString &text){
        QTextCharFormat myClassFormat;
        myClassFormat.setFontWeight(QFont::Bold);
        myClassFormat.setFontCapitalization(QFont::AllUppercase);
        myClassFormat.setForeground(Qt::darkMagenta);
        QString pattern = "(input)";
 
        QRegExp expression(pattern);
        int index = text.indexOf(expression);
        while (index >= 0) {
            int length = expression.matchedLength();
            setFormat(index, length, myClassFormat);
            index = text.indexOf(expression, index + length);
        }
    }
};
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QPlainTextEdit textEdit;
    dummyHighlighter highlighter(textEdit.document());
 
    textEdit.show();
 
    return a.exec();
}

#include <QApplication>
#include <QPlainTextEdit>
#include <QSyntaxHighlighter>

class dummyHighlighter : public QSyntaxHighlighter{
public:
    dummyHighlighter(QTextDocument *parent):
        QSyntaxHighlighter(parent)
    {

    }

    void highlightBlock(const QString &text){
        QTextCharFormat myClassFormat;
        myClassFormat.setFontWeight(QFont::Bold);
        myClassFormat.setFontCapitalization(QFont::AllUppercase);
        myClassFormat.setForeground(Qt::darkMagenta);
        QString pattern = "(input)";

        QRegExp expression(pattern);
        int index = text.indexOf(expression);
        while (index >= 0) {
            int length = expression.matchedLength();
            setFormat(index, length, myClassFormat);
            index = text.indexOf(expression, index + length);
        }
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QPlainTextEdit textEdit;
    dummyHighlighter highlighter(textEdit.document());

    textEdit.show();
    
    return a.exec();
}

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The word input becomes bold and purple but doesn't turn to uppercase.

[Durkin]

I went ahead and implemented a single QPlainTextEdit with multiple tabs and documents (which I made sure had a QPlainTextDocumentLayout). It didn't work - document didn't change as if setDocument didn't do anything. Switching to QTextEdit - no other changes - and it works. To me it seems these two things are bugs but the insight of someone more experienced in Qt would certainly be appreciated.

[Lykurg]

About the uppercase issue: interesting. I now remember, that I also went into it... but no solution I have tested it under Linux, you might also check it with windows or mac. Maybe it is a problem with the system font handling but there also some reports at bugreports.qt-project.org. Go and see if there is one which applies to your case, if not, create a new one.

[Durkin]

It didn't work on windows either. I could not find this issue on the tracker, therefore I created a new one. Feel free to vote for it.