QTableWidget || QListWIdget with syntax highlighting

[ericV]

Hi evryone,

I am faily new to QT so please dont shoot me for asking things that may be "dumb". :D


So to my question, I want to create a Table or List (to me a table with one colum) in wich i will have single lines of Script-Code, so I want them to be Highlighted.

I have already tried two things, using the QTextEdit as a delegate and a widget.

As a Widget id did exactly what I wanted, but I am worried that it might hurt performance as the table/List grows.

Because of that i would prefer to use the delegate...

When i tried the TextEdit delegate with syntax higlighter it only worked when i was in "editmode".
But as soon as the delegate was released the formating was lost... Since the table only takes plain text (?).

I have found little on the net to help me acomplish this. Only option that I have found is to create my own TableWidget subclass and reimplement the paint method. Is this truly the best way or is there something easier?

Greets,

Eric

[spirit]

you can still use an own delegate, all what you need it's a create your own syntaxhiglighter then attach it to QTextDocument and then render text document using QTextDocument::drawContents in your delegate.

[ericV]

Thank you for the fast reply... I will look into that.... Will post my results.

[ericV]

Hi, its been a while... but i was working on an other part of the project, so i have just circled back to this problem.

My Question is: How would i draw the contents of my QTextdocument onto a table-cell?

Haven't been able to find something similar in the QTableWidget documentation. Or would i have to subclass from it and re-implement the paintevent or repaint methods?

Greets

Eric

[spirit]

take a look at this example


#include <QtGui>
#include "test.h"
#include "highlighter.h"

HihghlighterDelegate::HihghlighterDelegate(QObject *parent)
: QItemDelegate(parent)
{
m_textDocument = new QTextDocument(this);
m_highlighter = new Highlighter(m_textDocument);
}

void HihghlighterDelegate::drawDisplay(QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect, const QString &text) const
{
Q_UNUSED(option);
m_textDocument->setPlainText(text);

QPixmap pixmap(rect.size());
pixmap.fill(Qt::transparent);
QPainter p(&pixmap);

m_textDocument->drawContents(&p);

painter->drawPixmap(rect, pixmap);
}

Test::Test(QWidget *parent)
: QDialog(parent)
{

QVBoxLayout *vbl = new QVBoxLayout(this);
QTableWidget *table = new QTableWidget(10, 10);
table->horizontalHeader()->setCascadingSectionResizes(true);
table->horizontalHeader()->setResizeMode(QHeaderView::Interactive);
table->horizontalHeader()->setStretchLastSection(true);
table->setItemDelegate(new HihghlighterDelegate(table));

QStringList keywords;
keywords << "char" << "class" << "const"
<< "double" << "enum" << "explicit"
<< "friend" << "inline" << "int"
<< "long" << "namespace" << "operator"
<< "private" << "protected" << "public"
<< "short" << "signals" << "signed"
<< "slots" << "static" << "struct"
<< "template" << "typedef" << "typename"
<< "union" << "unsigned" << "virtual"
<< "void" << "volatile";

for (int r = 0; r < table->rowCount(); ++r) {
for (int c = 0; c < table->columnCount(); ++c) {
QTableWidgetItem *item = new QTableWidgetItem(keywords.at(qrand() % keywords.size()));
table->setItem(r, c, item);
}
}

vbl->addWidget(table);
}




#ifndef TEST_H
#define TEST_H

#include <QDialog>

#include <QItemDelegate>

class Highlighter;
class QTextDocument;

class HihghlighterDelegate: public QItemDelegate
{
Q_OBJECT

public:
HihghlighterDelegate(QObject *parent = 0);

protected:
void drawDisplay(QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect, const QString &text) const;

private:
QTextDocument *m_textDocument;
Highlighter *m_highlighter;
};

class Test: public QDialog
{
Q_OBJECT

public:
Test(QWidget *parent = 0);
};

#endif//TEST_H





#include <QtGui>
#include <QApplication>
#include "test.h"

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

Test test;
test.show();

return app.exec();
}



Higlihgter is ther class from QTDIR/examples/richtext/syntaxhighlighter

[ericV]

Thank you! Thats great... was thinking way to complicated (as always) Was working with a QtextEdit in a delegate made from QStyledItemDelegate....

thanks again... will post if i succeeded. :)

[ericV]

I'm trying to implement your delegate, but it doesn't seem to be drawing the text into the cell. (?) I meen if I go int edit-mode the text is there, but when i leave it the cell is left blank. :(

I'm unsure if it has anything to do with my Highlighter class... since I re-implemented it to work on a QTextEdit instead of a QTextDocument...

(just tried it without the Highlighter and still not working)

Any ideas? Im going to experiment a litle with pen colors, but this shouldn't be the problem, right?

[ericV]

Just tried your code and there it works... (im stumped....)