Promoting QLabel

[jpn]

ui.label->setDrawingEnabled(true);

ui.label->setDrawingEnabled(true);

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I am unable to find setDrawingEnabled(). Dear JPN, can you tell me this is a Qt4.3.1 function or self to create. In my case error: ‘class QLabel’ has no member named ‘setDrawingEnabled’. Is this a function of other class?

I meant that he could write such function himself. All it would do is to enabled/disable the flag which is checked in paintEvent().

[ashukla]

I meant that he could write such function himself. All it would do is to enabled/disable the flag which is checked in paintEvent().

Yes! I have done it previously but not getting the output. Output means line inside a QLabel or QTextEdit using this way.

[anafor2004]

Yes I also done it but it doesnt work!!

[jpn]

May we see the relevant code?

[wysota]

Is this some school/academic task? Why are the two of you dealing with exactly the same problem?

[anafor2004]

I think we even not living same country , I know there are so many new beginner in Qt and people fall with same problems.

[wysota]

Problems of drawing a line across a label? I didn't know it was that common

[anafor2004]

mylabel.h

#ifndef MYLABEL_H
#define MYLABEL_H
#include <QLabel>
class MyLabel : public QLabel
{
	Q_OBJECT
public:
    MyLabel(QWidget *);
    void setDrawflag(bool a);
 
protected:
   void paintEvent ( QPaintEvent * event );
private:
	bool drawflag;
};
#endif

#ifndef MYLABEL_H
#define MYLABEL_H
#include <QLabel>
class MyLabel : public QLabel
{
	Q_OBJECT
public:
    MyLabel(QWidget *);
    void setDrawflag(bool a);
    
protected:
   void paintEvent ( QPaintEvent * event );
private:
	bool drawflag;
};
#endif

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mylabel.cpp

#include"MyLabel.h"
#include <QPainter>
#include <QLabel>
MyLabel::MyLabel(QWidget *parent)
		: QLabel(parent)
{
}
void MyLabel::paintEvent(QPaintEvent *event)
{
 
QPainter painter(this);
	if(drawflag==true)
	{
	QPainter painter(this);
	setBackgroundRole(QPalette::Dark);
	setAutoFillBackground(true);
	painter.setPen(Qt::blue);
	painter.drawLine(0,0,401,331);
	}
}
 
void MyLabel::setDrawflag(bool a)
{
	drawflag=a;
 
}

#include"MyLabel.h"
#include <QPainter>
#include <QLabel>
MyLabel::MyLabel(QWidget *parent)
		: QLabel(parent)
{
}
void MyLabel::paintEvent(QPaintEvent *event)
{
	
QPainter painter(this);
	if(drawflag==true)
	{
	QPainter painter(this);
	setBackgroundRole(QPalette::Dark);
	setAutoFillBackground(true);
	painter.setPen(Qt::blue);
	painter.drawLine(0,0,401,331);
	}
}

void MyLabel::setDrawflag(bool a)
{
	drawflag=a;

}

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[jpn]

Could you use the #-button instead of Qt-button for code blocks, thank you. Former is for code blocks, latter is for referencing docs of a Qt class.

So, what does "doesn't work" mean this time? Apparently you want to initialize the flag to a sane value, but I don't see why shouldn't the line get painted after you set the flag to true. But do you perhaps mean that the label should paint its content too, like text/pixmap/whatever you have set? In this case you would have to call the base class implementation of paintEvent().