make a .jpg or .bmp picture into a widget...?

[JimDaniel]

Try this:

#include "BlinkingIcon.h"
 
BlinkingIcon::BlinkingIcon(QWidget * parent) : QWidget(parent)
{
	setWindowTitle(tr("My Blinking Icon"));
	resize(50,50);
 
        display_image = new QLabel(this);
        display_image->setScaledContents(true);
 
	QTimer *timer = new QTimer(this);
	connect(timer, SIGNAL(timeout()), this, SLOT(startBlinking()));
	startBlinking();
        timer->start(1000);
}
 
void BlinkingIcon::startBlinking()
{
        display_image->clear();
 
        QTime time = QTime::currentTime();
	if ((time.second() % 2) == 0)
        {
           display_image->setPixmap(QPixmap("C:/my_first_image.png"));
        }
       else
       {
           display_image->setPixmap(QPixmap("C:/my_second_image.png"));
       }
 
      display_image->resize(50, 50);
}

#include "BlinkingIcon.h"

BlinkingIcon::BlinkingIcon(QWidget * parent) : QWidget(parent)
{
	setWindowTitle(tr("My Blinking Icon"));
	resize(50,50);

        display_image = new QLabel(this);
        display_image->setScaledContents(true);

	QTimer *timer = new QTimer(this);
	connect(timer, SIGNAL(timeout()), this, SLOT(startBlinking()));
	startBlinking();
        timer->start(1000);
}

void BlinkingIcon::startBlinking()
{
        display_image->clear();

        QTime time = QTime::currentTime();
	if ((time.second() % 2) == 0)
        {
           display_image->setPixmap(QPixmap("C:/my_first_image.png"));
        }
       else
       {
           display_image->setPixmap(QPixmap("C:/my_second_image.png"));
       }

      display_image->resize(50, 50);
}

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Althought I haven't compiled your code, I think you're crashing because each timeout you were creating new objects without deleting the previous object.

[mynahz]

Hello JimDaniel! Thanks for the code! it does not crash anymore... but... it doesn't blink... It will stay at the picture without changing to the other one...
is it because we are dealing with pixmap and we should use this?

void QPixmapCache::clear () [static]
Removes all pixmaps from the cache.

because i searched for "clear" in Assistant and this seem to be somehow close related...

[JimDaniel]

Okay, I finally whipped up a test app, and found some problems. Here is the working program:

#ifndef BLINKINGICON_H
#define BLINKINGICON_H
 
#include <QtGui>
#include <QtCore>
 
class BlinkingIcon : public QWidget
{
	Q_OBJECT
 
public:
	BlinkingIcon(QWidget * parent = 0);
	virtual ~BlinkingIcon();
 
public slots:
	void startBlinking();
 
private:
	QLabel * m_display_image;
};
 
#endif // BLINKINGICON_H
 
 
#include "blinkingicon.h"
 
BlinkingIcon::BlinkingIcon(QWidget * parent) : QWidget(parent)
{
	this->setWindowTitle(tr("My Blinking Icon"));    
	this->setFixedSize(50, 50);
 
	m_display_image = new QLabel(this);        
	m_display_image->setScaledContents(true); 
 
	this->startBlinking(); 
 
	QTimer * timer = new QTimer(this);    
	connect(timer, SIGNAL(timeout()), this, SLOT(startBlinking()));
	timer->start(1000);
}
 
BlinkingIcon::~BlinkingIcon()
{}
 
void BlinkingIcon::startBlinking()
{
	static bool on = false;
 
	m_display_image->clear();
 
	if (on)
	{
		m_display_image->setPixmap(QPixmap("C:/my_second_image.png"));
		on = false;
	}
	else
	{
		m_display_image->setPixmap(QPixmap("C:/my_first_image.png"));
		on = true;
	}
 
	m_display_image->resize(50, 50);
}

#ifndef BLINKINGICON_H
#define BLINKINGICON_H

#include <QtGui>
#include <QtCore>

class BlinkingIcon : public QWidget
{
	Q_OBJECT

public:
	BlinkingIcon(QWidget * parent = 0);
	virtual ~BlinkingIcon();

public slots:
	void startBlinking();

private:
	QLabel * m_display_image;
};

#endif // BLINKINGICON_H


#include "blinkingicon.h"

BlinkingIcon::BlinkingIcon(QWidget * parent) : QWidget(parent)
{
	this->setWindowTitle(tr("My Blinking Icon"));    
	this->setFixedSize(50, 50);

	m_display_image = new QLabel(this);        
	m_display_image->setScaledContents(true); 

	this->startBlinking(); 

	QTimer * timer = new QTimer(this);    
	connect(timer, SIGNAL(timeout()), this, SLOT(startBlinking()));
	timer->start(1000);
}

BlinkingIcon::~BlinkingIcon()
{}

void BlinkingIcon::startBlinking()
{
	static bool on = false;

	m_display_image->clear();

	if (on)
	{
		m_display_image->setPixmap(QPixmap("C:/my_second_image.png"));
		on = false;
	}
	else
	{
		m_display_image->setPixmap(QPixmap("C:/my_first_image.png"));
		on = true;
	}

	m_display_image->resize(50, 50);
}

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The first problem was that in your header file, you need to put your slot methods under:

public slots:

(or protected/private, depending who you want to be able to call)

After I changed that it worked fine, although sometimes the timer.second() test you were doing would not work as expected, so I changed the test to what you see now...

[mynahz]

oh yes! it works perfect!
Thank you, JimDaniel!!!

[mynahz]

Hi to all once again... I have a question related to this again... I have another way, of putting the picture(.png) into the QLabel within QT designer, but I am having problems making the image show/hide when I want them to. Do I use the functions from QWidget, show() and hide()? If so, then I have no idea why it doesn't hide my label when i call the hide function...
I will try to upload my project file soon just clarify how I get my picture up into QT, as currently I can only compress it into .rar file.
Also, just want to find out, anyone using canbus in QT? I am currently working on a project to configure a display for a vehicle and I have problems getting candata from the canbus and processing the candata such that my icon will blink when specific candata are received...

Thanks in advance to all.

[mynahz]

Here it is.
Take a look, I have tried to show/hide the icons using the timer (same mtd mentioned above.) but the functions show() / hide() doesn't seem to work.