Help needed to develop an audio editor

[franco.amato]

If you show me your code, I will have a look at it.

Hi,
I started writing some code.
The class interface:

#ifndef __WAVEFORMDISPLAY_H__
#define __WAVEFORMDISPLAY_H__
 
#include <QWidget>
 
class WaveFormDisplay : public QWidget
{
	Q_OBJECT
 
public:
	WaveFormDisplay( QWidget* parent = 0 );
 
protected:
	void paintEvent( QPaintEvent* event );
	void mousePressEvent(QMouseEvent *event);
	void mouseMoveEvent(QMouseEvent *event);
	void mouseReleaseEvent(QMouseEvent *event);
 
private:
};
 
#endif //__WAVEFORMDISPLAY_H__

#ifndef __WAVEFORMDISPLAY_H__
#define __WAVEFORMDISPLAY_H__

#include <QWidget>

class WaveFormDisplay : public QWidget
{
	Q_OBJECT

public:
	WaveFormDisplay( QWidget* parent = 0 );

protected:
	void paintEvent( QPaintEvent* event );
	void mousePressEvent(QMouseEvent *event);
	void mouseMoveEvent(QMouseEvent *event);
	void mouseReleaseEvent(QMouseEvent *event);

private:
};

#endif //__WAVEFORMDISPLAY_H__

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And the methods:

#include "waveformdisplay.h"
 
WaveFormDisplay::WaveFormDisplay( QWidget* parent /* = 0 */ )
{
	setPalette( QPalette( QColor( 250, 250, 200 ) ) );
	setAutoFillBackground(true);
	setWindowTitle( tr("Waveform display") );
	resize(500, 200);
}
// Paint event
void WaveFormDisplay::paintEvent( QPaintEvent* event )
{
	QLine line( 0, height() / 2.0, width(), height() / 2.0 );
	QPen pen( Qt::blue, 1 ); // red solid line, 1 pixels wide
 
	QPainter painter( this );
	painter.setPen( pen );
	painter.setRenderHint( QPainter::Antialiasing );
 
	painter.drawLine(line);
}
 
// Mouse press event
void mousePressEvent( QMouseEvent *event )
{
	event->accept();
}
 
// Mouse move event
void mouseMoveEvent( QMouseEvent *event )
{
	event->accept();
}
 
// Mouse release event
void mouseReleaseEvent( QMouseEvent *event )
{
	event->accept();
}

#include "waveformdisplay.h"

WaveFormDisplay::WaveFormDisplay( QWidget* parent /* = 0 */ )
{
	setPalette( QPalette( QColor( 250, 250, 200 ) ) );
	setAutoFillBackground(true);
	setWindowTitle( tr("Waveform display") );
	resize(500, 200);
}
// Paint event
void WaveFormDisplay::paintEvent( QPaintEvent* event )
{
	QLine line( 0, height() / 2.0, width(), height() / 2.0 );
	QPen pen( Qt::blue, 1 ); // red solid line, 1 pixels wide

	QPainter painter( this );
	painter.setPen( pen );
	painter.setRenderHint( QPainter::Antialiasing );

	painter.drawLine(line);
}

// Mouse press event
void mousePressEvent( QMouseEvent *event )
{
	event->accept();
}

// Mouse move event
void mouseMoveEvent( QMouseEvent *event )
{
	event->accept();
}

// Mouse release event
void mouseReleaseEvent( QMouseEvent *event )
{
	event->accept();
}

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Do you already have some suggestions? Code is just to start and I already got linker error about mouse event

[axeljaeger]

If you would have shown as the error message of the linker, it would be a lot easier to help.

Anyway, in this simple case I guess you just forgot the WaveFormDisplay:: in the method signature of your implementation to the linker does not know that the three mouse-event-handler belong to your class.

But also some comments to your code:

1. Why do you "accept" the mouse-events already?
2. Although it is good to write documentation, you "document the obvious": http://freeworld.thc.org/root/phun/unmaintain.html