I want to be able to draw in the graphics view. Drawing in the graphics view works but only when i click somewhere in the widget and not in the graphics view itself. It does not seem to respond at all to clicks in the graphics view. What am i doing wrong? I am new to C++ and Qt..
#include "mywidget.h"
#include "ui_mywidget.h"
#include <QDebug>
MyWidget::MyWidget(QWidget *parent) :
QWidget(parent),
ui(new Ui::MyWidget)
{
ui->setupUi(this);
scene = new QGraphicsScene(this);
ui->graphicsView->setScene(scene);
ui->graphicsView->setInteractive(true);
ui->graphicsView->setMouseTracking(true);
}
void MyWidget::paintEvent(QPaintEvent * event)
{
QWidget::paintEvent(event);
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing,true);
QPen linepen(Qt::blue);
linepen.setCapStyle(Qt::RoundCap);
linepen.setWidth(2);
painter.setPen(linepen);
scene->clear();
if (firstmouseclicked)
{
m_drawing << QPoint(x_mouse,y_mouse);
QPainterPath path;
path.addPolygon(m_drawing);
scene->addPath(path);
}
}
void MyWidget::mouseMoveEvent(QMouseEvent *event){
if (event->button() == Qt::LeftButton)
{
setMouseTracking(true);
}
x_mouse= event->x();
y_mouse= event->y();
firstmouseclicked = true;
update();
}
and my header file
#ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>
#include <QMouseEvent>
#include <QPainter>
#include <QGraphicsView>
#include <QPolygonF>
#include <QDebug>
#include <QtGui>
#include <QGraphicsScene>
#include <QGraphicsItem>
#include <QPainterPath>
#include <QGraphicsSceneMouseEvent>
namespace Ui {
class MyWidget;
}
class MyWidget : public QWidget
{
Q_OBJECT
public:
explicit MyWidget(QWidget *parent = 0);
~MyWidget();
QSize sizeHint() const;
protected:
void mouseMoveEvent(QMouseEvent *event);
void paintEvent(QPaintEvent *);
private:
Ui::MyWidget *ui;
float x_mouse = 0;
float y_mouse = 0;
QPolygon m_drawing;
bool firstmouseclicked = false;
QGraphicsScene* scene;
QGraphicsView* view;
//QGraphicsItem* item;
};
#endif // MYWIDGET_H
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