QGraphicsObject color change animation

[mvbhavsar]

I have created QGraphicsObject which has multiple rectangles attached to each other. All these rects has default color as orange. This is working correctly. Now I want to change color of one particular rect after certain condition is met. I am not sure how animation will take place to change color of one rect.

I am attaching my implemention for your reference.


Thanks

Manish

[wysota]

What's exactly the problem?

[mvbhavsar]

suppose using attached object, I made an object like this.

arrayitem *ai = new arrayitem(QStringList() << "55" << "77",QFont("Calibri",20)); // This will create 2 boxes containing text 55 and 77 having background orange
for(int i=0; i<20; i++) {
   if (i==10) {
       // want to change background color of 55 box to green. what changes are required in attached class.
   }
}

arrayitem *ai = new arrayitem(QStringList() << "55" << "77",QFont("Calibri",20)); // This will create 2 boxes containing text 55 and 77 having background orange
for(int i=0; i<20; i++) {
   if (i==10) {
       // want to change background color of 55 box to green. what changes are required in attached class.
   }
}

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[wysota]

You need to provide a method in the item class for setting the color (and scheduling an update) and the color needs to be taken into consideration when painting the item.

However you will have to get rid of the for loop, it doesn't make sense.

[mvbhavsar]

Pl. see below code code.
after using qpropertyanimation updation of qgraphicsobject is not happening properly.

#ifndef MYARRAY_H
#define MYARRAY_H
 
#include <QtGui>
 
class myarray : public QGraphicsObject
{
    Q_OBJECT
public:
    explicit myarray(QStringList nlist, QGraphicsItem *parent = 0);
    QRectF boundingRect() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
 
signals:
 
public slots:
 
private:
    QStringList vlist;
    QFont appFont;
    int x, y, wid, ht;
    int cntr;
    int totwid;
    bool isNonArray;
 
};
 
#endif // MYARRAY_H

#ifndef MYARRAY_H
#define MYARRAY_H

#include <QtGui>

class myarray : public QGraphicsObject
{
    Q_OBJECT
public:
    explicit myarray(QStringList nlist, QGraphicsItem *parent = 0);
    QRectF boundingRect() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);

signals:

public slots:

private:
    QStringList vlist;
    QFont appFont;
    int x, y, wid, ht;
    int cntr;
    int totwid;
    bool isNonArray;

};

#endif // MYARRAY_H

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#include "myarray.h"
 
myarray::myarray(QStringList nlist, QGraphicsItem *parent) :
    QGraphicsObject(parent)
{
    vlist = nlist;
    x=0;
    y=0;
    wid=0;
    ht=0;
    cntr=0;
    QFont font("Calibri",14);
    QFontMetrics fm(font);
    foreach(QString s, vlist){
        wid += fm.width(s);
        qDebug() << fm.width(s);
    }
    totwid=wid;
    ht = fm.height();
    appFont = font;
}
 
QRectF myarray::boundingRect() const
{
    return QRectF(0,0,wid+10,ht+10);
}
 
void myarray::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option);
    Q_UNUSED(widget);
    wid=0;
    cntr=0;
    if (cntr++==0){
        x=0;
        y=0;
    }
    qDebug() << cntr;
    painter->save();
    painter->setRenderHint(QPainter::Antialiasing, true);
    painter->setPen(Qt::red);
    painter->setBrush(Qt::yellow);
    foreach(QString s, vlist){
        QFontMetrics fm(appFont);
        wid = fm.width(s);
        painter->drawRect(x,y,wid+10,ht+10);
        painter->setFont(appFont);
        painter->drawText(QRect(x+5,y+5,wid,ht),Qt::AlignHCenter|Qt::AlignVCenter,s);
        x += wid+10;
    }
    painter->restore();
    update();
}

#include "myarray.h"

myarray::myarray(QStringList nlist, QGraphicsItem *parent) :
    QGraphicsObject(parent)
{
    vlist = nlist;
    x=0;
    y=0;
    wid=0;
    ht=0;
    cntr=0;
    QFont font("Calibri",14);
    QFontMetrics fm(font);
    foreach(QString s, vlist){
        wid += fm.width(s);
        qDebug() << fm.width(s);
    }
    totwid=wid;
    ht = fm.height();
    appFont = font;
}

QRectF myarray::boundingRect() const
{
    return QRectF(0,0,wid+10,ht+10);
}

void myarray::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option);
    Q_UNUSED(widget);
    wid=0;
    cntr=0;
    if (cntr++==0){
        x=0;
        y=0;
    }
    qDebug() << cntr;
    painter->save();
    painter->setRenderHint(QPainter::Antialiasing, true);
    painter->setPen(Qt::red);
    painter->setBrush(Qt::yellow);
    foreach(QString s, vlist){
        QFontMetrics fm(appFont);
        wid = fm.width(s);
        painter->drawRect(x,y,wid+10,ht+10);
        painter->setFont(appFont);
        painter->drawText(QRect(x+5,y+5,wid,ht),Qt::AlignHCenter|Qt::AlignVCenter,s);
        x += wid+10;
    }
    painter->restore();
    update();
}

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#ifndef TESTGRAPHICS_H
#define TESTGRAPHICS_H
 
#include <QtGui>
#include "myarray.h"
 
namespace Ui {
    class testgraphics;
}
 
class testgraphics : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit testgraphics(QWidget *parent = 0);
    ~testgraphics();
 
private slots:
    void fin();
 
private:
    Ui::testgraphics *ui;
    myarray *m;
};
 
#endif // TESTGRAPHICS_H

#ifndef TESTGRAPHICS_H
#define TESTGRAPHICS_H

#include <QtGui>
#include "myarray.h"

namespace Ui {
    class testgraphics;
}

class testgraphics : public QMainWindow
{
    Q_OBJECT

public:
    explicit testgraphics(QWidget *parent = 0);
    ~testgraphics();

private slots:
    void fin();

private:
    Ui::testgraphics *ui;
    myarray *m;
};

#endif // TESTGRAPHICS_H

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#include "testgraphics.h"
#include "ui_testgraphics.h"
 
testgraphics::testgraphics(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::testgraphics)
{
    ui->setupUi(this);
    QGraphicsScene *scene = new QGraphicsScene;
    ui->graphicsView->setScene(scene);
    scene->setSceneRect(QRect(0,0,500,500));
    QGraphicsRectItem *rect = new QGraphicsRectItem;
    rect->setRect(0,0,350,350);
    scene->addItem(rect);
    QGraphicsTextItem *text = new QGraphicsTextItem;
    text->setPlainText("Hello");
    text->setPos(100,100);
    text->setParentItem(rect);
 
    m = new myarray(QStringList() << "152" << "116");
    m->setPos(150,150);
    m->setParentItem(rect);
    m->setOpacity(0.2);
    QPropertyAnimation *anim = new QPropertyAnimation(m,"opacity");
    anim->setDuration(5000);
    anim->setEndValue(1.0);
    connect(anim,SIGNAL(finished()),this,SLOT(fin()));
    anim->start(QPropertyAnimation::DeleteWhenStopped);
}
 
testgraphics::~testgraphics()
{
    delete ui;
}
 
void testgraphics::fin()
{
    m->update();
}

#include "testgraphics.h"
#include "ui_testgraphics.h"

testgraphics::testgraphics(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::testgraphics)
{
    ui->setupUi(this);
    QGraphicsScene *scene = new QGraphicsScene;
    ui->graphicsView->setScene(scene);
    scene->setSceneRect(QRect(0,0,500,500));
    QGraphicsRectItem *rect = new QGraphicsRectItem;
    rect->setRect(0,0,350,350);
    scene->addItem(rect);
    QGraphicsTextItem *text = new QGraphicsTextItem;
    text->setPlainText("Hello");
    text->setPos(100,100);
    text->setParentItem(rect);

    m = new myarray(QStringList() << "152" << "116");
    m->setPos(150,150);
    m->setParentItem(rect);
    m->setOpacity(0.2);
    QPropertyAnimation *anim = new QPropertyAnimation(m,"opacity");
    anim->setDuration(5000);
    anim->setEndValue(1.0);
    connect(anim,SIGNAL(finished()),this,SLOT(fin()));
    anim->start(QPropertyAnimation::DeleteWhenStopped);
}

testgraphics::~testgraphics()
{
    delete ui;
}

void testgraphics::fin()
{
    m->update();
}

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Regards
Manish

[mvbhavsar]

Any suggession on this

[wysota]

Can you provide a compilable example reproducing the problem? The one you posted is incomplete.

[mvbhavsar]

Problem is resolved.

Thanks you.


Manish

[akash]

Hi,

Could you please provide us the complete working code of this.

Thanks,
Akash