Call Constructor within Designer

[NoRulez]

The BaseClass (QPushButton) calls the sizeHint() function. If you use debug messages in the overloaded functions you will see that the sizeHint() is called after the constructor. After the sizeHint() the other functions are called.

So when the size of my Pixmap is for example 250x130. then my button should also be the same size. To set the size of the button you could also write:

QSize MyButton::sizeHint() const {
return QSize(250,130);
//return normalButton.size();
}

QSize MyButton::sizeHint() const {
return QSize(250,130);
//return normalButton.size();
}

To copy to clipboard, switch view to plain text mode 

But within this function I haven't the pixmap when I can't set it within the constructor

I hope you could understand what i mean.

Regards
NoRulez

[wysota]

There is no "after the constructor". Besides, the sizeHint() can change, just call QWidget::updateGeometry() from within the methods used to set up the images. sizeHint() will be called again.

[NoRulez]

Thanks for the hint, i'll give it a try

Regards
NoRulez

[Lykurg]

Have you tested the approach? Now I see that the designer produced code give a layout to the ctor, which will invoke the size hint, because it adds the widget to the layout. But nonetheless I think when showing the widget size hint is called again and then your images are already set and the function will return the right size.

(But to call explicitly updateGeometry() is the saver way, also if you want to change the images at runtime)

[NoRulez]

Ok, i can't get it to work. Here is the sample code i have.
ownbutton.h:

#ifndef OWNBUTTON_H
#define OWNBUTTON_H
 
#include <QtGui>
#include <QPixmap>
 
class OwnButton : public QPushButton {
    Q_PROPERTY(QString MyImage READ getImage WRITE setImage)
 
public:
    OwnButton(QWidget *parent = 0);
    QSize sizeHint() const;
    void setImage(QPixmap _pixmap);
    QPixmap getImage();
 
protected:
    void paintEvent(QPaintEvent *event);
 
private:
    QPixmap pixmap;
};
 
#endif // OWNBUTTON_H

#ifndef OWNBUTTON_H
#define OWNBUTTON_H

#include <QtGui>
#include <QPixmap>

class OwnButton : public QPushButton {
    Q_PROPERTY(QString MyImage READ getImage WRITE setImage)

public:
    OwnButton(QWidget *parent = 0);
    QSize sizeHint() const;
    void setImage(QPixmap _pixmap);
    QPixmap getImage();

protected:
    void paintEvent(QPaintEvent *event);

private:
    QPixmap pixmap;
};

#endif // OWNBUTTON_H

To copy to clipboard, switch view to plain text mode 

ownbutton.cpp:

#include "ownbutton.h"
#include <QtGui>
 
OwnButton::OwnButton(QWidget *parent) : QPushButton(parent) {
}
 
QSize OwnButton::sizeHint() const {
    qDebug() << "Pixmap size: " << pixmap.size();
    return pixmap.size();
}
 
void OwnButton::paintEvent(QPaintEvent *event) {
    QPainter painter(this);
 
    painter.drawPixmap(0, 0, pixmap.size().width(), pixmap.size().height(), pixmap);
}
 
void OwnButton::setImage(QPixmap _pixmap) {
    pixmap = _pixmap;
    QWidget::updateGeometry();
}
 
QPixmap OwnButton::getImage() {
    return pixmap;
}

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

OwnButton::OwnButton(QWidget *parent) : QPushButton(parent) {
}

QSize OwnButton::sizeHint() const {
    qDebug() << "Pixmap size: " << pixmap.size();
    return pixmap.size();
}

void OwnButton::paintEvent(QPaintEvent *event) {
    QPainter painter(this);

    painter.drawPixmap(0, 0, pixmap.size().width(), pixmap.size().height(), pixmap);
}

void OwnButton::setImage(QPixmap _pixmap) {
    pixmap = _pixmap;
    QWidget::updateGeometry();
}

QPixmap OwnButton::getImage() {
    return pixmap;
}

To copy to clipboard, switch view to plain text mode 

In the designer, I used a simple QPushButton, and add a Pixmap Property "setImage".
The value of the property is an image of the resource file.

Hope you can help me
Thanks in advance

Regards
NoRulez

[Lykurg]

setImage is the setter not the property! So use MyImage (as you defined as a property), second, you need to provide a function which accept a QString, since this is the value the designer deals with when using embedded images. your QPixmap function is never called...

[NoRulez]

I've updated the code, but it also does nothing

ownbutton.cpp

#include "ownbutton.h"
#include <QtGui>
 
OwnButton::OwnButton(QWidget *parent) : QPushButton(parent) {
}
 
QSize OwnButton::sizeHint() const {
    qDebug() << "Pixmap size: " << pixmap.size();
    return pixmap.size();
}
 
void OwnButton::paintEvent(QPaintEvent *event) {
    QPainter painter(this);
 
    painter.drawPixmap(0, 0, pixmap.size().width(), pixmap.size().height(), pixmap);
}
 
void OwnButton::MyImage(const QString& image) {
    pixmap = QPixmap(image);
    //pixmap = QPixmap(QString(":/") + image);
    QWidget::updateGeometry();
}
 
void OwnButton::setImage(QPixmap _pixmap) {
    pixmap = _pixmap;
    QWidget::updateGeometry();
}
 
QPixmap OwnButton::getImage() {
    return pixmap;
}

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

OwnButton::OwnButton(QWidget *parent) : QPushButton(parent) {
}

QSize OwnButton::sizeHint() const {
    qDebug() << "Pixmap size: " << pixmap.size();
    return pixmap.size();
}

void OwnButton::paintEvent(QPaintEvent *event) {
    QPainter painter(this);

    painter.drawPixmap(0, 0, pixmap.size().width(), pixmap.size().height(), pixmap);
}

void OwnButton::MyImage(const QString& image) {
    pixmap = QPixmap(image);
    //pixmap = QPixmap(QString(":/") + image);
    QWidget::updateGeometry();
}

void OwnButton::setImage(QPixmap _pixmap) {
    pixmap = _pixmap;
    QWidget::updateGeometry();
}

QPixmap OwnButton::getImage() {
    return pixmap;
}

To copy to clipboard, switch view to plain text mode 

#ifndef OWNBUTTON_H
#define OWNBUTTON_H
 
#include <QtGui>
#include <QPixmap>
 
class OwnButton : public QPushButton {
    Q_PROPERTY(QString MyImage READ getImage WRITE setImage)
 
public:
    OwnButton(QWidget *parent = 0);
    QSize sizeHint() const;
    void MyImage(const QString& image);
    void setImage(QPixmap _pixmap);
    QPixmap getImage();
 
protected:
    void paintEvent(QPaintEvent *event);
 
private:
    QPixmap pixmap;
};
 
#endif // OWNBUTTON_H

#ifndef OWNBUTTON_H
#define OWNBUTTON_H

#include <QtGui>
#include <QPixmap>

class OwnButton : public QPushButton {
    Q_PROPERTY(QString MyImage READ getImage WRITE setImage)

public:
    OwnButton(QWidget *parent = 0);
    QSize sizeHint() const;
    void MyImage(const QString& image);
    void setImage(QPixmap _pixmap);
    QPixmap getImage();

protected:
    void paintEvent(QPaintEvent *event);

private:
    QPixmap pixmap;
};

#endif // OWNBUTTON_H

To copy to clipboard, switch view to plain text mode 

Regards
NoRulez

[Lykurg]

You got me wrong! The setter for MyImage must accept a QString.

OwnButton::setImage(const QString& image)

OwnButton::setImage(const QString& image)

To copy to clipboard, switch view to plain text mode 

And how looks the uic generated code for your dynamic property?

[NoRulez]

I have changed it to look like this:

public:
    OwnButton(QWidget *parent = 0);
    QSize sizeHint() const;
    void setImage(const QString& image);
    QPixmap getImage();
 
protected:
    void paintEvent(QPaintEvent *event);

public:
    OwnButton(QWidget *parent = 0);
    QSize sizeHint() const;
    void setImage(const QString& image);
    QPixmap getImage();

protected:
    void paintEvent(QPaintEvent *event);

To copy to clipboard, switch view to plain text mode 

void OwnButton::paintEvent(QPaintEvent *event) {
    QPainter painter(this);
 
    painter.drawPixmap(0, 0, pixmap.size().width(), pixmap.size().height(), pixmap);
}
 
void OwnButton::setImage(const QString& image) {
    pixmap = QPixmap(image);
    QWidget::updateGeometry();
}
 
QPixmap OwnButton::getImage() {
    return pixmap;
}

void OwnButton::paintEvent(QPaintEvent *event) {
    QPainter painter(this);

    painter.drawPixmap(0, 0, pixmap.size().width(), pixmap.size().height(), pixmap);
}

void OwnButton::setImage(const QString& image) {
    pixmap = QPixmap(image);
    QWidget::updateGeometry();
}

QPixmap OwnButton::getImage() {
    return pixmap;
}

To copy to clipboard, switch view to plain text mode 

I got the following result without a button/image drawn.

Could you please give me a simple working example?

Thanks in advance

Regards
NoRulez

[Lykurg]

please make a minimal compilable example.

[NoRulez]

I've attached an example

Thanks in advance
Regards
NoRulez

[Lykurg]

• use Q_OBJECT in your class OwnButton
• use the right property name in the designer! (MyImage not setImate)

and then, if you set QPixmap as a value in the custom property folowing is created:

pushButton->setProperty("MyImage", QVariant(QPixmap(QString::fromUtf8(":/button_1.png"))));

pushButton->setProperty("MyImage", QVariant(QPixmap(QString::fromUtf8(":/button_1.png"))));

To copy to clipboard, switch view to plain text mode 

So you have to provide QPixmap-setter like in your first code post, but also inside the Q_PROPERTY! then it works.

[wysota]

You forgot the Q_OBJECT macro.