Resize widget force layout resizing

[talk2amulya]

implement the resizeEvent function and do all relevant changes there, it shouldn't be difficult

[^NyAw^]

Hi,

Setting the minimum size of the widget don't work.

Reimplementing the sizeEvent it's not easy as you said, I think. How can I know all the widgets sizes including layout sizes?
Is there another way to do it? Or if I have to reimplement resizeEvent, how can I get all sizes?

Thanks,

[jpn]

See QxtLetterBoxWidget.

[^NyAw^]

Hi,

Thanks JPN. I think that this is what I need.

Good job on this extension library.

[^NyAw^]

Hi,

Not exactly waht I need. As I read from docs, "QxtLetterBoxWidget preserves the aspect ratio of its content widget". What I need is to resize the widget and also force the dialog to adjust the size to show the widgets on its new size.

Really can QxtLetterBoxWidget helps me to this job?

Thanks,

[jpn]

What I need is to resize the widget and also force the dialog to adjust the size to show the widgets on its new size.

You can make the dialog non-resizable:

dialog->layout()->setSizeConstraint(QLayout::SetFixedSize);

dialog->layout()->setSizeConstraint(QLayout::SetFixedSize);

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and it will follow the size hint of the content. You just need to implement sizeHint() for your content widget and call updateGeometry() whenever the size hint changes.

Really can QxtLetterBoxWidget helps me to this job?

Well, why do you care about the dialog size when the aspect ratio of the content is correct?

[^NyAw^]

Hi,

and it will follow the size hint of the content. You just need to implement sizeHint() for your content widget and call updateGeometry() whenever the size hint changes.

The widget not will resize itself. On myDialog constructor I need to change the size of myWidget:

myDialog::myDialog(...)
{
...
int iWidth = obj->getWidth();
int iHeight = obj->getHeight();
float dAspRat = (float)iWidth/(float)iHeight;
 
int iWidthWidget, iHeightWidget;
iWidthWidget = 640;
iHeightWidget = (640/dAspRat );
 
m_pqWidget->resize(iWidthWidget,iHeightWidget);
...
 
//Here I want to force "this"(dialog) to fit the widgets size.
}

myDialog::myDialog(...)
{
...
int iWidth = obj->getWidth();
int iHeight = obj->getHeight();
float dAspRat = (float)iWidth/(float)iHeight;

int iWidthWidget, iHeightWidget;
iWidthWidget = 640;
iHeightWidget = (640/dAspRat );

m_pqWidget->resize(iWidthWidget,iHeightWidget);
...

//Here I want to force "this"(dialog) to fit the widgets size.
}

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Well, why do you care about the dialog size when the aspect ratio of the content is correct?

Because I want to force the Widget to be 640 width and Y width(that depends on the aspect ratio).

Thanks,

[jpn]

The widget not will resize itself.

I said you have to implement sizeHint(), not to call resize(). The latter has no effect together with QLayout::SetFixedSize. The layout will follow the size hint, strictly.

[^NyAw^]

Hi,

myLayout::myLayout(...)
{
...
this->layout()->setSizeConstraint(QLayout::SetFixedSize);
...
}
 
QSize myWidget::sizeHint()
{
  //Here I have to calculate the size -> 640xY
}

myLayout::myLayout(...)
{
...
this->layout()->setSizeConstraint(QLayout::SetFixedSize);
...
}

QSize myWidget::sizeHint()
{
  //Here I have to calculate the size -> 640xY
}

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The "sizeHint" method of myWidget is never called.

I don't really understand "sizeHint" behaviour, maybe because I'm not english and don't understand it's function.

See the attached image. I have this dialog and I use the QWidget(that is difficult) to see(it is on top of the other widgets). I use this QWidget as the parent of my widget(because I have not created the QtDesigner plugin).

Thanks,

[talk2amulya]

u forgot to attach the "attached image"

[jpn]

Ok, here's an example dummy widget that changes its size hint periodically:

class Widget : public QWidget
{
public:
    Widget(QWidget* parent = 0) : QWidget(parent), sh(320, 240) {
        setStyleSheet("background: red"); // just to make it easier to see
        startTimer(2000);
    }
    QSize sizeHint() const { return sh; } // notice "const"
 
protected:
    void timerEvent(QTimerEvent* /*event*/) {
        sh += QSize(40, 30);
        if (sh.width() > 640)
            sh = QSize(320, 240);
        updateGeometry(); // inform that the size hint has changed
    }
 
private:
    QSize sh;
};

class Widget : public QWidget
{
public:
    Widget(QWidget* parent = 0) : QWidget(parent), sh(320, 240) {
        setStyleSheet("background: red"); // just to make it easier to see
        startTimer(2000);
    }
    QSize sizeHint() const { return sh; } // notice "const"

protected:
    void timerEvent(QTimerEvent* /*event*/) {
        sh += QSize(40, 30);
        if (sh.width() > 640)
            sh = QSize(320, 240);
        updateGeometry(); // inform that the size hint has changed
    }

private:
    QSize sh;
};

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Now, a dummy dialog that contains the above widget and a dialog button box:

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QDialog dialog;
    QVBoxLayout* layout = new QVBoxLayout(&dialog);
    layout->setSizeConstraint(QLayout::SetFixedSize); // make the layout follow size hint
    layout->addWidget(new Widget);
    layout->addWidget(new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel));
    dialog.setLayout(layout);
    return dialog.exec();
}

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QDialog dialog;
    QVBoxLayout* layout = new QVBoxLayout(&dialog);
    layout->setSizeConstraint(QLayout::SetFixedSize); // make the layout follow size hint
    layout->addWidget(new Widget);
    layout->addWidget(new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel));
    dialog.setLayout(layout);
    return dialog.exec();
}

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This makes the whole dialog follow the size hint of the "red widget". Is this what you wanted?

[^NyAw^]

Hi,

I've been trying it but I'm not able to make it works. Why the Widget have a timer that informs that its sizeHint have changed? Can't it be done on "resizeEvent", so when I call resize of the Widget it informs that the sizeHint have changed? Althought, sizeHint method is never called

It's so dificult to obtain the size of the internal widgets and the "spacing" between them and then resize the dialog to a calculated size?

Thanks,