QWidget with ScrollArea as standalone window

LeoC

Hey,

what I need is a dynamically created qWidget with a Scrollarea and a reasonable size.

First I tried creating a class like the following:

class myWindow: public QWidget

Inside this class I created a QScrollArea and set the widget (the class itself) to the ScrollArea.
To show this window I executed show on the scrollArea.

scrollArea->setWidget(this);
scrollArea->show();

Actually this worked pretty good. The layout was shown as expected and was wrapped inside a scollArea.
The issues started when I wanted to implement a closeEvent. By pressing the X of the window, it actually never called the closeEvent. I assume it didn't happend, because I actually didn't close the widget itself but rather the scrollArea. So actually the closeEvent of the scrollArea was executed.

So I changed the definition of my class to

class myWindow: public QScrollArea

Hitting the "X" of the window, it now executes the closeEvent and I can save some values before the window actually closes.

But now the layout is completey messed up. I have a QGridLayout which is set to "this", but now the QScrollArea tries to display the entire Layout, but it is much more than you can put on a normal screen. So, the window is huge. That is what the attached code produces.

When I try to resize (like this->resize(500,500) ) the scrollarea, my layout is completey squeezed. It looks like the whole inner layout is pushed inside these 500x500. But in this case I do not need the scrollbar anymore, because everything is visible now :)
Right now, my implementation of myWindow looks like the following. What I need is the layout with is original size and the scrollArea around it. Any ideas?

#include "myWindow.h"

myWindow::myWindow(QWidget *parent) : QScrollArea(parent)
{

}

void myWindow::addValues(QList<QStringList> strL_IN) {
   
    //create new grid layout
    QGridLayout *gL_AED = new QGridLayout();

    for(int i_CtrLengthOfList = 0; i_CtrLengthOfList < strL_IN.count(); i_CtrLengthOfList++) {

        //create a qLabel
        gL_AED->addWidget(new QLabel("Label1",i_CtrLengthOfList,0);

        //create a qTextEdit 
        QTextEdit *tE_ValuesOneRow = new QTextEdit();
        l_TextEdit.append(tE_ValuesOneRow);

        //set the html formatted text to the qTextEdit
        tE_ValuesOneRow->setHtml(strL_IN.at(i_CtrLengthOfList).at(1));

        QFont f_serifFont("Times", 10, QFont::Bold);
        QFontMetrics fM_serifFont(f_serifFont);

        //calculates the width and height of the qTextEdit
        int i_Width= fM_serifFont.horizontalAdvance(tE_ValuesOneRow->toPlainText());
        int i_Height= fM_serifFont.height();

        //set the width and height of the qTextEdit
        tE_ValuesOneRow->setFixedSize(i_Width > 50 ? i_Width : 50,i_Height + 12);

        //add the qTextEdit to gridlayout
        gL_AED->addWidget(tE_ValuesOneRow,i_CtrLengthOfList,1);
    }

    //create the save button. Add the button to the layout
    QPushButton *pB_Save = new QPushButton("Save");
    gL_AED->addWidget(pB_Save,strL_IN.count()+1, 0);
    connect(pB_Save,SIGNAL(clicked()),this,SLOT(saveValues()));

    this->setLayout(gL_AED);
}

void myWindow::closeEvent(QCloseEvent *event) {
    qDebug() << "x was pressed";
    event->accept();
}

void myWindow::showMe() {
    this->show();
}

Bonnie

You shouldn't set a layout to a scroll area (aka. call this->setLayout(gL_AED)).
Instead, you should create a QWidget, then

widget->setLayout(gL_AED);
this->setWidget(widget);

SGaist

Hi,

Beside @Bonnie good points, there's rarely a need to subclass QScrollArea. It's usually a class you use to put a widget in it rather that make the widget parts of it.

LeoC

well... after the weekend I just read my post again and suddenly I had the following idea in my mind:

my class is sublcassing QWidget instead of QScrollArea now

    w_WrapWidget->setLayout(gL_AED);
    QScrollArea *sA_ScrollArea = new QScrollArea();
    sA_ScrollArea->setWidget(w_WrapWidget);
    QHBoxLayout *hb_Layout = new QHBoxLayout();
    hb_Layout->addWidget(sA_ScrollArea);
    this->setLayout(hb_Layout);

What sall I say to this? The result is exactly what I wanted to have :)

Sometimes it really makes sense to take a break while programming in order to get fresh ideas.

Thanks for your hints @Bonnie @SGaist