react on the resizing of a QMainWindow for adjust

问题:

How do I react on the resize of a QMainWindow? I have QTextBrowsers in a QScrollArea and I adjust them to the size of the content on creating them (the only thing that should scroll is the QScrollArea).

Everything works for now, but if I resize the mainWindow, the height of the QTextBrowsers isn't changed, because the reflow function isn't triggered.

Do you have any better idea to adjust a QTextBrowser to it's content? My current code is:

void RenderFrame::adjustTextBrowser(QTextBrowser* e) const {
    e->document()->setTextWidth(e->parentWidget()->width());
    e->setMinimumHeight(e->document()->size().toSize().height());
    e->setMaximumHeight(e->minimumHeight());
}

The parentWidget() is necessary because running width() on the widget itself returns always 100, regardless of the real size.

回答1:

If there is only text or html, you could use QLabel instead, because it already adapts its size to the available space. You'll have to use:

label->setWordWrap(true);        
label->setTextInteractionFlags(Qt::TextBrowserInteraction); 

to have almost the same behavior as a QTextBrowser.

---

If you really want to use a QTextBrowser, you can try something like this (adapted from QLabel source code):

class TextBrowser : public QTextBrowser {
    Q_OBJECT
public:
    explicit TextBrowser(QWidget *parent) : QTextBrowser(parent) {
        // updateGeometry should be called whenever the size changes
        // and the size changes when the document changes        
        connect(this, SIGNAL(textChanged()), SLOT(onTextChanged()));

        QSizePolicy policy = sizePolicy();
        // Obvious enough ? 
        policy.setHeightForWidth(true);
        setSizePolicy(policy);
    }

    int heightForWidth(int width) const {
        int left, top, right, bottom;
        getContentsMargins(&left, &top, &right, &bottom);
        QSize margins(left + right, top + bottom);

        // As working on the real document seems to cause infinite recursion,
        // we create a clone to calculate the width
        QScopedPointer<QTextDocument> tempDoc(document()->clone());
        tempDoc->setTextWidth(width - margins.width());

        return qMax(tempDoc->size().toSize().height() + margins.height(),
                    minimumHeight());
    }
private slots:
    void onTextChanged() {
        updateGeometry();
    }
};