How to change Qtreeview expand or collapse icon position

[abdullahzubair109]

I have a Qtreeview object.. With a custom QItemDelegate, can I Change expand icon position a bit to the right?? Like for 50 pixel??

[sierdzio]

You can modify these icons using several methods:

• QStyle
• https://doc.qt.io/qt-5/qtreeview.html#drawBranches
• https://doc.qt.io/qt-5/qtreeview.html#indentation-prop
• QSS: https://doc.qt.io/qt-5/stylesheet-examples.html#customizing-qtreeview (see the branch pictures below)

[abdullahzubair109]

@sierdzio maybe I am wrong..indentation sets distance from viewport edge to first column.. Not from viewport edge to expand / collapse icon

[sierdzio]

@abdullahzubair109 said in How to change Qtreeview expand or collapse icon position:

@sierdzio maybe I am wrong..indentation sets distance from viewport edge to first column.. Not from viewport edge to expand / collapse icon

You're probably right.

[abdullahzubair109]

@sierdzio in that case setting indentation doesn't change expand icon position.. I want to set indentation for tree expansion / collapse icon (+-) ..not for column

[sierdzio]

Even supplying custom branch pictures does not help? Have you tried reimplementing drawBranches() then?

[abdullahzubair109]

@sierdzio i tried to reimplement drawBranch function.. i studied the source code from here : https://code.woboq.org/qt5/qtbase/src/widgets/itemviews/qtreeview.cpp.html#_ZNK9QTreeView12drawBranchesEP8QPainterRK5QRectRK11QModelIndex but i couldn't find out which portion draws the expand icon..

[mrjj]

Hi
Just as a note.
You can also do

class MyStyleProxy : public QProxyStyle
{
public:
    MyStyleProxy(): QProxyStyle() { }
public:
    virtual void drawPrimitive(PrimitiveElement pe, const QStyleOption *opt, QPainter *p,
                               const QWidget *w) const override
    {
        QStyleOption option = *opt;
        if ( pe == PE_IndicatorBranch )
            option.rect.adjust(25, 0, 0, 0);        

        QProxyStyle::drawPrimitive(pe, &option, p, w);

    }

};

Which does move it but it will overlay text then.

[abdullahzubair109]

@mrjj yes that's a good idea.. thanks.

[abdullahzubair109]

@mrjj it is working.. but unfortunately as i click on items, they become invisible

[abdullahzubair109]

@mrjj i overrode drawBranches ..

void TreeView::drawBranches(QPainter *painter, const QRect &rect, const QModelIndex &index) const
{
	
        QRect newRect = rect;
	newRect.moveLeft(10);
	QTreeView::drawBranches(painter, rect, index);

}

you are right.. it is overlaying text.. any way to overcome it??

[mrjj]

@abdullahzubair109
There is also a https://doc.qt.io/qt-5/qtreeview.html#drawRow
that i assume, draws the text.
So I guess you must change that also to move the text also.

[abdullahzubair109]

@mrjj unfortunately i got no success with drawRow.. changed header offset but now the focus rect doesn't cover the whole row.. it excludes offset

[mrjj]

@abdullahzubair109
Hmm , well i guess that's kinda expected if we just offset the
rect.
I wonder if we combined it with a delegate if we could get text offset working while selection would still
cover the normal area. but i didnt test it.

[abdullahzubair109]

@mrjj well let me test

[abdullahzubair109]

@mrjj can you kindly post a pseudo code?? i tried modifying QStyleOptionViewItem rect under paint function.. but got weird result

[mrjj]

@abdullahzubair109
well that was my idea too but altering the options rect might do strange stuff and
we might end up needing to draw the text manually for it to be possible.

• but got weird result
  in what way ?

[abdullahzubair109]

@mrjj i am using painter->drawText();

[mrjj]

@abdullahzubair109
Hi
tested a bit.
seems to be possible

class TextDelegate : public QStyledItemDelegate
{

public:
    TextDelegate(QObject *parent)
        : QStyledItemDelegate(parent)
    {

    }
    QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const
    {
        QSize ret = QStyledItemDelegate::sizeHint(option, index);
        return ret;
    }
    void paint(QPainter *painter, const QStyleOptionViewItem &option,
               const QModelIndex &index) const
    {
        QStyleOptionViewItem itemOption(option);

        initStyleOption(&itemOption, index);
        itemOption.rect.adjust(130, 0, 0, 0);
        QApplication::style()->drawControl(QStyle::CE_ItemViewItem, &itemOption, painter, nullptr);

    }
};

ui->treeWidget->setStyle( new MyStyleProxy );
ui->treeWidget->setItemDelegate( new TextDelegate(this) );

[abdullahzubair109]

@mrjj i tried something like this, but didn't work

void StyledDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{

	if (index.column() == 0) {
	
		QString qs = index.data().toString();
		QPoint pt = option.rect.center(); 
		pt += QPoint(40, 0);
		painter->drawText( pt, qs);
	}
	QStyledItemDelegate::paint(painter, option, index);

}