Different Font Color and Style, QStandardItem

[qblacky]

Is it possible to set different Color and Style for QStandardItem into QTreeView dependent on data from Model?
with QStyleSheet or other Methods?

[eyllanesc]

@qblacky what is the meaning of custom style?

[JoeCFD]

@qblacky said in Different Font Color and Style, QStandardItem:

QStandardItem

https://forum.qt.io/topic/63715/how-to-style-qtreeview-items-by-role-with-css/9

[eyllanesc]

@qblacky QStandardItem is not a visual element but a container for information (texts, colors, etc.) so the question makes little sense, if you want to change the view then use a delegate:

class Delegate: public QStyledItemDelegate{
public: 
    using QStyledItemDelegate::QStyledItemDelegate;
protected:
    void initStyleOption(QStyleOptionViewItem * option, const QModelIndex & index) const{
        QVariant data = index.data();
        qDebug() << data;
        QStyledItemDelegate::initStyleOption(option, index);
        if(/*some conditions*/){
            QFont font(option->font);
            /*modify fonts*/
            option->font = font;
            option->fontMetrics = QFontMetrics(font);
        }
    }
}

treview->setItemDelegate(new Delegate);

[qblacky]

Hello,

thanks for answer, i have same solution,
but FontColor , Foreground or color of QPalette::WindowText
have no effects for Item.

void ItemDelegate::initStyleOption(QStyleOptionViewItem *option, const QModelIndex &index) const 
{

    QStyleOptionViewItem localOpt(*option);
    bool ok = false;
// value from item 
    double data = index.data(Qt::DisplayRole).toDouble(&ok);
// data range from item 
    ItemDisclosure *id = new ItemDisclosure(index.data(QtExtUserRoles::LastRole + 1).value<ItemDisclosure>());
    if (id != nullptr)
    {
      if (ok && (id->maxValue() <= data || id->minValue() >= data))
      {
        //option = id->itemOption();
        if (id->itemOption() != nullptr)
        {

          option->font = id->itemOption()->font;
          option->palette = id->itemOption()->palette;
          option->palette.setBrush(QPalette::Text, id->itemOption()->palette.brush(QPalette::Text));
          option->palette.setBrush(QPalette::WindowText, id->itemOption()->palette.brush(QPalette::WindowText));
          option->palette.setColor(QPalette::Text, id->itemOption()->palette.color(QPalette::Text));
          option->palette.setColor(QPalette::WindowText, id->itemOption()->palette.color(QPalette::WindowText));

        }
      }
      
    }
    QStyledItemDelegate::initStyleOption(option, index);
  }

only font style and font size are change but not color.

Thank you.

[eyllanesc]

@qblacky You have to make the changes after QStyledItemDelegate::initStyleOption(option, index);:

    void initStyleOption(QStyleOptionViewItem * option, const QModelIndex & index) const{
        QVariant data = index.data();
        qDebug() << data;
        QStyledItemDelegate::initStyleOption(option, index);
        if(/*some conditions*/){
            QFont font(option->font);
            /*modify fonts*/
            option->font = font;
            option->fontMetrics = QFontMetrics(font);
            option->palette.setBrush(QPalette::Text, QBrush(QColor("red")));
        }
    }

[qblacky]

void ItemDelegate::initStyleOption(QStyleOptionViewItem *option, const QModelIndex &index) const 
{

    QStyleOptionViewItem localOpt(*option);
    bool ok = false;
// value from item 
    double data = index.data(Qt::DisplayRole).toDouble(&ok);
// data range from item 
    ItemDisclosure *id = new ItemDisclosure(index.data(QtExtUserRoles::LastRole + 1).value<ItemDisclosure>());
    if (id != nullptr)
    {
      QStyledItemDelegate::initStyleOption(option, index);
      if (ok && (id->maxValue() <= data || id->minValue() >= data))
      {
        //option = id->itemOption();
        if (id->itemOption() != nullptr)
        {
           option->font = id->itemOption()->font;          
           option->palette = id->itemOption()->palette; 
           option->palette.setBrush(QPalette::Text, QBrush(QColor("red")));
           option->palette.setBrush(QPalette::WindowText, QBrush(QColor("red")));      }
      }
      
    }

  }

This has no effects on the color of the item.

[eyllanesc]

@qblacky I do not reproduce what you indicate:

#include <QApplication>
#include <QStandardItemModel>
#include <QStyledItemDelegate>
#include <QTreeView>

class StyledItemDelegate: public QStyledItemDelegate{
public:
    using QStyledItemDelegate::QStyledItemDelegate;
protected:
    void initStyleOption(QStyleOptionViewItem * option, const QModelIndex & index) const{

        QStyledItemDelegate::initStyleOption(option, index);
        QFont font(option->font);
        // change font
        font.setBold(true);
        option->font = font;
        option->fontMetrics = QFontMetrics(font);
        //change text color
        option->palette.setBrush(QPalette::Text, QBrush(QColor("red")));
    }

};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    a.setStyle("fusion");
    QTreeView w;
    w.setItemDelegate(new StyledItemDelegate);
    QStandardItemModel model;
    model.appendRow(new QStandardItem("FOO"));
    w.setModel(&model);
    w.show();
    return a.exec();
}

[qblacky]

We have a StyleSheet behind of QTreeView.
I want change only from one Item the Color.
Not all.

Without StyleSheet:

With StyleSheet:

[eyllanesc]

@qblacky You cannot use both technologies: Either you use the delegate OR you use the stylesheet but not both. What happens is that when you use QtStyleSheet a private QStyle is used that interprets the stylesheet and sometimes takes some information but mostly discards the information from QStyleOption.

[qblacky]

If i'm not define the StyleSheet for item,
then work initStyleOption() from delegate.

Thank you.