[Qt-jambi-interest] Manual Selection in QTableView does not select and does not repaint

[Curt Nowak]

Hi Gunnar,
 
Thanks a lot for your help. It does work now.
My second problem was that when debugging, "this.currentIndex()" would sometimes return "null". But I could fix that myself. If anyone's interested, I attached the working sample. However, it's a minor pitty that now, when the user clicks on the table the "on_selectionChanged()"-method is invoked twice. If anybody knows a more elegant way to do this, please let me know.
 
Curt
 
 
import java.util.Arrays;

import com.trolltech.qt.core.QModelIndex;
import com.trolltech.qt.gui.QApplication;
import com.trolltech.qt.gui.QItemSelection;
import com.trolltech.qt.gui.QMouseEvent;
import com.trolltech.qt.gui.QStandardItem;
import com.trolltech.qt.gui.QStandardItemModel;
import com.trolltech.qt.gui.QTableView;
import com.trolltech.qt.gui.QWidget;
import com.trolltech.qt.gui.QItemSelectionModel.SelectionFlag;

public class QTableViewExample extends QTableView{

    public static void main(String[] args) {
        QApplication.initialize(args);

        QTableViewExample example = new QTableViewExample(null);
        example.show();

        QApplication.exec();
    }

    
    public QTableViewExample(QWidget parent)
    {
        super(parent);
        setSelectionMode(SelectionMode.ContiguousSelection);
        setSelectionBehavior(SelectionBehavior.SelectRows);
        
        QStandardItemModel model = new QStandardItemModel();
        String[] header = { "A", "B", "C"};
        model.setHorizontalHeaderLabels(Arrays.asList(header));
        
        for(int i=0; i<5; i++){
            for(int j=0; j<3; j++){
                String text = String.valueOf(i) + ", " + String.valueOf(j);
                QStandardItem item = new QStandardItem(text);
                model.setItem(i, j, item);
            }
        }
        setModel(model);
        
        this.selectionModel().currentChanged.connect(this, "on_selectionChanged()");
    }
    
    
    
    @SuppressWarnings("unused")
    private void on_selectionChanged()
    {
        QModelIndex currentIndex = this.currentIndex();
        int row;
        if(currentIndex == null){
            row = 0;
        }
        else{
            // never actually mark the last row
            row = Math.min(currentIndex.row(), model().rowCount()-2);
        }
        
        
        // avoid multiple loops
        this.selectionModel().currentChanged.disconnect(this, "on_selectionChanged()");
        {
            this.selectionModel().clear();
            QModelIndex indexTopLeft = this.model().index(row, 0);
            QModelIndex indexBottomRight = this.model().index(row+1, 2);
            QItemSelection selection = new QItemSelection(indexTopLeft, indexBottomRight);
            this.selectionModel().select(selection, SelectionFlag.ClearAndSelect);
            this.selectionModel().setCurrentIndex(this.model().index(row, 0), SelectionFlag.Current);
        }
        this.selectionModel().currentChanged.connect(this, "on_selectionChanged()");
    }
    
    
    @Override
    protected void mouseReleaseEvent(QMouseEvent event)
    {
        super.mouseReleaseEvent(event);
        on_selectionChanged();
    }
}


 
________________________________

Von: Gunnar Sletta [mailto:gunnar at trolltech.com]
Gesendet: Mi 27.08.2008 12:15
An: Curt Nowak
Cc: qt-jambi-interest at trolltech.com
Betreff: Re: [Qt-jambi-interest] Manual Selection in QTableView does not select and does not repaint



Curt Nowak wrote:
> Hi all,
> 
> I'm trying to implement a QTableView in which two consecutive rows are always marked as selected. For example: If the user clicks on row 1 then row 1 and row 2 should both be marked.
> I created a small example that shows where I'm stuck.
> There are two problems that I am having:
> [1] The blue marks on the table change only when it re-gains the window focus. (Click on a different window and then back on the application to see what I mean.)

Hi Curt,

The problem is that QTableView does a reset of the selection in the
mouseReleaseEvent() based on the current mouse position in the view. You
need to reimplement mouseReleaseEvent() to keep on selecting what you want.

> [2] I realize that in "on_selectionChanged" I always get a null-Index. The commented line in the same method aims to correct that but I can't figure out the correct settings.

I don't get what you mean here. The index is always valid when you have
the mouse inside the view.

best regards,
Gunnar