Filter tree view

[Ginsengelf]

Hi, I have a QTreeView with the following structure:

-1
  |-A
  |  |-a
  |  |-b
  |
  |-B
  |  |-a
  |  
  |-C
     |-b

-1
  |-A
  |  |-a
  |  |-b
  |
  |-B
  |  |-a
  |  
  |-C
     |-b

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I would like to filter this and show only the nodes that contain a "a" item, like this:

-1
  |-A
  |  |-a
  |
  |-B
     |-a

-1
  |-A
  |  |-a
  |
  |-B
     |-a

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but using a custom QSortFilterProxyModel I only achieved this:

-1
  |-A
  |  |-a
  |
  |-B
  |  |-a
  | 
  |-C

-1
  |-A
  |  |-a
  |
  |-B
  |  |-a
  | 
  |-C

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which is understandable since my filter condition is applied to the a,b,c items only.
I also tried to filter the filtered output with a second QSortFilterProxyModel, but that did not help since the hasChildren() method for the model indexes always returned 0 and all items got filtered out...

Is there a simple way to completely filter out the nodes that do not contain an "a" item (the "C" node in the example above)?

Thanks,

Ginsengelf

[nix]

I faced the same problem few month ago, I solve it by using the folowing class :

songtreeproxyfilter.h :

#ifndef SONGTREEPROXYFILTER_H
#define SONGTREEPROXYFILTER_H
 
#include <QSortFilterProxyModel>
 
class SongTreeProxyFilter : public QSortFilterProxyModel
{
public:
    SongTreeProxyFilter(QObject *parent = NULL);
    bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const;
private :
    bool hasToBeDisplayed(const QModelIndex index) const;
};
 
#endif // SONGTREEPROXYFILTER_H

#ifndef SONGTREEPROXYFILTER_H
#define SONGTREEPROXYFILTER_H

#include <QSortFilterProxyModel>

class SongTreeProxyFilter : public QSortFilterProxyModel
{
public:
    SongTreeProxyFilter(QObject *parent = NULL);
    bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const;
private :
    bool hasToBeDisplayed(const QModelIndex index) const;
};

#endif // SONGTREEPROXYFILTER_H

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songtreeproxyfilet.c

#include "songtreeproxyfilter.h"
 
#include <QtDebug>
 
SongTreeProxyFilter::SongTreeProxyFilter(QObject *parent):
        QSortFilterProxyModel(parent)
{
}
 
bool SongTreeProxyFilter::filterAcceptsRow(int sourceRow,
         const QModelIndex &sourceParent) const
 {
     QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);
 
     return hasToBeDisplayed(index);
 }
 
bool SongTreeProxyFilter::hasToBeDisplayed(const QModelIndex index) const
{
    bool result = false;
    // How many child this element have
    if ( sourceModel()->rowCount(index) > 0 )
    {
        for( int ii = 0; ii < sourceModel()->rowCount(index); ii++)
        {
            QModelIndex childIndex = sourceModel()->index(ii,0,index);
            if ( ! childIndex.isValid() )
                break;
            result = hasToBeDisplayed(childIndex);
            if (result)
            {
                // there is atless one element to display
                break;
            }
        }
    }
    else
    {
        QModelIndex useIndex = sourceModel()->index(index.row(), 1, index.parent());
        QString type = sourceModel()->data(useIndex, Qt::DisplayRole).toString();
        if ( ! type.contains(filterRegExp()))
        {
           result = false;
        }
        else
        {
            result = true;
        }
    }
    return result;
}

#include "songtreeproxyfilter.h"

#include <QtDebug>

SongTreeProxyFilter::SongTreeProxyFilter(QObject *parent):
        QSortFilterProxyModel(parent)
{
}

bool SongTreeProxyFilter::filterAcceptsRow(int sourceRow,
         const QModelIndex &sourceParent) const
 {
     QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);

     return hasToBeDisplayed(index);
 }

bool SongTreeProxyFilter::hasToBeDisplayed(const QModelIndex index) const
{
    bool result = false;
    // How many child this element have
    if ( sourceModel()->rowCount(index) > 0 )
    {
        for( int ii = 0; ii < sourceModel()->rowCount(index); ii++)
        {
            QModelIndex childIndex = sourceModel()->index(ii,0,index);
            if ( ! childIndex.isValid() )
                break;
            result = hasToBeDisplayed(childIndex);
            if (result)
            {
                // there is atless one element to display
                break;
            }
        }
    }
    else
    {
        QModelIndex useIndex = sourceModel()->index(index.row(), 1, index.parent());
        QString type = sourceModel()->data(useIndex, Qt::DisplayRole).toString();
        if ( ! type.contains(filterRegExp()))
        {
           result = false;
        }
        else
        {
            result = true;
        }
    }
    return result;
}

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I hope it can help.