Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
Qt4 Updating TreeModel
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Portage & Programming
View previous topic :: View next topic  
Author Message
Kenji Miyamoto
Veteran
Veteran


Joined: 28 May 2005
Posts: 1452
Location: Looking over your shoulder.

PostPosted: Sun Jun 01, 2008 4:43 pm    Post subject: Qt4 Updating TreeModel Reply with quote

I've started working with Qt4, but I can't seem to figure out how to get a QTreeView to update with a tree model. So far, these two functions don't work:
Code:
void ExecListModel::clearData(void) {
   this->beginRemoveRows(QModelIndex(), 0, this->execs.count() - 1);
   this->execs.clear();
   this->endRemoveRows();
}
void ExecListModel::addData(const Exec * data) {
   this->beginInsertRows(QModelIndex(), this->execs.count(), this->execs.count() + 1);
   this->execs << data;
   this->endInsertRows();
}
The execs QList is updated and everything, but the QTreeView isn't updated past the initial stuff put into the QList. What's the proper way to get a QTreeView to update when its model changes?
_________________
[ Kawa-kun, new and improved!! ]

Alex Libman seems to be more of an anarchist than a libertarian.
Back to top
View user's profile Send private message
d3roga
n00b
n00b


Joined: 30 Jan 2008
Posts: 14

PostPosted: Mon Jun 02, 2008 8:20 am    Post subject: Reply with quote

When setData method is called in the QAbstractItemModel it emits dataChanged signal, which informs QTreeView that it should update.

As long as you've set QTreeView to use your model, this should be enough to add new data in it:
Code:

insertRow(execs.count());
setData(index(execs.count(), 0), data);
Back to top
View user's profile Send private message
Kenji Miyamoto
Veteran
Veteran


Joined: 28 May 2005
Posts: 1452
Location: Looking over your shoulder.

PostPosted: Mon Jun 02, 2008 4:25 pm    Post subject: Reply with quote

Where would these calls go?

Here's what I have now, but it still doesn't update the list. It does, however, print the pointers:
Code:
void ExecListModel::clearData(void) {
   this->beginRemoveRows(QModelIndex(), 0, this->execs.count() - 1);
   this->execs.clear();
   this->endRemoveRows();
}
void ExecListModel::addData(const Exec * data) {
   std::cout << data << std::endl;
   this->insertRow(execs.count());
   QAbstractListModel::setData(index(execs.count(), 0), data);
   this->execs << data;
}
void ExecListModel::setData(QList<const Exec *> & data) {
   this->execs = data;
}

_________________
[ Kawa-kun, new and improved!! ]

Alex Libman seems to be more of an anarchist than a libertarian.
Back to top
View user's profile Send private message
sno35
Guru
Guru


Joined: 15 May 2004
Posts: 334
Location: Paris, France

PostPosted: Mon Jun 02, 2008 8:22 pm    Post subject: Reply with quote

d3roga wrote:
When setData method is called in the QAbstractItemModel it emits dataChanged signal, which informs QTreeView that it should update.

As long as you've set QTreeView to use your model, this should be enough to add new data in it:
Code:

insertRow(execs.count());
setData(index(execs.count(), 0), data);


As I read from http://doc.trolltech.com/4.3/qabstractitemmodel.html#setData
one has to explicitely emit dataChanged in the setData method.

@Kenji from what class do you inherit ?
Back to top
View user's profile Send private message
Kenji Miyamoto
Veteran
Veteran


Joined: 28 May 2005
Posts: 1452
Location: Looking over your shoulder.

PostPosted: Tue Jun 03, 2008 12:26 am    Post subject: Reply with quote

I'm inheriting from QAbstractListModel.

Here's some code that produces almost the right result, but around half of the time I get a QTreeView::rowsInserted internal representation of the model has been corrupted, resetting.:
Code:
void ExecListModel::clearData(void) {
   this->removeRows(0, this->execs.count(), this->index(this->execs.count(), 0));
   this->execs.clear();
}
void ExecListModel::addData(const Exec * data) {
   this->execs << data;
   this->insertRow(this->execs.count(), this->index(this->execs.count(), 0));
   QAbstractListModel::setData(this->index(this->execs.count(), 0), QVariant(data));
}
What's really weird is that the first item in the data used in the model is skipped every other time, so the '|ls' in the data below only appears half of the time, alternating regularly:
Code:
ls
QTreeView::rowsInserted internal representation of the model has been corrupted, resetting.
QTreeView::rowsInserted internal representation of the model has been corrupted, resetting.
QTreeView::rowsInserted internal representation of the model has been corrupted, resetting.
|ls -> /bin/ls
|lsattr -> /bin/lsattr
|lsdev -> /usr/bin/lsdev
|lsdvd -> /usr/bin/lsdvd
|lshal -> /usr/bin/lshal
|lsmod -> /bin/lsmod

_________________
[ Kawa-kun, new and improved!! ]

Alex Libman seems to be more of an anarchist than a libertarian.
Back to top
View user's profile Send private message
d3roga
n00b
n00b


Joined: 30 Jan 2008
Posts: 14

PostPosted: Tue Jun 03, 2008 5:01 am    Post subject: Reply with quote

When using QAbstractListModel or just QAbstractItemModel, the removeRows method needs to be reimplemented (http://doc.trolltech.com/4.3/qabstractitemmodel.html#removeRows).

Here is a nice looking guide about implementing custom models: http://doc.trolltech.com/4.3/model-view-creating-models.html.

If you don't want to use custom model, you can use http://doc.trolltech.com/4.3/qstringlistmodel.html or http://doc.trolltech.com/4.3/qstandarditemmodel.html.
Back to top
View user's profile Send private message
Kenji Miyamoto
Veteran
Veteran


Joined: 28 May 2005
Posts: 1452
Location: Looking over your shoulder.

PostPosted: Tue Jun 03, 2008 3:33 pm    Post subject: Reply with quote

Actually, I did implement both of those methods before:
Code:
bool ExecListModel::insertRows(int position, int rows, const QModelIndex & parent) {
   int row;
   void * ptr = parent.data().value<void *>();
   this->beginInsertRows(QModelIndex(), position, position + rows - 1);
   for(row = 0; row < rows; ++row)
      if(ptr)
         this->execs.insert(position, (const Exec *)ptr);
   this->endInsertRows();
   return true;
}
bool ExecListModel::removeRows(int position, int rows, const QModelIndex & parent) {
   int row;
   this->beginRemoveRows(QModelIndex(), position, position + rows - 1);
   for(row = 0; row < rows; ++row)
      this->execs.removeAt(position);
   this->endRemoveRows();
   return true;
}
I'll look into QStandardItemModel.

EDIT: Do you know of any examples of QStandardItem than use two columns?
_________________
[ Kawa-kun, new and improved!! ]

Alex Libman seems to be more of an anarchist than a libertarian.
Back to top
View user's profile Send private message
sno35
Guru
Guru


Joined: 15 May 2004
Posts: 334
Location: Paris, France

PostPosted: Tue Jun 03, 2008 9:22 pm    Post subject: Reply with quote

Hi
How your data() and rowCount() look like ?
Back to top
View user's profile Send private message
Kenji Miyamoto
Veteran
Veteran


Joined: 28 May 2005
Posts: 1452
Location: Looking over your shoulder.

PostPosted: Wed Jun 04, 2008 3:24 pm    Post subject: Reply with quote

Code:
int ExecListModel::rowCount(const QModelIndex &parent) const {
   return this->execs.count();
}
int ExecListModel::columnCount(const QModelIndex &parent) const {
   return 2;
}
QVariant ExecListModel::data(const QModelIndex &index, int role) const {
   if(!index.isValid())
      return QVariant();
   else if(index.row() >= this->execs.size() || index.column() >= 2)
      return QVariant();
   else if(role == Qt::DisplayRole) {
      switch(index.column()) {
         case 0: return this->execs.at(index.row())->base;
         case 1: return this->execs.at(index.row())->fullpath;
         default: return QVariant();
      }
   }
   else
      return QVariant();
}

_________________
[ Kawa-kun, new and improved!! ]

Alex Libman seems to be more of an anarchist than a libertarian.
Back to top
View user's profile Send private message
sno35
Guru
Guru


Joined: 15 May 2004
Posts: 334
Location: Paris, France

PostPosted: Wed Jun 04, 2008 7:25 pm    Post subject: Reply with quote

Hi
You don't want to show a tree, do you ?
So give QmodelIndex() to insertRow as second parameter, because you just want to add a child to the unvisible topmost root == QModelIndex()
Hth
Back to top
View user's profile Send private message
Kenji Miyamoto
Veteran
Veteran


Joined: 28 May 2005
Posts: 1452
Location: Looking over your shoulder.

PostPosted: Wed Jun 04, 2008 8:50 pm    Post subject: Reply with quote

I think that fixed the problem, but I'll need to play around with it more before I can verify.
_________________
[ Kawa-kun, new and improved!! ]

Alex Libman seems to be more of an anarchist than a libertarian.
Back to top
View user's profile Send private message
sno35
Guru
Guru


Joined: 15 May 2004
Posts: 334
Location: Paris, France

PostPosted: Thu Jun 05, 2008 12:05 am    Post subject: Reply with quote

I think you were trying to include the data to add in the insertion but at the insertion stage you just have to make room.
You provide data that fills this rooms just when ... data(,,) is called.
Regards
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Portage & Programming All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum