QCompleter - isslplpue

[sajis997]

Hello forum,

I am sure that some one over here have used QCompleter somewhere in their project and i need you help. The manual says something related to file system.

How to customize it if it a customized item model derived from QAbstractItemModel ?

I have a tree model preety much same as the simple tree model example. A snapshot might help:

tree.jpg


I want the completer to provide the user the look-up hint in such a manner that if the user type X3D, then all the names that starts with "X3D...." pop up in the lookup completion hint.

I think in that we have to lookup all the levels at a time. What do you think? I already did the following changes, but i am not getting what i need and i believe i am far away from what i want to get.

QCompleter *completer = new QCompleter(this);
    completer->setModel(m_h3dTreeModel);
    m_nodeHighlightingEditor->setCompleter(completer);

QCompleter *completer = new QCompleter(this);
    completer->setModel(m_h3dTreeModel);
    m_nodeHighlightingEditor->setCompleter(completer);

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I need more hints to achieve this behavior.

Let me know if i am clear enough with my requirement explanation.


Regards
Sajjad

[ChrisW67]

Have you read: Handling Tree Models?

[wysota]

Create a proxy model that will "flatten" your tree model. Then assign that proxy model to your completer.

[sajis997]

Hi

I did not actually get what do you mean by flattening the model. Does it happen by itself once i assign the source model to the proxy model or i have re-program it and break the hierarchy while building the proxy model.


Looking forward to more on this !!


Regards
Sajjad

[wysota]

No, nothing happens by itself. By flattening I mean that the proxy model needs to transform the original model in such a way that all children of each item become siblings of that item so that you don't have children anymore and all elements are directly under the root of the model.

[sajis997]

Hi

I think that in this case i have subclass the QProxyModel and over-ride the following functions as follows:

class FlatTreeModel : public QAbstractProxyModel
{
public:
     QModelIndex mapFromSource(...);
     QModelIndex mapToSource(....);
 
};

class FlatTreeModel : public QAbstractProxyModel
{
public:
     QModelIndex mapFromSource(...);
     QModelIndex mapToSource(....);

};

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I am not sure what would be inside the definition of those above functions . As per suggestion i need to flatten down the existing tree hierarchy model and send it to the QCompleter.


Some more hint or example is appreciated.


Regards
Sajjad

[wysota]

Take a piece of paper, draw a schema of your tree model (including branches and children) and think what needs to be done step by step to obtain a situation where the model is flat. When you find the algorithm of recalculating model indexes, implement it in mapFromSource() and mapToSource().

[sajis997]

Hi

If i flatten down the tree hierarchy , it will eventually look like a list model, right?


Regards
Sajjad

[wysota]

A list or a table model, depending on the number of columns your original model has.