FAster approach for Completetion

[codeman]

Hello Friends,

I experiment with the standard approach for implementing QCompleter in a QLineEdit.
But when the wordlist grows up to 20000 or more the delay before the popup widget for completetion comes ist to long.

Is there another aproach for implementing completetion with big amount of words?

[Lykurg]

Are you using a QStringListModel? If so, create a SQLite database in the memory, or if the wordlist wont change on your disk, and use that with a QSqlTableModel. This will speed up the process.

[wysota]

Someone should really write a completer class based on a suffix (or prefix) tree...

[codeman]

I use this:

QCompleter *completer = new QCompleter(qstrL_mylist, this);
    completer->setCompletionMode(QCompleter::PopupCompletion);
    qle_myLineEdit->setCompleter(completer);

QCompleter *completer = new QCompleter(qstrL_mylist, this);
    completer->setCompletionMode(QCompleter::PopupCompletion);
    qle_myLineEdit->setCompleter(completer);

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[Lykurg]

then, as told, try to use a sqlite database.

[codeman]

so now I implement this one:

QSqlTableModel *model = new QSqlTableModel;
         model->setTable("mytable");
         model->select();
    QCompleter *completer = new QCompleter(model, this);
    completer->setCompletionMode(QCompleter::PopupCompletion);
    completer->setCompletionColumn(0);
    qle_myLineEdit->setCompleter(completer);

QSqlTableModel *model = new QSqlTableModel;
         model->setTable("mytable");
         model->select();
    QCompleter *completer = new QCompleter(model, this);
    completer->setCompletionMode(QCompleter::PopupCompletion);
    completer->setCompletionColumn(0);
    qle_myLineEdit->setCompleter(completer);

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now the delay is ca. 0.3 seconds by 40000 words feels ok or exists there a better approach??

[wysota]

You can implement your own completer class based on Patricia trie and optionally populated in a worker thread with caching completion traces (so that removing the last character of completion prefix doesn't cause the completion list to be rebuilt). That's pretty much maximum you can squeeze from a completer mechanism.

[codeman]

Patricia trie ???????

[Lykurg]

Patricia trie ???????

Google is your friend: http://en.wikipedia.org/wiki/Radix_tree!