How to change completion rule of QCompleter

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24th August 2009, 14:13
freud

How to change completion rule of QCompleter

The standard QCompleter classs uses completionPrefix to search for all completions, so all the completions have the same prefix which is completionPrefix, what i want to achieve is this:if the string in the completion model contains the chars under the cursor,it should appear in the completion, and i also want to use different rules to decide which should appear in the completions.

For example:
the completion model:QListModel<<"manual"<<"anual"
When i type 'nual', i want both "manual" and "anual" appear in the completion, because they both contains "nual",so how can i achieve this?

I don't know how to change the completion rule,it seems that the standard QCompleter use prfix matching to find completions.

Any suggestions?

Re: How to change completion rule of QCompleter

Using this QCompleter example and this custom QCompleter example, I implemented what you want.

Header:

Code:

#ifndef LINEEDIT_H
#define LINEEDIT_H
 
#include <QLineEdit>
#include <QStringList>
#include <QStringListModel>
#include <QString>
#include <QCompleter>
 
class MyCompleter : public QCompleter
{
    Q_OBJECT
 
public:
    inline MyCompleter(const QStringList& words, QObject * parent) :
            QCompleter(parent), m_list(words), m_model()
    {
        setModel(&m_model);
    }
 
    inline void update(QString word)
    {
        // Do any filtering you like.
        // Here we just include all items that contain word.
        QStringList filtered = m_list.filter(word, caseSensitivity());
        m_model.setStringList(filtered);
        m_word = word;
        complete();
    }
 
    inline QString word()
    {
        return m_word;
    }
 
private:
    QStringList m_list;
    QStringListModel m_model;
    QString m_word;
};
 
class MyLineEdit : public QLineEdit
{
    Q_OBJECT
 
public:
    MyLineEdit(QWidget *parent = 0);
    ~MyLineEdit();
 
    void setCompleter(MyCompleter *c);
    MyCompleter *completer() const;
 
protected:
    void keyPressEvent(QKeyEvent *e);
 
private slots:
    void insertCompletion(const QString &completion);
 
private:
    MyCompleter *c;
};
 
#endif // LINEEDIT_H

CPP:

Code:

MyLineEdit::MyLineEdit(QWidget *parent)
    : QLineEdit(parent), c(0)
{
}
 
MyLineEdit::~MyLineEdit()
{
}
 
void MyLineEdit::setCompleter(MyCompleter *completer)
{
    if (c)
        QObject::disconnect(c, 0, this, 0);
 
    c = completer;
 
    if (!c)
        return;
 
    c->setWidget(this);
    connect(completer, SIGNAL(activated(const QString&)), this, SLOT(insertCompletion(const QString&)));
}
 
MyCompleter *MyLineEdit::completer() const
{
    return c;
}
 
void MyLineEdit::insertCompletion(const QString& completion)
{
    setText(completion);
    selectAll();
}
 
 
void MyLineEdit::keyPressEvent(QKeyEvent *e)
{
    if (c && c->popup()->isVisible())
    {
        // The following keys are forwarded by the completer to the widget
        switch (e->key())
        {
        case Qt::Key_Enter:
        case Qt::Key_Return:
        case Qt::Key_Escape:
        case Qt::Key_Tab:
        case Qt::Key_Backtab:
            e->ignore();
            return; // Let the completer do default behavior
        }
    }
 
    bool isShortcut = (e->modifiers() & Qt::ControlModifier) && e->key() == Qt::Key_E;
    if (!isShortcut)
        QLineEdit::keyPressEvent(e); // Don't send the shortcut (CTRL-E) to the text edit.
 
    if (!c)
        return;
 
    bool ctrlOrShift = e->modifiers() & (Qt::ControlModifier | Qt::ShiftModifier);
    if (!isShortcut && !ctrlOrShift && e->modifiers() != Qt::NoModifier)
    {
        c->popup()->hide();
        return;
    }
 
    c->update(text());
    c->popup()->setCurrentIndex(c->completionModel()->index(0, 0));
}

Usage:

Code:

MyLineEdit * te = new MyLineEdit;
     MyCompleter * completer = new MyCompleter(QStringList() << "oneone" << "Twotwo", this);
     completer->setCaseSensitivity(Qt::CaseInsensitive);
     te->setCompleter(completer);

Re: How to change completion rule of QCompleter

:D
Many thanks,numbat,i just translated your code into Python,it works fine.

Code:

from PyQt4.QtCore import *
from PyQt4.QtGui import *
import sys
 
class TextEdit(QTextEdit):
 
    def __init__(self,parent=None):
        super(TextEdit,self).__init__(parent)
        self.cmp=None
 
    def setCompleter(self,completer):
        if self.cmp:
            self.disconnect(self.cmp,0,0)
        self.cmp=completer
        if (not self.cmp):
            return
        self.cmp.setWidget(self)
        self.cmp.setCompletionMode(QCompleter.PopupCompletion)
        self.cmp.setCaseSensitivity(Qt.CaseInsensitive)
        self.connect(self.cmp,SIGNAL('activated(QString)'),self.insertCompletion)
 
    def completer(self):
        return self.cmp
 
    def insertCompletion(self,string):
        tc=self.textCursor()
        tc.movePosition(QTextCursor.StartOfWord,QTextCursor.KeepAnchor)
        tc.insertText(string)
        self.setTextCursor(tc)
 
    def textUnderCursor(self):
        tc=self.textCursor()
        tc.select(QTextCursor.WordUnderCursor)
        return tc.selectedText()
 
    def keyPressEvent(self,e):
        print(e.text())
        if (self.cmp and self.cmp.popup().isVisible()):
            if e.key() in (Qt.Key_Enter,Qt.Key_Return,Qt.Key_Escape,Qt.Key_Tab,Qt.Key_Backtab):
                e.ignore()
                return
        isShortcut=((e.modifiers() & Qt.ControlModifier) and e.key()==Qt.Key_E)
        if (not self.cmp or not isShortcut):
            super().keyPressEvent(e)
 
        ctrlOrShift = e.modifiers() & (Qt.ControlModifier | Qt.ShiftModifier)
        if (not self.cmp or (ctrlOrShift and e.text().isEmpty())):
            return
 
        eow=QString("~!@#$%^&*()_+{}|:\"<>?,./;'[]\\-=")
        hasModifier = (e.modifiers() != Qt.NoModifier) and not ctrlOrShift
        completionPrefix = self.textUnderCursor()
        if (not isShortcut and (hasModifier or e.text().isEmpty() or completionPrefix.length()<2
                       or eow.contains(e.text().right(1)))):
            self.cmp.popup().hide()
            return
        self.cmp.update(completionPrefix)
        self.cmp.popup().setCurrentIndex(self.cmp.completionModel().index(0, 0))
 
        cr = self.cursorRect()
        cr.setWidth(self.cmp.popup().sizeHintForColumn(0)
                    + self.cmp.popup().verticalScrollBar().sizeHint().width())
        self.cmp.complete(cr)
 
class Completer(QCompleter):
    def __init__(self,stringlist,parent=None):
        super(Completer,self).__init__(parent)
        self.stringlist=stringlist
        self.setModel(QStringListModel())
 
    def update(self,completionText):
        filtered=self.stringlist.filter(completionText,Qt.CaseInsensitive)
        self.model().setStringList(filtered)
        self.popup().setCurrentIndex(self.model().index(0, 0))
 
 
app=QApplication(sys.argv)       
li=QStringList()
li<<'The'<<'that'<<'Red'<<'right'<<'what'
cmp=Completer(li)
window=QMainWindow()
edit=TextEdit()
edit.setCompleter(cmp)
window.setCentralWidget(edit)
window.show()
 
app.exec_()

26th September 2009, 21:27
jungle

Re: How to change completion rule of QCompleter

After a lot of studying up on how this works, I've finally figured it out. I've implemented my own version as well, but I have a question.

My problem is that when the first letter entered into the editable combobox is actually the first letter of an entry, that entry is automatically selected. This bypasses completion of a single letter.

For example. The list is:
chicken broth
cinnamon
boneless chicken breast

I want "c" to show all of these as possible completions. However, "c" will cause the combobox to select "chicken broth" instead. I've looked, but I can't figure out how to disable this behavior. Any suggestions?

Thanks
Bill

edit: btw, hitting "c" will make the edittext read "chicken broth." And hitting backspace will remove all but the "c." Then it completes like i want it to. Obviously, I don't want to have to hit backspace every time.
2nd October 2009, 00:41
jungle

Re: How to change completion rule of QCompleter

I'll just give this one bump to see if anyone missed it. I have looked into the issue more, and I still can't figure out exactly what is setting the text. But it definitely happens without any completer attached.

bill
10th December 2010, 06:44
medved6

Re: How to change completion rule of QCompleter

Thank you.
Ir was usefull for me as well
29th December 2011, 11:02
oximer

Re: How to change completion rule of QCompleter

There is a way of config the space between lines in the popup list?
I don find a way to choose the row height.

Thanks,
Urbano
30th December 2011, 13:17
amleto

Re: How to change completion rule of QCompleter

make your own thread instead of digging up old, relatively un-connected threads.

Re: How to change completion rule of QCompleter

Quote:

Originally Posted by numbat

Using this QCompleter example and this employee monitoring, I implemented what you want.

Header:

Code:

#ifndef LINEEDIT_H
#define LINEEDIT_H
 
#include <QLineEdit>
#include <QStringList>
#include <QStringListModel>
#include <QString>
#include <QCompleter>
 
class MyCompleter : public QCompleter
{
    Q_OBJECT
 
public:
    inline MyCompleter(const QStringList& words, QObject * parent) :
            QCompleter(parent), m_list(words), m_model()
    {
        setModel(&m_model);
    }
 
    inline void update(QString word)
    {
        // Do any filtering you like.
        // Here we just include all items that contain word.
        QStringList filtered = m_list.filter(word, caseSensitivity());
        m_model.setStringList(filtered);
        m_word = word;
        complete();
    }
 
    inline QString word()
    {
        return m_word;
    }
 
private:
    QStringList m_list;
    QStringListModel m_model;
    QString m_word;
};
 
class MyLineEdit : public QLineEdit
{
    Q_OBJECT
 
public:
    MyLineEdit(QWidget *parent = 0);
    ~MyLineEdit();
 
    void setCompleter(MyCompleter *c);
    MyCompleter *completer() const;
 
protected:
    void keyPressEvent(QKeyEvent *e);
 
private slots:
    void insertCompletion(const QString &completion);
 
private:
    MyCompleter *c;
};
 
#endif // LINEEDIT_H

CPP:

Code:

MyLineEdit::MyLineEdit(QWidget *parent)
    : QLineEdit(parent), c(0)
{
}
 
MyLineEdit::~MyLineEdit()
{
}
 
void MyLineEdit::setCompleter(MyCompleter *completer)
{
    if (c)
        QObject::disconnect(c, 0, this, 0);
 
    c = completer;
 
    if (!c)
        return;
 
    c->setWidget(this);
    connect(completer, SIGNAL(activated(const QString&)), this, SLOT(insertCompletion(const QString&)));
}
 
MyCompleter *MyLineEdit::completer() const
{
    return c;
}
 
void MyLineEdit::insertCompletion(const QString& completion)
{
    setText(completion);
    selectAll();
}
 
 
void MyLineEdit::keyPressEvent(QKeyEvent *e)
{
    if (c && c->popup()->isVisible())
    {
        // The following keys are forwarded by the completer to the widget
        switch (e->key())
        {
        case Qt::Key_Enter:
        case Qt::Key_Return:
        case Qt::Key_Escape:
        case Qt::Key_Tab:
        case Qt::Key_Backtab:
            e->ignore();
            return; // Let the completer do default behavior
        }
    }
 
    bool isShortcut = (e->modifiers() & Qt::ControlModifier) && e->key() == Qt::Key_E;
    if (!isShortcut)
        QLineEdit::keyPressEvent(e); // Don't send the shortcut (CTRL-E) to the text edit.
 
    if (!c)
        return;
 
    bool ctrlOrShift = e->modifiers() & (Qt::ControlModifier | Qt::ShiftModifier);
    if (!isShortcut && !ctrlOrShift && e->modifiers() != Qt::NoModifier)
    {
        c->popup()->hide();
        return;
    }
 
    c->update(text());
    c->popup()->setCurrentIndex(c->completionModel()->index(0, 0));
}

Usage:

Code:

MyLineEdit * te = new MyLineEdit;
     MyCompleter * completer = new MyCompleter(QStringList() << "oneone" << "Twotwo", this);
     completer->setCaseSensitivity(Qt::CaseInsensitive);
     te->setCompleter(completer);

Thank you, Numbat
It`s works for me