qt5base-lts/examples/widgets/tools/customcompleter/textedit.cpp

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/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd and its Subsidiary(-ies) nor the
** names of its contributors may be used to endorse or promote products
** derived from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "textedit.h"
#include <QCompleter>
#include <QKeyEvent>
#include <QAbstractItemView>
#include <QtDebug>
#include <QApplication>
#include <QModelIndex>
#include <QAbstractItemModel>
#include <QScrollBar>
//! [0]
TextEdit::TextEdit(QWidget *parent)
: QTextEdit(parent), c(0)
{
setPlainText(tr("This TextEdit provides autocompletions for words that have more than"
" 3 characters. You can trigger autocompletion using ") +
QKeySequence("Ctrl+E").toString(QKeySequence::NativeText));
}
//! [0]
//! [1]
TextEdit::~TextEdit()
{
}
//! [1]
//! [2]
void TextEdit::setCompleter(QCompleter *completer)
{
if (c)
QObject::disconnect(c, 0, this, 0);
c = completer;
if (!c)
return;
c->setWidget(this);
c->setCompletionMode(QCompleter::PopupCompletion);
c->setCaseSensitivity(Qt::CaseInsensitive);
QObject::connect(c, SIGNAL(activated(QString)),
this, SLOT(insertCompletion(QString)));
}
//! [2]
//! [3]
QCompleter *TextEdit::completer() const
{
return c;
}
//! [3]
//! [4]
void TextEdit::insertCompletion(const QString& completion)
{
if (c->widget() != this)
return;
QTextCursor tc = textCursor();
int extra = completion.length() - c->completionPrefix().length();
tc.movePosition(QTextCursor::Left);
tc.movePosition(QTextCursor::EndOfWord);
tc.insertText(completion.right(extra));
setTextCursor(tc);
}
//! [4]
//! [5]
QString TextEdit::textUnderCursor() const
{
QTextCursor tc = textCursor();
tc.select(QTextCursor::WordUnderCursor);
return tc.selectedText();
}
//! [5]
//! [6]
void TextEdit::focusInEvent(QFocusEvent *e)
{
if (c)
c->setWidget(this);
QTextEdit::focusInEvent(e);
}
//! [6]
//! [7]
void TextEdit::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
default:
break;
}
}
bool isShortcut = ((e->modifiers() & Qt::ControlModifier) && e->key() == Qt::Key_E); // CTRL+E
if (!c || !isShortcut) // do not process the shortcut when we have a completer
QTextEdit::keyPressEvent(e);
//! [7]
//! [8]
const bool ctrlOrShift = e->modifiers() & (Qt::ControlModifier | Qt::ShiftModifier);
if (!c || (ctrlOrShift && e->text().isEmpty()))
return;
static QString eow("~!@#$%^&*()_+{}|:\"<>?,./;'[]\\-="); // end of word
bool hasModifier = (e->modifiers() != Qt::NoModifier) && !ctrlOrShift;
QString completionPrefix = textUnderCursor();
if (!isShortcut && (hasModifier || e->text().isEmpty()|| completionPrefix.length() < 3
|| eow.contains(e->text().right(1)))) {
c->popup()->hide();
return;
}
if (completionPrefix != c->completionPrefix()) {
c->setCompletionPrefix(completionPrefix);
c->popup()->setCurrentIndex(c->completionModel()->index(0, 0));
}
QRect cr = cursorRect();
cr.setWidth(c->popup()->sizeHintForColumn(0)
+ c->popup()->verticalScrollBar()->sizeHint().width());
c->complete(cr); // popup it up!
}
//! [8]