VCS: auto-completion in the description text edit

In the description field of the commit editor, class
VCSBaseSubmitEditor provides completion of file names and C++
entities (based on QtCreator's internal C++ code model).

Change-Id: Ie5323714dbf6f6e635953dfbb35596201d86fc37
Reviewed-by: Tobias Hunger <tobias.hunger@nokia.com>
Reviewed-by: Hugues Delorme <delorme.hugues@fougsys.fr>

src/libs/utils/completingtextedit.cpp

@@ -0,0 +1,178 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+**
+** GNU Lesser General Public License Usage
+**
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this file.
+** Please review the following information to ensure the GNU Lesser General
+** Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** Other Usage
+**
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**************************************************************************/
+
+#include "completingtextedit.h"
+
+#include <QtGui/QAbstractItemView>
+#include <QtGui/QCompleter>
+#include <QtGui/QKeyEvent>
+#include <QtGui/QScrollBar>
+
+static bool isEndOfWordChar(const QChar &c)
+{
+    return !c.isLetterOrNumber() && c.category() != QChar::Punctuation_Connector;
+}
+
+/*! \class Utils::CompletingTextEdit
+
+  \brief A QTextEdit with auto-completion support
+
+  Excerpted from Qt examples/tools/customcompleter
+*/
+
+namespace Utils {
+
+class CompletingTextEditPrivate
+{
+public:
+    CompletingTextEditPrivate(CompletingTextEdit *textEdit);
+
+    void insertCompletion(const QString &completion);
+    QString textUnderCursor() const;
+
+    QCompleter *m_completer;
+
+private:
+    CompletingTextEdit *m_backPointer;
+};
+
+CompletingTextEditPrivate::CompletingTextEditPrivate(CompletingTextEdit *textEdit)
+    : m_completer(0),
+      m_backPointer(textEdit)
+{
+}
+
+void CompletingTextEditPrivate::insertCompletion(const QString &completion)
+{
+    if (m_completer->widget() != m_backPointer)
+        return;
+    QTextCursor tc = m_backPointer->textCursor();
+    int extra = completion.length() - m_completer->completionPrefix().length();
+    tc.movePosition(QTextCursor::Left);
+    tc.movePosition(QTextCursor::EndOfWord);
+    tc.insertText(completion.right(extra));
+    m_backPointer->setTextCursor(tc);
+}
+
+QString CompletingTextEditPrivate::textUnderCursor() const
+{
+    QTextCursor tc = m_backPointer->textCursor();
+    tc.select(QTextCursor::WordUnderCursor);
+    return tc.selectedText();
+}
+
+CompletingTextEdit::CompletingTextEdit(QWidget *parent)
+    : QTextEdit(parent),
+      d(new CompletingTextEditPrivate(this))
+{
+}
+
+CompletingTextEdit::~CompletingTextEdit()
+{
+    delete d;
+}
+
+void CompletingTextEdit::setCompleter(QCompleter *c)
+{
+    if (completer())
+        disconnect(completer(), 0, this, 0);
+
+    d->m_completer = c;
+
+    if (!c)
+        return;
+
+    completer()->setWidget(this);
+    completer()->setCompletionMode(QCompleter::PopupCompletion);
+    connect(completer(), SIGNAL(activated(QString)), this, SLOT(insertCompletion(QString)));
+}
+
+QCompleter *CompletingTextEdit::completer() const
+{
+    return d->m_completer;
+}
+
+void CompletingTextEdit::keyPressEvent(QKeyEvent *e)
+{
+    if (completer() && completer()->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;
+        }
+    }
+
+    const bool isShortcut = ((e->modifiers() & Qt::ControlModifier) && e->key() == Qt::Key_E); // CTRL+E
+    if (completer() == 0 || !isShortcut) // do not process the shortcut when we have a completer
+        QTextEdit::keyPressEvent(e);
+
+    const bool ctrlOrShift = e->modifiers() & (Qt::ControlModifier | Qt::ShiftModifier);
+    if (completer() == 0 || (ctrlOrShift && e->text().isEmpty()))
+        return;
+
+    const bool hasModifier = (e->modifiers() != Qt::NoModifier) && !ctrlOrShift;
+    const QString newCompletionPrefix = d->textUnderCursor();
+    const QChar lastChar = e->text().isEmpty() ? QChar() : e->text().right(1).at(0);
+
+    if (!isShortcut && (hasModifier || e->text().isEmpty() || newCompletionPrefix.length() < 3
+                        || isEndOfWordChar(lastChar))) {
+        completer()->popup()->hide();
+        return;
+    }
+
+    if (newCompletionPrefix != completer()->completionPrefix()) {
+        completer()->setCompletionPrefix(newCompletionPrefix);
+        completer()->popup()->setCurrentIndex(completer()->completionModel()->index(0, 0));
+    }
+    QRect cr = cursorRect();
+    cr.setWidth(completer()->popup()->sizeHintForColumn(0)
+                + completer()->popup()->verticalScrollBar()->sizeHint().width());
+    completer()->complete(cr); // popup it up!
+}
+
+void CompletingTextEdit::focusInEvent(QFocusEvent *e)
+{
+    if (completer() != 0)
+        completer()->setWidget(this);
+    QTextEdit::focusInEvent(e);
+}
+
+} // namespace Utils
+
+#include "moc_completingtextedit.cpp"