New code assist API

This is a re-work of our completion engine. Primary goals are:

- Allow the computation to run in a separate thread so the GUI is not locked.
- Support a model-based approach. QStrings are still needed (filtering, etc), but
internal structures are free to use more efficient representations.
- Unifiy all kinds of *assist* into a more reusable and extensible framework.
- Remove unnecessary dependencies on the text editor so we have more generic
and easily "plugable" components (still things to be resolved).

src/plugins/texteditor/codeassist/basicproposalitem.cpp

@@ -0,0 +1,142 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (info@qt.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 info@qt.nokia.com.
+**
+**************************************************************************/
+
+#include "basicproposalitem.h"
+
+#include <texteditor/basetexteditor.h>
+#include <texteditor/quickfix.h>
+
+#include <QtGui/QTextCursor>
+
+using namespace TextEditor;
+
+BasicProposalItem::BasicProposalItem()
+    : m_order(0)
+{}
+
+BasicProposalItem::~BasicProposalItem()
+{}
+
+void BasicProposalItem::setIcon(const QIcon &icon)
+{
+    m_icon = icon;
+}
+
+const QIcon &BasicProposalItem::icon() const
+{
+    return m_icon;
+}
+
+void BasicProposalItem::setText(const QString &text)
+{
+    m_text = text;
+}
+
+const QString &BasicProposalItem::text() const
+{
+    return m_text;
+}
+
+void BasicProposalItem::setDetail(const QString &detail)
+{
+    m_detail = detail;
+}
+
+const QString &BasicProposalItem::detail() const
+{
+    return m_detail;
+}
+
+void BasicProposalItem::setData(const QVariant &var)
+{
+    m_data = var;
+}
+
+const QVariant &BasicProposalItem::data() const
+{
+    return m_data;
+}
+
+int BasicProposalItem::order() const
+{
+    return m_order;
+}
+
+void BasicProposalItem::setOrder(int order)
+{
+    m_order = order;
+}
+
+bool BasicProposalItem::implicitlyApplies() const
+{
+    return !data().canConvert<QString>() && !data().canConvert<QuickFixOperation::Ptr>();
+}
+
+bool BasicProposalItem::prematurelyApplies(const QChar &c) const
+{
+    Q_UNUSED(c);
+    return false;
+}
+
+void BasicProposalItem::apply(BaseTextEditor *editor, int basePosition) const
+{
+    if (data().canConvert<QString>())
+        applySnippet(editor, basePosition);
+    else if (data().canConvert<QuickFixOperation::Ptr>())
+        applyQuickFix(editor, basePosition);
+    else
+        applyContextualContent(editor, basePosition);
+}
+
+void BasicProposalItem::applyContextualContent(BaseTextEditor *editor, int basePosition) const
+{
+    const int currentPosition = editor->position();
+    editor->setCursorPosition(basePosition);
+    editor->replace(currentPosition - basePosition, text());
+}
+
+void BasicProposalItem::applySnippet(BaseTextEditor *editor, int basePosition) const
+{
+    BaseTextEditorWidget *editorWidget = static_cast<BaseTextEditorWidget *>(editor->widget());
+    QTextCursor tc = editorWidget->textCursor();
+    tc.setPosition(basePosition, QTextCursor::KeepAnchor);
+    editorWidget->insertCodeSnippet(tc, data().toString());
+}
+
+void BasicProposalItem::applyQuickFix(BaseTextEditor *editor, int basePosition) const
+{
+    Q_UNUSED(editor)
+    Q_UNUSED(basePosition)
+
+    QuickFixOperation::Ptr op = data().value<QuickFixOperation::Ptr>();
+    op->perform();
+}