CppEditor: refactor FollowSymbol

Create an interface to get the ability to use
another FollowSymbol implementation

Change-Id: I5802f62523ff3ee47b8a14e487adf43edcb6c9b1
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/clangcodemodel/clangfollowsymbol.cpp

@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "clangfollowsymbol.h"
+#include "clangeditordocumentprocessor.h"
+#include "texteditor/texteditor.h"
+#include "texteditor/convenience.h"
+
+namespace ClangCodeModel {
+namespace Internal {
+
+TextEditor::TextEditorWidget::Link ClangFollowSymbol::findLink(
+        const CppTools::CursorInEditor &data,
+        bool resolveTarget,
+        const CPlusPlus::Snapshot &,
+        const CPlusPlus::Document::Ptr &,
+        CppTools::SymbolFinder *,
+        bool)
+{
+    Link link;
+
+    int lineNumber = 0, positionInBlock = 0;
+    QTextCursor cursor = TextEditor::Convenience::wordStartCursor(data.cursor());
+    TextEditor::Convenience::convertPosition(cursor.document(), cursor.position(), &lineNumber,
+                                             &positionInBlock);
+    const unsigned line = lineNumber;
+    const unsigned column = positionInBlock + 1;
+
+    if (!resolveTarget)
+        return link;
+    ClangEditorDocumentProcessor *processor = ClangEditorDocumentProcessor::get(
+                data.filePath().toString());
+    if (!processor)
+        return link;
+
+    QFuture<CppTools::SymbolInfo> info
+            = processor->requestFollowSymbol(static_cast<int>(line),
+                                             static_cast<int>(column),
+                                             resolveTarget);
+    if (info.isCanceled())
+        return link;
+
+    while (!info.isFinished()) {
+        if (info.isCanceled())
+            return link;
+        QCoreApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
+    }
+    CppTools::SymbolInfo result = info.result();
+
+    if (result.failedToFollow)
+        return link;
+
+    // We did not fail but the result is empty
+    if (result.fileName.isEmpty())
+        return link;
+
+    return Link(result.fileName, result.startLine, result.startColumn - 1);
+}
+
+} // namespace Internal
+} // namespace ClangCodeModel