ProjectExplorer: No more pointer to the parent project node

That information is used rarely, and is not too expensive to regenerate,
so there is no need to store and manage it for every node.

Change-Id: I2261853431cd4328ec447031de3b9f5d5347e796
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/projectexplorer/projectnodes.cpp

@@ -98,7 +98,12 @@ NodeType Node::nodeType() const
   */
 ProjectNode *Node::parentProjectNode() const
 {
-    return m_projectNode;
+    if (!m_parentFolderNode)
+        return nullptr;
+    auto pn = m_parentFolderNode->asProjectNode();
+    if (pn)
+        return pn;
+    return m_parentFolderNode->parentProjectNode();
 }
 
 /*!
@@ -109,6 +114,19 @@ FolderNode *Node::parentFolderNode() const
     return m_parentFolderNode;
 }
 
+ProjectNode *Node::managingProject()
+{
+    if (asSessionNode())
+        return nullptr;
+    ProjectNode *pn = parentProjectNode();
+    return pn ? pn : asProjectNode(); // projects manage themselves...
+}
+
+const ProjectNode *Node::managingProject() const
+{
+    return const_cast<Node *>(this)->managingProject();
+}
+
 /*!
   The path of the file or folder in the filesystem the node represents.
   */
@@ -155,11 +173,6 @@ void Node::setEnabled(bool enabled)
     emitNodeUpdated();
 }
 
-void Node::setProjectNode(ProjectNode *project)
-{
-    m_projectNode = project;
-}
-
 void Node::emitNodeUpdated()
 {
     if (parentFolderNode())
@@ -496,36 +509,41 @@ QString FolderNode::addFileFilter() const
 
 bool FolderNode::addFiles(const QStringList &filePaths, QStringList *notAdded)
 {
-    if (parentProjectNode())
-        return parentProjectNode()->addFiles(filePaths, notAdded);
+    ProjectNode *pn = managingProject();
+    if (pn)
+        return pn->addFiles(filePaths, notAdded);
     return false;
 }
 
 bool FolderNode::removeFiles(const QStringList &filePaths, QStringList *notRemoved)
 {
-    if (parentProjectNode())
-        return parentProjectNode()->removeFiles(filePaths, notRemoved);
+    ProjectNode *pn = managingProject();
+    if (pn)
+        return pn->removeFiles(filePaths, notRemoved);
     return false;
 }
 
 bool FolderNode::deleteFiles(const QStringList &filePaths)
 {
-    if (parentProjectNode())
-        return parentProjectNode()->deleteFiles(filePaths);
+    ProjectNode *pn = managingProject();
+    if (pn)
+        return pn->deleteFiles(filePaths);
     return false;
 }
 
 bool FolderNode::canRenameFile(const QString &filePath, const QString &newFilePath)
 {
-    if (parentProjectNode())
-        return parentProjectNode()->canRenameFile(filePath, newFilePath);
+    ProjectNode *pn = managingProject();
+    if (pn)
+        return pn->canRenameFile(filePath, newFilePath);
     return false;
 }
 
 bool FolderNode::renameFile(const QString &filePath, const QString &newFilePath)
 {
-    if (parentProjectNode())
-        return parentProjectNode()->renameFile(filePath, newFilePath);
+    ProjectNode *pn = managingProject();
+    if (pn)
+        return pn->renameFile(filePath, newFilePath);
     return false;
 }
 
@@ -545,7 +563,8 @@ FolderNode::AddNewInformation FolderNode::addNewInformation(const QStringList &f
 
 void FolderNode::addFileNodes(const QList<FileNode *> &files)
 {
-    Q_ASSERT(parentProjectNode());
+    Q_ASSERT(managingProject());
+
     if (files.isEmpty())
         return;
 
@@ -556,7 +575,6 @@ void FolderNode::addFileNodes(const QList<FileNode *> &files)
                    qDebug("File node has already a parent folder"));
 
         file->setParentFolderNode(this);
-        file->setProjectNode(parentProjectNode());
         // Now find the correct place to insert file
         if (m_fileNodes.count() == 0
                 || m_fileNodes.last() < file) {
@@ -581,7 +599,7 @@ void FolderNode::addFileNodes(const QList<FileNode *> &files)
 
 void FolderNode::removeFileNodes(const QList<FileNode *> &files)
 {
-    Q_ASSERT(parentProjectNode());
+    Q_ASSERT(managingProject());
 
     if (files.isEmpty())
         return;
@@ -612,7 +630,7 @@ void FolderNode::removeFileNodes(const QList<FileNode *> &files)
 */
 void FolderNode::addFolderNodes(const QList<FolderNode*> &subFolders)
 {
-    Q_ASSERT(parentProjectNode());
+    Q_ASSERT(managingProject());
 
     if (subFolders.isEmpty())
         return;
@@ -622,7 +640,6 @@ void FolderNode::addFolderNodes(const QList<FolderNode*> &subFolders)
         QTC_ASSERT(!folder->parentFolderNode(),
                    qDebug("Project node has already a parent folder"));
         folder->setParentFolderNode(this);
-        folder->setProjectNode(parentProjectNode());
 
         // Find the correct place to insert
         if (m_folderNodes.count() == 0
@@ -651,7 +668,7 @@ void FolderNode::addFolderNodes(const QList<FolderNode*> &subFolders)
 */
 void FolderNode::removeFolderNodes(const QList<FolderNode*> &subFolders)
 {
-    Q_ASSERT(parentProjectNode());
+    Q_ASSERT(managingProject());
 
     if (subFolders.isEmpty())
         return;
@@ -720,8 +737,6 @@ int VirtualFolderNode::priority() const
 ProjectNode::ProjectNode(const Utils::FileName &projectFilePath) :
     FolderNode(projectFilePath, NodeType::Project)
 {
-    // project node "manages" itself
-    setProjectNode(this);
     setDisplayName(projectFilePath.fileName());
 }