Projects: Create QIcons in the UI thread

Creating QIcons elsewhere is not safe because of image reader plugin
loading and the pixmap cache.

Fixes: QTCREATORBUG-25301
Change-Id: Ia22a0cd571f808d7f5c639353fdf2e548743f8ca
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/cmakeprojectmanager/cmakeprojectnodes.cpp

@@ -46,17 +46,14 @@ CMakeInputsNode::CMakeInputsNode(const Utils::FilePath &cmakeLists) :
 {
     setPriority(Node::DefaultPriority - 10); // Bottom most!
     setDisplayName(QCoreApplication::translate("CMakeFilesProjectNode", "CMake Modules"));
-    static const QIcon modulesIcon = Core::FileIconProvider::directoryIcon(
-                ProjectExplorer::Constants::FILEOVERLAY_MODULES);
-    setIcon(modulesIcon);
+    setIcon(DirectoryIcon(ProjectExplorer::Constants::FILEOVERLAY_MODULES));
     setListInProject(false);
 }
 
 CMakeListsNode::CMakeListsNode(const Utils::FilePath &cmakeListPath) :
     ProjectExplorer::ProjectNode(cmakeListPath)
 {
-    static QIcon folderIcon = Core::FileIconProvider::directoryIcon(Constants::FILE_OVERLAY_CMAKE);
-    setIcon(folderIcon);
+    setIcon(DirectoryIcon(Constants::FILE_OVERLAY_CMAKE));
     setListInProject(false);
 }
 
@@ -74,9 +71,7 @@ CMakeProjectNode::CMakeProjectNode(const Utils::FilePath &directory) :
     ProjectExplorer::ProjectNode(directory)
 {
     setPriority(Node::DefaultProjectPriority + 1000);
-    static const QIcon productIcon = Core::FileIconProvider::directoryIcon(
-                ProjectExplorer::Constants::FILEOVERLAY_PRODUCT);
-    setIcon(productIcon);
+    setIcon(DirectoryIcon(ProjectExplorer::Constants::FILEOVERLAY_PRODUCT));
     setListInProject(false);
 }
 
@@ -90,7 +85,7 @@ CMakeTargetNode::CMakeTargetNode(const Utils::FilePath &directory, const QString
 {
     m_target = target;
     setPriority(Node::DefaultProjectPriority + 900);
-    setIcon(QIcon(":/projectexplorer/images/build.png")); // TODO: Use proper icon!
+    setIcon(":/projectexplorer/images/build.png"); // TODO: Use proper icon!
     setListInProject(false);
     setProductType(ProductType::Other);
 }

src/plugins/cmakeprojectmanager/fileapidataextractor.cpp

@@ -474,7 +474,8 @@ FolderNode *createSourceGroupNode(const QString &sourceGroupName,
             if (!existingNode) {
                 auto node = createCMakeVFolder(sourceDirectory, Node::DefaultFolderPriority + 5, p);
                 node->setListInProject(false);
-                node->setIcon(QIcon::fromTheme("edit-copy", ::Utils::Icons::COPY.icon()));
+                node->setIcon(
+                    [] { return QIcon::fromTheme("edit-copy", ::Utils::Icons::COPY.icon()); });
 
                 existingNode = node.get();
 

src/plugins/cmakeprojectmanager/projecttreehelper.cpp

@@ -182,14 +182,12 @@ void addHeaderNodes(ProjectNode *root,
     if (root->isEmpty())
         return;
 
-    static QIcon headerNodeIcon = Core::FileIconProvider::directoryIcon(
-        ProjectExplorer::Constants::FILEOVERLAY_H);
     auto headerNode = std::make_unique<VirtualFolderNode>(root->filePath());
     headerNode->setPriority(Node::DefaultPriority - 5);
     headerNode->setDisplayName(
         QCoreApplication::translate("CMakeProjectManager::Internal::ProjectTreeHelper",
                                     "<Headers>"));
-    headerNode->setIcon(headerNodeIcon);
+    headerNode->setIcon(DirectoryIcon(ProjectExplorer::Constants::FILEOVERLAY_H));
 
     // Add scanned headers:
     for (const FileNode *fn : allFiles) {
@@ -212,15 +210,13 @@ void addFileSystemNodes(ProjectNode *root, const QList<const FileNode *> &allFil
 {
     QTC_ASSERT(root, return );
 
-    static QIcon fileSystemNodeIcon = Core::FileIconProvider::directoryIcon(
-        ProjectExplorer::Constants::FILEOVERLAY_UNKNOWN);
     auto fileSystemNode = std::make_unique<VirtualFolderNode>(root->filePath());
     // just before special nodes like "CMake Modules"
     fileSystemNode->setPriority(Node::DefaultPriority - 6);
     fileSystemNode->setDisplayName(
         QCoreApplication::translate("CMakeProjectManager::Internal::ProjectTreeHelper",
                                     "<File System>"));
-    fileSystemNode->setIcon(fileSystemNodeIcon);
+    fileSystemNode->setIcon(DirectoryIcon(ProjectExplorer::Constants::FILEOVERLAY_UNKNOWN));
 
     for (const FileNode *fn : allFiles) {
         if (!fn->filePath().isChildOf(root->filePath()))

src/plugins/mesonprojectmanager/project/projecttree/mesonprojectnodes.cpp

@@ -38,18 +38,15 @@ namespace Internal {
 MesonProjectNode::MesonProjectNode(const Utils::FilePath &directory)
     : ProjectExplorer::ProjectNode{directory}
 {
-    static const auto MesonIcon = QIcon(Constants::Icons::MESON);
     setPriority(Node::DefaultProjectPriority + 1000);
-    setIcon(MesonIcon);
+    setIcon(Constants::Icons::MESON);
     setListInProject(false);
 }
 
 MesonFileNode::MesonFileNode(const Utils::FilePath &file)
     : ProjectExplorer::ProjectNode{file}
 {
-    static const auto MesonFolderIcon = Core::FileIconProvider::directoryIcon(
-        Constants::Icons::MESON);
-    setIcon(MesonFolderIcon);
+    setIcon(ProjectExplorer::DirectoryIcon(Constants::Icons::MESON));
     setListInProject(true);
 }
 
@@ -58,7 +55,7 @@ MesonTargetNode::MesonTargetNode(const Utils::FilePath &directory, const QString
     , m_name{name}
 {
     setPriority(Node::DefaultProjectPriority + 900);
-    setIcon(QIcon(":/projectexplorer/images/build.png"));
+    setIcon(":/projectexplorer/images/build.png");
     setListInProject(false);
     setShowWhenEmpty(true);
     setProductType(ProjectExplorer::ProductType::Other);

src/plugins/projectexplorer/projectnodes.cpp

@@ -46,16 +46,19 @@
 #include <utils/qtcassert.h>
 #include <utils/stringutils.h>
 
-#include <QFileInfo>
 #include <QDir>
+#include <QFileInfo>
 #include <QIcon>
 #include <QStyle>
+#include <QThread>
 #include <QTimer>
 
 #include <memory>
 
 namespace ProjectExplorer {
 
+QHash<QString, QIcon> DirectoryIcon::m_cache;
+
 static FolderNode *recursiveFindOrCreateFolderNode(FolderNode *folder,
                                                    const Utils::FilePath &directory,
                                                    const Utils::FilePath &overrideBaseDir,
@@ -482,15 +485,27 @@ QString FolderNode::displayName() const
 
 /*!
     Contains the icon that should be used in a view. Default is the directory icon
- (QStyle::S_PDirIcon).
-  s\a setIcon()
+    (QStyle::S_PDirIcon). Calling this method is only safe in the UI thread.
+
+    \sa setIcon()
  */
 QIcon FolderNode::icon() const
 {
+    QTC_CHECK(QThread::currentThread() == QCoreApplication::instance()->thread());
+
     // Instantiating the Icon provider is expensive.
-    if (m_icon.isNull())
+    if (auto strPtr = Utils::get_if<QString>(&m_icon)) {
+        m_icon = QIcon(*strPtr);
+    } else if (auto directoryIconPtr = Utils::get_if<DirectoryIcon>(&m_icon)) {
+        m_icon = directoryIconPtr->icon();
+    } else if (auto creatorPtr = Utils::get_if<IconCreator>(&m_icon)) {
+        m_icon = (*creatorPtr)();
+    } else {
+        auto iconPtr = Utils::get_if<QIcon>(&m_icon);
+        if (!iconPtr || iconPtr->isNull())
             m_icon = Core::FileIconProvider::icon(QFileIconProvider::Folder);
-    return m_icon;
+    }
+    return Utils::get<QIcon>(m_icon);
 }
 
 Node *FolderNode::findNode(const std::function<bool(Node *)> &filter)
@@ -724,11 +739,38 @@ void FolderNode::setDisplayName(const QString &name)
     m_displayName = name;
 }
 
+/*!
+    Sets the \a icon for this node. Note that creating QIcon instances is only safe in the UI thread.
+*/
 void FolderNode::setIcon(const QIcon &icon)
 {
     m_icon = icon;
 }
 
+/*!
+    Sets the \a directoryIcon that is used to create the icon for this node on demand.
+*/
+void FolderNode::setIcon(const DirectoryIcon &directoryIcon)
+{
+    m_icon = directoryIcon;
+}
+
+/*!
+    Sets the \a path that is used to create the icon for this node on demand.
+*/
+void FolderNode::setIcon(const QString &path)
+{
+    m_icon = path;
+}
+
+/*!
+    Sets the \a iconCreator function that is used to create the icon for this node on demand.
+*/
+void FolderNode::setIcon(const IconCreator &iconCreator)
+{
+    m_icon = iconCreator;
+}
+
 void FolderNode::setLocationInfo(const QVector<FolderNode::LocationInfo> &info)
 {
     m_locations = info;
@@ -1048,4 +1090,34 @@ void ContainerNode::handleSubTreeChanged(FolderNode *node)
     m_project->handleSubTreeChanged(node);
 }
 
+/*!
+    \class ProjectExplorer::DirectoryIcon
+
+    The DirectoryIcon class represents a directory icon with an overlay.
+
+    The QIcon is created on demand and globally cached, so other DirectoryIcon
+    instances with the same overlay share the same QIcon instance.
+*/
+
+/*!
+    Creates a DirectoryIcon for the specified \a overlay.
+*/
+DirectoryIcon::DirectoryIcon(const QString &overlay)
+    : m_overlay(overlay)
+{}
+
+/*!
+    Returns the icon for this DirectoryIcon. Calling this method is only safe in the UI thread.
+*/
+QIcon DirectoryIcon::icon() const
+{
+    QTC_CHECK(QThread::currentThread() == QCoreApplication::instance()->thread());
+    const auto it = m_cache.find(m_overlay);
+    if (it != m_cache.end())
+        return it.value();
+    const QIcon icon = Core::FileIconProvider::directoryIcon(m_overlay);
+    m_cache.insert(m_overlay, icon);
+    return icon;
+}
+
 } // namespace ProjectExplorer

src/plugins/projectexplorer/projectnodes.h

@@ -34,6 +34,7 @@
 #include <utils/fileutils.h>
 #include <utils/id.h>
 #include <utils/optional.h>
+#include <utils/variant.h>
 
 #include <functional>
 
@@ -93,6 +94,20 @@ class FolderNode;
 class ProjectNode;
 class ContainerNode;
 
+class PROJECTEXPLORER_EXPORT DirectoryIcon
+{
+public:
+    explicit DirectoryIcon(const QString &overlay);
+
+    QIcon icon() const; // only safe in UI thread
+
+private:
+    QString m_overlay;
+    static QHash<QString, QIcon> m_cache;
+};
+
+using IconCreator = std::function<QIcon()>;
+
 // Documentation inside.
 class PROJECTEXPLORER_EXPORT Node
 {
@@ -218,6 +233,7 @@ public:
     explicit FolderNode(const Utils::FilePath &folderPath);
 
     QString displayName() const override;
+    // only safe from UI thread
     QIcon icon() const;
 
     bool isFolderNodeType() const override { return true; }
@@ -253,7 +269,11 @@ public:
     bool replaceSubtree(Node *oldNode, std::unique_ptr<Node> &&newNode);
 
     void setDisplayName(const QString &name);
+    // you have to make sure the QIcon is created in the UI thread if you are calling setIcon(QIcon)
     void setIcon(const QIcon &icon);
+    void setIcon(const DirectoryIcon &directoryIcon);
+    void setIcon(const QString &path);
+    void setIcon(const IconCreator &iconCreator);
 
     class LocationInfo
     {
@@ -328,7 +348,7 @@ private:
 
     QString m_displayName;
     QString m_addFileFilter;
-    mutable QIcon m_icon;
+    mutable Utils::variant<QIcon, DirectoryIcon, QString, IconCreator> m_icon;
     bool m_showWhenEmpty = false;
 };
 

src/plugins/qbsprojectmanager/qbsnodes.cpp

@@ -73,8 +73,7 @@ const QbsProductNode *parentQbsProductNode(const ProjectExplorer::Node *node)
 
 QbsGroupNode::QbsGroupNode(const QJsonObject &grp) : ProjectNode(FilePath()), m_groupData(grp)
 {
-    static QIcon groupIcon = QIcon(QString(ProjectExplorer::Constants::FILEOVERLAY_GROUP));
-    setIcon(groupIcon);
+    setIcon(ProjectExplorer::Constants::FILEOVERLAY_GROUP);
     setDisplayName(grp.value("name").toString());
     setEnabled(grp.value("is-enabled").toBool());
 }
@@ -108,9 +107,7 @@ QVariant QbsGroupNode::data(Id role) const
 
 QbsProductNode::QbsProductNode(const QJsonObject &prd) : ProjectNode(FilePath()), m_productData(prd)
 {
-    static QIcon productIcon = Core::FileIconProvider::directoryIcon(
-                ProjectExplorer::Constants::FILEOVERLAY_PRODUCT);
-    setIcon(productIcon);
+    setIcon(DirectoryIcon(ProjectExplorer::Constants::FILEOVERLAY_PRODUCT));
     if (prd.value("is-runnable").toBool()) {
         setProductType(ProductType::App);
     } else {
@@ -265,9 +262,7 @@ QJsonObject QbsProductNode::mainGroup() const
 QbsProjectNode::QbsProjectNode(const QJsonObject &projectData)
     : ProjectNode(FilePath()), m_projectData(projectData)
 {
-    static QIcon projectIcon = Core::FileIconProvider::directoryIcon(
-                ProjectExplorer::Constants::FILEOVERLAY_QT);
-    setIcon(projectIcon);
+    setIcon(DirectoryIcon(ProjectExplorer::Constants::FILEOVERLAY_QT));
     setDisplayName(projectData.value("name").toString());
 }
 

src/plugins/qmlprojectmanager/qmlprojectnodes.cpp

@@ -40,8 +40,7 @@ QmlProjectNode::QmlProjectNode(Project *project)
 {
     setDisplayName(project->projectFilePath().toFileInfo().completeBaseName());
 
-    static QIcon qmlProjectIcon = Core::FileIconProvider::directoryIcon(":/projectexplorer/images/fileoverlay_qml.png");
-    setIcon(qmlProjectIcon);
+    setIcon(DirectoryIcon(":/projectexplorer/images/fileoverlay_qml.png"));
 }
 
 } // namespace Internal

src/plugins/resourceeditor/resourcenode.cpp

@@ -243,7 +243,7 @@ ResourceTopLevelNode::ResourceTopLevelNode(const FilePath &filePath,
                                            const QString &contents)
     : FolderNode(filePath)
 {
-    setIcon(FileIconProvider::icon(filePath.toFileInfo()));
+    setIcon([filePath] { return FileIconProvider::icon(filePath.toFileInfo()); });
     setPriority(Node::DefaultFilePriority);
     setListInProject(true);
     setAddFileFilter("*.png; *.jpg; *.gif; *.svg; *.ico; *.qml; *.qml.ui");