Vcs: Re-implement Fossil's topic indicator using a TopicCache sub-class

The functionality for tracking project's current topic/branch has
long been folded into a base class Core::IVersionControl::TopicCache.
Fossil plugin should just sub-class it and pass the instance to the base.

Change-Id: I1b6c1631f5fc10987d8a608d573defeecbc31b37
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

plugins/fossil/fossilclient.cpp

@@ -568,36 +568,17 @@ QString FossilClient::synchronousGetRepositoryURL(const QString &workingDirector
     return output;
 }
 
-struct TopicData
-{
-    QDateTime timeStamp;
-    QString topic;
-};
-
 QString FossilClient::synchronousTopic(const QString &workingDirectory)
 {
-    static QMap<QString, TopicData> topicCache;
-
     if (workingDirectory.isEmpty())
         return QString();
 
     // return current branch name
-
-    const QString topLevel = findTopLevelForFile(workingDirectory);
-    const QFileInfo currentStateFile(topLevel + "/" + Constants::FOSSILREPO);
-
-    TopicData &data = topicCache[workingDirectory];
-    const QDateTime lastModified = currentStateFile.lastModified();
-    if (lastModified == data.timeStamp)
-        return data.topic;
-
     const BranchInfo branchInfo = synchronousCurrentBranch(workingDirectory);
     if (branchInfo.name().isEmpty())
         return QString();
 
-    data.timeStamp = lastModified;
-    data.topic = branchInfo.name();
-    return data.topic;
+    return branchInfo.name();
 }
 
 bool FossilClient::synchronousCreateRepository(const QString &workingDirectory, const QStringList &extraOptions)

plugins/fossil/fossilcontrol.cpp

@@ -41,9 +41,33 @@
 #include <QDir>
 #include <QUrl>
 
-using namespace Fossil::Internal;
+namespace Fossil {
+namespace Internal {
+
+class FossilTopicCache : public Core::IVersionControl::TopicCache
+{
+public:
+    FossilTopicCache(FossilClient *client) :
+        m_client(client)
+    { }
+
+protected:
+    QString trackFile(const QString &repository) final
+    {
+        return repository + "/" + Constants::FOSSILREPO;
+    }
+
+    QString refreshTopic(const QString &repository) final
+    {
+        return m_client->synchronousTopic(repository);
+    }
+
+private:
+    FossilClient *m_client;
+};
 
 FossilControl::FossilControl(FossilClient *client) :
+    Core::IVersionControl(new FossilTopicCache(client)),
     m_client(client)
 { }
 
@@ -156,11 +180,6 @@ bool FossilControl::vcsAnnotate(const QString &file, int line)
     return true;
 }
 
-QString FossilControl::vcsTopic(const QString &directory)
-{
-    return m_client->synchronousTopic(directory);
-}
-
 Core::ShellCommand *FossilControl::createInitialCheckoutCommand(const QString &sourceUrl,
                                                                 const Utils::FileName &baseDirectory,
                                                                 const QString &localName,
@@ -287,3 +306,6 @@ void FossilControl::changed(const QVariant &v)
         break;
     }
 }
+
+} // namespace Internal
+} // namespace Fossil

plugins/fossil/fossilcontrol.h

@@ -59,7 +59,6 @@ public:
     bool vcsMove(const QString &from, const QString &to) final;
     bool vcsCreateRepository(const QString &directory) final;
     bool vcsAnnotate(const QString &file, int line) final;
-    QString vcsTopic(const QString &directory) final;
     Core::ShellCommand *createInitialCheckoutCommand(const QString &sourceUrl,
                                                      const Utils::FileName &baseDirectory,
                                                      const QString &localName,