1.4

1 files changed, 64 insertions, 0 deletions

diff --git a/library/multithreading.h b/library/multithreading.h
new file mode 100644
index 00000000..8466bb01
--- /dev/null
+++ b/library/multithreading.h
@@ -0,0 +1,64 @@
+#ifndef MULTITHREADING_H_INCLUDED
+#define MULTITHREADING_H_INCLUDED
+
+#include <wx/string.h>
+#include <wx/thread.h>
+
+//interface for status updates (can be implemented by UI or commandline)
+//overwrite virtual methods for respective functionality
+class StatusUpdater
+{
+public:
+    StatusUpdater() : abortionRequested(false) {}
+    virtual ~StatusUpdater() {}
+
+    //these four methods have to be implemented in the derived classes to handle error and status information
+    virtual void updateStatusText(const wxString& text) = 0;
+    virtual void initNewProcess(int objectsTotal, double dataTotal, int processID) = 0; //informs about the total amount of data that will be processed from now on
+    virtual void updateProcessedData(int objectsProcessed, double dataProcessed) = 0; //called periodically after data was processed
+    virtual int  reportError(const wxString& text) = 0;
+
+    //this method is triggered repeatedly and can be used to refresh the ui by dispatching pending events
+    virtual void triggerUI_Refresh() {}
+
+    void requestAbortion() //opportunity to abort must be implemented in the three virtual status and error methods (for example in triggerUI_Refresh())
+    {                      //currently used by the UI status information screen, when button "Abort is pressed"
+        abortionRequested = true;
+    }
+    static const int continueNext = -1;
+    static const int retry        = -2;
+
+protected:
+    bool abortionRequested;
+};
+
+
+const int uiUpdateInterval = 100; //perform ui updates not more often than necessary, 100 seems to be a good value with only a minimal performance loss
+
+class WorkerThread;
+
+
+//class handling execution of a method while updating the UI
+class UpdateWhileExecuting
+{
+    friend class WorkerThread;
+
+public:
+    UpdateWhileExecuting();
+    virtual ~UpdateWhileExecuting();
+
+    void waitUntilReady();
+    void execAndUpdate(StatusUpdater* statusUpdater);
+
+
+private:
+    //implement a longrunning method without dependencies (e.g. copy file function) returning "true" on success
+    virtual void longRunner() = 0;
+
+    WorkerThread* theWorkerThread;
+
+    wxMutex     readyToReceiveResult;
+    wxCondition receivingResult;
+};
+
+#endif // MULTITHREADING_H_INCLUDED