Thread for generating thumbnail images;

Used for card list;
Implemented reordering from card list

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@115 0fc631ac-6414-0410-93d0-97cfa31319b6

src/gui/thumbnail_thread.hpp

@@ -0,0 +1,81 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+#ifndef HEADER_GUI_THUMBNAIL_THREAD
+#define HEADER_GUI_THUMBNAIL_THREAD
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <util/prec.hpp>
+#include <wx/datetime.h>
+#include <wx/filename.h>
+#include <queue>
+
+DECLARE_POINTER_TYPE(ThumbnailRequest);
+
+// ----------------------------------------------------------------------------- : ThumbnailRequest
+
+/// A request for some kind of thumbnail
+class ThumbnailRequest {
+  public:
+	ThumbnailRequest(void* owner, const String& cache_name, const wxDateTime& modified)
+		: owner(owner), cache_name(cache_name), modified(modified) {}
+	
+	/// Generate the thumbnail, called in another thread
+	virtual Image generate() = 0;
+	/// Store the thumbnail, called from the main thread
+	virtual void store(const Image&) = 0;
+	
+	/// Object that requested the thumbnail
+	void* const owner;
+	/// Name under which this object will be stored in the image cache
+	String cache_name;
+	/// Modification time for the object of which the thumnail is generated
+	wxDateTime modified;
+};
+
+// ----------------------------------------------------------------------------- : ThumbnailThread
+
+/// A (generic) class that generates thumbnails in another thread
+/** All requests have an 'owner', the object that requested the thumbnail.
+ *  This object should regularly call "done(this)".
+ *  Multiple requests can be open at the same time.
+ *  Thumbnails are cached, and need not be generated in a thread
+ */
+class ThumbnailThread {
+  public:
+	ThumbnailThread();
+	~ThumbnailThread();
+	
+	/// Request a thumbnail, it may be store()d immediatly if the thumbnail is cached
+	void request(const ThumbnailRequestP& request);
+	/// Is one or more thumbnail for the given owner finished?
+	/** If so, call their store() functions */
+	bool done(void* owner);
+	/// Abort all thumbnail requests for the given owner
+	void abort(void* owner);
+	/// Abort all computations
+	void abortAll();
+	
+  private:
+	wxMutex     mutex;  ///< Mutex used by the worker when accessing the request lists or the thread pointer
+	wxCondition completed; ///< Event signaled when a request is completed
+	
+	deque<ThumbnailRequestP>                open_requests;		///< Requests on which work hasn't finished
+	vector<pair<ThumbnailRequestP,Image> >  closed_requests;	///< Requests for which work is completed
+	set<ThumbnailRequestP>                  request_names;      ///< Requests that haven't been stored yet, to prevent duplicates
+	friend class ThumbnailThreadWorker;
+	ThumbnailThreadWorker* worker;								///< The worker thread. invariant: no requests ==> worker==nullptr
+	
+	/// A name that is safe to use as a filename, for the cache
+	static String safeFilename(const String& str);
+};
+
+/// The global thumbnail generator thread
+extern ThumbnailThread thumbnail_thread;
+
+// ----------------------------------------------------------------------------- : EOF
+#endif