small explanation of how backendish things work, maybe DESIGN is a too BIG name for the small text inside

svn path=/trunk/KDE/kdegraphics/okular/; revision=671160

generators/ghostview/DESIGN

@@ -0,0 +1,16 @@
+Quick Ghostview Generator design explanation
+--------------------------------------------
+
+libgs has a limitation that there can only be a gs instance per process.
+
+To overcome that problem there is zero (when no gs document has been opened)
+or one GSInterpreterCMD threads running (when on or more gs documents are open
+in the same okular process)
+
+GSHandler is the libgs dependant code, it could be in GSInterpreterCMD as there
+is the same amount of GSHandler and GSInterpreterCMD instances but i thought it 
+made sense to separate them
+
+As there is only one GSInterpreterCMD for potentially N GSGenerator, the imageDone
+signal from GSInterpreterCMD also emits the request and the GSGenerator checks
+if it is its request that was done or from another GSGenerator.