start async_render branch. RItemImage is not switched from surface cache to uuid cache
change api, not finished
RenderCache everywhere!
use callback for cnstrctRItem
asynchronous rendering event mockup using system event
move nextevent and sysevent function to Hoodle.Coroutine.Draw
working prototype of asynchronous update: tested with embedded image.
Simple part of RBackground is now being implemented with render cache. RenderEvent subevent class
refactor callRender out
move getFileContent to Hoodle.Coroutine.File. accordingly change initialization (Initialized (Maybe FilePath))
move constructNewHoodleStateFromHoodle to Coroutine.File, and callRenderer there,
make sure handler is using postGUIAsync
doing asynchronous background update whenever new page / zoom update happens
add callRenderer_ , rename to updateBkgCache, newPageFromOld
for simple background, rendering is much enhanced by reflecting zoom ratio!
pdf background rendering now has asynchronous buffer updating (not fully asynchronized though)
Renderer monad (= ReaderT handler IO). so now implicitly carrying handler.
sample TVar in Renderer monady
change TVar Int to TVar (Seq (UUID,Cairo.Surface))
semi-working pdf renderer coroutine
replace direct poppler call by indirect poppler coroutine call