Interface to be able to subscribe at AlbumPlayer notifications

AlbumPlayer Handle:
===================

The application which wants to receive messages from AP has to use "FindWindow" API and search for AP class named "TfrmPlayer" to get the AP Handle. 



Now Playing Info:
==========================
 
The AP writes track info in a file called "ap_info.txt" in a directory everytime new tracks starts to play. The communication directory is:

....\Documents and Settings\...user....\Application Data\AlbumPlayer 

You can get the "Application Data" directory using windows shell function. See:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/reference/functions/shgetspecialfolderlocation.asp

Then use CSIDL_APPDATA .



The ap_info.txt contains the following:


Artist=<album artist>
Album=<album title>
Genre=<genre>
Rating=<rating>
Year=<release date>
CoverFile=<full path to cover image>
Track=<track title>
TrackArtist=<track artist>
TrackNr=<track number>
TrackFile=<full path to track>
TrackRating=<track rating>



Provide New Cover:
==================

The AP can read new cover for an album. The communication directory is the same one as for AP track info. The add-on has to write the cover in a file called ap_cover.jpg. Information about the cover has to be written in ap_cover.txt . The text file should contain:

Artist=<album artist>
Album=<album title>

Notification that a new cover is available is reported using a message (see below).


Message Interface:
==================
 

Here the interface messages which you should send to the AlbumPlayer :
 

WM_REMOTE_CONTROL = WM_USER + 10;            // remote control the AlbumPlayer
WM_SUBSCRIBE_FOR_INFO = WM_USER + 11;        // subscribe to AlbumPlayer notifications
WM_NEW_COVER_AVAILABLE = WM_USER + 12;       // notify a new cover is available
WM_NEW_RATING = WM_USER + 13;                // notify new rating
WM_ADJUST_VOLUME = WM_USER + 14;             // adjust volume
 

Add-on should provide the following parameters in WM_REMOTE_CONTROL message: 

WParam=1   ->  Play/Pause (Toggle)
WParam=2   ->  Stop
WParam=3   ->  Next Track
WParam=4   ->  Prev Track
WParam=5   ->  Play
WParam=6   ->  Pause
WParam=7   ->  Increase Play Speed Factor
WParam=8   ->  Decrease Play Speed Factor


Add-on should provide the following parameters in WM_SUBSCRIBE_FOR_INFO message:

WParam   ->   Handle of Application to be notified
LParam   ->   Message number to use as notification


No additional parameters required in WM_NEW_COVER_AVAILABLE message.

Add-on should provide the following parameters in WM_NEW_RATING message: 

WParam   ->   Track Rating 0 to 10
-- lparam = 0 -> track rating
-- lparam = 1 -> album rating


Add-on should provide the following parameters in WM_ADJUST_VOLUME message: 

lParam   ->   toggle mute (0=no effect,  1=toggle mute (wparam is ignored))
WParam   ->   Volume percentage steps to adjust (so when wparam=-5, volume was 17%, volume gets 12%)


The AP can send the following notifications using different parameters:

wparam = 0 -> new track notification, ap_info.txt is written
wparam = 1 -> new play state
-- lparam = 0 -> stopped
-- lparam = 1 -> playing
-- lparam = 2 -> paused
wparam = 2 -> albumplayer will be closed
wparam = 3 -> new cover is accepted
wparam = 4 -> track update notification, ap_info.txt is written, same track
wparam = 5 -> new track progress
-- lparam = progress in seconds