From 48540940b6c28bb4378abfeb500ec45a625b37b6 Mon Sep 17 00:00:00 2001
From: Vadim Dashevskiy <watcherhd@gmail.com>
Date: Tue, 15 May 2012 10:38:20 +0000
Subject: initial commit

git-svn-id: http://svn.miranda-ng.org/main/trunk@2 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
---
 plugins/avs/README | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 plugins/avs/README

(limited to 'plugins/avs/README')

diff --git a/plugins/avs/README b/plugins/avs/README
new file mode 100644
index 0000000000..d82d1d7fec
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+++ b/plugins/avs/README
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+
+        Load avatars 0.0.1.0
+        --------------------
+        
+This is a SERVICE plugin, which means, it doesn't provide anything useful 
+on its own except for a few service(s) and event(s) which can be used by 
+other plugins.
+
+What it does?
+-------------
+
+It loads avatars on demand and maintains an internal cache of avatar 
+bitmap handles. It also handles avatar changes transparently and can 
+notify event subscribers about avatar changes.
+
+How it works?
+-------------
+
+The service MS_AV_GETAVATARBITMAP returns a pointer to a cache entry, if an 
+avatar is present for that contact. The service MAY return 0, in which 
+case, there is no valid avatar yet. However, that doesn't mean there 
+isn't ANY avatar, just that the avatar is not yet ready for use. When 
+someone calls the service requesting an avatar, the plugin will try 
+to get the avatar (if possible) and notify all subscribers via a 
+hookable event as soon as the avatar is ready. If the avatar is 
+already in the cache, it simply returns the cached entry.
+
+Whenever an avatar changes, the plugin fires an event, passing the 
+contacts handle in wParam and a data structure with the avatar information 
+in lParam. Plugins which use the bitmap handles returned by 
+MS_AV_GETAVATARBITMAP MUST subscribe to ME_AV_AVATARCHANGED, because the 
+original bitmap handle may become invalid when the avatar changes.
+
+Fetching avatars is done in a separate thread with reasonable delays to 
+avoid getting into troubles with flood protection(s). Avatars are cached
+"in memory".
+
+
+The included clist_nicer_plus.dll is a demonstration of how the avatar 
+service works and can be used by developers. Having a central instance 
+which maintains avatars saves resources and increases performance.
+
+
+// example, how to use it (FOR DEVS only)
+
+#include "m_avatars.h"
+
+struct avatarCacheEntry *ace = 0;
+HBITMAP hbmAvatar = 0;
+
+ace = (struct avatarCacheEntry *)CallService(MS_AV_GETAVATARBITMAP, (WPARAM)hContact, 0);
+
+/*
+   now, check the return value. if it is 0, then the avatar is not yet ready or unavailble
+   for that contact. if it was only "not ready", your plugin will be notified by the
+   hookable event ME_AV_AVATARCHANGED
+   
+   if the return value is != 0, then it is a valid bitmap handle. DON'T DESTROY IT IN YOUR CODE
+*/
+
+
+/*
+ * event function
+ * initialise with:
+ * HANDLE hEvent = HookEvent(ME_AV_AVATARCHANGED, AvatarChanged);
+ */
+ 
+static int AvatarChanged(WPARAM wParam, LPARAM lParam)
+{
+        struct avatarCacheEntry *ace = (struct avatarCacheEntry *)lParam;
+        HANDLE hContact = (HANDLE)wParam;
+        
+        if(ace == NULL)
+                return 0;
+        if(ace->cbSize != sizeof(struct avatarCacheEntry))
+                return 0;               // safety check(s)
+
+        HBITMAP hbmAvatar = ace->hbmPic;
+        ...
+        ...                
+}
+
+
+TODO: maybe more intelligent cache managment, including auto-expire of avatars which
+      have not been used for a while.
+      
+
+Copyright and license:
+----------------------
+
+This plugin is released under the terms of the GNU general public license V2 or any later
+version. 
+
+Written, 2005 by Nightwish, silvercircle@gmail.com
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