Just a followup to Dmitry's advice which is - as usual - accurate.
Caching is the most important key. You can organize your own cache or use the
system cache - the code is bellow.
---------------------------------------------
#define dmMaxVersionStrLength 16
typedef struct tagLaunchCacheRecord
{
UInt32 dbType ;
UInt32 dbCreator ;
UInt32 id ;
UInt16 cardNo ;
UInt16 attr ;
UInt16 version ;
char name[dmDBNameLength] ;
short largeIconOffset ;
short smallIconOffset ;
char applName[dmDBNameLength] ;
char versionStr[dmMaxVersionStrLength] ;
UInt8 flags;
}
LauncherCacheRecord ;
g_launchDB =
- usually "psysLaunchDB"
- "HomeLaunchDB" in case of Zodiac (g_bLauncherNative=TRUE)
MemHandle recH ;
LauncherCacheRecord* recHdr ;
// Search the launcher database
for( i=0; i<recCnt; i++ )
{
recH = DmQueryRecord(g_launchDB, i) ;
if( recH != NULL )
{
recHdr = (LauncherCacheRecord*)MemHandleLock(recH) ;
if( recHdr->dbCreator == expectedHdrCreatorID )
{
hdrIconOffset = bSmall ? recHdr->smallIconOffset :
recHdr->largeIconOffset ;
if( hdrIconOffset != NULL )
{
BitmapPtr bmp ;
if( g_bLauncherNative )
swap16(&hdrIconOffset) ;
bmp = (BitmapPtr)(((char*)recHdr) +
hdrIconOffset ) ;
if( (((UInt32)bmp)&3) == 0 )
{
// you have the bitmap
// Test on bmp!=NULL probably solves
(occasional) problem of empty icons after Hotsync.
}
}
MemHandleUnlock( recH ) ;
break ;
}
MemHandleUnlock( recH ) ;
}
}
---------------------------------------------
Run Resco Explorer (Applications tab) to see the performance of the icon
caching.
Take into account that Explorer does a lot more to speed up the cache. It
internally organizes access tables for LRU icons and for creatorID's with no
existing icon plus another cache for items not found in the system cache.
However, as long as you use only RAM apps icons, you won't need these fancy
things.
Regards,
Jan Slodicka, Resco
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