document that CanRead() and GetImageCount() functions of wxImageHandlers do NOT modify the current stream position and that they require seekable streams; rename current GetImageCount() functions to DoGetImageCount() and put save-and-restore stream position logic in GetImageCount(); add comments in the various DoCanRead() and in DoGetImageCount() where the stream position is modified; remove unneeded SeekI(0) calls from DoCanRead() and DoGetImageCount() functions: they didn't allow to load images from non-seekable streams; implement forward-seeking in wxInputStream::SeekI() also for non-seekable streams

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@60852 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Francesco Montorsi
2009-06-01 11:43:36 +00:00
parent 1f51673bb8
commit 8faef7ccbc
25 changed files with 236 additions and 93 deletions

View File

@@ -98,14 +98,18 @@ bool wxGIFHandler::DoCanRead( wxInputStream& stream )
{
wxGIFDecoder decod;
return decod.CanRead(stream);
// it's ok to modify the stream position here
}
int wxGIFHandler::GetImageCount( wxInputStream& stream )
int wxGIFHandler::DoGetImageCount( wxInputStream& stream )
{
wxGIFDecoder decod;
wxGIFErrorCode error = decod.LoadGIF(stream);
if ( (error != wxGIF_OK) && (error != wxGIF_TRUNCATED) )
return -1;
// NOTE: this function modifies the current stream position but it's ok
// (see wxImageHandler::GetImageCount)
return decod.GetFrameCount();
}