A file requester can filter out certain file and directory entries using the "wildcard" feature of AmigaDOS. To activate the wildcard feature for a file requester, you use the ASL_FuncFlags tag. Each bit in the ASL_FuncFlags tag item controls a special option of the requester depending on its type (file or font). See <libraries/asl.h> for a complete listing of the options that the ASL_FuncFlags tag controls. File Requester Flag Used For ------------------- -------- FILF_PATGAD Enables the file name pattern matching gadget FILF_MULTISELECT Enables multiple selection of files FILF_NEWIDCMP Use separate IDCMP for requester sharing a custom screen (see below) FILF_SAVE Makes the file requester a save requester (see below) If the FILF_PATGAD bit of the ASL_FuncFlags tag is set, the file requester will appear with a "Pattern" gadget in addition to the usual file name and directory name gadgets. The user can type an AmigaDOS wildcard pattern into this gadget and the pattern will be used to limit the file names that appear in the requester. An application can also supply a default pattern using the ASL_Pattern tag item. A hidden unchangeable pattern can be created by supplying an ASL_Pattern without a FILF_PATGAD gadget. Such invisible patterns should not be used if there is any reason that the user may need to access a file which does not match the pattern. Another feature of the ASL file requester is multiple selection. When multiple selection is enabled, the user can choose more than one file name in a single directory by selecting names in the requester's scrolling list gadget with the mouse. This option, like pattern matching, is set up with the ASL_FuncFlags tag. If the FILF_MULTISELECT bit of the ASL_FuncFlags tag is set, the file requester will allow multiple selection. When the user selects several file names through the multiple selection feature, the FileRequester's rf_NumArgs field contains the number of files selected and the rf_ArgList field contains a pointer to an array of WBArg structures (defined in <workbench/startup.h>). There is a WBArg structure containing a file name for each file the user selected. The following example illustrates a file requester with both a pattern matching gadget and multiple selection enabled. filepat.c The previous example demonstrates two alternate functions for creating and using ASL requesters: APTR AllocAslRequestTags( unsigned long type, Tag Tag1, ... ); BOOL AslRequestTags( APTR request, Tag Tag1, ... ); AllocAslRequestTags() can be used instead of AllocAslRequest() to allocate and set up the file requester. This is an amiga.lib function that will accept TagItems directly in its parameter list, rather than a pointer to an array of TagItems. Similarly, AslRequestTags() will accept TagItems directly instead of requiring a pointer to an array of TagItems as AslRequest() does.
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