ASL File Requester - Revision history

Costel Mincea: Text replacement - "" to ""

2025-01-26T19:08:56Z

Text replacement - "<syntaxhighlight>" to "<syntaxhighlight lang="C" line>"

← Older revision		Revision as of 19:08, 26 January 2025
Line 1:		Line 1:
	The ASL library contains a file requester. First, allocate a requester structure with AllocAslRequest() or AllocAslRequestTags(). The type should be set to ASL_FileRequest in order to get a FileRequester structure:		The ASL library contains a file requester. First, allocate a requester structure with AllocAslRequest() or AllocAslRequestTags(). The type should be set to ASL_FileRequest in order to get a FileRequester structure:

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	struct FileRequester { /* (from <libraries/asl.h>) */		struct FileRequester { /* (from <libraries/asl.h>) */
	APTR rf_Reserved1;		APTR rf_Reserved1;
Line 79:		Line 79:
	Here's a short example showing how to create a file requester with asl.library. If AslRequest() returns TRUE then the rf_File and rf_Dir fields of the requester data structure contain the name and directory of the file the user selected. Note that the user can type in the a name for the file and directory, which makes it possible for a file requester to return a file and directory that do not (currently) exist.		Here's a short example showing how to create a file requester with asl.library. If AslRequest() returns TRUE then the rf_File and rf_Dir fields of the requester data structure contain the name and directory of the file the user selected. Note that the user can type in the a name for the file and directory, which makes it possible for a file requester to return a file and directory that do not (currently) exist.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	// filereq.c		// filereq.c
	#include <exec/types.h>		#include <exec/types.h>
Line 161:		Line 161:
	The following example illustrates a file requester with both a pattern matching gadget and multiple selection enabled.		The following example illustrates a file requester with both a pattern matching gadget and multiple selection enabled.

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	/*		/*
	** filepat.c		** filepat.c

Steven Solie at 14:56, 25 April 2014

2014-04-25T14:56:38Z

← Older revision		Revision as of 14:56, 25 April 2014
Line 1:		Line 1:
	== Creating a File Requester ==

	The ASL library contains a file requester. First, allocate a requester structure with AllocAslRequest() or AllocAslRequestTags(). The type should be set to ASL_FileRequest in order to get a FileRequester structure:		The ASL library contains a file requester. First, allocate a requester structure with AllocAslRequest() or AllocAslRequestTags(). The type should be set to ASL_FileRequest in order to get a FileRequester structure:

Line 30:		Line 28:
	When the requester is no longer needed, call FreeAslRequest() to deallocate the requester data structure.		When the requester is no longer needed, call FreeAslRequest() to deallocate the requester data structure.

	=== Specifying Requester Options With TagItems ===		= Specifying Requester Options With TagItems =

	The file requester is specified with a TagItem list. There are several tags that are specific to the file requester:		The file requester is specified with a TagItem list. There are several tags that are specific to the file requester:
Line 77:		Line 75:
	\|}		\|}

	=== Simple ASL File Requester Example ===		= Simple ASL File Requester Example =

	Here's a short example showing how to create a file requester with asl.library. If AslRequest() returns TRUE then the rf_File and rf_Dir fields of the requester data structure contain the name and directory of the file the user selected. Note that the user can type in the a name for the file and directory, which makes it possible for a file requester to return a file and directory that do not (currently) exist.		Here's a short example showing how to create a file requester with asl.library. If AslRequest() returns TRUE then the rf_File and rf_Dir fields of the requester data structure contain the name and directory of the file the user selected. Note that the user can type in the a name for the file and directory, which makes it possible for a file requester to return a file and directory that do not (currently) exist.
Line 138:		Line 136:
	</syntaxhighlight>		</syntaxhighlight>

	=== File Pattern Matching and Multiple Selects ===		= File Pattern Matching and Multiple Selects =

	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.		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.
Line 276:		Line 274:
	</syntaxhighlight>		</syntaxhighlight>

	=== The Save Requester ===		= The Save Requester =

	The save requester is a special type of file requester used for save operations. It differs from the regular ASL file requester in several ways.		The save requester is a special type of file requester used for save operations. It differs from the regular ASL file requester in several ways.
Line 286:		Line 284:
	To create a save requester, set the ASLFR_DoSaveMode tag to TRUE. Note that it does not make sense to have multiselection in a save requester, so the ASLFR_DoSaveMode tag overrides the ASLFR_DoMultiSelect tag.		To create a save requester, set the ASLFR_DoSaveMode tag to TRUE. Note that it does not make sense to have multiselection in a save requester, so the ASLFR_DoSaveMode tag overrides the ASLFR_DoMultiSelect tag.

	=== The Directory Requester ===		= The Directory Requester =

	Sometimes a program may only require a directory name from the user. There is another variation on asl.library's file requester that allows this. If the ASLFR_DrawersOnly tag is set to TRUE, the requester will appear without a string gadget for file names and will display only directory names in the scrolling list gadget. When AslRequest() (or AslRequestTags() ) returns successfully, the rf_Dir field of the FileRequester structure contains the name of the directory the user selected.		Sometimes a program may only require a directory name from the user. There is another variation on asl.library's file requester that allows this. If the ASLFR_DrawersOnly tag is set to TRUE, the requester will appear without a string gadget for file names and will display only directory names in the scrolling list gadget. When AslRequest() (or AslRequestTags() ) returns successfully, the rf_Dir field of the FileRequester structure contains the name of the directory the user selected.

Steven Solie: /* File Pattern Matching and Multiple Selects */

2014-04-25T14:52:20Z

File Pattern Matching and Multiple Selects

@@ Line 275: / Line 275: @@
+}
 </syntaxhighlight>
 === The Save Requester ===

Steven Solie: /* ASL Requesters and Custom Screens */

2014-04-25T14:51:03Z

ASL Requesters and Custom Screens

← Older revision		Revision as of 14:51, 25 April 2014
Line 286:		Line 286:

	Similarly, AslRequestTags() will accept TagItems directly instead of requiring a pointer to an array of TagItems as AslRequest() does.		Similarly, AslRequestTags() will accept TagItems directly instead of requiring a pointer to an array of TagItems as AslRequest() does.

	=== ASL Requesters and Custom Screens ===

	An application that uses a custom screen normally wants its requesters to open on its screen. Using the ASL_Window tag, a program can associate a requester with a specific window so that the requester appears on the same screen as the window. The ASL_Window tag is followed by a pointer to a window structure. ASL_Window works with both file and font requesters. The example above shows how the ASL_Window tag is used with a file requester.

	Normally, a requester associated with a window (using ASL_Window) shares that window's IDCMP port for its communication. An application may not want to share an IDCMP port with the requester. Using the ASL_FuncFlags tag, a program can ask for a requester that creates its own IDCMP port. There are two flags that accomplish this. The first, FILF_NEWIDCMP, is used on file requesters. The other, FONF_NEWIDCMP, is used on font requesters.

	=== The Save Requester ===		=== The Save Requester ===

Steven Solie: /* Specifying Requester Options With TagItems */

2014-04-25T14:48:56Z

Specifying Requester Options With TagItems

← Older revision		Revision as of 14:48, 25 April 2014
Line 32:		Line 32:
	=== Specifying Requester Options With TagItems ===		=== Specifying Requester Options With TagItems ===

	The file requester is specified with a TagItem list. There are several tags that are specific to the ~~font~~ requester:		The file requester is specified with a TagItem list. There are several tags that are specific to the file requester:

	{\| class="wikitable"		{\| class="wikitable"
Line 76:		Line 76:
	\| ASLFR_FilterDrawers \|\| Makes ASLFR_RejectPattern and ASLFR_AcceptPattern apply to drawer names.		\| ASLFR_FilterDrawers \|\| Makes ASLFR_RejectPattern and ASLFR_AcceptPattern apply to drawer names.
	\|}		\|}

	Note that you are currently limited to about six characters for the replacement text if you use either the ASL_OKText or ASL_CancelText tags to change the text that appears in the OK and Cancel gadgets.

	The contents of an ASL requester data structure are preserved across calls to AslRequest(). So, until the requester is freed, tag settings and user selections will remain in the data structure unless they are altered by tags in subsequent calls to AslRequest(). This is very useful because it allows the requester to remember and redisplay the user's previous selections. However, this also means that the programmer must assure that any addresses passed in ASL tags remain valid, or are refreshed on each call to AslRequest().

	Generally, options that you wish to specify only once, such as the initial position and size, should be specified as tags when you allocate the requester. Options that you wish to control for each use of the requester should be passed as tags each time the requester is opened with AslRequest().

	=== Simple ASL File Requester Example ===		=== Simple ASL File Requester Example ===

Steven Solie: /* Specifying Requester Options With TagItems */

2014-04-25T14:45:12Z

Specifying Requester Options With TagItems

← Older revision		Revision as of 14:45, 25 April 2014
Line 32:		Line 32:
	=== Specifying Requester Options With TagItems ===		=== Specifying Requester Options With TagItems ===

	~~Both~~ ~~AllocAslRequest()~~ ~~and~~ ~~AslRequest()~~ ~~accept~~ a TagItem ~~array or tag~~ list as an ~~argument.~~ ~~The~~ ~~tag~~ ~~list~~ ~~is used~~ to ~~initialize or alter~~ the ~~values in the~~ requester ~~data structure.~~		The file requester is specified with a TagItem list. There are several tags that are specific to the font requester:

	A single TagItem consists of a tag name and an associated tag value. Tag items that apply to the asl.library are defined in <libraries/asl.h>. The basic tag items (used in the first example listed below) are:

	{\| class="wikitable"		{\| class="wikitable"
	! Requester Tag Name		! File Requester Tag Name
	! Used For		! Used For
	\|-		\|-

Steven Solie: /* Creating a File Requester */

2014-04-25T14:43:38Z

Creating a File Requester

@@ Line 1: / Line 1: @@
 == Creating a File Requester ==
 <syntaxhighlight>
@@ Line 34: / Line 24: @@
 </syntaxhighlight>
 [[File:LibFig16-1.png|frame|center|The ASL File Requester]]
 === Specifying Requester Options With TagItems ===

Steven Solie: Created page with "== Creating a File Requester == Opening an ASL requester requires the use of three functions:

 APTR request = AllocAslRequest( ULONG type, struct TagItem *tagList ); BO..."

2014-04-25T14:34:35Z

Created page with "== Creating a File Requester == Opening an ASL requester requires the use of three functions: <pre> APTR request = AllocAslRequest( ULONG type, struct TagItem *tagList ); BO..."

New page

== Creating a File Requester ==

Opening an ASL requester requires the use of three functions:

<pre>
APTR request = AllocAslRequest( ULONG type, struct TagItem *tagList );
BOOL success = AslRequest( APTR request, struct TagItem *tagList );
VOID FreeAslRequest( APTR request );
</pre>

The first function you should call is AllocAslRequest(). This allocates the main data structure you will use, either a FileRequester structure or a FontRequester structure. You specify the type of requester you want for AllocAslRequest() by setting the type argument. This can be one of two values defined in <libraries/asl.h>: either ASL_FileRequest, to ask for a FileRequester structure, or ASL_FontRequest, to ask for a FontRequester structure.

Here's a listing of the FileRequester structure.

<syntaxhighlight>
struct FileRequester { /* (from <libraries/asl.h>) */
APTR rf_Reserved1;
BYTE *rf_File; /* Filename pointer */
BYTE *rf_Dir; /* Directory name pointer */
CPTR rf_Reserved2;
UBYTE rf_Reserved3;
UBYTE rf_Reserved4;
APTR rf_Reserved5;
WORD rf_LeftEdge,rf_TopEdge; /* Preferred window pos */
WORD rf_Width,rf_Height; /* Preferred window size */
WORD rf_Reserved6;
LONG rf_NumArgs; /* A-la WB Args, for multiselects */
struct WBArg *rf_ArgList;
APTR rf_UserData; /* Applihandle (you may write!!) */
APTR rf_Reserved7;
APTR rf_Reserved8;
BYTE *rf_Pat; /* Pattern match pointer */
}; /* note - more reserved fields follow */
</syntaxhighlight>

Whichever requester type you use, you must allocate the requester structure with the AllocAslRequest() function call. Do not create the data structure yourself. The values in this structure are for ''read access only''. Any changes to them must be performed only through asl.library function calls.

Once you have set up a requester structure with AllocAslRequest(), call AslRequest() to make the requester appear on screen. AslRequest() takes the requester data structure as an argument using it as a specification for the requester that it creates on screen.

[[File:LibFig16-1.png|frame|center|The ASL File Requester]]

AslRequest() is always synchronous to the calling program. That is, control does not return to your program until the user makes a selection or cancels. AslRequest() returns TRUE, if the user selects a file (or a font). In that case the file (or font) name that the user selected is returned in the requester data structure. AslRequest() returns FALSE if the user cancels the requester or the requester failed for some reason.

When you have finished with a requester use the FreeAslRequest() function to deallocate the requester data structure.

=== Specifying Requester Options With TagItems ===

Both AllocAslRequest() and AslRequest() accept a TagItem array or tag list as an argument. The tag list is used to initialize or alter the values in the requester data structure.

A single TagItem consists of a tag name and an associated tag value. Tag items that apply to the asl.library are defined in <libraries/asl.h>. The basic tag items (used in the first example listed below) are:

{| class="wikitable"
! Requester Tag Name
! Used For
|-
| ASLFR_Window || Specifies the parent window of the requester
|-
| ASLFR_TitleText || String to place in the title bar of the requester window
|-
| ASLFR_InitialWidth || Requester window width
|-
| ASLFR_InitialHeight || Requester window height
|-
| ASLFR_InitialLeftEdge || Requester window y origin
|-
| ASLFR_InitialTopEdge || Requester window x origin
|-
| ASLFR_PositiveText || String to place in OK gadget of requester
|-
| ASLFR_NegativeText || String to place in Cancel gadget of requester
|-
| ASLFR_InitialFile || Default file name (for file requesters only)
|-
| ASLFR_InitialDrawer || Default directory name (for file requesters only)
|-
| ASLFR_InitialPattern || Initial pattern-matching string
|-
| ASLFR_DoSaveMode || Specifies that this file requester is a save requester (this replaces the FILF_SAVE flag in the ASL_FuncFlags tag used in V37).
|-
| ASLFR_DoMultiSelect || Enables multiple selection of files (this replaces the FILF_MULTISELECT flag in ASL_FuncFlags used in V37).
|-
| ASLFR_DoPatterns || Causes a pattern gadget to be included in the requester (this replaces the FILF_PATGAD flag in ASL_FuncFlags used in V37).
|-
| ASLFR_DrawersOnly || Causes the requester to only display drawers (this replaces the FIL1F_NOFILES flag in ASL_ExtFlags1 used in V37).
|-
| ASLFR_RejectIcons || Causes the requester not to display Workbench icons.
|-
| ASLFR_RejectPattern || Specifies an AmigaDOS pattern used to reject files.
|-
| ASLFR_AcceptPattern || Specifies an AmigaDOS pattern used to accept files.
|-
| ASLFR_FilterDrawers || Makes ASLFR_RejectPattern and ASLFR_AcceptPattern apply to drawer names.
|}

Note that you are currently limited to about six characters for the replacement text if you use either the ASL_OKText or ASL_CancelText tags to change the text that appears in the OK and Cancel gadgets.

The contents of an ASL requester data structure are preserved across calls to AslRequest(). So, until the requester is freed, tag settings and user selections will remain in the data structure unless they are altered by tags in subsequent calls to AslRequest(). This is very useful because it allows the requester to remember and redisplay the user's previous selections. However, this also means that the programmer must assure that any addresses passed in ASL tags remain valid, or are refreshed on each call to AslRequest().

Generally, options that you wish to specify only once, such as the initial position and size, should be specified as tags when you allocate the requester. Options that you wish to control for each use of the requester should be passed as tags each time the requester is opened with AslRequest().

=== Simple ASL File Requester Example ===

Here's a short example showing how to create a file requester with asl.library. If AslRequest() returns TRUE then the rf_File and rf_Dir fields of the requester data structure contain the name and directory of the file the user selected. Note that the user can type in the a name for the file and directory, which makes it possible for a file requester to return a file and directory that do not (currently) exist.

<syntaxhighlight>
// filereq.c
#include <exec/types.h>
#include <exec/libraries.h>
#include <libraries/asl.h>

#include <proto/dos.h>
#include <proto/exec.h>
#include <proto/asl.h>

#define MYLEFTEDGE 0
#define MYTOPEDGE 0
#define MYWIDTH 320
#define MYHEIGHT 400

struct AslIFace *IAsl = NULL;

struct TagItem frtags[] =
{
ASL_Hail, (uint32)"The Amiga file requester",
ASL_Height, MYHEIGHT,
ASL_Width, MYWIDTH,
ASL_LeftEdge, MYLEFTEDGE,
ASL_TopEdge, MYTOPEDGE,
ASL_OKText, (uint32)"O KAY",
ASL_CancelText, (uint32)"not OK",
ASL_File, (uint32)"asl.library",
ASL_Dir, (uint32)"libs:",
TAG_END
};

int main(int argc, char **argv)
{
struct Library *AslBase = IExec->OpenLibrary("asl.library", 50);
IAsl = (struct AslIFace*)IExec->GetInterface(AslBase, "main", 1, NULL);
if (IAsl != NULL)
{
struct FileRequester *fr = IAsl->AllocAslRequest(ASL_FileRequest, frtags);
if (fr != NULL)
{
if (IAsl->AslRequest(fr, NULL))
{
IDOS->Printf("PATH=%s FILE=%s\n", fr->rf_Dir, fr->rf_File);
IDOS->Printf("To combine the path and filename, copy the path\n");
IDOS->Printf("to a buffer, add the filename with Dos AddPart().\n");
}
IAsl->FreeAslRequest(fr);
}
else IDOS->Printf("User Cancelled\n");
}

DropInterface((struct Interface*)IAsl);
CloseLibrary(AslBase);
return 0;
}
</syntaxhighlight>

=== File Pattern Matching and Multiple Selects ===

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.

{| class="wikitable"
! 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.

<syntaxhighlight>
/*
** filepat.c
*/
#include <exec/types.h>
#include <intuition/intuition.h>
#include <intuition/screens.h>
#include <graphics/displayinfo.h>
#include <libraries/asl.h>
#include <workbench/startup.h>

#include <proto/asl.h>
#include <proto/exec.h>
#include <proto/intuition.h>
#include <proto/dos.h>

struct AslIFace *IAsl = NULL;
struct IntuitionIFace *IIntuition = NULL;

struct Screen *screen = NULL;
struct Window *window = NULL;

int main(int argc, char **argv)
{
struct FileRequester *fr;
struct WBArg *frargs;
int x;

struct Library *AslBase = IExec->OpenLibrary("asl.library", 50);
IAsl = (struct AslIFace*)IExec->GetInterface(AslBase, "main", 1, NULL);

struct Library *IntuitionBase = IExec->OpenLibrary("intuition.library", 50);
IIntuition = (struct IntuitionIFace*)IExec->GetInterface(IntuitionBase, "main", 1, NULL);

if (IAsl != NULL && IIntuition != NULL)
{
if (screen = IIntuition->OpenScreenTags(NULL,
SA_DisplayID, HIRESLACE_KEY,
SA_Title, "ASL Test Screen",
TAG_END))
{
if (window = IIntuition->OpenWindowTags(NULL,
WA_CustomScreen, screen,
WA_Title, "Demo Customscreen, File Pattern, Multi-select",
WA_Flags, WINDOWDEPTH | WINDOWDRAG,
TAG_END))
{
if (fr = (struct FileRequester *)
IAsl->AllocAslRequestTags(ASL_FileRequest,
ASL_Hail, "FilePat/MultiSelect Demo",
ASL_Dir, "libs:",
ASL_File, "asl.library",

/* Initial pattern string for pattern matching */
ASL_Pattern, "~(rexx#?|math#?)",

/* Enable multiselection and pattern match gadget */
ASL_FuncFlags, FILF_MULTISELECT | FILF_PATGAD,

/* This requester comes up on the screen of this
** window (and uses window's message port, if any).
*/
ASL_Window, window,
TAG_END))
{
/* Put up file requester */
if (IAsl->AslRequest(fr, 0L))
{
/* If the file requester's rf_NumArgs field
** is not zero, the user multiselected. The
** number of files is stored in rf_NumArgs.
*/
if (fr->rf_NumArgs)
{
/* rf_ArgList is an array of WBArg structures
** (see <workbench/startup.h>). Each entry in
** this array corresponds to one of the files
** the user selected (in alphabetical order).
*/
frargs = fr->rf_ArgList;

/* The user multiselected, step through
** the list of selected files.
*/
for ( x=0; x < fr->rf_NumArgs; x++ )
IDOS->Printf("Argument %ld: PATH=%s FILE=%s\n",
x, fr->rf_Dir, frargs[x].wa_Name);
}
else
/* The user didn't multiselect, use the
** normal way to get the file name.
*/
IDOS->Printf("PATH=%s FILE=%s\n", fr->rf_Dir, fr->rf_File);
}
/* Done with the FileRequester, better return it */
IAsl->FreeAslRequest(fr);
}
IIntuition->CloseWindow(window);
}
IIntuition->CloseScreen(screen);
}
}

IExec->DropInterface((struct Interface*)IIntuition);
IExec->CloseLibrary(IntuitionBase);

IExec->DropInterface((struct Interface*)IAsl);
IExec->CloseLibrary(AslBase);

return 0;
}
</syntaxhighlight>

The previous example demonstrates two alternate functions for creating and using ASL requesters:

<syntaxhighlight>
APTR AllocAslRequestTags( uint32 type, Tag Tag1, ... );
BOOL AslRequestTags( APTR request, Tag Tag1, ... );
</syntaxhighlight>

AllocAslRequestTags() can be used instead of AllocAslRequest() to allocate and set up the file requester. This is a 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.

=== ASL Requesters and Custom Screens ===

An application that uses a custom screen normally wants its requesters to open on its screen. Using the ASL_Window tag, a program can associate a requester with a specific window so that the requester appears on the same screen as the window. The ASL_Window tag is followed by a pointer to a window structure. ASL_Window works with both file and font requesters. The example above shows how the ASL_Window tag is used with a file requester.

Normally, a requester associated with a window (using ASL_Window) shares that window's IDCMP port for its communication. An application may not want to share an IDCMP port with the requester. Using the ASL_FuncFlags tag, a program can ask for a requester that creates its own IDCMP port. There are two flags that accomplish this. The first, FILF_NEWIDCMP, is used on file requesters. The other, FONF_NEWIDCMP, is used on font requesters.

=== The Save Requester ===

The save requester is a special type of file requester used for save operations. It differs from the regular ASL file requester in several ways.

A save requester does not allow the user to select an existing file name by double-clicking on an entry in the scrolling list gadget. This helps prevent the user from accidentally overwriting the wrong file.

Save requesters can also create directories. If the user types a directory name into the save requester and the directory doesn't exist, the save requester will create that directory (after getting the user's permission via another requester).

To create a save requester, set the ASLFR_DoSaveMode tag to TRUE. Note that it does not make sense to have multiselection in a save requester, so the ASLFR_DoSaveMode tag overrides the ASLFR_DoMultiSelect tag.

=== The Directory Requester ===

Sometimes a program may only require a directory name from the user. There is another variation on asl.library's file requester that allows this. If the ASLFR_DrawersOnly tag is set to TRUE, the requester will appear without a string gadget for file names and will display only directory names in the scrolling list gadget. When AslRequest() (or AslRequestTags() ) returns successfully, the rf_Dir field of the FileRequester structure contains the name of the directory the user selected.

Another flag defined for ASL_ExtFlags1 is FIL1F_MATCHDIRS. If file pattern matching is on (see the FILF_PATGAD flag for ASL_FuncFlags), setting FIL1F_MATCHDIRS tells the file requester to pattern match directory names as well as file names. Of course, if both of these ASL_ExtFlags1 flags are set, the requester will only pattern match directory names.