Version 1 (modified by Thore Böckelmann, 4 years ago) (diff)


Super class



As a subclass of popstring class, popasl can be used to pop up any kinds of standard system asl requesters. A seperate task is spawned to handle these requesters, the application continues to run.

Using an asl popup class, you don't need to worry about handling asl requesters. MUI will automatically open one when the popup button is pressed and update the corresponding string gadget when the user terminates the requester. From the programmers point of view, all you have to do is to handle the string gadgets contents.

IMPORTANT: At object creation time, you can use all ASL library tags as well. They will be passed to the AllocAslRequest() call without further interpretation, but some of the tags may get overloaded by Popasl's normal requester opening procedure - namely ASLFR_InitialFile and ASLFR_InitialDrawer. These can be changed by using MUIA_Popasl_StartHook.


Attribute Version ISG Type
MUIA_Popasl_Active V7..GBOOL
MUIA_Popasl_StartHook V7ISGstruct Hook *
MUIA_Popasl_StopHook V7ISGstruct Hook *



MUIA_Popasl_Active — V7 [..G], BOOL, 0x80421b37


Popasl creates asynchronous popups. Requesters are opened in a seperately spawned task and don't disturb the rest of the application. You can ask for the state of a requester by querying the MUIA_Popasl_Active attribute. It will return TRUE when the requester is currently open, FALSE otherwise.

Common use for this attribute is to prevent an application from being terminated while a requester is open. If you try to dispose the popasl object with a currently open requester, MUI will freeze your task as long as the requester stays there.


case MUIV_Application_ReturnID_Quit:
  LONG active;

  get(pop1, MUIA_Popasl_Active, &active);
  if(!active) get(pop2, MUIA_Popasl_Active, &active);
  if(!active) get(pop3, MUIA_Popasl_Active, &active);
  if(!active) get(pop4, MUIA_Popasl_Active, &active);

    MUI_Request(app,window, 0, NULL, "OK",
                "Cannot quit now, still some asl popups opened.");
    running = FALSE;


MUIA_Popasl_StartHook, MUIA_Popasl_StopHook, MUIA_Popasl_Type



MUIA_Popasl_StartHook — V7 [ISG], struct Hook *, 0x8042b703


Before popasl class opens the asl requester, it has to get some kind of parameters describing its initial contents. A file popup would e.g. need to split the string gadgets contents into path and file name part and pass these as ASLFR_InititalFile and ASLFR_InitialDrawer to the requester.

The MUIA_Popasl_StartHook tag describes a hook function that will be called immediately before the requester is opened. It will receive a pointer to itself in A0, a pointer to the popasl object in A2 and a pointer to a taglist in A1. This taglist already contains some tags:

ASLFR/FO/..._Screen          : parent screen
ASLFR/FO/..._PrivateIDCMP    : TRUE
ASLFR/FO/..._InititalLeftEdge: left edge of popasl object
ASLFR/FO/..._InititalTopEdge : bottom edge of popasl object
ASLFR/FO/..._InititalWidth   : width of popasl object, only present when the
                               popup is called for the first time.

You may add other tags to the list, but beware that the maximum allowed number of tags is 15. If you need more, use the TAG_MORE tag.

Since the asl requester will run in a seperate task, you should not change the state of the ASLFR_PrivateIDCMP tag!

If your hook returns TRUE, popasl class opens the requester with the given taglist. A return value of FALSE should be used when something went wrong, no requester will be opened in this case.

For file and font requester, popasl class will fall back to a default tag handling when no start hook is specified. A file name is automatically split into path and file part and passed to the requester a ASLFR_InitialFile and ASLFR_InitialDrawer. A font requester splits a string like "topaz/8" into font name and size for ASLFO_InitialName and ASLFO_InitialSize.


MUIA_Popasl_StopHook, MUIA_Popasl_Type



MUIA_Popasl_StopHook — V7 [ISG], struct Hook *, 0x8042d8d2


When the requester terminates, MUIA_Popasl_StopHook will be called with a pointer to itself in A0, a pointer to the popasl object in A2 and a pointer to the asl requester structure in A1. The hook can then parse the requester structure and set the string gadgets contents respectively.

For file and font requesters, a default handling is provided.


MUIA_Popasl_StartHook, MUIA_Popasl_Type



MUIA_Popasl_Type — V7 [I.G], ULONG, 0x8042df3d


This tag allows to set the type of asl requester. Pass the same value you would use for AllocAslRequest(), e.g. ASL_FileRequest, ASL_FontRequest or ASL_ScreenModeRequest.

For ASL_FileRequest and ASL_FontRequest, popasl class offers a standard start/stop handling. When a file requester is opened, MUI splits the string gadgets contents into a path and a file name and uses these as initial parameters for the requester. Font popups translate a font into a name/size pair, e.g. "topaz/8". You can override these translations by specifying a MUIA_Popasl_StartHook and a MUIA_Popasl_StopHook.

For ASL_ScreenModeRequest, no standard handling is available. Using such a popup without Start and Stop hooks won't make much sense.


MUIA_Popasl_StartHook, MUIA_Popasl_StopHook

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Copyright © 2006-2020 by Thore Böckelmann, Jens Maus

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Updated: 01-Jul-2020