MUI Autodocs: Popasl.mui

Copyright © 1998, Stefan Stuntz

Popasl.mui Background

        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

        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.

Popasl.mui Attributes

    Attribute                           Ver ISG Type
    ----------------------------------- --- --- --------------------
    MUIA_Popasl_Active                  V7  ..G BOOL
    MUIA_Popasl_StartHook               V7  ISG struct Hook *
    MUIA_Popasl_StopHook                V7  ISG struct Hook *
    MUIA_Popasl_Type                    V7  I.G ULONG


        MUIA_Popasl_Active -- (V7 ) [..G], BOOL

        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;

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

           if (active)
                          "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 *

        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

        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

        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 *

        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

        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
        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 paremeters 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

© 1998, Stefan Stuntz [MUI Homepage] [Autodoc Index] [Feedback] Updated: 22-Feb-98