TABLE OF CONTENTS

gadtools.library/CreateContext
gadtools.library/CreateGadgetA
gadtools.library/CreateMenusA
gadtools.library/DrawBevelBoxA
gadtools.library/FreeGadgets
gadtools.library/FreeMenus
gadtools.library/FreeVisualInfo
gadtools.library/GetVisualInfoA
gadtools.library/GT_BeginRefresh
gadtools.library/GT_EndRefresh
gadtools.library/GT_FilterIMsg
gadtools.library/GT_GetIMsg
gadtools.library/GT_PostFilterIMsg
gadtools.library/GT_RefreshWindow
gadtools.library/GT_ReplyIMsg
gadtools.library/GT_SetGadgetAttrsA
gadtools.library/LayoutMenuItemsA
gadtools.library/LayoutMenusA
gadtools.library/CreateContext                 gadtools.library/CreateContext

   NAME
        CreateContext -- Create a place for GadTools context data. (V36)

   SYNOPSIS
        gad = CreateContext(glistpointer);
        D0                  A0

        struct Gadget *CreateContext(struct Gadget **);

   FUNCTION
        Creates a place for GadTools to store any context data it might
        need for your window.  In reality, an unselectable invisible
        gadget is created, with room for the context data.
        This function also establishes the linkage from a glist type
        pointer to the individual gadget pointers.  Call this function
        before any of the other gadget creation calls.

   INPUTS
        glistptr - Address of a pointer to a Gadget, which was previously
            set to NULL.  When all the gadget creation is done, you may
            use that pointer as your NewWindow.FirstGadget, or
            in intuition.library/AddGList(), intuition.library/RefreshGList(),
            FreeGadgets(), etc.

   RESULT
        gad - Pointer to context gadget, or NULL if failure.

   EXAMPLE

        struct Gadget *gad;
        struct Gadget *glist = NULL;
        gad = CreateContext(&glist);
        /*  Other creation calls go here */
        if (gad)
        {
            myNewWindow.FirstGadget = glist;
            if ( myWindow = OpenWindow(&myNewWindow) )
            {
                GT_RefreshWindow(win);
                /* other stuff */
                CloseWindow(myWindow);
            }
        }
        FreeGadgets(glist);

   NOTES

   BUGS

   SEE ALSO

gadtools.library/CreateGadgetA                 gadtools.library/CreateGadgetA

   NAME
        CreateGadgetA -- Allocate and initialize a gadtools gadget. (V36)
        CreateGadget -- Varargs stub for CreateGadgetA(). (V36)

   SYNOPSIS
        gad = CreateGadgetA(kind, previous, newgad, taglist)
        D0                  D0    A0        A1      A2

        struct Gadget *CreateGadgetA(ULONG, struct Gadget *,
            struct NewGadget *, struct TagItem *);

        gad = CreateGadget(kind, previous, newgad, firsttag, ...)

        struct Gadget *CreateGadget(ULONG, struct Gadget *,
            struct NewGadget *, Tag, ...);

   FUNCTION
        CreateGadgetA() allocates and initializes a new gadget of the
        specified kind, and attaches it to the previous gadget.  The
        gadget is created based on the supplied kind, NewGadget structure,
        and tags.

   INPUTS
        kind - to indicate what kind of gadget is to be created.
        previous - pointer to the previous gadget that this new gadget
            is to be attached to.
        newgad - a filled in NewGadget structure describing the desired
            gadget's size, position, label, etc.
        taglist - pointer to a TagItem list.

   TAGS
        All kinds:
        GT_Underscore (GadTools V37 and higher only).
            Indicates the symbol that precedes the character in the gadget
            label to be underscored.  This would be to indicate keyboard
            equivalents for gadgets (note that GadTools does not process
            the keys - it just displays the underscore).
            Example: To underscore the "M" in "Mode"...
                ng.ng_GadgetText = "_Mode:";
                gad = CreateGadget(..._KIND, &ng, prev,
                        GT_Underscore, '_',
                        ...
                        );

        BUTTON_KIND (action buttons):
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        CHECKBOX_KIND (on/off items):
        GTCB_Checked (BOOL) - Initial state of checkbox, defaults to FALSE.
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        CYCLE_KIND (multiple state selections):
        GTCY_Labels (STRPTR *) - Pointer to NULL-terminated array of strings
            that are the choices offered by the cycle gadget (required).
        GTCY_Active (UWORD) - The ordinal number (counting from zero) of
            the initially active choice of a cycle gadget (defaults to zero).
        GA_Disabled (BOOL) - (GadTools V37 and higher only)
            Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        INTEGER_KIND (numeric entry):
        GTIN_Number (ULONG) - The initial contents of the integer gadget
            (default zero).
        GTIN_MaxChars (UWORD) - The maximum number of digits that the
            integer gadget is to hold (defaults to 10).
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).
        STRINGA_ExitHelp (BOOL) - (New for V37) Set to TRUE to have the
            help-key cause an exit from the integer gadget.  You will
            then receive a GADGETUP with code = 0x5F (rawkey for help).
        GA_TabCycle (BOOL) - (New for V37) Set to TRUE so that pressing
            <TAB> or <Shift-TAB> will activate the next or previous
            such gadget. (defaults to TRUE, unlike regular Intuition string
            gadgets, which default to FALSE).
        GTST_EditHook (struct Hook *) - (new for V37) Hook to use as a custom
            integer gadget edit hook (StringExtend->EditHook) for this gadget.
            GadTools will allocate the StringExtend->WorkBuffer for you.
            Defaults to NULL.
        STRINGA_Justification - (new for V37) Controls the justification of
            the contents of an integer gadget.  Choose one of STRINGLEFT,
            STRINGRIGHT, or STRINGCENTER.  (Defaults to STRINGLEFT).
        STRINGA_ReplaceMode (BOOL) - (new for V37) If TRUE, this integer gadget
            is in replace-mode.  Defaults to FALSE (insert-mode).

        LISTVIEW_KIND (scrolling list):
        GTLV_Top (WORD) - Top item visible in the listview.  This value
            will be made reasonable if out-of-range (defaults to zero).
        GTLV_Labels (struct List *) - List of labels whose ln_Name fields
            are to be displayed in the listview.
        GTLV_ReadOnly (BOOL) - If TRUE, then listview is read-only.
        GTLV_ScrollWidth (UWORD) - Width of scroll bar for listview.
            Must be greater than zero (defaults to 16).
        GTLV_ShowSelected (struct Gadget *) - NULL to have the currently
            selected item displayed beneath the listview, or pointer to
            an already-created GadTools STRING_KIND gadget to have an
            editable display of the currently selected item.
        GTLV_Selected (UWORD) - Ordinal number of currently selected
            item, or ~0 to have no current selection (defaults to ~0).
        LAYOUTA_Spacing - Extra space to place between lines of listview
            (defaults to zero).

        MX_KIND (mutually exclusive, radio buttons):
        GTMX_Labels (STRPTR *) - Pointer to a NULL-terminated array of
            strings which are to be the labels beside each choice in a
            set of mutually exclusive gadgets.
        GTMX_Active (UWORD) - The ordinal number (counting from zero) of
            the initially active choice of an mx gadget (Defaults to zero).
        GTMX_Spacing (UWORD) - The amount of space between each choice
            of a set of mutually exclusive gadgets.  This amount is added
            to the font height to produce the vertical shift between
            choices. (defaults to one).
        LAYOUTA_Spacing - FOR COMPATIBILITY ONLY.  Use GTMX_Spacing instead.
            The number of extra pixels to insert between
            each choice of a mutually exclusive gadget.  This is added
            to the present gadget image height (9) to produce the
            true spacing between choices.  (defaults to
            FontHeight-8, which is zero for 8-point font users).

        NUMBER_KIND (read-only numeric):
        GTNM_Number - A signed long integer to be displayed as a read-only
             number (default 0).
        GTNM_Border (BOOL) - If TRUE, this flag asks for a recessed
            border to be placed around the gadget.

        PALETTE_KIND (color selection):
        GTPA_Depth (UWORD) - Number of bitplanes in the palette
            (defaults to 1).
        GTPA_Color (UBYTE) - Initially selected color of the palette
            (defaults to 1).
        GTPA_ColorOffset (UBYTE) - First color to use in palette
            (defaults to zero).
        GTPA_IndicatorWidth (UWORD) - The desired width of the current-color
            indicator, if you want one to the left of the palette.
        GTPA_IndicatorHeight (UWORD) - The desired height of the current-color
            indicator, if you want one above the palette.
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        SCROLLER_KIND (for scrolling through areas or lists):
        GTSC_Top (WORD) - Top visible in area scroller represents
            (defaults to zero).
        GTSC_Total (WORD) - Total in area scroller represents
            (defaults to zero).
        GTSC_Visible (WORD) - Number visible in scroller (defaults to 2).
        GTSC_Arrows (UWORD) - Asks for arrows to be attached to the scroller.
            The value supplied will be taken as the width of each arrow button
            for a horizontal scroller, or the height of each button for a
            vertical scroller (the other dimension will match the whole
            scroller).
        PGA_Freedom - Whether scroller is horizontal or vertical.
            Choose LORIENT_VERT or LORIENT_HORIZ (defaults to horiz).
        GA_Immediate (BOOL) - Hear every IDCMP_GADGETDOWN event from scroller
            (defaults to FALSE).
        GA_RelVerify (BOOL) - Hear every IDCMP_GADGETUP event from scroller
            (defaults to FALSE).
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        SLIDER_KIND (to indicate level or intensity):
        GTSL_Min (WORD) - Minimum level for slider (default 0).
        GTSL_Max (WORD) - Maximum level for slider (default 15).
        GTSL_Level (WORD) - Current level of slider (default 0).
        GTSL_MaxLevelLen (UWORD) - Max. length in characters of level string
            when rendered beside slider.
        GTSL_LevelFormat (STRPTR) - C-Style formatting string for slider
            level.  Be sure to use the 'l' (long) modifier.  This string
            is processed using exec/RawDoFmt(), so refer to that function
            for details.
        GTSL_LevelPlace - One of PLACETEXT_LEFT, PLACETEXT_RIGHT,
            PLACETEXT_ABOVE, or PLACETEXT_BELOW, indicating where the level
            indicator is to go relative to slider (default to PLACETEXT_LEFT).
        GTSL_DispFunc ( LONG (*function)(struct Gadget *, WORD) ) - Function
            to calculate level to be displayed.  A number-of-colors slider
            might want to set the slider up to think depth, and have a
            (1 << n) function here.  Defaults to none.  Your function must
            take a pointer to gadget as the first parameter, the level
            (a WORD) as the second, and return the result as a LONG.
        GA_Immediate (BOOL) - If you want to hear each slider IDCMP_GADGETDOWN
            event.
        GA_RelVerify (BOOL) - If you want to hear each slider IDCMP_GADGETUP
            event.
        PGA_Freedom - Set to LORIENT_VERT or LORIENT_HORIZ to have a
            vertical or horizontal slider.
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        STRING_KIND (text-entry):
        GTST_String (STRPTR) - The initial contents of the string gadget,
             or NULL (default) if string is to start empty.
        GTST_MaxChars (UWORD) - The maximum number of characters that the
            string gadget is to hold.
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).
        STRINGA_ExitHelp (BOOL) - (New for V37) Set to TRUE to have the
            help-key cause an exit from the string gadget.  You will
            then receive a GADGETUP with code = 0x5F (rawkey for help).
        GA_TabCycle (BOOL) - (New for V37) Set to TRUE so that pressing
            <TAB> or <Shift-TAB> will activate the next or previous
            such gadget. (defaults to TRUE, unlike regular Intuition string
            gadgets, which default to FALSE).
        GTST_EditHook (struct Hook *) - (new for V37) Hook to use as a custom
            string gadget edit hook (StringExtend->EditHook) for this gadget.
            GadTools will allocate the StringExtend->WorkBuffer for you.
            Defaults to NULL.
        STRINGA_Justification - (new for V37) Controls the justification of
            the contents of a string gadget.  Choose one of STRINGLEFT,
            STRINGRIGHT, or STRINGCENTER.  (Defaults to STRINGLEFT).
        STRINGA_ReplaceMode (BOOL) - (new for V37) If TRUE, this string gadget
            is in replace-mode.  Defaults to FALSE (insert-mode).

        TEXT_KIND (read-only text):
        GTTX_Text - Pointer to a NULL terminated string to be displayed,
            as a read-only text-display gadget, or NULL. defaults to NULL.
        GTTX_CopyText (BOOL) -  This flag instructs the text-display gadget
            to copy the supplied text string, instead of using only
            pointer to the string.  This only works for the initial value
            of GTTX_Text set at CreateGadget() time.  If you subsequently
            change GTTX_Text, the new text will be referenced by pointer,
            not copied.  Do not use this tag with a NULL GTTX_Text.
        GTTX_Border (BOOL) - If TRUE, this flag asks for a recessed
            border to be placed around the gadget.


   RESULT
        gad - pointer to the new gadget, or NULL if the allocation failed
            or if previous was NULL.

   EXAMPLE

   NOTES
        Note that the ng_VisualInfo and ng_TextAttr fields of the
        NewGadget structure must be set to valid VisualInfo and
        TextAttr pointers, or this function will fail.

        Starting with V37, string and integer gadgets have the GFLG_TABCYCLE
        feature automatically.  If the user presses Tab or Shift-Tab while
        in a string or integer gadget, the next or previous one in
        sequence will be activated.  You will hear a GADGETUP with a code
        of 0x09.  Use {GA_TabCycle, FALSE} to supress this.


   BUGS

   SEE ALSO
        FreeGadgets(), GT_SetGadgetAttrs(), GetVisualInfo().

gadtools.library/CreateMenusA                   gadtools.library/CreateMenusA

   NAME
        CreateMenusA -- Allocate and fill out a menu structure. (V36)
        CreateMenus -- Varargs stub for CreateMenus(). (V36)

   SYNOPSIS
        menu = CreateMenusA(newmenu, taglist)
        D0                  A0       A1

        struct Menu *CreateMenusA(struct NewMenu *, struct TagItem *);

        menu = CreateMenus(newmenu, firsttag, ...)

        struct Menu *CreateMenus(struct NewMenu *, Tag, ...);

   FUNCTION
        CreateMenusA() allocates and initializes a complete menu
        structure based on the supplied array of NewMenu structures.
        Optionally, CreateMenusA() can allocate and initialize a complete
        set of menu items and sub-items for a single menu title.  This
        is dictated by the contents of the array of NewMenus.

   INPUTS
        newmenu - Pointer to an array of initialized struct NewMenus.
        taglist - Pointer to a TagItem list.

   TAGS
        GTMN_FrontPen (UBYTE) - Pen number to be used for menu text.
            (defaults to zero).
        GTMN_FullMenu (BOOL) - (GadTools V37 and higher only)
            Requires that the NewMenu specification describes a complete
            menu strip, not a fragment.  If a fragment is found,
            CreateMenusA() will fail with a secondary error of
            GTMENU_INVALID.  (defaults to FALSE).
        GTMN_SecondaryError (ULONG *) - (GadTools V37 and higher only)
            Supply a pointer to a NULL-initialized ULONG to receive a
            descriptive error code.  Possible values:
            GTMENU_INVALID - NewMenu structure describes an illegal
                menu.  (CreateMenusA() will fail with a NULL result).
            GTMENU_TRIMMED - NewMenu structure has too many menus, items,
                or subitems (CreateMenusA() will succeed, returning a
                trimmed-down menu structure).
            GTMENU_NOMEM - CreateMenusA() ran out of memory.

   RESULT
        menu - Pointer to the resulting initialized menu structure (or
            the resulting FirstItem), with all the links for menu items
            and subitems in place.
            The result will be NULL if CreateMenusA() could not allocate
            memory for the menus, or if the NewMenu array had an
            illegal arrangement (eg. NM_SUB following NM_TITLE).
            (see also the GTMN_SecondaryError tag above).

   EXAMPLE

   NOTES
        The strings you supply for menu text are not copied, and must
        be preserved for the life of the menu.
        The resulting menus have no positional information.  You will
        want to call LayoutMenusA() (or LayoutMenuItemsA()) to supply that.
        CreateMenusA() automatically provides you with a UserData field
        for each menu, menu-item or sub-item.  Use the GTMENU_USERDATA(menu)
        or GTMENUITEM_USERDATA(menuitem) macro to access it.

   BUGS
        At present, if you put images into menus using IM_ITEM
        or IM_SUB for a NewMenu->Type, the image you supply must
        be an ordinary struct Image.  You may not use a 'custom
        image' (eg. one obtained from a boopsi image-class).

   SEE ALSO
        LayoutMenusA(), FreeMenus(), gadtools.h/GTMENU_USERDATA(),
        gadtools.h/GTMENUITEM_USERDATA()

gadtools.library/DrawBevelBoxA                 gadtools.library/DrawBevelBoxA

   NAME
        DrawBevelBoxA -- Draws a bevelled box. (V36)
        DrawBevelBox -- Varargs stub for DrawBevelBox(). (V36)

   SYNOPSIS
        DrawBevelBoxA(rport, left, top, width, height, taglist)
                      A0     D0    D1   D2     D3      A1

        VOID DrawBevelBoxA(struct RastPort *, WORD, WORD, WORD, WORD,
            struct TagItem *taglist);

        DrawBevelBox(rport, left, top, width, height, firsttag, ...)

        VOID DrawBevelBox(struct RastPort *, WORD, WORD, WORD, WORD,
            Tag, ...);

   FUNCTION
        DrawBevelBoxA() renders a bevelled box of specified dimensions
        into the supplied RastPort.

   INPUTS
        rport - The RastPort into which the box is to be drawn.
        left - The left edge of the box.
        top - The top edge of the box.
        width - The width of the box.
        height - The height of the box.
        taglist - Pointer to a TagItem list.

   TAGS
        GTBB_Recessed (BOOL):  Set to anything for a recessed-looking box.
            If absent, the box defaults, it would be raised.
        GT_VisualInfo (APTR):  You MUST supply the value you obtained
            from an earlier call to GetVisualInfoA().

   RESULT
        None.

   EXAMPLE

   NOTES
        DrawBevelBox() is a rendering operation, not a gadget.  That
        means you must refresh it at the appropriate time, like any
        other rendering operation.

   BUGS

   SEE ALSO
        GetVisualInfoA()

gadtools.library/FreeGadgets                     gadtools.library/FreeGadgets

   NAME
        FreeGadgets -- Free a linked list of gadgets. (V36)

   SYNOPSIS
        FreeGadgets(glist)
                    A0

        VOID FreeGadgets(struct Gadget *glist);
                         A0

   FUNCTION
        Frees any GadTools gadgets found on the linked list of gadgets
        beginning with the specified one.  Frees all the memory that was
        allocated by CreateGadgetA().  This function will return safely
        with no action if it receives a NULL parameter.

   INPUTS
        glist - pointer to first gadget in list to be freed.

   RESULT
        none

   EXAMPLE

   NOTES

   BUGS

   SEE ALSO
        CreateGadgetA()

gadtools.library/FreeMenus                         gadtools.library/FreeMenus

   NAME
        FreeMenus -- Frees memory allocated by CreateMenusA(). (V36)

   SYNOPSIS
        FreeMenus(menu)
                  A0

        VOID FreeMenus(struct Menu *);

   FUNCTION
        Frees the menus allocated by CreateMenusA().  It is safe to
        call this function with a NULL parameter.

   INPUTS
        menu - Pointer to menu structure (or first MenuItem) obtained
        from CreateMenusA().

   RESULT
        None.

   EXAMPLE

   NOTES

   BUGS

   SEE ALSO
        CreateMenusA()

gadtools.library/FreeVisualInfo               gadtools.library/FreeVisualInfo

   NAME
        FreeVisualInfo -- Return any resources taken by GetVisualInfo. (V36)

   SYNOPSIS
        FreeVisualInfo(vi)
                       A0

        VOID FreeVisualInfo(APTR);

   FUNCTION
        FreeVisualInfo() returns any memory or other resources that
        were allocated by GetVisualInfoA().  You should only call this function
        once you are done with using the gadgets (i.e. after CloseWindow()),
        but while the screen is still valid (i.e. before CloseScreen() or
        UnlockPubScreen()).

   INPUTS
        vi - Pointer that was obtained by calling GetVisualInfoA().

   RESULT
        None.

   EXAMPLE

   NOTES

   BUGS

   SEE ALSO
        GetVisualInfoA()

gadtools.library/GetVisualInfoA               gadtools.library/GetVisualInfoA

   NAME
        GetVisualInfoA -- Get information GadTools needs for visuals. (V36)
        GetVisualInfo -- Varargs stub for GetVisualInfoA(). (V36)

   SYNOPSIS
        vi = GetVisualInfoA(screen, taglist)
        D0                  A0      A1

        APTR vi = GetVisualInfoA(struct Screen *, struct TagItem *);

        vi = GetVisualInfo(screen, firsttag, ...)

        APTR vi = GetVisualInfo(struct Screen *, Tag, ...);

   FUNCTION
        Get a pointer to a (private) block of data containing various bits
        of information that GadTools needs to ensure the best quality
        visuals.  Use the result in the NewGadget structure of any gadget
        you create, or as a parameter to the various menu calls.  Once the
        gadgets/menus are no longer needed (after the last CloseWindow),
        call FreeVisualInfo().

   INPUTS
        screen - Pointer to the screen you will be opening on.
        taglist - Pointer to list of TagItems.

   RESULT
        vi - Pointer to private data.

   EXAMPLE

   NOTES

   BUGS

   SEE ALSO
        FreeVisualInfo(), intuition/LockPubScreen(),
        intuition/UnlockPubScreen()

gadtools.library/GT_BeginRefresh             gadtools.library/GT_BeginRefresh

   NAME
        GT_BeginRefresh -- Begin refreshing friendly to GadTools. (V36)

   SYNOPSIS
        GT_BeginRefresh(win)
                        A0

        VOID GT_BeginRefresh(struct Window *);

   FUNCTION
        Invokes the intuition.library/BeginRefresh() function in a manner
        friendly to the Gadget Toolkit.  This function call permits the
        GadTools gadgets to refresh themselves at the correct time.
        Call GT_EndRefresh() function when done.

   INPUTS
        win - Pointer to Window structure for which a IDCMP_REFRESHWINDOW
            IDCMP event was received.

   RESULT
        None.

   EXAMPLE

   NOTES
        The nature of GadTools precludes the use of the IDCMP flag
        WFLG_NOCAREREFRESH.  You must handle IDCMP_REFRESHWINDOW events
        in at least the minimal way, namely:

                case IDCMP_REFRESHWINDOW:
                    GT_BeginRefresh(win);
                    GT_EndRefresh(win, TRUE);
                    break;

   BUGS

   SEE ALSO
        intuition.library/BeginRefresh()

gadtools.library/GT_EndRefresh                 gadtools.library/GT_EndRefresh

   NAME
        GT_EndRefresh -- End refreshing friendly to GadTools. (V36)

   SYNOPSIS
        GT_EndRefresh(win, complete)
                      A0   D0

        VOID GT_EndRefresh(struct Window *, BOOL complete);

   FUNCTION
        Invokes the intuition.library/EndRefresh() function in a manner
        friendly to the Gadget Toolkit.  This function call permits
        GadTools gadgets to refresh themselves at the correct time.
        Call this function to EndRefresh() when you have used
        GT_BeginRefresh().

   INPUTS
        win - Pointer to Window structure for which a IDCMP_REFRESHWINDOW
            IDCMP event was received.
        complete - TRUE when done with refreshing.

   RESULT
        None.

   EXAMPLE

   NOTES

   BUGS

   SEE ALSO
        intuition.library/EndRefresh()

gadtools.library/GT_FilterIMsg                 gadtools.library/GT_FilterIMsg

   NAME
        GT_FilterIMsg -- Filter an IntuiMessage through GadTools. (V36)

   SYNOPSIS
        modimsg = GT_FilterIMsg(imsg)
        D0                      A1

        struct IntuiMessage *GT_FilterIMsg(struct IntuiMessage *);

   FUNCTION
        NOTE WELL:  Extremely few programs will actually need this function.
        You almost certainly should be using GT_GetIMsg() and GT_ReplyIMsg()
        only, and not GT_FilterIMsg() and GT_PostFilterIMsg().

        GT_FilterIMsg() takes the supplied IntuiMessage and asks the
        Gadget Toolkit to consider and possibly act on it.  Returns
        NULL if the message was only of significance to a GadTools gadget
        (i.e. not to you), else returns a pointer to a modified IDCMP
        message, which may contain additional information.
        You should examine the Class, Code, and IAddress fields of
        the returned message to learn what happened.  Do not make
        interpretations based on the original imsg.
        You should use GT_PostFilterIMsg() to revert to the original
        IntuiMessage once you are done with the modified one.

   INPUTS
        imsg - An IntuiMessage you obtained from a Window's UserPort.

   RESULT
        modimsg - A modified IntuiMessage, possibly with extra information
            from GadTools, or NULL.

   EXAMPLE

   NOTES

   BUGS

   SEE ALSO
        GT_GetIMsg(), GT_PostFilterIMsg()

gadtools.library/GT_GetIMsg                       gadtools.library/GT_GetIMsg

   NAME
        GT_GetIMsg -- Get an IntuiMessage, with GadTools processing. (V36)

   SYNOPSIS
        imsg = GT_GetIMsg(intuiport)
        D0                A0

        struct IntuiMessage *GT_GetIMsg(struct MsgPort *);

   FUNCTION
        Use GT_GetIMsg() in place of the usual exec.library/GetMsg() when
        reading IntuiMessages from your window's UserPort.  If needed,
        the GadTools dispatcher will be invoked, and suitable processing
        will be done for gadget actions.  This function returns a pointer
        to a modified IntuiMessage (which is a copy of the original,
        possibly with some supplementary information from GadTools).
        If there are no messages (or if the only messages are meaningful
        only to GadTools, NULL will be returned.

   INPUTS
        intuiport - The Window->UserPort of a window that is using the
            Gadget Toolkit.

   RESULT
        imsg - Pointer to modified IntuiMessage, or NULL if there are
            no applicable messages.

   EXAMPLE

   NOTES
        Be sure to use GT_ReplyIMsg() and not exec.library/ReplyMsg() on
        messages obtained with GT_GetIMsg().
        If you intend to do more with the resulting message than read
        its fields, act on it, and reply it, you may find GT_FilterIMsg()
        more appropriate.

   BUGS

   SEE ALSO
        GT_ReplyIMsg(), GT_FilterIMsg()

gadtools.library/GT_PostFilterIMsg         gadtools.library/GT_PostFilterIMsg

   NAME
        GT_PostFilterIMsg -- Return the unfiltered message after
            GT_FilterIMsg() was called, and clean up. (V36)

   SYNOPSIS
        imsg = GT_PostFilterIMsg(modimsg)
        D0                       A1

        struct IntuiMessage *GT_PostFilterIMsg(struct IntuiMessage *);

   FUNCTION
        NOTE WELL:  Extremely few programs will actually need this function.
        You almost certainly should be using GT_GetIMsg() and GT_ReplyIMsg()
        only, and not GT_FilterIMsg() and GT_PostFilterIMsg().

        Performs any clean-up necessitated by a previous call to
        GT_FilterIMsg().  The original IntuiMessage is now yours to handle.
        Do not interpret the fields of the original IntuiMessage, but
        rather use only the one you got from GT_FilterIMsg().  You
        may only do message related things at this point, such as queueing
        it up or replying it.  Since you got the message with
        exec.library/GetMsg(), your responsibilities do include replying
        it with exec.library/ReplyMsg(). This function may be safely
        called with a NULL parameter.

   INPUTS
        modimsg - A modified IntuiMessage obtained with GT_FilterIMsg().

   RESULT
        imsg - A pointer to the original IntuiMessage, if GT_FilterIMsg()
            returned non-NULL.

   EXAMPLE

   NOTES
        Be sure to use exec.library/ReplyMsg() on the original IntuiMessage
        you obtained with GetMsg(), (which is the what you passed to
        GT_FilterIMsg()), and not on the parameter of this function.

   BUGS

   SEE ALSO
        GT_FilterIMsg()

gadtools.library/GT_RefreshWindow           gadtools.library/GT_RefreshWindow

   NAME
        GT_RefreshWindow -- Refresh all the GadTools gadgets. (V36)

   SYNOPSIS
        GT_RefreshWindow(win, req)
                         A0   A1

        VOID GT_RefreshWindow(struct Window *, struct Requester *);

   FUNCTION
        Perform the initial refresh of all the GadTools gadgets you have
        created.  After you have opened your window, you must call this
        function.  Or, if you have opened your window without gadgets,
        you add the gadgets with intuition.library/AddGList(),
        refresh them using intuition.library/RefreshGList(), then call
        this function.
        You should not need this function at other times.

   INPUTS
        win - Pointer to the Window containing GadTools gadgets.
        req - Pointer to requester, or NULL if not a requester (currently
            ignored - use NULL).

   RESULT
        None.

   EXAMPLE

   NOTES
        req must currently be NULL.  GadTools gadgets are not supported
        in requesters.  This field may allow such support at a future date.

   BUGS

   SEE ALSO
        GT_BeginRefresh()

gadtools.library/GT_ReplyIMsg                   gadtools.library/GT_ReplyIMsg

   NAME
        GT_ReplyIMsg -- Reply a message obtained with GT_GetIMsg(). (V36)

   SYNOPSIS
        GT_ReplyIMsg(imsg)
                     A1

        VOID GT_ReplyIMsg(struct IntuiMessage *);

   FUNCTION
        Reply a modified IntuiMessage obtained with GT_GetIMsg().
        If you use GT_GetIMsg(), use this function where you would normally
        have used exec.library/ReplyMsg().
        You may safely call this routine with a NULL pointer (nothing
        will be done).

   INPUTS
        imsg - A modified IntuiMessage obtained with GT_GetIMsg().

   RESULT
        None.

   EXAMPLE

   NOTES
        When using GadTools, you MUST explicitly GT_ReplyIMsg()
        all messages you receive.  You cannot depend on CloseWindow()
        to handle messages you have not replied.

   BUGS

   SEE ALSO
        GT_GetIMsg()

gadtools.library/GT_SetGadgetAttrsA       gadtools.library/GT_SetGadgetAttrsA

   NAME
        GT_SetGadgetAttrsA -- Change the attributes of a GadTools gadget. (V36)
        GT_SetGadgetAttrs -- Varargs stub for GT_SetGadgetAttrsA(). (V36)

   SYNOPSIS
        GT_SetGadgetAttrsA(gad, win, req, taglist)
                           A0   A1   A2   A3

        VOID GT_SetGadgetAttrsA(struct Gadget *, struct Window *,
            struct Requester *, struct TagItem *);

        GT_SetGadgetAttrs(gad, win, req, firsttag, ...)

        VOID GT_SetGadgetAttrs(struct Gadget *, struct Window *,
            struct Requester *, Tag, ...);

   FUNCTION
        Change the attributes of the specified gadget, according to the
        attributes chosen in the tag list.

   INPUTS
        gad - Pointer to the gadget in question.
        win - Pointer to the window containing the gadget.
        req - Pointer to the requester containing the gadget, or NULL if
            not in a requester.  (Not yet implemented, use NULL).
        taglist - Pointer to TagItem list.

   TAGS
        BUTTON_KIND:
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        CHECKBOX_KIND:
        GTCB_Checked (BOOL) - Initial state of checkbox, defaults to FALSE.
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        CYCLE_KIND:
        GTCY_Active (UWORD) - The ordinal number (counting from zero) of
            the active choice of a cycle gadget (defaults to zero).
        GTCY_Labels (STRPTR *) - (GadTools V37 and higher only)
            Pointer to NULL-terminated array of strings
            that are the choices offered by the cycle gadget.
        GA_Disabled (BOOL) - (GadTools V37 and higher only)
            Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        INTEGER_KIND:
        GTIN_Number (ULONG) - The initial contents of the integer gadget
            (default zero).
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        LISTVIEW_KIND:
        GTLV_Top (WORD) - Top item visible in the listview.  This value
            will be made reasonable if out-of-range (defaults to zero).
        GTLV_Labels (struct List *) - List of labels whose ln_Name fields
            are to be displayed in the listview.  Use a value of ~0 to
            "detach" your List from the display.  You must detach your list
            before modifying the List structure, since GadTools reserves
            the right to traverse it on another task's schedule.  When you
            are done, attach the list by using the tag pair
            {GTLV_Labels, list}.
        GTLV_Selected (UWORD) - Ordinal number of currently selected
            item (defaults to zero if GTLV_ShowSelected is set).

        MX_KIND:
        GTMX_Active (UWORD) - The ordinal number (counting from zero) of
            the active choice of an mx gadget (Defaults to zero).

        NUMBER_KIND:
        GTNM_Number - A signed long integer to be displayed as a read-only
             number (default 0).

        PALETTE_KIND:
        GTPA_Color (UBYTE) - Initially selected color of the palette
            (defaults to 1).
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        SCROLLER_KIND:
        GTSC_Top (WORD) - Top visible in scroller (defaults to zero).
        GTSC_Total (WORD) - Total in scroller area (defaults to zero).
        GTSC_Visible (WORD) - Number visible in scroller (defaults to 2).
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        SLIDER_KIND:
        GTSL_Min (WORD) - Minimum level for slider (default 0).
        GTSL_Max (WORD) - Maximum level for slider (default 15).
        GTSL_Level (WORD) - Current level of slider (default 0).
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        STRING_KIND:
        GTST_String (STRPTR) - The initial contents of the string gadget,
             or NULL (default) if string is to start empty.
        GA_Disabled (BOOL) - Set to TRUE to disable gadget, FALSE otherwise
            (defaults to FALSE).

        TEXT_KIND:
        GTTX_Text - Pointer to a NULL terminated string to be displayed,
            as a read-only text-display gadget, or NULL. defaults to NULL.

   RESULT
        None.

   EXAMPLE

   NOTES
        req must currently be NULL.  GadTools gadgets are not supported
        in requesters.  This field may allow such support at a future date.

        This function may not be called inside of a GT_BeginRefresh() /
        GT_EndRefresh() session.  (As always, restrict yourself to simple
        rendering functions).

   BUGS

   SEE ALSO

gadtools.library/LayoutMenuItemsA           gadtools.library/LayoutMenuItemsA

   NAME
        LayoutMenuItemsA -- Position all the menu items. (V36)
        LayoutMenuItems -- Varargs stub for LayoutMenuItemsA(). (V36)

   SYNOPSIS
        success = LayoutMenuItemsA(menuitem, vi, taglist)
        D0                         A0        A1  A2

        BOOL LayoutMenuItemsA(struct MenuItem *, APTR, struct TagItem *);

        success = LayoutMenuItems(menuitem, vi, firsttag, ...)

        BOOL LayoutMenuItemsA(struct MenuItem *, APTR, Tag, ...);

   FUNCTION
        Lays out all the menu items and sub-items according to
        the supplied visual information and tag parameters.  You would use this
        if you used CreateMenusA() to make a single menu-pane (with sub-items,
        if any), instead of a whole menu strip.
        This routine attempts to columnize and/or shift the MenuItems in
        the event that a menu would be too tall or too wide.

   INPUTS
        menuitem - Pointer to first MenuItem in a linked list of
            items.
        vi - Pointer returned by GetVisualInfoA().
        taglist - Pointer to a TagItem list.

   TAGS
        GTMN_TextAttr (struct TextAttr *) - Text Attribute to use for
            menu-items and sub-items.  If not supplied, the screen's
            font will be used.  This font must be openable via OpenFont()
            when this function is called.
        GTMN_Menu (struct Menu *) - Pointer to the Menu structure whose
            FirstItem is the MenuItem supplied above.  If the menu items are
            such that they need to be columnized or shifted, the Menu
            structure is needed to perform the complete calculation.
            It is suggested you always provide this information.

   RESULT
        success - TRUE if successful, false otherwise (signifies that
            the TextAttr wasn't openable).

   EXAMPLE

   NOTES

   BUGS
        If a menu ends up being wider than the whole screen, it will
        run off the right-hand side.

   SEE ALSO
        CreateMenusA(), GetVisualInfoA()

gadtools.library/LayoutMenusA                   gadtools.library/LayoutMenusA

   NAME
        LayoutMenusA -- Position all the menus and menu items. (V36)
        LayoutMenus -- Varargs stub for LayoutMenusA(). (V36)

   SYNOPSIS
        success = LayoutMenusA(menu, vi, taglist)
        D0                     A0    A1  A2

        BOOL LayoutMenusA(struct Menu *, APTR, struct TagItem *);

        success = LayoutMenus(menu, vi, firsttag, ...)

        BOOL LayoutMenus(struct Menu *, APTR, Tag, ...);

   FUNCTION
        Lays out all the menus, menu items and sub-items in the supplied
        menu according to the supplied visual information and tag parameters.
        This routine attempts to columnize and/or shift the MenuItems in
        the event that a menu would be too tall or too wide.

   INPUTS
        menu - Pointer to menu obtained from CreateMenusA().
        vi - Pointer returned by GetVisualInfoA().
        taglist - Pointer to a TagItem list.

   TAGS
        GTMN_TextAttr (struct TextAttr *) - Text Attribute to use for
            menu-items and sub-items.  If not supplied, the screen's
            font will be used.  This font must be openable via OpenFont()
            when this function is called.

   RESULT
        success - TRUE if successful, false otherwise (signifies that
            the TextAttr wasn't openable).

   EXAMPLE

   NOTES
        When using this function, there is no need to also call
        LayoutMenuItemsA().

   BUGS
        If a menu ends up being wider than the whole screen, it will
        run off the right-hand side.

   SEE ALSO
        CreateMenusA(), GetVisualInfoA()