GetAsmGadgetAttr
Synopsis
value = GetAsmGadgetAttr(rei, AsmGadget, name, attribute)
D0 A0 A1 A2 D0C Prototype
ULONG GetAsmGadgetAttr(struct REI *, struct AsmGadget *, STRPTR, ULONG);Description
Retrieves information about the elements that make up an AsmGadget. This function allows querying a single attribute at a time, unlike GetREIAttrsA() which can query multiple attributes. This design choice follows boopsi conventions (write operations are far more common than reads) and results in faster execution in terms of clock cycles.
Inputs
- rei — Pointer to a REI structure.
- AsmGadget — Pointer to the AsmGadget to query. If NULL, the
nameparameter will be used to locate the AsmGadget. - name — Pointer to a null-terminated string indicating the name of the AsmGadget to query. This parameter is only considered if
AsmGadgetis NULL. - attribute — The
ti_Tagof the attribute to read.
Tags
All gadtools.library tags are accepted, plus:
- AGAT_AsmGadgetHook (struct Hook *) — Address of the Hook attached to this AsmGadget.
For LISTVIEW_KIND (scrolling list) gadgets:
- AGATLV_SelectedNode (struct Node *) — Returns the address of the currently selected node. Returns NULL if no element in the listview is currently selected.
Result
- value — The value of the requested attribute. Warning: This result cannot be checked for errors, because the value represents the content of the requested tag, which can legitimately be 0 (NULL). All possible values are valid as a result.
See Also
<libraries/gadtools.h>
Implementation
The original 68020 assembly implementation:
; (24-Feb-1995) --- value = GetAsmGadgetAttr(rei,AsmGadget,name, attribute) (A0/A1/A2/D0)
GAGTable
dc.l GAGExit,GAGNewHook
dc.l GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit
dc.l GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit,GAGExit
dc.l GAGSelNode
;--------------------------------------------------------------------------------------
_LVOGetAsmGadgetAttr
movem.l d6-d7/a2-a6,-(sp)
move.l d0,d6 * Attribute NULL??
beq.s GAGExit * then exit...
move.l a0,d0
bne.s GAGFind * Ok, there is a rei, so operate on this one...
GAGExit movem.l (sp)+,d6-d7/a2-a6
rts
GAGFind move.l ab_GadToolsBase(a6),a6 * Only This...
move.l d0,a4 * Save i (REI)
move.l a1,d7 * Was the AsmGadget address passed?
bne.s GAGGad * yes...
move.l a2,a1 * search it via name...
lea rei_HEADAsmGadget(a4),a0 * List
FINDNAME
move.l d0,d7 * D7 = (struct AsmGadget *)
beq.s GAGExit
GAGGad move.l d7,a5 * A5 = (struct AsmGadget *)
move.l d6,d0 * attribute...
swap d0
andi.w #~$8000,d0 * can I handle it myself...??
bne.s GGADROU * No, then use GT_GetGadgetAttrsA()
;--------------------------------------------------------------------------------------
swap d0
lea GAGTable(pc),a1
jmp ([a1,d0.w*4])
;--------------------------------------------------------------------------------------
GGADROU suba.l a2,a2 * Request
move.l a2,-(sp) * Hole... this space addr not needed
move.l sp,d7 * &list
move.l a2,-(sp) * TAG_DONE
move.l d7,-(sp) * &list
move.l d6,-(sp) * attribute to read
move.l sp,a3 * TagList
move.l rei_Window(a4),a1 * Window
move.l agg_Gadget(a5),a0 * Gadget
jsr _LVOGT_GetGadgetAttrsA(a6)
move.l 12(sp),d0 * RESULT...
lea 16(sp),sp * restore Stack...
movem.l (sp)+,d6-d7/a2-a6
rts
;--------------------------------------------------------------------------------------
GAGNewHook
move.l agg_NewGadget+gng_UserData(a5),d0
movem.l (sp)+,d6-d7/a2-a6
rts
;--------------------------------------------------------------------------------------
GAGSelNode
suba.l a2,a2 * Request
move.l a2,-(sp) * Hole... this space addr not needed
move.l sp,d7 * &attr
move.l a2,-(sp) * TAG_DONE
move.l d7,-(sp) * &attr
pea GTLV_Labels * first read the labels...
move.l sp,a3 * TagList
move.l rei_Window(a4),a1 * Window
move.l agg_Gadget(a5),a0 * Gadget
jsr _LVOGT_GetGadgetAttrsA(a6)
move.l 12(sp),d0 * RESULT...
lea 16(sp),sp * restore Stack...
move.l d0,d6
beq.s GAGFine * there are no Lists attached to the gadget
move.l a2,-(sp) * Hole... this space addr not needed
move.l sp,d7 * &attr
move.l a2,-(sp) * TAG_DONE
move.l d7,-(sp) * &attr
pea GTLV_Selected * first read the labels...
move.l sp,a3 * TagList
move.l rei_Window(a4),a1 * Window
move.l agg_Gadget(a5),a0 * Gadget
jsr _LVOGT_GetGadgetAttrsA(a6)
move.l 12(sp),d1 * Ordinal number selected...
lea 16(sp),sp * restore Stack..
move.l d6,a0 * Labels (struct List *)
NNode move.l LN_SUCC(a0),d0
move.l d0,a0
dbf d1,NNode
GAGFine movem.l (sp)+,d6-d7/a2-a6
rtsLast updated on