How to change a gadtools button's text?

[alkis]

I am trying to find a way to change the text of a button.
I've tried to find anything on the internet and failed

I got 29 gadgets. The first one is of STRING_KIND and all the others of BUTTON_KIND.

I've tried updating the text without removing the gadget and failed.
I've tried updating the text after removing the gadget and then readding the gadget and failed.

(full source here: https://github.com/alexalkis/acalc/blob/master/acalc.c )

Relevant snippet

case GD_SIN:
      #ifdef USEMPFR
      mpfr_sin(res, res, MPFR_RNDN);
      #else
      res = sin(res);
      #endif
      RemoveGadget(wp, gadgets[1]);
      gadgets[1]->GadgetText->IText = "Ok";
      Gadgetdata[1].ng_GadgetText = "shit";
      int pos = AddGadget(wp, gadgets[1], 0);
      RefreshGList(gadgets[1], wp, NULL, 1);
      GT_RefreshWindow(wp, NULL);
      printf("new gadget pos: %d\n", pos);

What am I doing wrong?

Thanks.

[alkis]

I am trying to change a button from saying "sin" on the button to anything else. (for example "ok")

The above snippet gets executed, but the button's text stays the same.

[alkis]

gadget[1] is a pointer to a "Gadget"

struct Gadget
        {
        struct Gadget *NextGadget;
        WORD LeftEdge, TopEdge;
        WORD Width, Height;
        UWORD Flags;
        UWORD Activation;
        UWORD GadgetType;
        APTR GadgetRender;
        APTR SelectRender;
        struct IntuiText *GadgetText;
        LONG MutualExclude;
        APTR SpecialInfo;
        UWORD GadgetID;
        APTR UserData;
        };

GadgetText is

struct IntuiText
{
    UBYTE FrontPen, BackPen;	/* the pen numbers for the rendering */
    UBYTE DrawMode;		/* the mode for rendering the text */
    WORD LeftEdge;		/* relative start location for the text */
    WORD TopEdge;		/* relative start location for the text */
    struct TextAttr *ITextFont;	/* if NULL, you accept the default */
    UBYTE *IText;		/* pointer to null-terminated text */
    struct IntuiText *NextText; /* pointer to another IntuiText to render */
};

IText is a (UBYTE *) and so gadgets[1]->GadgetText->IText="Ok"; looks ok.

[alkis]

RemoveGadget(wp, gadgets[1]);
      gadgets[1]->GadgetText->IText = "Ok";
      Gadgetdata[1].ng_GadgetText = "shit";
      int pos = AddGadget(wp, gadgets[1], 0);
      RefreshGList(gadgets[0], wp, NULL, -1);
      GT_RefreshWindow(wp, NULL);
      printf("new gadget pos: %d with text \"%s\"\n", pos, gadgets[1]->GadgetText->IText);

this prints:

new gadget pos: 0 with text "Ok"

So, it's a refresh problem.

Further, if I comment out the whole block except the RemoveGadget() then the button is "dead" (i.e. you can't press it) but it is still there!!!
[EDIT] if I just comment out the AddGadget it has the same behavior. Button still visible but dead.

[alkis]

Originally Posted by chip

I afraid i can't help you anymore on this, since i know C only for command line programs purposes .-)

No problem, thanks for the effort!

[Leffmann]

What about GT_SetGadgetAttrs? It's used to change all attributes of gadgets, so if it's doable it should be in there.

[alkis]

Only GA_DISABLED is supported on BUTTON_KIND. (http://amigadev.elowar.com/read/ADCD.../node03F6.html)

PS: I've tried GT_SetGadgetAttrs(gadgets[1], wp, NULL, GTTX_Text ,"Ok", TAG_END); and failed anyways

[bubbob42]

I'm not sure, but are you trying to change the text by just assigning a new string?

[alkis]

Originally Posted by bubbob42

I'm not sure, but are you trying to change the text by just assigning a new string?

I've tried that.
I've tried, remove gadget, change text, add gadget

Both fail.

[bubbob42]

Create two strings at the start of the program, remove the gadget, set pointer to 2nd string and add it again.

Or copy new string over old text with strcpy or sprintf, after removing the gadget.

[alkis]

Originally Posted by bubbob42

Create two strings at the start of the program, remove the gadget, set pointer to 2nd string and add it again.

Or copy new string over old text with strcpy or sprintf, after removing the gadget.

The first idea is already tried.
Although the second idea is mega-hack, I've tried it. Still doesn't work.

[bubbob42]

Hrm...I am tempted to try it myself. Maybe at the weekend.

[bubbob42]

If I am interpreting the RKM correctly, gadget data is allocated (and thus copied) when calling CreateGadget(). You cannot modify gadget text via SetGadgetAttr(), as you already found out.

Only way is to remove all gadgets, call FreeGadgets() and create a new gadget list.

Alternative: create your own gadget with pure Intuition or BOOPSI.

[alkis]

Originally Posted by bubbob42

Only way is to remove all gadgets, call FreeGadgets() and create a new gadget list.

Alternative: create your own gadget with pure Intuition or BOOPSI.

I was so afraid that I had to remove all, free all and recreate the whole list. Seems so terribly inefficient.

Oh well, will give it a shot. Thanks.

[bubbob42]

GadTools gadgets have been implemented as an easy, "no hassle"-framework for the most common UI-tasks. That's why you hit the wall quickly if you try something the developers didn't regard as common.

I'm currently struggling with a BOOPSI-class for a button-gadget displaying changing imagery. Believe me, it's not getting any better

[alkis]

Indeed removing all and readding worked! (Yay)

so this does work

      Gadgetdata[1].ng_GadgetText = "new";
      ReAddGadgets();

with ReAddGadgets written as:

void ReAddGadgets(void) {
  struct Gadget *pgad;
  int i;

  if (glist) {
    RemoveGList(wp, glist, -1);
    FreeGadgets(glist);
  }

  pgad = CreateContext(&glist);  /* ContextData ! */

  for (i=0; i < 29; i++) {
    if (gadgets[i] = pgad = CreateGadgetA(
            (i == 0) ? STRING_KIND : BUTTON_KIND,
            pgad,
            &Gadgetdata[i],
            (i == 0) ? (struct TagItem *)&GadgetTags[i]: NULL)) {
      if (i == 0) {
        display = pgad;
      }
    } else {
      printf("Failed to create gadget %d.\n", i);
    }
  }
  AddGList(wp, glist, -1, -1, NULL);
  RefreshGList(glist, wp, NULL, -1);
  GT_RefreshWindow(wp, NULL);
}

That will do, I guess. Thank you all!