Rick's b.log - entry 2017/12/17

A random Christmas-season-sucks song - NSFW!

A toolbar window

I will demonstrate a toolbar at the bottom left, using DeskLib. Essentially, this:

With many thanks to Martin Avison for some source code in assembler that demonstrated how to use the toolbar window functions and helped explain some of the things in the API that weren't clear.

Create the window

Note - the actual height of the scrollbar is 38 OS units, but a toolbar that tall didn't seem to sit nicely in the space beside the scrollbar. Experiment, see what works for you.

Load the toolbar

   // Create and attach the main window
   main_window = Window_Create("main", 128); // Title and page
   if (main_window == 0)
   {
      Error_ReportWithType(Error_ProgramStop, 0, message_read("wimp.tempfail"), "main", appname);
      exit(EXIT_FAILURE);
   }
   Event_Claim(event_CLICK, main_window, event_ANY, main_clickhandler, NULL);

In here, insert some code to load your toolbar window. It will look like this:

   // Load the definition of the toolbar window, but do NOT create it yet.
   if ( event_wimpversion >= 380 )
   {
      // Don't bother doing this if the Wimp version is too old
      toolbar_window = toolbar_create("toolbar"); // No title
      if (toolbar_window == 0)
      {
         Error_ReportWithType(Error_ProgramStop, 0, message_read("wimp.tempfail"), "toolbar", appname);
         exit(EXIT_FAILURE);
      }
      Event_Claim(event_CLICK, toolbar_window, event_ANY, toolbar_clickhandler, NULL);
   }

You do not need to call the Wimp with version 380 in order to make use of the toolbar attachment functions, however you should check that the current Wimp version is at least 380 in order that the toolbar behaviour works as expected.
Notice that we must call a special function to load the window, but we can set up the normal event handlers.

Open the toolbar

   // Alt-click toggles the toolbar
   if ( Kbd_KeyDown(inkey_ALT) )
   {
      if ( event_wimpversion >= 380 )
      {
         Wimp_GetWindowState(toolbar_window, &wstate);
         if ( !wstate.flags.data.open )
            toolbar_attach(); // not open? attach it to the main window
         else
            Window_Hide(toolbar_window); // open? close it
      }
      else
      {
         Error_Report(1, message_read("wimp.nonested"),
                      (float)( (float)event_wimpversion / (float)100) );
      }

      return TRUE;
   }

This code will make the toolbar visible, via a custom routine, or hide it (using the standard Window_Hide), or pop up a notification if the Wimp version is too old.

If you simply want to paste a toolbar onto the window, you could cut that down to:

   if ( event_wimpversion >= 380 )
      toolbar_attach();

Creating the toolbar

static window_handle toolbar_create(char *templname)
{
   // This is Window_Create, only we fudge a flag prior to creating the window.
  windowrec     *record;
  window_block  *windowptr;
  window_handle window;

  windowptr = Template_Clone(templname, 8);
  if (windowptr == NULL)
    return NULL;

  windowptr->flags.data.dummy23 = 1; // flag it as a "furniture" window
  windowptr->colours[0] = 0xFF;      // no outline
  Wimp_CreateWindow(windowptr, &window);

  record = (windowrec *) malloc(sizeof(windowrec));
  if (record == NULL)
     return NULL;

  LinkList_AddToHead(&window_listanchor, &(record->header));

  strncpy(record->templatename, templname, wimp_MAXNAME);
  record->templatename[wimp_MAXNAME] = 0;       /* Record of name for help   */

  record->window = window;                      /* Remember window handle    */
  record->memory = windowptr;                   /* remember to dealloc later */

  return(window);
}

Showing the toolbar

static void toolbar_attach(void)
{
   window_outline main_outline;
   window_state   wstate;

   // Okay, so the first thing we must do is locate the bottom left of the parent window ("main").
   main_outline.window = main_window;
   Wimp_GetWindowOutline(&main_outline);

   // Now pick up the state of the toolbar window
   Wimp_GetWindowState(toolbar_window, &wstate);
   wstate.openblock.behind = -1;

   // Fudge our on-screen dimensions
   wstate.openblock.screenrect.min.x = main_outline.screenrect.min.x + 2;   // Left
   wstate.openblock.screenrect.min.y = main_outline.screenrect.min.y + 2;   // Bottom
   wstate.openblock.screenrect.max.x = main_outline.screenrect.min.x + 248; // Right (width)
   wstate.openblock.screenrect.max.y = main_outline.screenrect.min.y + 38;  // Top (height)

   // Now we can't just call Wimp_OpenWindow() as it doesn't understand the extended flags, so...
   __asm
   {
      MOV   R1, &wstate.openblock
      MOV   R2, 0x4B534154
      MOV   R3, main_window
      MOV   R4, 0x00550000
      SWI   (SWI_Wimp_OpenWindow + XOS_Bit), {R1-R4}, {R0}, {LR, PSR}
   }

   return;
}

The first thing we do is to work out where the "main_window" is placed. This is the parent window of the toolbar. Next, we pick up the data block relating to the toolbar. The "openblock" (data passed to Wimp_OpenWindow) is manipulated to place the toolbar at the bottom left of the parent. The two +2s are to fudge the position a little so it looks better. The right and top position are also set accordingly from the size of the window.
We then drop to some inline assembler as the current DeskLib OpenWindow call does not support the extended API. That is to say, R2 is "TASK" (the magic value traditionally given to Wimp SWIs to indicate a better API is being used), R3 is a pointer to the parent window, and R4 specifies alignment to the lower left.

The Wimp needs the alignment to be specified as being lower right and the window to be touching the correct placement. If these conditions are both satisfied, it'll adjust the scroll bar accordingly.

Interacting with the toolbar

Caveats

It is your responsibility to check the Wimp version. Earlier (RISC OS 3.xx) Wimps do not support this functionality and won't work as expected (David Pilling did something complicated for Ovation where both the toolbar and the horizontal scroll bar were separate windows that moved with the main window, and thus behaved like a window with a toolbar in it - quite clever, but it complicated window handling as you can imagine...).

Theoretically you can have a toolbar on the right, or vertical toolbars at the top or bottom of the vertical scrollbar. One might suppose that it would be possible to have, for instance, two toolbars - to the left and right of the scrollbar, for instance. Or possibly a toolbar within the toolbar?

I hope this introduction to creating a toolbar with the nested Wimp helps to demonstrate some of the flexibility that you can use in your own programs.

Vanishing comments

A quiet December

Other times, I've probably been working on Manga. I'm in the course of removing all of the embedded messages and texts and getting it to use a Messages file. You know, in case somebody wants to translate it into French or something... ☺

Your comments:

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David Pilling, 18th December 2017, 22:38

Oh the agonies of that tool/scroll bar in Ovation (which might have been copied from Quark). Good idea to use the nested wimp.    I wonder if one could get rid of scroll bars. Doesn't RISC OS have this thing of scrolling with Adjust on the scroll bar. No scroll bars just drag the work area around. Of course why you'd do that with modern screens which are so much bigger than those of the late 80s.

Rick, 18th December 2017, 23:12

You could look at it that RISC OS took about a decade and a half to catch up with you? ;-)    Adjust clicking on the scroll bar engages two dimensional scrolling.  I think we might need scroll bars to indicate to people that there's more than visible in the window (and give an idea of roughly how much more).

Rob, 9th January 2018, 22:26

Damn. Sorry about the comments thing. I found 2.5G (!!) of bounce emails sitting in root's mailbox, so killed them. Also set up logrotate, which is keeping the log files you mentioned under control. Server is looking a little more healthy now.. :)

Rick, 9th January 2018, 23:09

It's okay about the comments. Gave me a chance to dust off my blog code and realise how much PHP I've forgotten. :-/    Damn this useless out-of-warranty memory I have installed...

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