Python swi.block contents

I need to get the title of my python app main window.
The following code executes without errors:

  def debug(self, event, id_block, poll_block):
        bufsize = 16
        buffer = swi.block(bufsize)
        swi.swi(ToolBox_ObjectMiscOp, 'IIIbI',
                0, jvars.win_id, 12, buffer, bufsize) 
        win_title = buffer           
        print(f'from Catkin Debug request')
        print(f'    window title: {win_title}')

the output is:

 from Catkin Debug request
      window title: <swi.block object at 0x553010>

Python is printing out the class of the block object.
How can I get at the contents?

@ John

How can I get at the contents?

I am not on a RISC OS system to try the following code, so apologies if it may not work, however have your tried the following?

def debug(self, event, id_block, poll_block):
    bufsize = 16
    buffer = swi.block(bufsize)
    swi.swi(ToolBox_ObjectMiscOp, 'IIIbI',
            0, jvars.win_id, 12, buffer, bufsize) 
    win_title = buffer.tostring(3)  # try to convert the data from the first element into a string
    print(f'from Catkin Debug request')
    print(f'    window title: {win_title}')

I added a comment to the line that looks a little suspicious to me.

Where .tostring is to process the content of the buffer to a string and 3 is just the block index in the buffer from where to start, you can use 0 or wherever the window title might be located.

Basically the issue is that you ARE refering to the full buffer object insted of its content, so you need to add a method to get to the content.

Also, quick question, isn’t reason 12 = reserved?

HTH

Also, quick question, isn’t reason 12 = reserved?

Easy answer first:

Module:Window
Syntax: Window_GetTitle
Veneer: window_get_title>

On entry:
    r0 = flags
    r1 = window object ID
    r2 = 12
    r3 = pointer to buffer
    r4 = size of buffer

On exit:
    if r3=0 r4=size of buffer requd, else buffer contains title text.

Purpose:Method read the title text in a window's title bar.

Basically the issue is that you ARE refering to the full buffer object insted of its content, so you need to add a method to get to the content.

tried .tostring method without conspicuous success.

Here is a list of methods for ‘buffer’ reported by dir(buffer):

buffer attrs:
    ['__add__', '__class__', '__delattr__', '__delitem__',
    '__dir__', '__doc__', '__eq__', '__format__', '__ge__',
    '__getattribute__', '__getitem__', '__gt__', '__hash__',
    '__init__', '__init_subclass__', '__le__', '__len__',
    '__lt__' ?=>

The ‘__getitem__’ method looks promising
but I have not been able to find any documentation for it.

wasn’t there a StrongHelp manual for Python?

I think Andrew Conroy may have a copy of it, I don’t know, I usually read the C source here:

https://github.com/c-jo/cpython/blob/riscos/RISCOS/swimodule.c

wasn’t there a StrongHelp manual for Python?
I think Andrew Conroy may have a copy of it

One of the earlier versions of Python came with a SH manual, I’ve no idea how horribly out of date it will be now though.

One of the earlier versions of Python came with a SH manual, I’ve no idea how horribly out of date it will be now though.

Ha, thanks Andrew. Sorry, I didn’t know that. As I mentioned, I just look at the specific swimodule.c which contains the latest and greatest details.

This excerpt from the Toolbox library might help:

def _miscop_get_string(self, op):
            buf_size = swi.swi('Toolbox_ObjectMiscOp', 'IiIi00;.....i',
                               0, self.menu.id, op, self.id)
            buf = swi.block((buf_size + 3) // 4)
            swi.swi('Toolbox_ObjectMiscOp', 'IiIibi',
                    0, self.menu.id, op, self.id, buf, buf_size)
            return buf.nullstring()

Thanks to everybody who has suggested solutions to this problem.
After a lot of work which included learning C:-) so that I might make sense of the swimodule.c code, and discussions at the “proggie parley” last night I have concluded that my copy of the ToolBox does not support what I want to do.

The python Toobox has has seen a lot of changes since I uploaded it from PackMan. Unfortunately the changes have not been packaged for download so I am having a think about what to do.

Meanwhile Lauren has just forked the repository in order to commit some more changes.

Think I will wait a bit and see what comes along.

The main sticking point to the next Toolbox update is the signedness of the values returned by the various toolbox things. At the moment they are unsigned, but I’m now pretty sure at least one of them should be unsigned. The main issue with this is if you need to call the SWI yourself and the I/i doesn’t match, it all goes bang.

TBH it might be easier to fix the swi module itself to handle either case.