TextView / Scroll Example doesn't work

[Scimon]

The TextView in an ScrolledWindow exmaple fails. It would appear that TestViews can't be editted within the code giving an error of "Cannot modify an immutable Str ()"

[jonathanstowe]

I think you're going to have to talk us through this as I can't get the as-is examples/17-scrolled-window-with-textview.p6 to do anything untoward.

[Scimon]

Sorry, was mostly working through my Advent calender article at the time (suprise guess what it's about?).
I'll investigate further.

[Scimon]

Ok. Using GTK::Simple:ver<0.1.10> (from zef). I ran the following code :

#!/usr/bin/env perl6

use v6;
use GTK::Simple;
use GTK::Simple::App;

my $app = GTK::Simple::App.new(title=> 'Test');
my $text = GTK::Simple::TextView.new(text=>'Original');
my $button = GTK::Simple::ToggleButton.new(label=>'Update');

$button.clicked.tap( { $text.text = "New" } );

$app.set-content(
    GTK::Simple::VBox.new( 
	$text,
	$button,
    )
);
$app.border-width = 20;
$app.run;

The App opens but the Text box is empty and when I click the update I get the following :

Cannot modify an immutable Str ()
  in block <unit> at src/perl6/desktop-apps/text-test.p6 line 11

Perl6 version 2018.11 built on MoarVM version 2018.11

[Xliff]

This is due to the fact that the accessor method:

method text() {
    Proxy.new:
        FETCH => {
            gtk_text_buffer_get_text($!buffer, self!start-iter(),
                self!end-iter(), 1)
        },
        STORE => -> \c, \text {
            gtk_text_buffer_set_text($!buffer, text.Str, -1);
        }
}

Is not "is rw". I think this code worked up until a recent commit of Perl6, where the bug that allowed this to work without the 'rw' trait was fixed.

[jonathanstowe]

Yeah that's entirely what it is.

Let me have a quick look at that.

[jonathanstowe]

As it stands the constructor for the TextView doesn't do anything with a text argument. Arguably it should but that should probably be handled separately as it will require a bit of a rework of the whole class.