Look, and the window

The keywords every element takes, the palette, and what the window itself brings.

The keywords every element takes

Fifteen properties ride on every element under one name and one meaning: width, height, min_width, max_width, disabled, theme, animate, easing, enter, exit, col_span, row_span, role, a11y_label, tooltip.

    button("save", disabled => $busy, tooltip => "write the file", width => 120);
    text("total", role => "heading", a11y_label => "the running total");

An element that owns one of those names under its own meaning keeps it: a text's width is the text's, and the box leaves it alone.

Themes and animation

The palette and any movement are keywords too.

    column(@cells, theme => "dark");
    text("saved", animate => 150, easing => "out", enter => true);

theme swaps the palette under one part of the screen. animate is how many milliseconds a change takes and easing is its shape (linear, in, out, inOut), with enter and exit for what appears and disappears. A color is a hex string or one of the palette's own names (accent, muted, danger), so a screen written once follows both palettes.

The window

Four things come from the window itself, declared after the app is made and before run:

use Rakugan;

class Keys {
    use Rakugan;
    field $count = 0;
    field $saved = 0;
    field $last  = "-";

    method save  { $saved = $count }
    method clear { $count = 0; $saved = 0 }

    method typed :Sig(Str) ($key) {
        $last = $key;
    }

    method view {
        return column(
            text("count: $count  saved: $saved"),
            text("last key: $last"),
            button("+1", on_click => sub { $count += 1 }),
            spacing => 8,
            padding => 12,
        );
    }
}

my $app = Keys->new;

menu_item("Count", "Clear", sub { $app->clear });
shortcut("cmd+s", sub { $app->save });
on_key(sub ($chord) { $app->typed($chord) });

run($app, title => "keys");

on_file_drop(sub ($path) { ... }) is the fourth. These live for as long as the app does.

The clipboard is a pair of calls:

    clipboard_set_text($text);
    $text = clipboard_get_text();

A file dialog waits for a person, so it belongs off the window's thread, which is what task is for:

    task(sub { fs_open_dialog("Choose a file") },
         on_done => sub ($path) { $self->took($path) });
    task(sub { fs_save_dialog("notes.txt") },
         on_done => sub ($path) { $self->write_to($path) });

A headless script answers a dialog with a file:<path> step, which is what makes a dialog a checked interaction like any other.

Sound is a file played and then forgotten:

    audio_play("demo/assets/sound/blip.wav");        # as it was recorded
    audio_play("demo/assets/sound/blast.wav", 0.4);  # at a level, 0.0 to 1.0
    audio_stop();

The call answers at once; nothing waits for the end of the sound. A run under a script is silent — a gate must not need a machine with speakers — and a machine with no audio device, or a file that cannot be read, plays nothing rather than failing the app. WAV is what the engine decodes.