Cursor Animation

{$codepage utf-8}
{$H+}

program test_cursor;

uses
    BearLibTerminal, sysutils, dateutils;

var
    cx, cy: Integer;

const
    CURSOR_LAYER = 2;
    ANIMATION_DELAY = 25;

procedure on_animation();
var
    previous_layer: Integer;
begin
    previous_layer := terminal_state(TK_LAYER);
    terminal_layer(CURSOR_LAYER);
    terminal_clear_area(0, 0, terminal_state(TK_WIDTH), terminal_state(TK_HEIGHT));
    if MillisecondOfTheDay(Now) mod 1000 > 500 then
        terminal_put(cx, cy, '_')
    else
        terminal_put(cx, cy, 0);
    terminal_layer(previous_layer);
end;

function terminal_read_animated(): Integer;
begin
    while not terminal_has_input() do begin
        on_animation();
        terminal_refresh();
        terminal_delay(ANIMATION_DELAY);
    end;
    terminal_read_animated := terminal_read();
end;

begin
    terminal_open();
    terminal_set('input.filter = keyboard, close');

    cx := 2; cy := 1;

    cx := cx + terminal_print(cx, cy, 'Whatever');
    repeat
        terminal_refresh();
    until (terminal_read_animated() = TK_CLOSE);

    terminal_close();
end.