NAME
SYNOPSIS
DESCRIPTION
REQUIREMENTS
METHODS
CONSTANTS
- EXPORT
- Exportable constants
KNOWN BUGS
SEE ALSO
AUTHOR
THANKS
COPYRIGHT AND LICENSE

NAME

X11::Aosd - libaosd binding for Cairo powered on screen display

SYNOPSIS

  use X11::Aosd ':all';

  my $aosd = X11::Aosd->new;

  $aosd->set_transparency(TRANSPARENCY_COMPOSITE);

  $aosd->set_position_with_offset(
    COORDINATE_CENTER,
    COORDINATE_CENTER,
    200, 200, 0, 0
  );

  $aosd->set_renderer(sub {
    my ($cr) = @_;
    $cr->set_source_rgba (1, 0, 0, 0.5);
    $cr->rectangle (0, 0, 200, 200);
    $cr->fill;
  });

  $aosd->show;
  $aosd->loop_for(2000);

DESCRIPTION

This Perl extensions binds the aosd library. For now just the Cairo part is supported, Pango support may be added later.

REQUIREMENTS

This module needs libaosd version 2.4.0 or better installed on your system. Additionally the following Perl modules are required:

  Glib
  Cairo
  Gtk2

METHODS

Constructor

$aosd = X11::Aosd->new(): The constructor takes no arguments. Everthing is controlled through the $aosd object.

Object configurators

$aosd->set_name($name, $class)

Sets XClassHint name and class of the window.

$aosd->set_transparency($mode)

Sets the transparency mode of the window. Valid modes are:

  TRANSPARENCY_COMPOSITE
  TRANSPARENCY_FAKE
  TRANSPARENCY_NONE

$aosd->set_geometry($x, $y, $width, $height)

Changes absolute position and dimensions of the window.

$aosd->set_position_offset($x_offset, $y_offset)

Changes the current position by moving the window by the given offsets.

$aosd->set_position_with_offset($abscissa, $ordinate, $width, $height, $x_offset, $y_offset)

Changes window position and dimension on the screen by positioning it horizontally ($abscissa) and vertically ($ordinate) adding the given offsets ($x_offset, $y_offset).

Use these constants to specify the window attachment parameters $abscissa and $ordinate.

  COORDINATE_CENTER
  COORDINATE_MAXIMUM
  COORDINATE_MINIMUM

$aosd->set_renderer($renderer, $user_data)

Apply a renderer to the OSD window, which is subroutine resp. a closure with this signature:

  sub renderer {
    my ($cr, $user_data) = @_;
    ...
  }

$cr is the Cairo surface managed by libaosd you can draw on. Anytime the surface needs to be (re)drawn it's called. You can force calling it using the $aosd->render method (or even better $aosd->update - see below).

$aosd->set_mouse_event_cb($callback, $user_data)

libaosd catches mouse clicks on the window. You can handle these events by specifiying a callback, which has the following signature:

  sub mouse_event {
    my ($event, $user_data) = @_;
    ...
  }

$event is a hash reference with the following keys (all integers) corresponding to libaosd's AosdMouseEvent structure:

  x
  y
  x_root
  y_root
  send_event
  button
  int

$aosd->set_hide_upon_mouse_event($boolean)

Set this to a true value if the OSD window should automatically hide on mouse click.

Object inspectors

($name, $class) = $aosd->get_name

Returns XClassHint name and class of the window.

($trans) = $aosd->get_transparency;

Returns the current transparency mode of the window. Valid modes are:

  TRANSPARENCY_COMPOSITE
  TRANSPARENCY_FAKE
  TRANSPARENCY_NONE

($x, $y, $width, $height) = $aosd->get_geometry;

Returns position and dimensions of the window.

($width, $height) = $aosd->get_screen_size;

Returns the dimensions of the X screen.

($shown) = $aosd->get_is_shown;

Returns a boolean whether the window is currently visible or not.

Object manipulators

$aosd->render: This actually renders the window. Note that the X mainloop need to run at least one time ($aosd->loop_once) to take rendering effect. You can use the $aosd->update convenience method for render + loop_once.
$aosd->show: Shows the OSD window (and renders it, if not rendered yet).
$aosd->hide: Hides the OSD window.

Mainloop processing

libaosd can take control of the mainloop, but note that your program blocks when libaosd's mainloop is running. For simple programs libaosd's maninloop is Ok, but for more complex situations, e.g. drawing an animation, you should use Glib's mainloop instead.

Animations are always controlled through timeouts, so with Glib's mainloop this will look this way:

  my $main_loop = Glib::MainLoop->new;

  my $animation_step = 0;

  $aosd->set_renderer(sub {
    my ($cr) = @_;
    #-- draw animation corresponding to $animation_step.
    ...
    #-- quit mainloop when animation is finished
    $main_loop->quit if $animation_step == $finished;
  });

  Glib::Timeout->add (20, sub {
    ++$animation_step;
    $aosd->update;
  });

  $main_loop->run;

Of course you don't need to quit the mainloop at the end of the animation. This is just for the simplicity of the example ;)

$aosd->loop_once: Run the X mainloop one time. Needs to be called after rendering. You can use the $aosd->update convenience method for render + loop_once.
$aosd->loop_for($loop_ms): Runs the X mainloop for $loop_ms milliseconds, blocking your program for this amount of time.

Automatic object manipulator

$aosd->flash($fade_in_ms, $full_ms, $fade_out_ms)

Fades the OSD window in in $fade_in_ms milliseconds, let it stay for $full_ms milliseconds and fades it out in $fade_out_ms milliseconds.

$aosd->update

This is a convenience method for the combination:

  $aosd->render;
  $aosd->loop_once;

CONSTANTS

EXPORT

None by default.

Exportable constants

Catch these with the ':all' import tag.

Required for set_position_with_offset():

  COORDINATE_CENTER
  COORDINATE_MAXIMUM
  COORDINATE_MINIMUM

Required for set_transparency():

  TRANSPARENCY_COMPOSITE
  TRANSPARENCY_FAKE
  TRANSPARENCY_NONE

KNOWN BUGS

Currently attached callbacks leak memory which won't be freed, even if the X11::Aosd instance is destroyed (note: attaching the callback leaks, not calling it, so it's not that evil ;).

AUTHOR

Joern Reder <joern AT zyn DOT de>

THANKS

Many thanks to Thorsten Schönfeld, who supported me with providing details of the Glib/Cairo/Perl binding stuff, which I didn't fully understand by myself ;)

COPYRIGHT AND LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.

CPAN RT