Crate wayland_window [−] [src]
Wayland Window, a minimalistic decoration-drawing library for wayland applications.
This crate is only usable in conjuction of the
wayland-client
crate.
Creating a window with decorations
Creating a decorated frame for your window is simply done using the provided init function:
use wayland_window::create_frame; // if using the legacy wl_shell global let shell = Shell::Wl(my_wl_shell); // if using the new not-yet-stable xdg_shell let shell = Shell::Xdg(my_xdh_shell); let frame = create_frame( &mut event_queue, my_implementation, my_implementation_data, &my_surface, width, height, &compositor, &subcompositor, &shm, &shell, Some(seat) ).unwrap(); // creation can fail
As you can see, you need to pass several references to global objects as well as a WlSeat
.
It is required for the library to be able to create the surfaces to draw the borders, react
to user input in the borders, for resizing and move. It will use the events provided on the
seat you passed as argument. (So if you are on a setup with more than one pointer,
only the one associated with this seat will be able to resize the window).
See next section for example use of the my_implementation
and
my_implementation_data
arguments.
Configure events
The Frame
object will not resize your window itself, as it cannot do it.
When the user clicks on a border and starts a resize, the server will start to generate a
number of configure
events on the shell surface. You'll need to process the events generated
by the surface to handle them.
The wayland server can (and will) generate a ton of configure
events during a single
WlDisplay::dispatch()
if the user is currently resizing the window. You are only required to
process the last one, and if you try to handle them all your aplication will be very
laggy.
The proper way is to accumulate them in your subhandler, overwriting the the previous one each time, and manually checking if one has been received in the main loop of your program. For example like this
use wayland_window::{Frame, create_frame, FrameImplementation}; // define a state to accumulate sizes struct ConfigureState { new_size: Option<(i32,i32)> } // insert it in your event queue state let configure_token = event_queue.state().insert(ConfigureState { new_size: None }); // use it in your implementation: let my_implementation = FrameImplementation { configure: |evqh, token, _, newsize| { let configure_state: &mut ConfigureState = evqh.state().get_mut(token); configure_state.new_size = newsize; }, close: |_, _| { /* ... */ }, refresh: |_, _| { /* ... */ } }; // create the decorated surface: let frame = create_frame( &mut event_queue, // the event queue my_implementation, // our implementation configure_token.clone(), // the implementation data &my_surface, width, height, &compositor, &subcompositor, &shm, &shell, Some(seat) ).unwrap(); // then, while running your event loop loop { display.flush().unwrap(); event_queue.dispatch().unwrap(); // check if a resize is needed let mut configure_state = event_queue.state().get_mut(&configure_token); if let Some((w, h)) = configure_state.new_size.take() { // The compositor suggests we take a new size of (w, h) // Handle it as needed (see next section) } }
Resizing the surface
When resizing your main surface, you need to tell the Frame
that it
must update its dimensions. This is very simple:
// update your contents size (here by attaching a new buffer) surface.attach(Some(&new_buffer)); surface.commit(); // update the borders size frame.resize(width, height); // refresh the frame so that it actually draws the new size frame.refresh();
If you do this as a response of a configure
event, note the following points:
- You do not have to respect the exact sizes provided by the compositor, it is just a hint. You can even ignore it if you don't want the window to be resized.
- In case you chose to ignore the resize, it can be appropiate to still resize your window to its current size (update the buffer to the compositor), as the compositer might have resized your window without telling you.
- The size hint provided to your implementation is a size hint for the interior of the
window: the dimensions of the border has been subtracted from the hint the compositor
gave. If you need to compute dimensions taking into account the sizes of the borders,
you can use the
add_borders
andsubtract_borders
functions.
Structs
Frame |
A decorated frame for a window |
FrameImplementation |
For handling events that occur to a Frame. |
Enums
Configure |
Configure data for a decorated surface handler. |
Shell |
Enum over the supported shells |
State |
Possible requested state for a window |
Functions
add_borders |
Adds the border dimensions to the given dimensions. |
create_frame |
Create a decoration frame for a wl_surface |
subtract_borders |
Subtracts the border dimensions from the given dimensions. |