data_device: move default_action_chooser into smithay

anvil/src/main.rs

@@ -16,7 +16,6 @@ use smithay::wayland_server::{calloop::EventLoop, Display};
 mod shaders;
 mod glium_drawer;
 mod input_handler;
-mod misc;
 #[cfg(feature = "tty_launch")]
 mod raw_drm;
 mod shell;

anvil/src/misc.rs

@@ -1,19 +0,0 @@
-use smithay::wayland_server::protocol::wl_data_device_manager::DndAction;
-
-pub fn dnd_action_chooser(available: DndAction, preferred: DndAction) -> DndAction {
-    // if the preferred action is valid (a single action) and in the available actions, use it
-    // otherwise, follow a fallback stategy
-    if [DndAction::Move, DndAction::Copy, DndAction::Ask].contains(&preferred)
-        && available.contains(preferred)
-    {
-        preferred
-    } else if available.contains(DndAction::Ask) {
-        DndAction::Ask
-    } else if available.contains(DndAction::Copy) {
-        DndAction::Copy
-    } else if available.contains(DndAction::Move) {
-        DndAction::Move
-    } else {
-        DndAction::empty()
-    }
-}

anvil/src/udev.rs

@@ -42,7 +42,7 @@ use smithay::{
     input::Libinput,
     wayland::{
         compositor::CompositorToken,
-        data_device::{init_data_device, set_data_device_focus},
+        data_device::{default_action_chooser, init_data_device, set_data_device_focus},
         output::{Mode, Output, PhysicalProperties},
         seat::{Seat, XkbConfig},
         shm::init_shm_global,
@@ -111,7 +111,7 @@ pub fn run_udev(mut display: Display, mut event_loop: EventLoop<()>, log: Logger
     init_data_device(
         &mut display.borrow_mut(),
         |_| {},
-        ::misc::dnd_action_chooser,
+        default_action_chooser,
         log.clone(),
     );
 

anvil/src/winit.rs

@@ -11,7 +11,7 @@ use smithay::{
         winit,
     },
     wayland::{
-        data_device::{init_data_device, set_data_device_focus},
+        data_device::{default_action_chooser, init_data_device, set_data_device_focus},
         output::{Mode, Output, PhysicalProperties},
         seat::{Seat, XkbConfig},
         shm::init_shm_global,
@@ -54,7 +54,7 @@ pub fn run_winit(display: &mut Display, event_loop: &mut EventLoop<()>, log: Log
 
     let (compositor_token, _, _, window_map) = init_shell(display, log.clone());
 
-    init_data_device(display, |_| {}, ::misc::dnd_action_chooser, log.clone());
+    init_data_device(display, |_| {}, default_action_chooser, log.clone());
 
     let (mut seat, _) = Seat::new(display, "winit".into(), log.clone());
 

src/wayland/data_device/mod.rs

@@ -23,6 +23,27 @@
 //!   for your clients
 //! - the freestanding function `start_dnd` allows you to initiate a drag'n'drop event from the compositor
 //!   itself and receive interactions of clients with it via an other dedicated callback.
+//!
+//! ## Initialization
+//!
+//! ```
+//! # extern crate wayland_server;
+//! # #[macro_use] extern crate smithay;
+//! use smithay::wayland::data_device::{init_data_device, default_action_chooser};
+//!
+//! # fn main(){
+//! # let mut event_loop = wayland_server::calloop::EventLoop::<()>::new().unwrap();
+//! # let mut display = wayland_server::Display::new(event_loop.handle());
+//! // init the data device:
+//! init_data_device(
+//!     &mut display,           // the display
+//!     |dnd_event| { /* a callback to react to client DnD/selection actions */ },
+//!     default_action_chooser, // a closure to choose the DnD action depending on clients
+//!                             // negociation
+//!     None                    // insert a logger here
+//! );
+//! # }
+//! ```
 
 use std::os::unix::io::RawFd;
 use std::sync::{Arc, Mutex};
@@ -423,3 +444,25 @@ where
         dd_data,
     )
 }
+
+/// A simple action chooser for DnD negociation
+///
+/// If the preferred action is available, it'll pick it. Otherwise, it'll pick the first
+/// available in the following order: Ask, Copy, Move.
+pub fn default_action_chooser(available: DndAction, preferred: DndAction) -> DndAction {
+    // if the preferred action is valid (a single action) and in the available actions, use it
+    // otherwise, follow a fallback stategy
+    if [DndAction::Move, DndAction::Copy, DndAction::Ask].contains(&preferred)
+        && available.contains(preferred)
+    {
+        preferred
+    } else if available.contains(DndAction::Ask) {
+        DndAction::Ask
+    } else if available.contains(DndAction::Copy) {
+        DndAction::Copy
+    } else if available.contains(DndAction::Move) {
+        DndAction::Move
+    } else {
+        DndAction::empty()
+    }
+}