1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
use wayland_client::protocol::wl_data_device_manager::DndAction;
use wayland_client::protocol::wl_data_offer;
use wayland_client::NewProxy;

use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
use std::sync::{Arc, Mutex};
use std::{fs, io};

struct Inner {
    mime_types: Vec<String>,
    actions: DndAction,
    current_action: DndAction,
    serial: u32,
}

/// A data offer for receiving data though copy/paste or
/// drag and drop
pub struct DataOffer {
    pub(crate) offer: wl_data_offer::WlDataOffer,
    inner: Arc<Mutex<Inner>>,
}

impl DataOffer {
    pub(crate) fn new(offer: NewProxy<wl_data_offer::WlDataOffer>) -> DataOffer {
        let inner = Arc::new(Mutex::new(Inner {
            mime_types: Vec::new(),
            actions: DndAction::None,
            current_action: DndAction::None,
            serial: 0,
        }));
        let inner2 = inner.clone();
        let offer = offer.implement_closure(
            move |event, _| {
                use self::wl_data_offer::Event;
                let mut inner = inner2.lock().unwrap();
                match event {
                    Event::Offer { mime_type } => {
                        inner.mime_types.push(mime_type);
                    }
                    Event::SourceActions { source_actions } => {
                        inner.actions = DndAction::from_bits_truncate(source_actions);
                    }
                    Event::Action { dnd_action } => {
                        inner.current_action = DndAction::from_bits_truncate(dnd_action);
                    }
                    _ => unreachable!(),
                }
            },
            (),
        );

        DataOffer { offer, inner }
    }

    /// Access the list of mime types proposed by this offer
    pub fn with_mime_types<F, T>(&self, f: F) -> T
    where
        F: FnOnce(&[String]) -> T,
    {
        let inner = self.inner.lock().unwrap();
        f(&inner.mime_types)
    }

    /// Get the list of available actions for this offer
    pub fn get_available_actions(&self) -> DndAction {
        self.inner.lock().unwrap().actions
    }

    /// Get the currently set final action for this offer
    pub fn get_current_action(&self) -> DndAction {
        self.inner.lock().unwrap().current_action
    }

    /// Accept a mime type for receiving data through this offer
    pub fn accept(&self, mime_type: Option<String>) {
        let serial = self.inner.lock().unwrap().serial;
        self.offer.accept(serial, mime_type);
    }

    /// Request to receive the data of a given mime type
    ///
    /// You can do this several times, as a reaction to motion of
    /// the dnd cursor, or to inspect the data in order to choose your
    /// response.
    ///
    /// Note that you should *not* read the contents right way in a
    /// blocking way, as you may deadlock your application doing so.
    /// At least make sure you flush your events to the server before
    /// doing so.
    ///
    /// Fails if too many file descriptors were already open and a pipe
    /// could not be created.
    pub fn receive(&self, mime_type: String) -> Result<ReadPipe, ()> {
        use nix::fcntl::OFlag;
        use nix::unistd::{close, pipe2};
        // create a pipe
        let (readfd, writefd) = pipe2(OFlag::O_CLOEXEC).map_err(|_| ())?;

        self.offer.receive(mime_type, writefd);

        if let Err(err) = close(writefd) {
            eprintln!("[SCTK] Data offer: failed to close write pipe: {}", err);
        }

        Ok(unsafe { FromRawFd::from_raw_fd(readfd) })
    }

    /// Notify the send and compositor of the dnd actions you accept
    ///
    /// You need to provide the set of supported actions, as well as
    /// a single preferred action.
    pub fn set_actions(&self, supported: DndAction, preferred: DndAction) {
        self.offer
            .set_actions(supported.to_raw(), preferred.to_raw());
    }

    /// Notify that you are finished with this offer, and will no longer
    /// be using it
    ///
    /// Note that it is a protocol error to finish if no action or mime
    /// type was accepted.
    pub fn finish(&self) {
        self.offer.finish();
        self.offer.destroy();
    }
}

impl Drop for DataOffer {
    fn drop(&mut self) {
        self.offer.destroy();
    }
}

/// A file descriptor that can only be written to
pub struct ReadPipe {
    file: fs::File,
}

impl io::Read for ReadPipe {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        self.file.read(buf)
    }
}

impl FromRawFd for ReadPipe {
    unsafe fn from_raw_fd(fd: RawFd) -> ReadPipe {
        ReadPipe {
            file: FromRawFd::from_raw_fd(fd),
        }
    }
}

impl AsRawFd for ReadPipe {
    fn as_raw_fd(&self) -> RawFd {
        self.file.as_raw_fd()
    }
}

impl IntoRawFd for ReadPipe {
    fn into_raw_fd(self) -> RawFd {
        self.file.into_raw_fd()
    }
}