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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
//! Cursor utilities
//!
//! This module contains bindings to the `libwayland-cursor.so` library.
//!
//! These utilities allow you to load cursor images in order to match
//! your cursors to the ones of the system.
//!
//! First of all, the function `load_theme` will allow you to load a
//! `CursorTheme`, which represents the full cursor theme.
//!
//! From this theme, you can load a specific `Cursor`, which can contain
//! several images if the cursor is animated. It also provides you with the
//! means of querying which frame of the animation should be displayed at
//! what time, as well as handles to the buffers containing these frames, to
//! attach them to a wayland surface.

use protocol::wl_buffer::WlBuffer;
use protocol::wl_shm::WlShm;
use std::ffi::{CStr, CString};
use std::marker::PhantomData;
use std::ops::Deref;
use std::os::raw::c_int;
use std::ptr;
use wayland_sys::cursor::*;
use Proxy;

/// Checks if the wayland-cursor library is available and can be used
///
/// Trying to call any function of this module if the library cannot
/// be used will result in a panic.
pub fn is_available() -> bool {
    is_lib_available()
}

/// Represents a cursor theme loaded from the system.
pub struct CursorTheme {
    theme: *mut wl_cursor_theme,
}

unsafe impl Send for CursorTheme {}

/// Attempts to load a cursor theme.
///
/// If no name is given or the requested theme is not found, the default theme
/// will be loaded.
///
/// Other arguments are the requested size for the cursor images (ex: 16)
/// and a handle to the global `WlShm` object.
///
/// # Panics
///
/// - Panics if the `wayland-cursor` lib is not available
///   (see `is_available()` function) in this module.
/// - Panics in case of memory allocation failure.
/// - Panics if `name` contains an interior null.
pub fn load_theme(name: Option<&str>, size: u32, shm: &WlShm) -> CursorTheme {
    let ptr = if let Some(theme) = name {
        let cstr = CString::new(theme).expect("Theme name contained an interior null.");
        unsafe {
            ffi_dispatch!(
                WAYLAND_CURSOR_HANDLE,
                wl_cursor_theme_load,
                cstr.as_ptr(),
                size as c_int,
                shm.as_ref().c_ptr()
            )
        }
    } else {
        unsafe {
            ffi_dispatch!(
                WAYLAND_CURSOR_HANDLE,
                wl_cursor_theme_load,
                ptr::null(),
                size as c_int,
                shm.as_ref().c_ptr()
            )
        }
    };

    assert!(!ptr.is_null(), "Memory allocation failure while loading a theme.");

    CursorTheme { theme: ptr }
}

impl CursorTheme {
    /// Retrieves a cursor from the theme.
    ///
    /// Returns `None` if this cursor is not provided by the theme.
    ///
    /// # Panics
    ///
    /// Panics if the name contains an interior null.
    pub fn get_cursor(&self, name: &str) -> Option<Cursor> {
        let cstr = CString::new(name).expect("Cursor name contained an interior null.");
        let ptr = unsafe {
            ffi_dispatch!(
                WAYLAND_CURSOR_HANDLE,
                wl_cursor_theme_get_cursor,
                self.theme,
                cstr.as_ptr()
            )
        };
        if ptr.is_null() {
            None
        } else {
            Some(Cursor {
                _theme: PhantomData,
                cursor: ptr,
            })
        }
    }
}

impl Drop for CursorTheme {
    fn drop(&mut self) {
        unsafe {
            ffi_dispatch!(WAYLAND_CURSOR_HANDLE, wl_cursor_theme_destroy, self.theme);
        }
    }
}

/// A cursor from a theme. Can contain several images if animated.
pub struct Cursor<'a> {
    _theme: PhantomData<&'a CursorTheme>,
    cursor: *mut wl_cursor,
}

unsafe impl<'a> Send for Cursor<'a> {}

impl<'a> Cursor<'a> {
    /// Returns the name of this cursor.
    pub fn name(&self) -> String {
        let name = unsafe { CStr::from_ptr((*self.cursor).name) };
        name.to_string_lossy().into_owned()
    }

    /// Returns the number of images contained in this animated cursor
    pub fn image_count(&self) -> usize {
        let count = unsafe { (*self.cursor).image_count };
        count as usize
    }

    /// Returns which frame of an animated cursor should be displayed at a given time.
    ///
    /// The time is given in milliseconds after the beginning of the animation.
    pub fn frame(&self, duration: u32) -> usize {
        let frame = unsafe { ffi_dispatch!(WAYLAND_CURSOR_HANDLE, wl_cursor_frame, self.cursor, duration) };
        frame as usize
    }

    /// Returns the frame number and its remaining duration.
    ///
    /// Same as `frame()`, but also returns the amount of milliseconds this
    /// frame should continue to be displayed.
    pub fn frame_and_duration(&self, duration: u32) -> (usize, u32) {
        let mut out_duration = 0u32;
        let frame = unsafe {
            ffi_dispatch!(
                WAYLAND_CURSOR_HANDLE,
                wl_cursor_frame_and_duration,
                self.cursor,
                duration,
                &mut out_duration as *mut u32
            )
        } as usize;
        (frame, out_duration)
    }

    /// Returns a `CursorImageBuffer` containing the given image of an animation.
    ///
    /// It can be attached to a surface as a classic `WlBuffer`.
    ///
    /// Returns `None` if the frame is out of bounds.
    ///
    /// Note: destroying this buffer (using the `destroy` method) will corrupt
    /// your theme data, so you might not want to do it.
    pub fn frame_buffer(&self, frame: usize) -> Option<CursorImageBuffer> {
        if frame >= self.image_count() {
            None
        } else {
            unsafe {
                let image = *(*self.cursor).images.offset(frame as isize);
                let ptr = ffi_dispatch!(WAYLAND_CURSOR_HANDLE, wl_cursor_image_get_buffer, image);
                let buffer = Proxy::from_c_ptr(ptr).into();

                Some(CursorImageBuffer {
                    _cursor: PhantomData,
                    buffer,
                })
            }
        }
    }

    /// Returns the metadata associated with a given frame of the animation.
    ///
    /// The tuple contains: `(width, height, hotspot_x, hotspot_y, delay)`
    ///
    /// Returns `None` if the frame is out of bounds.
    pub fn frame_info(&self, frame: usize) -> Option<(u32, u32, u32, u32, u32)> {
        if frame >= self.image_count() {
            None
        } else {
            let image = unsafe { &**(*self.cursor).images.offset(frame as isize) };
            Some((
                image.width,
                image.height,
                image.hotspot_x,
                image.hotspot_y,
                image.delay,
            ))
        }
    }
}

/// A buffer containing a cursor image.
///
/// You can access the `WlBuffer` via `Deref`.
///
/// Note that this proxy will be considered as "unmanaged" by the crate, as such you should
/// not try to act on it beyond assigning it to `wl_surface`s.
pub struct CursorImageBuffer<'a> {
    _cursor: PhantomData<&'a Cursor<'a>>,
    buffer: WlBuffer,
}

unsafe impl<'a> Send for CursorImageBuffer<'a> {}

impl<'a> Deref for CursorImageBuffer<'a> {
    type Target = WlBuffer;
    fn deref(&self) -> &WlBuffer {
        &self.buffer
    }
}