flo_ui 0.1.0

Implementation-free user interface description library
Documentation 
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

use super::*;

use std::io::{Read, Result};
use futures::*;

#[derive(Clone)]
struct ImageStreamIterator {
    /// The bytes in the image data
    bytes: Arc<Vec<u8>>,

    /// Current position
    pos: usize
}

impl Iterator for ImageStreamIterator {
    type Item=u8;

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        if self.pos < self.bytes.len() {
            let res = (*self.bytes)[self.pos];
            self.pos += 1;
            Some(res)
        } else {
            None
        }
    }
}

impl Stream for ImageStreamIterator {
    type Item = u8;
    type Error = ();

    fn poll(&mut self) -> Poll<Option<u8>, ()> {
        use self::Async::*;

        Ok(Ready(self.next()))
    }
}

impl Read for ImageStreamIterator {
    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
        // Work out how many bytes to read
        let mut num_to_read = buf.len();
        if self.pos+num_to_read > self.bytes.len() {
            num_to_read = self.bytes.len()-self.pos;
        }

        // Copy to the buffer
        buf[..num_to_read].copy_from_slice(&self.bytes[self.pos..(self.pos+num_to_read)]);
        
        // Update the position
        self.pos += num_to_read;

        Ok(num_to_read)
    }
}

///
/// Represents an image whose data is stored in memory 
///
pub struct InMemoryImageData {
    /// The bytes making up this stream
    bytes: Arc<Vec<u8>>
}

impl InMemoryImageData {
    ///
    /// Creates a new image data object from a set of bytes
    /// 
    pub fn new(bytes: Vec<u8>) -> InMemoryImageData {
        InMemoryImageData {
            bytes: Arc::new(bytes)
        }
    }
}

impl From<Vec<u8>> for InMemoryImageData {
    fn from(bytes: Vec<u8>) -> InMemoryImageData {
        InMemoryImageData::new(bytes)
    }
}

impl From<Arc<Vec<u8>>> for InMemoryImageData {
    fn from(bytes: Arc<Vec<u8>>) -> InMemoryImageData {
        InMemoryImageData {
            bytes: bytes
        }
    }
}

impl<'a> From<&'a Arc<Vec<u8>>> for InMemoryImageData {
    fn from(bytes: &'a Arc<Vec<u8>>) -> InMemoryImageData {
        InMemoryImageData {
            bytes: Arc::clone(bytes)
        }
    }
}

impl ImageData for InMemoryImageData {
    fn read(&self) -> Box<Read+Send> {
        Box::new(ImageStreamIterator { bytes: self.bytes.clone(), pos: 0 })
    }

    fn read_future(&self) -> Box<Stream<Item=u8, Error=()>> {
        Box::new(ImageStreamIterator { bytes: self.bytes.clone(), pos: 0 })
    }
}

#[cfg(test)]
mod test {
    use super::*;
    use futures::executor;

    #[test]
    fn can_read_all_image_data() {
        let data_test       = InMemoryImageData::new(vec![1,2,3,4,5,6]);
        let read_data       = data_test.read_future();
        let read_collect    = read_data.collect();

        let bytes_back      = executor::spawn(read_collect).wait_future().unwrap();

        assert!(bytes_back == vec![1,2,3,4,5,6]);
    }
}