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

//! Support for scrolling ascii text horizontally.
//!
//! # Examples
//!
//! ```ignore
//! use rmicrobit::prelude::*;
//! use rmicrobit::display::{MicrobitDisplay, MicrobitFrame};
//! use rmicrobit::graphics::scrolling_text::ScrollingStaticText;
//! let mut display = MicrobitDisplay::new(...);
//! let mut scroller = ScrollingStaticText::default();
//! let frame = MicrobitFrame::default();
//! scroller.set_message(b"Hello, world!");
//! while !scroller.is_finished() {
//!     // every 50ms or so
//!     scroller.tick();
//!     frame.set(scroller);
//!     display.set_frame(frame);
//! }
//! ```
//!
//! See examples/scroll_text.rs for a complete example.

use tiny_led_matrix::Render;

use crate::graphics::font;
use crate::graphics::image::BitImage;
use crate::graphics::scrolling::{Animate, ScrollingState, Scrollable};

/// A [`Scrollable`] displaying a static ascii byte-string slice.
#[derive(Default)]
#[derive(Copy, Clone)]
pub struct ScrollingStaticText {
    message: &'static [u8],
    state: ScrollingState,
}

impl ScrollingStaticText {

    /// Specifies the ascii byte-string slice to be displayed.
    ///
    /// This also resets the animation to the beginning.
    pub fn set_message(&mut self, message: &'static [u8]) {
        self.message = message;
        self.reset();
    }

}

impl Scrollable for ScrollingStaticText {

    type Subimage = BitImage;

    fn length(&self) -> usize {
        self.message.len()
    }

    fn state(&self) -> &ScrollingState {
        &self.state
    }

    fn state_mut(&mut self) -> &mut ScrollingState {
        &mut self.state
    }

    fn subimage(&self, index: usize) -> &BitImage {
        font::character(self.message[index])
    }

}


impl Render for ScrollingStaticText {

    fn brightness_at(&self, x: usize, y: usize) -> u8 {
        self.current_brightness_at(x, y)
    }

}


/// A [`Scrollable`] displaying an ascii byte-string of up to 128 bytes.
#[derive(Copy, Clone)]
pub struct ScrollingBufferedText {
    length: usize,
    message: [u8; 128],
    state: ScrollingState,
}

impl ScrollingBufferedText {

    /// Specifies the ascii byte-string to be displayed.
    ///
    /// Makes a copy of the byte-string.
    ///
    /// This also resets the animation to the beginning.
    ///
    /// # Panics
    ///
    /// Panics if `message` is more than 128 bytes long.
    pub fn set_message(&mut self, message: &[u8]) {
        assert!(message.len() <= 128, "message too long");
        self.length = message.len();
        self.message[..self.length].copy_from_slice(message);
        self.reset();
    }


}

impl Default for ScrollingBufferedText {

    fn default() -> ScrollingBufferedText {
        ScrollingBufferedText {
            length: 0,
            message: [0; 128],
            state: Default::default(),
        }
    }

}

impl Scrollable for ScrollingBufferedText {

    type Subimage = BitImage;

    fn length(&self) -> usize {
        self.length
    }

    fn state(&self) -> &ScrollingState {
        &self.state
    }

    fn state_mut(&mut self) -> &mut ScrollingState {
        &mut self.state
    }

    fn subimage(&self, index: usize) -> &BitImage {
        font::character(self.message[index])
    }

}

impl Render for ScrollingBufferedText {

    fn brightness_at(&self, x: usize, y: usize) -> u8 {
        self.current_brightness_at(x, y)
    }

}