more changes to the displaydimension trait

examples/embedded_linux_epd1in54/src/main.rs

@@ -8,7 +8,7 @@ extern crate eink_waveshare_rs;
 use eink_waveshare_rs::{
     EPD1in54, 
     Buffer1in54,
-    graphics::{Display, DisplayRotation},
+    graphics::{Display, DisplayRotation, DisplayDimension},
     color::Color,
     WaveshareDisplay,
 };
@@ -126,7 +126,7 @@ fn run() -> Result<(), std::io::Error> {
 
     println!("Test all the rotations");
     let mut buffer = Buffer1in54::default();
-    let mut display = Display::new(buffer.width, buffer.height, &mut buffer.buffer);
+    let mut display = Display::new(buffer.width(), buffer.height(), &mut buffer.buffer);
     display.set_rotation(DisplayRotation::Rotate0);
     display.draw(
             Font6x8::render_str("Rotate 0!")

src/epd1in54/graphics.rs

@@ -4,7 +4,7 @@ use graphics::DisplayDimension;
 pub struct DisplayEink1in54BlackWhite {
     width: u32,
     height: u32,
-    buffer: [u8; WIDTH as usize * HEIGHT as usize / 8],
+    pub buffer: [u8; WIDTH as usize * HEIGHT as usize / 8],
 }
 
 
@@ -23,8 +23,8 @@ impl Default for DisplayEink1in54BlackWhite {
 }
 
 impl DisplayDimension for DisplayEink1in54BlackWhite {
-    fn buffer(&self) -> &[u8] {
-        &self.buffer
+    fn buffer(&mut self) -> &mut [u8] {
+        &mut self.buffer
     }
     fn width(&self) -> u32 {
         self.width

src/epd4in2/graphics.rs

@@ -21,8 +21,8 @@ impl Default for DisplayEink4in2BlackWhite {
 }
 
 impl DisplayDimension for DisplayEink4in2BlackWhite {
-    fn buffer(&self) -> &[u8] {
-        &self.buffer
+    fn buffer(&mut self) -> &mut [u8] {
+        &mut self.buffer
     }
     fn width(&self) -> u32 {
         self.width

src/graphics.rs

@@ -21,7 +21,7 @@ impl Default for DisplayRotation {
 }
 
 pub trait DisplayDimension {
-    fn buffer(&self) -> &[u8];
+    fn buffer(&mut self) -> &mut [u8];
     fn width(&self) -> u32;
     fn height(&self) -> u32;
 }