Do not hardcode display size

ili driver family is pretty generic with support
of multiple display sizes. By having width and size
as parameter this driver can support broader range
of ili displays.

src/lib.rs

@@ -34,8 +34,29 @@ pub trait Interface {
     ) -> Result<(), Self::Error>;
 }
 
-const WIDTH: usize = 240;
-const HEIGHT: usize = 320;
+/// Trait that defines display size information
+pub trait DisplaySize {
+    /// Width in pixels
+    const WIDTH: usize;
+    /// Height in pixels
+    const HEIGHT: usize;
+}
+
+/// Generic display size of 240x320 pixels
+pub struct DisplaySize240x320;
+
+impl DisplaySize for DisplaySize240x320 {
+    const WIDTH: usize = 240;
+    const HEIGHT: usize = 320;
+}
+
+/// Generic display size of 320x480 pixels
+pub struct DisplaySize320x480;
+
+impl DisplaySize for DisplaySize320x480 {
+    const WIDTH: usize = 320;
+    const HEIGHT: usize = 480;
+}
 
 #[derive(Debug)]
 pub enum Error<PinE> {
@@ -72,6 +93,7 @@ pub struct Ili9341<IFACE, RESET> {
     reset: RESET,
     width: usize,
     height: usize,
+    mode: Orientation,
 }
 
 impl<PinE, IFACE, RESET> Ili9341<IFACE, RESET>
@@ -79,16 +101,23 @@ where
     IFACE: WriteOnlyDataCommand,
     RESET: OutputPin<Error = PinE>,
 {
-    pub fn new<DELAY: DelayMs<u16>>(
+    pub fn new<DELAY, SIZE>(
         interface: IFACE,
         reset: RESET,
         delay: &mut DELAY,
-    ) -> Result<Self, Error<PinE>> {
+        mode: Orientation,
+        _display_size: SIZE,
+    ) -> Result<Self, Error<PinE>>
+    where
+        DELAY: DelayMs<u16>,
+        SIZE: DisplaySize,
+    {
         let mut ili9341 = Ili9341 {
             interface,
             reset,
-            width: WIDTH,
-            height: HEIGHT,
+            width: SIZE::WIDTH,
+            height: SIZE::HEIGHT,
+            mode: Orientation::Portrait,
         };
 
         // Do hardware reset by holding reset low for at least 10us
@@ -108,7 +137,7 @@ where
         // and 120ms before sending Sleep Out
         delay.delay_ms(120);
 
-        ili9341.set_orientation(Orientation::Portrait)?;
+        ili9341.set_orientation(mode)?;
 
         // Set pixel format to 16 bits per pixel
         ili9341.command(Command::PixelFormatSet, &[0x55])?;
@@ -167,7 +196,11 @@ where
         fixed_top_lines: u16,
         fixed_bottom_lines: u16,
     ) -> Result<Scroller, Error<PinE>> {
-        let scroll_lines = HEIGHT as u16 - fixed_top_lines - fixed_bottom_lines;
+        let height = match self.mode {
+            Orientation::Landscape | Orientation::LandscapeFlipped => self.width,
+            Orientation::Portrait | Orientation::PortraitFlipped => self.height,
+        } as u16;
+        let scroll_lines = height as u16 - fixed_top_lines - fixed_bottom_lines;
 
         self.command(
             Command::VerticalScrollDefine,
@@ -181,7 +214,7 @@ where
             ],
         )?;
 
-        Ok(Scroller::new(fixed_top_lines, fixed_bottom_lines))
+        Ok(Scroller::new(fixed_top_lines, fixed_bottom_lines, height))
     }
 
     pub fn scroll_vertically(
@@ -189,11 +222,10 @@ where
         scroller: &mut Scroller,
         num_lines: u16,
     ) -> Result<(), Error<PinE>> {
-        let height = HEIGHT as u16;
         scroller.top_offset += num_lines;
-        if scroller.top_offset > (height - scroller.fixed_bottom_lines) {
+        if scroller.top_offset > (scroller.height - scroller.fixed_bottom_lines) {
             scroller.top_offset = scroller.fixed_top_lines
-                + (scroller.top_offset - height + scroller.fixed_bottom_lines)
+                + (scroller.top_offset - scroller.height + scroller.fixed_bottom_lines)
         }
 
         self.command(
@@ -249,28 +281,33 @@ where
 
     /// Change the orientation of the screen
     pub fn set_orientation(&mut self, mode: Orientation) -> Result<(), Error<PinE>> {
-        match mode {
+        let was_landscape = match self.mode {
+            Orientation::Landscape | Orientation::LandscapeFlipped => true,
+            Orientation::Portrait | Orientation::PortraitFlipped => false,
+        };
+        let is_landscape = match mode {
             Orientation::Portrait => {
-                self.width = WIDTH;
-                self.height = HEIGHT;
-                self.command(Command::MemoryAccessControl, &[0x40 | 0x08])
+                self.command(Command::MemoryAccessControl, &[0x40 | 0x08])?;
+                false
             }
             Orientation::Landscape => {
-                self.width = HEIGHT;
-                self.height = WIDTH;
-                self.command(Command::MemoryAccessControl, &[0x20 | 0x08])
+                self.command(Command::MemoryAccessControl, &[0x20 | 0x08])?;
+                true
             }
             Orientation::PortraitFlipped => {
-                self.width = WIDTH;
-                self.height = HEIGHT;
-                self.command(Command::MemoryAccessControl, &[0x80 | 0x08])
+                self.command(Command::MemoryAccessControl, &[0x80 | 0x08])?;
+                false
             }
             Orientation::LandscapeFlipped => {
-                self.width = HEIGHT;
-                self.height = WIDTH;
-                self.command(Command::MemoryAccessControl, &[0x40 | 0x80 | 0x20 | 0x08])
+                self.command(Command::MemoryAccessControl, &[0x40 | 0x80 | 0x20 | 0x08])?;
+                true
             }
+        };
+        if was_landscape ^ is_landscape {
+            core::mem::swap(&mut self.height, &mut self.width);
         }
+        self.mode = mode;
+        Ok(())
     }
 
     /// Get the current screen width. It can change based on the current orientation
@@ -290,14 +327,16 @@ pub struct Scroller {
     top_offset: u16,
     fixed_bottom_lines: u16,
     fixed_top_lines: u16,
+    height: u16,
 }
 
 impl Scroller {
-    fn new(fixed_top_lines: u16, fixed_bottom_lines: u16) -> Scroller {
+    fn new(fixed_top_lines: u16, fixed_bottom_lines: u16, height: u16) -> Scroller {
         Scroller {
             top_offset: fixed_top_lines,
             fixed_top_lines,
             fixed_bottom_lines,
+            height,
         }
     }
 }