Merge pull request #17 from fhars/load-image

Separate loading image files from setting button images

src/images.rs

@@ -1,7 +1,7 @@
 use std::str::FromStr;
 
 use image::io::Reader;
-use image::jpeg::JPEGEncoder;
+use image::jpeg::JpegEncoder;
 use image::DynamicImage;
 use image::{imageops::FilterType, ColorType, Pixel, Rgba};
 
@@ -143,8 +143,8 @@ pub(crate) fn load_image(
 
  // Convert to vector with correct encoding
  let v = match colour_order {
- ColourOrder::BGR => image.to_bgr().into_vec(),
- ColourOrder::RGB => image.to_rgb().into_vec(),
+ ColourOrder::BGR => image.to_bgr8().into_vec(),
+ ColourOrder::RGB => image.to_rgb8().into_vec(),
  };
 
  if v.len() != x * y * 3 {
@@ -157,7 +157,7 @@ pub(crate) fn load_image(
 /// Encodes a BGR bitmap into a JPEG image for outputting to a V2 device
 pub(crate) fn encode_jpeg(image: &[u8], width: usize, height: usize) -> Result<Vec<u8>, Error> {
  let mut buf = Vec::new();
- let mut encoder = JPEGEncoder::new_with_quality(&mut buf, 100);
+ let mut encoder = JpegEncoder::new_with_quality(&mut buf, 100);
  encoder.encode(image, width as u32, height as u32, ColorType::Rgb8)?;
  Ok(buf)
 }

src/lib.rs

@@ -1,4 +1,3 @@
-use std::borrow::Cow;
 use std::io::Error as IoError;
 use std::time::Duration;
 
@@ -69,6 +68,10 @@ pub enum Error {
  NoData,
 }
 
+pub struct DeviceImage {
+ data: Vec<u8>,
+}
+
 /// Device USB Product Identifiers (PIDs)
 pub mod pids {
  pub const ORIGINAL: u16 = 0x0060;
@@ -236,6 +239,22 @@ impl StreamDeck {
  self.kind.image_size()
  }
 
+ /// Convert an image into the device dependent format
+ fn convert_image(&self, image: Vec<u8>) -> Result<DeviceImage, Error> {
+ // Check image dimensions
+ if image.len() != self.kind.image_size_bytes() {
+ return Err(Error::InvalidImageSize);
+ }
+ let image = match self.kind.image_mode() {
+ ImageMode::Bmp => image,
+ ImageMode::Jpeg => {
+ let (w, h) = self.kind.image_size();
+ encode_jpeg(&image, w, h)?
+ }
+ };
+ Ok(DeviceImage{ data: image })
+ }
+
  /// Set a button to the provided RGB colour
  pub fn set_button_rgb(&mut self, key: u8, colour: &Colour) -> Result<(), Error> {
  let mut image = vec![0u8; self.kind.image_size_bytes()];
@@ -259,8 +278,7 @@ impl StreamDeck {
  _ => unreachable!(),
  };
  }
-
- self.write_button_image(key, &image)?;
+ self.write_button_image(key, &self.convert_image(image)?)?;
 
  Ok(())
  }
@@ -269,10 +287,10 @@ impl StreamDeck {
  pub fn set_button_image(&mut self, key: u8, image: DynamicImage) -> Result<(), Error> {
  let image = apply_transform(image, self.kind.image_rotation(), self.kind.image_mirror());
  let image = match self.kind.image_colour_order() {
- ColourOrder::BGR => image.into_bgr().into_vec(),
- ColourOrder::RGB => image.into_rgb().into_vec(),
+ ColourOrder::BGR => image.into_bgra8().into_vec(),
+ ColourOrder::RGB => image.into_rgb8().into_vec(),
  };
- self.write_button_image(key, &image)
+ self.write_button_image(key, &self.convert_image(image)?)
  }
 
  /// Sets a button to the provided text.
@@ -310,6 +328,16 @@ impl StreamDeck {
  image: &str,
  opts: &ImageOptions,
  ) -> Result<(), Error> {
+
+ self.write_button_image(key, &self.load_image(image, opts)?)
+ }
+
+ /// Load an image file into the device specific representation
+ pub fn load_image(
+ &self,
+ image: &str,
+ opts: &ImageOptions,
+ ) -> Result<DeviceImage, Error> {
  let (x, y) = self.kind.image_size();
  let rotate = self.kind.image_rotation();
  let mirror = self.kind.image_mirror();
@@ -323,10 +351,7 @@ impl StreamDeck {
  opts,
  self.kind.image_colour_order(),
  )?;
-
- self.write_button_image(key, &image)?;
-
- Ok(())
+ self.convert_image(image)
  }
 
  /// Transforms a key from zero-indexed left-to-right into the device-correct coordinate system
@@ -350,22 +375,11 @@ impl StreamDeck {
 
  /// Writes an image to a button
  /// Image at this point in correct dimensions and in device native colour order.
- fn write_button_image(&mut self, key: u8, image: &[u8]) -> Result<(), Error> {
- // Check image dimensions
- if image.len() != self.kind.image_size_bytes() {
- return Err(Error::InvalidImageSize);
- }
+ pub fn write_button_image(&mut self, key: u8, image: &DeviceImage) -> Result<(), Error> {
 
+ let image = &image.data;
  let key = self.translate_key_index(key)?;
 
- let image = match self.kind.image_mode() {
- ImageMode::Bmp => Cow::from(image),
- ImageMode::Jpeg => {
- let (w, h) = self.kind.image_size();
- Cow::from(encode_jpeg(image, w, h)?)
- }
- };
-
  let mut buf = vec![0u8; self.kind.image_report_len()];
  let base = self.kind.image_base();
  let hdrlen = self.kind.image_report_header_len();