refactor(core): remove image dependency (#1859)

.changes/remove-image-crate.md

@@ -0,0 +1,6 @@
+---
+"tauri": patch
+"tauri-runtime-wry": patch
+---
+
+Removes `image` dependency. For now only `.ico` icons on Windows are supported, and we'll implement other types on demand to optimize bundle size.

core/tauri-runtime-wry/Cargo.toml

@@ -15,8 +15,11 @@ readme = "README.md"
 wry = { version = "0.9.2", default-features = false, features = [ "file-drop", "protocol", "win32" ] }
 tauri-runtime = { version = "0.1.1", path = "../tauri-runtime" }
 tauri-utils = { version = "1.0.0-beta.0", path = "../tauri-utils" }
-image = "0.23"
 uuid = { version = "0.8.2", features = [ "v4" ] }
+infer = "0.4"
+
+[target."cfg(windows)".dependencies]
+ico = "0.1"
 
 [features]
 dox = [ "wry/dox" ]

core/tauri-runtime-wry/src/lib.rs

@@ -23,7 +23,6 @@ use tauri_runtime::SystemTrayEvent;
 #[cfg(feature = "system-tray")]
 use wry::application::platform::system_tray::SystemTrayBuilder;
 
-use image::{GenericImageView, Pixel};
 use tauri_utils::config::WindowConfig;
 use uuid::Uuid;
 use wry::{
@@ -47,6 +46,7 @@ use wry::{
 use std::{
   collections::HashMap,
   convert::TryFrom,
+  fs::read,
   sync::{
     mpsc::{channel, Receiver, Sender},
     Arc, Mutex,
@@ -64,38 +64,42 @@ type MainThreadTask = Box<dyn FnOnce() + Send>;
 type WindowEventHandler = Box<dyn Fn(&WindowEvent) + Send>;
 type WindowEventListeners = Arc<Mutex<HashMap<Uuid, WindowEventHandler>>>;
 
-#[repr(C)]
-#[derive(Debug)]
-struct PixelValue {
-  r: u8,
-  g: u8,
-  b: u8,
-  a: u8,
-}
-
-const PIXEL_SIZE: usize = std::mem::size_of::<PixelValue>();
-
 /// Wrapper around a [`wry::application::window::Icon`] that can be created from an [`Icon`].
 pub struct WryIcon(WindowIcon);
 
+fn icon_err<E: std::error::Error + Send + 'static>(e: E) -> Error {
+  Error::InvalidIcon(Box::new(e))
+}
+
 impl TryFrom<Icon> for WryIcon {
   type Error = Error;
   fn try_from(icon: Icon) -> std::result::Result<Self, Self::Error> {
-    let image = match icon {
-      Icon::File(path) => image::open(path).map_err(|e| Error::InvalidIcon(Box::new(e)))?,
-      Icon::Raw(raw) => {
-        image::load_from_memory(&raw).map_err(|e| Error::InvalidIcon(Box::new(e)))?
-      }
+    let image_bytes = match icon {
+      Icon::File(path) => read(path).map_err(icon_err)?,
+      Icon::Raw(raw) => raw,
       _ => unimplemented!(),
     };
-    let (width, height) = image.dimensions();
-    let mut rgba = Vec::with_capacity((width * height) as usize * PIXEL_SIZE);
-    for (_, _, pixel) in image.pixels() {
-      rgba.extend_from_slice(&pixel.to_rgba().0);
+    let extension = infer::get(&image_bytes)
+      .expect("could not determine icon extension")
+      .extension();
+    match extension {
+      #[cfg(windows)]
+      "ico" => {
+        let icon_dir = ico::IconDir::read(std::io::Cursor::new(image_bytes)).map_err(icon_err)?;
+        let entry = &icon_dir.entries()[0];
+        let icon = WindowIcon::from_rgba(
+          entry.decode().map_err(icon_err)?.rgba_data().to_vec(),
+          entry.width(),
+          entry.height(),
+        )
+        .map_err(icon_err)?;
+        Ok(Self(icon))
+      }
+      _ => panic!(
+        "image `{}` extension not supported; please file a Tauri feature request",
+        extension
+      ),
     }
-    let icon =
-      WindowIcon::from_rgba(rgba, width, height).map_err(|e| Error::InvalidIcon(Box::new(e)))?;
-    Ok(Self(icon))
   }
 }
 

core/tauri/Cargo.toml

@@ -62,7 +62,6 @@ open = "1.7.0"
 shared_child = "0.3"
 os_pipe = "0.9"
 minisign-verify = "0.1.8"
-image = "0.23"
 state = "0.4"
 bincode = "1.3"
 

core/tauri/src/app.rs

@@ -535,7 +535,7 @@ where
         }
 
         #[cfg(not(target_os = "linux"))]
-        if let Some(Icon::File(bytes)) = icon {
+        if let Some(Icon::File(_)) = icon {
           return Err(crate::Error::InvalidIcon(Box::new(Error::new(
             ErrorKind::InvalidInput,
             "system tray icons on non-linux platforms must be the raw bytes",