feat: switch android_fn! to a proc_macro (#654)

* feat: switch android_fn! to a proc_macro

* document the macros

* add to CI

* fix ci

* again

* one more

.changes/config.json

@@ -78,6 +78,10 @@
     "tao": {
       "path": "./",
       "manager": "rust"
+    },
+    "tao-macros": {
+      "path": "./tao-macros",
+      "manager": "rust"
     }
   }
 }

.github/workflows/audit.yml

@@ -6,8 +6,8 @@ on:
     - cron: '0 0 * * *'
   push:
     paths:
-      - "Cargo.lock"
-      - "Cargo.toml"
+      - "**/Cargo.lock"
+      - "**/Cargo.toml"
 
 jobs:
   audit-rust:

.github/workflows/ci.yml

@@ -98,6 +98,25 @@ jobs:
           !contains(matrix.platform.target, 'ios'))
         run: cargo $CMD test --verbose --target ${{ matrix.platform.target }} $OPTIONS --features serde,tray,$FEATURES
 
+  test_tao_macros:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Cache cargo folder
+        uses: actions/cache@v1
+        with:
+          path: ~/.cargo
+          key: ${{ matrix.platform.target }}-cargo-${{ matrix.rust_version }}
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+
+      - name: Run tests
+        shell: bash
+        run: cargo test --package tao-macros
+
   fmt:
     name: fmt check
     runs-on: ubuntu-latest

Cargo.toml

@@ -15,6 +15,9 @@ repository = "https://github.com/tauri-apps/tao"
 documentation = "https://docs.rs/tao"
 categories = [ "gui" ]
 
+[workspace]
+members = [ "tao-macros" ]
+
 [package.metadata.docs.rs]
 features = [ "serde", "tray", "dox" ]
 default-target = "x86_64-unknown-linux-gnu"
@@ -54,7 +57,7 @@ ndk = "0.6"
 ndk-sys = "0.3"
 ndk-context = "0.1"
 once_cell = "1"
-paste = "1.0"
+tao-macros = { version = "0.0.0", path = "./tao-macros" }
 
 [target."cfg(any(target_os = \"ios\", target_os = \"macos\"))".dependencies]
 objc = "0.2"

examples/window.rs

@@ -42,7 +42,7 @@ fn main() {
       }
       Event::MainEventsCleared => {
         if let Some(w) = &window {
-          // w.request_redraw();
+          w.request_redraw();
         }
       }
       _ => (),

src/lib.rs

@@ -147,6 +147,9 @@
 )]
 #![deny(rustdoc::broken_intra_doc_links)]
 
+#[cfg(target_os = "android")]
+pub use tao_macros::{android_fn, generate_package_name};
+
 use std::{
   collections::hash_map::DefaultHasher,
   hash::{Hash, Hasher},

src/platform_impl/android/mod.rs

@@ -487,7 +487,7 @@ impl<T: 'static> EventLoopWindowTarget<T> {
   }
 
   #[inline]
-  pub fn monitor_from_point(&self, x: f64, y: f64) -> Option<MonitorHandle> {
+  pub fn monitor_from_point(&self, _x: f64, _y: f64) -> Option<MonitorHandle> {
     warn!("`Window::monitor_from_point` is ignored on Android");
     return None;
   }
@@ -553,7 +553,7 @@ impl Window {
   }
 
   #[inline]
-  pub fn monitor_from_point(&self, x: f64, y: f64) -> Option<monitor::MonitorHandle> {
+  pub fn monitor_from_point(&self, _x: f64, _y: f64) -> Option<monitor::MonitorHandle> {
     warn!("`Window::monitor_from_point` is ignored on Android");
     None
   }

src/platform_impl/android/ndk_glue.rs

@@ -24,58 +24,37 @@ use std::{
   thread,
 };
 
+// pub static PACKAGE: OnceCell<&str> = OnceCell::new();
+pub static PACKAGE: OnceCell<&str> = OnceCell::new();
+
 #[macro_export]
 macro_rules! android_binding {
   ($domain:ident, $package:ident, $setup: ident, $main: ident) => {
-    paste::paste! {
-        #[no_mangle]
-        unsafe extern "C" fn [< Java_ $domain _ $package _ TauriActivity_create >](
-          env: JNIEnv,
-          class: JClass,
-          object: JObject,
-        ) {
-            let domain = stringify!($domain).replace("_", "/");
-            let package = format!("{}/{}", domain, stringify!($package).replace("_1","_"));
-            PACKAGE.get_or_init(move || package);
-            create(env, class, object, $setup, $main)
-        }
-
-        android_fn!($domain, $package, TauriActivity, start);
-        android_fn!($domain, $package, TauriActivity, stop);
-        android_fn!($domain, $package, TauriActivity, resume);
-        android_fn!($domain, $package, TauriActivity, pause);
-        android_fn!($domain, $package, TauriActivity, save);
-        android_fn!($domain, $package, TauriActivity, destroy);
-        android_fn!($domain, $package, TauriActivity, memory);
-        android_fn!($domain, $package, TauriActivity, focus, i32);
+    fn __store_package_name__() {
+      PACKAGE.get_or_init(move || generate_package_name!($domain, $package));
     }
-  };
-}
 
-#[macro_export]
-macro_rules! android_fn {
-  ($domain:ident, $package:ident, $class:ident, $function:ident) => {
-    android_fn!($domain, $package, $class, $function, JObject)
-  };
-  ($domain:ident, $package:ident, $class:ident, $function:ident, $arg:ty) => {
-    android_fn!($domain, $package, $class, $function, $arg, ())
-  };
-  ($domain:ident, $package:ident, $class:ident, $function:ident, $arg:ty, $ret: ty) => {
-    paste::paste! {
-        #[no_mangle]
-        unsafe extern "C" fn [< Java_ $domain _ $package _ $class _ $function >](
-          env: JNIEnv,
-          class: JClass,
-          object: $arg,
-        ) -> $ret {
-            $function(env, class, object)
-        }
-    }
+    android_fn!(
+      $domain,
+      $package,
+      TauriActivity,
+      create,
+      [JObject],
+      __VOID__,
+      [$setup, $main],
+      __store_package_name__,
+    );
+    android_fn!($domain, $package, TauriActivity, start, [JObject]);
+    android_fn!($domain, $package, TauriActivity, stop, [JObject]);
+    android_fn!($domain, $package, TauriActivity, resume, [JObject]);
+    android_fn!($domain, $package, TauriActivity, pause, [JObject]);
+    android_fn!($domain, $package, TauriActivity, save, [JObject]);
+    android_fn!($domain, $package, TauriActivity, destroy, [JObject]);
+    android_fn!($domain, $package, TauriActivity, memory, [JObject]);
+    android_fn!($domain, $package, TauriActivity, focus, [i32]);
   };
 }
 
-pub static PACKAGE: OnceCell<String> = OnceCell::new();
-
 /// `ndk-glue` macros register the reading end of an event pipe with the
 /// main [`ThreadLooper`] under this `ident`.
 /// When returned from [`ThreadLooper::poll_*`](ThreadLooper::poll_once)

tao-macros/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "tao-macros"
+description = "Proc macros for tao"
+version = "0.0.0"
+edition = "2021"
+authors = ["Tauri Programme within The Commons Conservancy"]
+rust-version = "1.56"
+license = "MIT OR Apache-2.0"
+readme = "../README.md"
+repository = "https://github.com/tauri-apps/tao"
+documentation = "https://docs.rs/tao-macros"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1"
+quote = "1"
+syn = { version = "1", features = ["full"] }

tao-macros/examples/android_fn.rs

@@ -0,0 +1,33 @@
+use tao_macros::android_fn;
+
+struct JNIEnv;
+struct JClass;
+
+android_fn![com_example, tao_app, SomeClass, add, [i32, i32], i32];
+unsafe fn add(_env: JNIEnv, _class: JClass, a: i32, b: i32) -> i32 {
+  a + b
+}
+
+android_fn!(com_example, tao_app, SomeClass, add2, [i32, i32]);
+unsafe fn add2(_env: JNIEnv, _class: JClass, a: i32, b: i32) {
+  let _ = a + b;
+}
+
+fn __store_package_name__() {}
+
+android_fn!(
+  com_example,
+  tao_app,
+  SomeClass,
+  add3,
+  [i32, i32],
+  __VOID__,
+  [setup, main],
+  __store_package_name__,
+);
+unsafe fn add3(_env: JNIEnv, _class: JClass, a: i32, b: i32, _setup: fn(), _main: fn()) {
+  let _ = a + b;
+}
+
+fn setup() {}
+fn main() {}

tao-macros/examples/generate_package_name.rs

@@ -0,0 +1,5 @@
+use tao_macros::generate_package_name;
+
+pub const PACKAGE: &str = generate_package_name!(com_example, tao_app);
+
+fn main() {}