From 2bfc6c3d2e0cc6c3922d125f678ab30c00b89483 Mon Sep 17 00:00:00 2001
From: Jeffrey Hutchins <complife@gmail.com>
Date: Wed, 7 Sep 2022 06:08:22 -0600
Subject: [PATCH] feat(android): JNI execution handle (#689)

* feat(android): JNI execution handle

* changefile

Co-authored-by: Amr Bashir <amr.bashir2015@gmail.com>
---
 .changes/android-jni-handle.md   |  5 +++++
 src/webview/android/main_pipe.rs |  7 ++++++-
 src/webview/android/mod.rs       | 14 ++++++++++++++
 src/webview/mod.rs               | 15 +++++++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 .changes/android-jni-handle.md

diff --git a/.changes/android-jni-handle.md b/.changes/android-jni-handle.md
new file mode 100644
index 000000000..fff57b6f5
--- /dev/null
+++ b/.changes/android-jni-handle.md
@@ -0,0 +1,5 @@
+---
+"wry": patch
+---
+
+Add `WebviewExtAndroid::handle` which can be used to execute some code using JNI context.
\ No newline at end of file
diff --git a/src/webview/android/main_pipe.rs b/src/webview/android/main_pipe.rs
index 4ebb3f28d..e79280e05 100644
--- a/src/webview/android/main_pipe.rs
+++ b/src/webview/android/main_pipe.rs
@@ -161,6 +161,11 @@ impl MainPipe<'_> {
             Err(e) => tx.send(Err(e.into())).unwrap(),
           }
         }
+        WebViewMessage::Jni(f) => {
+          if let Some(webview) = &self.webview {
+            f(env, activity, webview.as_obj());
+          }
+        }
       }
     }
     Ok(())
@@ -188,12 +193,12 @@ fn set_background_color<'a>(
   Ok(())
 }
 
-#[derive(Debug)]
 pub enum WebViewMessage {
   CreateWebView(CreateWebViewAttributes),
   Eval(String),
   SetBackgroundColor(RGBA),
   GetWebViewVersion(Sender<Result<String, Error>>),
+  Jni(Box<dyn FnOnce(JNIEnv, JObject, JObject) + Send>),
 }
 
 #[derive(Debug)]
diff --git a/src/webview/android/mod.rs b/src/webview/android/mod.rs
index ee1f4692d..f794476f1 100644
--- a/src/webview/android/mod.rs
+++ b/src/webview/android/mod.rs
@@ -242,6 +242,20 @@ impl InnerWebView {
   }
 }
 
+#[derive(Clone, Copy)]
+pub struct JniHandle;
+
+impl JniHandle {
+  /// Execute jni code on the thread of the webview.
+  /// Provided function will be provided with the jni evironment, Android activity and WebView
+  pub fn exec<F>(&self, func: F)
+  where
+    F: FnOnce(JNIEnv, JObject, JObject) + Send + 'static,
+  {
+    MainPipe::send(WebViewMessage::Jni(Box::new(func)));
+  }
+}
+
 pub fn platform_webview_version() -> Result<String> {
   let (tx, rx) = bounded(1);
   MainPipe::send(WebViewMessage::GetWebViewVersion(tx));
diff --git a/src/webview/mod.rs b/src/webview/mod.rs
index 8c35c07b7..d5d262d44 100644
--- a/src/webview/mod.rs
+++ b/src/webview/mod.rs
@@ -15,6 +15,8 @@ pub mod prelude {
   pub use super::android::{binding::*, setup};
 }
 #[cfg(target_os = "android")]
+pub use android::JniHandle;
+#[cfg(target_os = "android")]
 use android::*;
 #[cfg(any(
   target_os = "linux",
@@ -662,6 +664,19 @@ impl WebviewExtMacOS for WebView {
   }
 }
 
+#[cfg(target_os = "android")]
+/// Additional methods on `WebView` that are specific to Android
+pub trait WebviewExtAndroid {
+  fn handle(&self) -> JniHandle;
+}
+
+#[cfg(target_os = "android")]
+impl WebviewExtAndroid for WebView {
+  fn handle(&self) -> JniHandle {
+    JniHandle
+  }
+}
+
 #[cfg(test)]
 mod tests {
   use super::*;