Add is_current function

src/android/mod.rs

@@ -61,6 +61,11 @@ impl HeadlessContext {
         unimplemented!()
     }
 
+    /// See the docs in the crate root file.
+    pub fn is_current(&self) -> bool {
+        unimplemented!()
+    }
+
     /// See the docs in the crate root file.
     pub fn get_proc_address(&self, _addr: &str) -> *const () {
         unimplemented!()
@@ -312,6 +317,10 @@ impl Window {
         }
     }
 
+    pub fn is_current(&self) -> bool {
+        unsafe { ffi::egl::GetCurrentContext() == self.context }
+    }
+
     pub fn get_proc_address(&self, addr: &str) -> *const () {
         let addr = CString::from_slice(addr.as_bytes());
         let addr = addr.as_ptr();