Hook up the back and forward buttons to history traversal in Magic Leap Servo2D

ports/libmlservo/src/lib.rs

@@ -24,7 +24,6 @@ use servo::embedder_traits::EmbedderMsg;
 use servo::embedder_traits::EventLoopWaker;
 use servo::embedder_traits::resources::Resource;
 use servo::embedder_traits::resources::ResourceReaderMethods;
-use servo::euclid::Length;
 use servo::euclid::TypedPoint2D;
 use servo::euclid::TypedRect;
 use servo::euclid::TypedScale;
@@ -32,21 +31,18 @@ use servo::euclid::TypedSize2D;
 use servo::gl;
 use servo::gl::Gl;
 use servo::gl::GlesFns;
+use servo::msg::constellation_msg::TraversalDirection;
 use servo::script_traits::MouseButton;
 use servo::servo_url::ServoUrl;
-use servo::style_traits::DevicePixel;
 use servo::webrender_api::DevicePoint;
 use smallvec::SmallVec;
 use std::ffi::CStr;
 use std::ffi::CString;
 use std::io::Write;
 use std::os::raw::c_char;
-use std::os::raw::c_void;
 use std::path::PathBuf;
 use std::rc::Rc;
 
-type ServoInstance = *mut c_void;
-
 #[repr(u32)]
 pub enum MLLogLevel {
     Fatal = 0,
@@ -70,7 +66,7 @@ pub unsafe extern "C" fn init_servo(ctxt: EGLContext,
                                     url: *const c_char,
                                     width: u32,
                                     height: u32,
-                                    hidpi: f32) -> ServoInstance
+                                    hidpi: f32) -> *mut ServoInstance
 {
     // Servo initialization goes here!
     servo::embedder_traits::resources::set(Box::new(ResourceReaderInstance::new()));
@@ -93,9 +89,9 @@ pub unsafe extern "C" fn init_servo(ctxt: EGLContext,
     });
 
     info!("Starting servo");
-    let mut servo = Box::new(Servo::new(window));
-
+    let mut servo = Servo::new(window);
     let browser_id = BrowserId::new();
+
     let blank_url = ServoUrl::parse("about:blank").expect("Failed to parse about:blank!");
     let url = CStr::from_ptr(url).to_str().unwrap_or("about:blank");
     let url = ServoUrl::parse(url).unwrap_or(blank_url);
@@ -103,15 +99,19 @@ pub unsafe extern "C" fn init_servo(ctxt: EGLContext,
         WindowEvent::NewBrowser(url, browser_id),
     ]);
 
-    Box::into_raw(servo) as ServoInstance
+    let result = Box::new(ServoInstance {
+        browser_id: browser_id,
+        servo: servo,
+    });
+    Box::into_raw(result)
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn heartbeat_servo(servo: ServoInstance) {
+pub unsafe extern "C" fn heartbeat_servo(servo: *mut ServoInstance) {
     // Servo heartbeat goes here!
-    if let Some(servo) = (servo as *mut Servo<WindowInstance>).as_mut() {
-        servo.handle_events(vec![]);
-        for ((_browser_id, event)) in servo.get_events() {
+    if let Some(servo) = servo.as_mut() {
+        servo.servo.handle_events(vec![]);
+        for ((_browser_id, event)) in servo.servo.get_events() {
             match event {
                 // Respond to any messages with a response channel
                 // to avoid deadlocking the constellation
@@ -156,27 +156,47 @@ pub unsafe extern "C" fn heartbeat_servo(servo: ServoInstance) {
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn cursor_servo(servo: ServoInstance, x: f32, y: f32, trigger: bool) {
+pub unsafe extern "C" fn cursor_servo(servo: *mut ServoInstance, x: f32, y: f32, trigger: bool) {
     // Servo was triggered
-    if let Some(servo) = (servo as *mut Servo<WindowInstance>).as_mut() {
+    if let Some(servo) = servo.as_mut() {
         let point = DevicePoint::new(x, y);
         let window_event = if trigger {
             WindowEvent::MouseWindowEventClass(MouseWindowEvent::Click(MouseButton::Left, point))
         } else {
             WindowEvent::MouseWindowMoveEventClass(point)
         };
-        servo.handle_events(vec![window_event]);
+        servo.servo.handle_events(vec![window_event]);
     }
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn discard_servo(servo: ServoInstance) {
+pub unsafe extern "C" fn traverse_servo(servo: *mut ServoInstance, delta: i32) {
+    // Traverse the session history
+    if let Some(servo) = servo.as_mut() {
+        let window_event = if delta == 0 {
+            WindowEvent::Reload(servo.browser_id)
+        } else if delta < 0 {
+            WindowEvent::Navigation(servo.browser_id, TraversalDirection::Back(-delta as usize))
+        } else {
+            WindowEvent::Navigation(servo.browser_id, TraversalDirection::Forward(delta as usize))
+        };
+        servo.servo.handle_events(vec![window_event]);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn discard_servo(servo: *mut ServoInstance) {
     // Servo drop goes here!
     if !servo.is_null() {
-        Box::from_raw(servo as *mut Servo<WindowInstance>);
+        Box::from_raw(servo);
     }
 }
 
+pub struct ServoInstance {
+    browser_id: BrowserId,
+    servo: Servo<WindowInstance>,
+}
+
 struct WindowInstance {
     ctxt: EGLContext,
     surf: EGLSurface,
@@ -192,7 +212,7 @@ impl WindowMethods for WindowInstance {
         SwapBuffers(self.disp, self.surf);
     }
 
-    fn prepare_for_composite(&self, _w: Length<u32, DevicePixel>, _h: Length<u32, DevicePixel>) -> bool {
+    fn prepare_for_composite(&self) -> bool {
         MakeCurrent(self.disp, self.surf, self.surf, self.ctxt);
         self.gl.viewport(0, 0, self.width as i32, self.height as i32);
         true

support/magicleap/Servo2D/code/inc/Servo2D.h

@@ -11,7 +11,7 @@
 #include <lumin/resource/PlanarResource.h>
 #include <SceneDescriptor.h>
 
-typedef void* ServoInstance;
+typedef struct Opaque ServoInstance;
 
 /**
  * Servo2D Landscape Application
@@ -104,5 +104,5 @@ private:
   lumin::Prism* prism_ = nullptr;  // represents the bounded space where the App renders.
   lumin::PlanarResource* plane_ = nullptr; // the plane we're rendering into
   lumin::QuadNode* content_node_ = nullptr; // the node containing the plane
-  ServoInstance servo_ = nullptr; // the servo instance we're embedding
+  ServoInstance* servo_ = nullptr; // the servo instance we're embedding
 };

support/magicleap/Servo2D/code/src/Servo2D.cpp

@@ -6,6 +6,7 @@
 #include <lumin/node/RootNode.h>
 #include <lumin/node/QuadNode.h>
 #include <lumin/ui/Cursor.h>
+#include <lumin/ui/node/UiButton.h>
 #include <ml_logging.h>
 #include <scenesGen.h>
 #include <SceneDescriptor.h>
@@ -36,11 +37,12 @@ void logger(MLLogLevel lvl, char* msg) {
 
 // The functions Servo provides for hooking up to the ML.
 // For the moment, this doesn't handle input events.
-extern "C" ServoInstance init_servo(EGLContext, EGLSurface, EGLDisplay, MLLogger,
+extern "C" ServoInstance* init_servo(EGLContext, EGLSurface, EGLDisplay, MLLogger,
                                     const char* url, int width, int height, float hidpi);
-extern "C" void heartbeat_servo(ServoInstance);
-extern "C" void cursor_servo(ServoInstance, float x, float y, bool triggered);
-extern "C" void discard_servo(ServoInstance);
+extern "C" void heartbeat_servo(ServoInstance*);
+extern "C" void cursor_servo(ServoInstance*, float x, float y, bool triggered);
+extern "C" void traverse_servo(ServoInstance*, int delta);
+extern "C" void discard_servo(ServoInstance*);
 
 // Create a Servo2D instance
 Servo2D::Servo2D() {
@@ -125,6 +127,26 @@ int Servo2D::init() {
     return 1;
   }
 
+  // Add a callback to the back button
+  std::string back_button_id = Servo2D_exportedNodes::backButton;
+  lumin::ui::UiButton* back_button = lumin::ui::UiButton::CastFrom(prism_->findNode(back_button_id, root_node));
+  if (!back_button) {
+    ML_LOG(Error, "Servo2D Failed to get back button");
+    abort();
+    return 1;
+  }
+  back_button->onActivateSub(std::bind(traverse_servo, servo_, -1));
+
+  // Add a callback to the forward button
+  std::string fwd_button_id = Servo2D_exportedNodes::fwdButton;
+  lumin::ui::UiButton* fwd_button = lumin::ui::UiButton::CastFrom(prism_->findNode(fwd_button_id, root_node));
+  if (!fwd_button) {
+    ML_LOG(Error, "Servo2D Failed to get forward button");
+    abort();
+    return 1;
+  }
+  fwd_button->onActivateSub(std::bind(traverse_servo, servo_, +1));
+
   return 0;
 }