2 files changed, 46 insertions, 12 deletions

diff --git a/components/shared/compositing/constellation_msg.rs b/components/shared/compositing/constellation_msg.rs
index 8204ec6d2e3..64d593ee08c 100644
--- a/components/shared/compositing/constellation_msg.rs
+++ b/components/shared/compositing/constellation_msg.rs
@@ -11,13 +11,14 @@ use gfx_traits::Epoch;
 use ipc_channel::ipc::IpcSender;
 use keyboard_types::KeyboardEvent;
 use msg::constellation_msg::{
-    BrowsingContextId, PipelineId, TopLevelBrowsingContextId, TraversalDirection,
+    BrowsingContextId, PipelineId, TopLevelBrowsingContextId, TraversalDirection, WebViewId,
 };
 use script_traits::{
     AnimationTickType, CompositorEvent, GamepadEvent, LogEntry, MediaSessionActionType,
     WebDriverCommandMsg, WindowSizeData, WindowSizeType,
 };
 use servo_url::ServoUrl;
+use webrender_api::units::DeviceRect;
 
 /// Messages to the constellation.
 pub enum ConstellationMsg {
@@ -60,9 +61,17 @@ pub enum ConstellationMsg {
     CloseWebView(TopLevelBrowsingContextId),
     /// Panic a top level browsing context.
     SendError(Option<TopLevelBrowsingContextId>, String),
-    /// Make a top-level browsing context focused.
+    /// Move and/or resize a webview to the given rect.
+    MoveResizeWebView(TopLevelBrowsingContextId, DeviceRect),
+    /// Start painting a webview, and optionally stop painting all others.
+    ShowWebView(TopLevelBrowsingContextId, bool),
+    /// Stop painting a webview.
+    HideWebView(TopLevelBrowsingContextId),
+    /// Start painting a webview on top of all others, and optionally stop painting all others.
+    RaiseWebViewToTop(TopLevelBrowsingContextId, bool),
+    /// Make a webview focused.
     FocusWebView(TopLevelBrowsingContextId),
-    /// Make none of the top-level browsing contexts focused.
+    /// Make none of the webviews focused.
     BlurWebView,
     /// Forward an event to the script task of the given pipeline.
     ForwardEvent(PipelineId, CompositorEvent),
@@ -80,16 +89,23 @@ pub enum ConstellationMsg {
     SetWebViewThrottled(TopLevelBrowsingContextId, bool),
     /// Virtual keyboard was dismissed
     IMEDismissed,
-    /// Compositing done, but external code needs to present.
-    ReadyToPresent(TopLevelBrowsingContextId),
+    /// Notify the embedder that it needs to present a new frame.
+    ReadyToPresent(Vec<WebViewId>),
     /// Gamepad state has changed
     Gamepad(GamepadEvent),
 }
 
 impl fmt::Debug for ConstellationMsg {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "ConstellationMsg::{}", self.variant_name())
+    }
+}
+
+impl ConstellationMsg {
+    /// Return the variant name, for error logging that happens after the message is consumed.
+    pub fn variant_name(&self) -> &'static str {
         use self::ConstellationMsg::*;
-        let variant = match *self {
+        match *self {
             Exit => "Exit",
             GetBrowsingContext(..) => "GetBrowsingContext",
             GetPipeline(..) => "GetPipeline",
@@ -106,6 +122,10 @@ impl fmt::Debug for ConstellationMsg {
             LogEntry(..) => "LogEntry",
             NewWebView(..) => "NewWebView",
             CloseWebView(..) => "CloseWebView",
+            MoveResizeWebView(..) => "MoveResizeWebView",
+            ShowWebView(..) => "ShowWebView",
+            HideWebView(..) => "HideWebView",
+            RaiseWebViewToTop(..) => "RaiseWebViewToTop",
             FocusWebView(..) => "FocusWebView",
             BlurWebView => "BlurWebView",
             SendError(..) => "SendError",
@@ -120,7 +140,6 @@ impl fmt::Debug for ConstellationMsg {
             ClearCache => "ClearCache",
             ReadyToPresent(..) => "ReadyToPresent",
             Gamepad(..) => "Gamepad",
-        };
-        write!(formatter, "ConstellationMsg::{}", variant)
+        }
     }
 }
diff --git a/components/shared/compositing/lib.rs b/components/shared/compositing/lib.rs
index 8ab45b374ed..9c759bc4acf 100644
--- a/components/shared/compositing/lib.rs
+++ b/components/shared/compositing/lib.rs
@@ -24,7 +24,7 @@ use script_traits::{
     ScriptToCompositorMsg,
 };
 use style_traits::CSSPixel;
-use webrender_api::units::{DeviceIntPoint, DeviceIntSize};
+use webrender_api::units::{DeviceIntPoint, DeviceIntSize, DeviceRect};
 use webrender_api::{self, FontInstanceKey, FontKey, ImageKey};
 
 /// Sends messages to the compositor.
@@ -73,8 +73,18 @@ pub enum CompositorMsg {
     ShutdownComplete,
     /// Alerts the compositor that the given pipeline has changed whether it is running animations.
     ChangeRunningAnimationsState(PipelineId, AnimationState),
-    /// Replaces the current frame tree, typically called during main frame navigation.
-    SetFrameTree(SendableFrameTree),
+    /// Create or update a webview, given its frame tree.
+    CreateOrUpdateWebView(SendableFrameTree),
+    /// Remove a webview.
+    RemoveWebView(TopLevelBrowsingContextId),
+    /// Move and/or resize a webview to the given rect.
+    MoveResizeWebView(TopLevelBrowsingContextId, DeviceRect),
+    /// Start painting a webview, and optionally stop painting all others.
+    ShowWebView(TopLevelBrowsingContextId, bool),
+    /// Stop painting a webview.
+    HideWebView(TopLevelBrowsingContextId),
+    /// Start painting a webview on top of all others, and optionally stop painting all others.
+    RaiseWebViewToTop(TopLevelBrowsingContextId, bool),
     /// Script has handled a touch event, and either prevented or allowed default actions.
     TouchEventProcessed(EventResult),
     /// Composite to a PNG file and return the Image over a passed channel.
@@ -153,7 +163,12 @@ impl Debug for CompositorMsg {
             CompositorMsg::ChangeRunningAnimationsState(_, state) => {
                 write!(f, "ChangeRunningAnimationsState({:?})", state)
             },
-            CompositorMsg::SetFrameTree(..) => write!(f, "SetFrameTree"),
+            CompositorMsg::CreateOrUpdateWebView(..) => write!(f, "CreateOrUpdateWebView"),
+            CompositorMsg::RemoveWebView(..) => write!(f, "RemoveWebView"),
+            CompositorMsg::MoveResizeWebView(..) => write!(f, "MoveResizeWebView"),
+            CompositorMsg::ShowWebView(..) => write!(f, "ShowWebView"),
+            CompositorMsg::HideWebView(..) => write!(f, "HideWebView"),
+            CompositorMsg::RaiseWebViewToTop(..) => write!(f, "RaiseWebViewToTop"),
             CompositorMsg::TouchEventProcessed(..) => write!(f, "TouchEventProcessed"),
             CompositorMsg::CreatePng(..) => write!(f, "CreatePng"),
             CompositorMsg::IsReadyToSaveImageReply(..) => write!(f, "IsReadyToSaveImageReply"),