Improve IME messaging to embedder with insertion point index and multiline flag.

components/embedder_traits/lib.rs

@@ -197,7 +197,10 @@ pub enum EmbedderMsg {
     /// Open interface to request permission specified by prompt.
     PromptPermission(PermissionPrompt, IpcSender<PermissionRequest>),
     /// Request to present an IME to the user when an editable element is focused.
-    ShowIME(InputMethodType, Option<String>, DeviceIntRect),
+    /// If the input is text, the second parameter defines the pre-existing string
+    /// text content and the zero-based index into the string locating the insertion point.
+    /// bool is true for multi-line and false otherwise.
+    ShowIME(InputMethodType, Option<(String, i32)>, bool, DeviceIntRect),
     /// Request to hide the IME when the editable element is blurred.
     HideIME,
     /// Servo has shut down

components/script/dom/document.rs

@@ -1122,16 +1122,29 @@ impl Document {
                     Point2D::new(rect.origin.x.to_px(), rect.origin.y.to_px()),
                     Size2D::new(rect.size.width.to_px(), rect.size.height.to_px()),
                 );
-                let text = if let Some(input) = elem.downcast::<HTMLInputElement>() {
+                let (text, multiline) = if let Some(input) = elem.downcast::<HTMLInputElement>() {
-                    Some((&input.Value()).to_string())
+                    (
+                        Some((
+                            (&input.Value()).to_string(),
+                            input.GetSelectionEnd().unwrap_or(0) as i32,
+                        )),
+                        false,
+                    )
                 } else if let Some(textarea) = elem.downcast::<HTMLTextAreaElement>() {
-                    Some((&textarea.Value()).to_string())
+                    (
+                        Some((
+                            (&textarea.Value()).to_string(),
+                            textarea.GetSelectionEnd().unwrap_or(0) as i32,
+                        )),
+                        true,
+                    )
                 } else {
-                    None
+                    (None, false)
                 };
                 self.send_to_embedder(EmbedderMsg::ShowIME(
                     kind,
                     text,
+                    multiline,
                     DeviceIntRect::from_untyped(&rect),
                 ));
             }

ports/libmlservo/src/lib.rs

@@ -416,7 +416,8 @@ impl HostTrait for HostCallbacks {
     fn on_ime_show(
         &self,
         _input_type: InputMethodType,
-        _text: Option<String>,
+        _text: Option<(String, i32)>,
+        _multiline: bool,
         _bounds: DeviceIntRect,
     ) {
         if let Some(keyboard) = self.keyboard.0 {

ports/libsimpleservo/api/src/lib.rs

@@ -141,7 +141,13 @@ pub trait HostTrait {
     /// Servo finished shutting down.
     fn on_shutdown_complete(&self);
     /// A text input is focused.
-    fn on_ime_show(&self, input_type: InputMethodType, text: Option<String>, bounds: DeviceIntRect);
+    fn on_ime_show(
+        &self,
+        input_type: InputMethodType,
+        text: Option<(String, i32)>,
+        multiline: bool,
+        bounds: DeviceIntRect,
+    );
     /// Input lost focus
     fn on_ime_hide(&self);
     /// Gets sytem clipboard contents.
@@ -742,10 +748,10 @@ impl ServoGlue {
 
                     let _ = sender.send(result);
                 },
-                EmbedderMsg::ShowIME(kind, text, bounds) => {
+                EmbedderMsg::ShowIME(kind, text, multiline, bounds) => {
                     self.callbacks
                         .host_callbacks
-                        .on_ime_show(kind, text, bounds);
+                        .on_ime_show(kind, text, multiline, bounds);
                 },
                 EmbedderMsg::HideIME => {
                     self.callbacks.host_callbacks.on_ime_hide();

ports/libsimpleservo/capi/src/lib.rs

@@ -204,7 +204,15 @@ pub struct CHostCallbacks {
     pub on_history_changed: extern "C" fn(can_go_back: bool, can_go_forward: bool),
     pub on_animating_changed: extern "C" fn(animating: bool),
     pub on_shutdown_complete: extern "C" fn(),
-    pub on_ime_show: extern "C" fn(text: *const c_char, x: i32, y: i32, width: i32, height: i32),
+    pub on_ime_show: extern "C" fn(
+        text: *const c_char,
+        text_index: i32,
+        multiline: bool,
+        x: i32,
+        y: i32,
+        width: i32,
+        height: i32,
+    ),
     pub on_ime_hide: extern "C" fn(),
     pub get_clipboard_contents: extern "C" fn() -> *const c_char,
     pub set_clipboard_contents: extern "C" fn(contents: *const c_char),
@@ -803,17 +811,21 @@ impl HostTrait for HostCallbacks {
     fn on_ime_show(
         &self,
         _input_type: InputMethodType,
-        text: Option<String>,
+        text: Option<(String, i32)>,
+        multiline: bool,
         bounds: DeviceIntRect,
     ) {
         debug!("on_ime_show");
-        let text = text.and_then(|s| CString::new(s).ok());
+        let text_index = text.as_ref().map_or(0, |(_, i)| *i);
+        let text = text.and_then(|(s, _)| CString::new(s).ok());
         let text_ptr = text
             .as_ref()
             .map(|cstr| cstr.as_ptr())
             .unwrap_or(std::ptr::null());
         (self.0.on_ime_show)(
             text_ptr,
+            text_index,
+            multiline,
             bounds.origin.x,
             bounds.origin.y,
             bounds.size.width,

ports/libsimpleservo/jniapi/src/lib.rs

@@ -530,7 +530,14 @@ impl HostTrait for HostCallbacks {
         .unwrap();
     }
 
-    fn on_ime_show(&self, _type: InputEncoding, _text: Option<String>, _rect: DeviceIntRect) {}
+    fn on_ime_show(
+        &self,
+        _type: InputEncoding,
+        _text: Option<(String, i32)>,
+        _multiline: bool,
+        _rect: DeviceIntRect,
+    ) {
+    }
     fn on_ime_hide(&self) {}
 
     fn get_clipboard_contents(&self) -> Option<String> {

ports/winit/browser.rs

@@ -487,7 +487,7 @@ where
                     let permission_state = prompt_user(prompt);
                     let _ = sender.send(permission_state);
                 },
-                EmbedderMsg::ShowIME(_kind, _text, _rect) => {
+                EmbedderMsg::ShowIME(_kind, _text, _multiline, _rect) => {
                     debug!("ShowIME received");
                 },
                 EmbedderMsg::HideIME => {

support/hololens/ServoApp/ServoControl/Servo.cpp

@@ -66,7 +66,7 @@ void on_panic(const char *cbacktrace) {
   throw hresult_error(E_FAIL, backtrace);
 }
 
-void on_ime_show(const char *text, int32_t x, int32_t y, int32_t width,
+void on_ime_show(const char *text, int32_t text_index, bool multiline, int32_t x, int32_t y, int32_t width,
                  int32_t height) {
   hstring htext = L"";
   if (text != nullptr) {