Auto merge of #28308 - philip-lamb:phil-ime-textentry, r=jdm

Improve IME messaging to embedder with insertion point index and mult…

…iline flag.

<!-- Please describe your changes on the following line: -->
This improves handling of IME requests in the embedder by passing the location of the insertion point along with the current text, and a boolean flag 'multiline' (true for HTML textarea, false otherwise) which allows the embedder to be more clever about handling of the 'enter' or 'return' keys.

Tested and working in an embedding example.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

<!-- Either: -->
- [x] There are tests for these changes OR
- [ ] These changes do not require tests because ___

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<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

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>() {
-                    Some((&input.Value()).to_string())
+                let (text, multiline) = if let Some(input) = elem.downcast::<HTMLInputElement>() {
+                    (
+                        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

@@ -205,7 +205,15 @@ 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),
@@ -808,17 +816,21 @@ 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

@@ -66,8 +66,8 @@ 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,
-                 int32_t height) {
+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) {
     htext = char2hstring(text);