Auto merge of #20676 - fabricedesre:ime-embedding, r=cbrewster

Notify the embedder when it should display or hide an IME

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This adds a couple of embedder messages triggered when an editable element is focused or blured. The embedder also gets the type of data to edit so it can display a different keyboard type or a custom input method eg. for color choosing.

This is a partial fix for issue #12127

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach build-geckolib` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because there are no tests for the embedding api :(

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3 files changed, 47 insertions, 0 deletions

diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 71df0e70356..5c9cd57b128 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -812,6 +812,11 @@ impl Document {
             elem.set_focus_state(false);
             // FIXME: pass appropriate relatedTarget
             self.fire_focus_event(FocusEventType::Blur, node, None);
+
+            // Notify the embedder to hide the input method.
+            if elem.input_method_type().is_some() {
+                self.send_to_constellation(ScriptMsg::HideIME);
+            }
         }
 
         self.focused.set(self.possibly_focused.get().r());
@@ -826,6 +831,11 @@ impl Document {
             if focus_type == FocusType::Element {
                 self.send_to_constellation(ScriptMsg::Focus);
             }
+
+            // Notify the embedder to display an input method.
+            if let Some(kind) = elem.input_method_type() {
+                self.send_to_constellation(ScriptMsg::ShowIME(kind));
+            }
         }
     }
 
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index a53446fd4a3..11b9168eb41 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -83,6 +83,7 @@ use html5ever::serialize::TraversalScope;
 use html5ever::serialize::TraversalScope::{ChildrenOnly, IncludeNode};
 use js::jsapi::Heap;
 use js::jsval::JSVal;
+use msg::constellation_msg::InputMethodType;
 use net_traits::request::CorsSettings;
 use ref_filter_map::ref_filter_map;
 use script_layout_interface::message::ReflowGoal;
@@ -1087,6 +1088,22 @@ impl Element {
         None
     }
 
+    // Returns the kind of IME control needed for a focusable element, if any.
+    pub fn input_method_type(&self) -> Option<InputMethodType> {
+        if !self.is_focusable_area() {
+            return None;
+        }
+
+        if let Some(input) = self.downcast::<HTMLInputElement>() {
+            input.input_type().as_ime_type()
+        } else if self.is::<HTMLTextAreaElement>() {
+            Some(InputMethodType::Text)
+        } else {
+            // Other focusable elements that are not input fields.
+            None
+        }
+    }
+
     pub fn is_focusable_area(&self) -> bool {
         if self.is_actually_disabled() {
             return false;
diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index 5618b366702..ab7d55d5b9a 100755
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -40,6 +40,7 @@ use dom::virtualmethods::VirtualMethods;
 use dom_struct::dom_struct;
 use html5ever::{LocalName, Prefix};
 use mime_guess;
+use msg::constellation_msg::InputMethodType;
 use net_traits::{CoreResourceMsg, IpcSend};
 use net_traits::blob_url_store::get_blob_origin;
 use net_traits::filemanager_thread::{FileManagerThreadMsg, FilterPattern};
@@ -137,6 +138,25 @@ impl InputType {
             InputType::Week => "week",
         }
     }
+
+    pub fn as_ime_type(&self) -> Option<InputMethodType> {
+        match *self {
+            InputType::Color => Some(InputMethodType::Color),
+            InputType::Date => Some(InputMethodType::Date),
+            InputType::DatetimeLocal => Some(InputMethodType::DatetimeLocal),
+            InputType::Email => Some(InputMethodType::Email),
+            InputType::Month => Some(InputMethodType::Month),
+            InputType::Number => Some(InputMethodType::Number),
+            InputType::Password => Some(InputMethodType::Password),
+            InputType::Search => Some(InputMethodType::Search),
+            InputType::Tel => Some(InputMethodType::Tel),
+            InputType::Text => Some(InputMethodType::Text),
+            InputType::Time => Some(InputMethodType::Time),
+            InputType::Url => Some(InputMethodType::Url),
+            InputType::Week => Some(InputMethodType::Week),
+            _ => None,
+        }
+    }
 }
 
 impl<'a> From<&'a Atom> for InputType {