Draft `input_method` support

4 files changed, 54 insertions, 1 deletions

diff --git a/core/src/event.rs b/core/src/event.rs
index b6cf321e..323c5ffd 100644
--- a/core/src/event.rs
+++ b/core/src/event.rs
@@ -1,4 +1,5 @@
 //! Handle events of a user interface.
+use crate::input_method;
 use crate::keyboard;
 use crate::mouse;
 use crate::touch;
@@ -23,6 +24,9 @@ pub enum Event {
 
     /// A touch event
     Touch(touch::Event),
+
+    /// A input method event
+    InputMethod(input_method::Event),
 }
 
 /// The status of an [`Event`] after being processed.
diff --git a/core/src/input_method.rs b/core/src/input_method.rs
new file mode 100644
index 00000000..ceda39c3
--- /dev/null
+++ b/core/src/input_method.rs
@@ -0,0 +1,24 @@
+//! Listen to input method events.
+
+/// A input method event.
+///
+/// _**Note:** This type is largely incomplete! If you need to track
+/// additional events, feel free to [open an issue] and share your use case!_
+///
+/// [open an issue]: https://github.com/iced-rs/iced/issues
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Event {
+    // These events correspond to underlying winit ime events.
+    // https://docs.rs/winit/latest/winit/event/enum.Ime.html
+    /// the IME was enabled.
+    Enabled,
+
+    /// new composing text should be set at the cursor position.
+    Preedit(String, Option<(usize, usize)>),
+
+    /// text should be inserted into the editor widget.
+    Commit(String),
+
+    /// the IME was disabled.
+    Disabled,
+}
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 16b3aa0f..c7c38044 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -17,6 +17,7 @@ pub mod event;
 pub mod font;
 pub mod gradient;
 pub mod image;
+pub mod input_method;
 pub mod keyboard;
 pub mod layout;
 pub mod mouse;
@@ -72,6 +73,7 @@ pub use renderer::Renderer;
 pub use rotation::Rotation;
 pub use settings::Settings;
 pub use shadow::Shadow;
+pub use shell::CaretInfo;
 pub use shell::Shell;
 pub use size::Size;
 pub use svg::Svg;
diff --git a/core/src/shell.rs b/core/src/shell.rs
index 12ebbaa8..d2c1b9ec 100644
--- a/core/src/shell.rs
+++ b/core/src/shell.rs
@@ -1,6 +1,15 @@
-use crate::event;
 use crate::time::Instant;
 use crate::window;
+use crate::{event, Point};
+
+/// TODO
+#[derive(Clone, Copy, Debug)]
+pub struct CaretInfo {
+    /// TODO
+    pub position: Point,
+    /// TODO
+    pub input_method_allowed: bool,
+}
 
 /// A connection to the state of a shell.
 ///
@@ -15,6 +24,7 @@ pub struct Shell<'a, Message> {
     redraw_request: Option<window::RedrawRequest>,
     is_layout_invalid: bool,
     are_widgets_invalid: bool,
+    caret_info: Option<CaretInfo>,
 }
 
 impl<'a, Message> Shell<'a, Message> {
@@ -26,6 +36,7 @@ impl<'a, Message> Shell<'a, Message> {
             redraw_request: None,
             is_layout_invalid: false,
             are_widgets_invalid: false,
+            caret_info: None,
         }
     }
 
@@ -80,6 +91,16 @@ impl<'a, Message> Shell<'a, Message> {
         self.redraw_request
     }
 
+    /// TODO
+    pub fn update_caret_info(&mut self, caret_info: Option<CaretInfo>) {
+        self.caret_info = caret_info.or(self.caret_info);
+    }
+
+    /// TODO
+    pub fn caret_info(&self) -> Option<CaretInfo> {
+        self.caret_info
+    }
+
     /// Returns whether the current layout is invalid or not.
     pub fn is_layout_invalid(&self) -> bool {
         self.is_layout_invalid
@@ -130,6 +151,8 @@ impl<'a, Message> Shell<'a, Message> {
             );
         }
 
+        self.update_caret_info(other.caret_info());
+
         self.is_layout_invalid =
             self.is_layout_invalid || other.is_layout_invalid;