From c9d4c761bbc2ca17ca4fa69c1d2e20917f14f6ff Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Sat, 14 Sep 2013 19:51:15 +0800
Subject: [PATCH] Show IME's composition text on screen.

The composition text should only show on screen temporarily and gets
disappered when input is cancelled or done. We simply mark the
composition as selected, so it can not only indicate this is composition
text instead of normal text, but also updates the composition without
adding new interfaces.
---
 src/editor.coffee | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/editor.coffee b/src/editor.coffee
index 15a86f5a4..b14ae350b 100644
--- a/src/editor.coffee
+++ b/src/editor.coffee
@@ -699,7 +699,18 @@ class Editor extends View
 
   handleImeEvents: ->
     @on 'cursor:moved', =>
-      @hiddenInput.offset(@getCursorView().offset())
+      cursorView = @getCursorView()
+      @hiddenInput.offset(cursorView.offset()) if cursorView.is(':visible')
+
+    startScreenPosition = null
+    @hiddenInput.on 'compositionstart', =>
+      startScreenPosition = @getCursorScreenPosition()
+    @hiddenInput.on 'compositionupdate', (e) =>
+      @insertText(e.originalEvent.data)
+      @selectToScreenPosition(startScreenPosition)
+    @hiddenInput.on 'compositionend', =>
+      @delete()
+      startScreenPosition = null
 
   selectOnMousemoveUntilMouseup: ->
     lastMoveEvent = null