Add two libcros interfaces for handwriting: SendHandwritingStrokes and CancelHandwriting.

chromeos_input_method.h

 // Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_INPUT_METHOD_H_
 #define CHROMEOS_INPUT_METHOD_H_
 
 #include <sstream>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include <base/basictypes.h>
 #include <base/logging.h>  // DCHECK
 
 namespace chromeos {
 
 // A structure which represents an input method. All methods in this class have
 // to be in chromeos_input_method.h since Chrome also creates an instance of
 // the class.
@@ skipping 251 matching lines @@
 extern bool (*SetImeConfig)(InputMethodStatusConnection* connection,
                             const char* section,
                             const char* config_name,
                             const ImeConfigValue& value);
 
 // Returns the keyboard overlay ID corresponding to |input_method_id|.
 // Returns an empty string if there is no corresponding keyboard overlay ID.
 extern std::string (*GetKeyboardOverlayId)(
     const std::string& input_method_id);
 
+// Sends a handwriting stroke to ibus-daemon. The std::pair contains x and y
+// coordinates. (0.0, 0.0) represents the top-left corner of a handwriting area,
+// and (1.0, 1.0) does the bottom-right. For example, the second stroke for ロ
+// (Katakana character Ro) would be something like [(0,0), (1,0), (1,1)].
+// stroke.size() should always be >= 2 (i.e. a single dot is not allowed).
+typedef std::vector<std::pair<double, double> > HandwritingStroke;
+extern void (*SendHandwritingStroke)(
+    InputMethodStatusConnection* connection, const HandwritingStroke& stroke);
+
+// Clears the last N handwriting strokes. Pass zero for clearing all strokes.
+// TODO(yusukes): Currently ibus-daemon only accepts 0 for |n_strokes|.
+extern void (*CancelHandwriting)(InputMethodStatusConnection* connection,
+                                 int n_strokes);
+
 //
 // FUNCTIONS BELOW ARE ONLY FOR UNIT TESTS. DO NOT USE THEM.
 //
 bool InputMethodIdIsWhitelisted(const std::string& input_method_id);
 bool XkbLayoutIsSupported(const std::string& xkb_layout);
 InputMethodDescriptor CreateInputMethodDescriptor(
     const std::string& id,
     const std::string& display_name,
     const std::string& raw_layout,
     const std::string& language_code);
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_INPUT_METHOD_H_