Add spellcheck and word suggestion to the prediction service

services/keyboard_native/predictor.cc

Index: services/keyboard_native/predictor.cc
diff --git a/services/keyboard_native/predictor.cc b/services/keyboard_native/predictor.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2465c4488520f348ac84cec24b821fcb62385ce7
--- /dev/null
+++ b/services/keyboard_native/predictor.cc
@@ -0,0 +1,129 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <iterator>
+#include <sstream>
+#include <string>
+
+#include "base/bind.h"
+#include "services/keyboard_native/predictor.h"
+#include "services/keyboard_native/text_update_key.h"
+
+namespace keyboard {
+
+Predictor::Predictor(mojo::Shell* shell) {
+  mojo::ServiceProviderPtr prediction_service_provider;
+  shell->ConnectToApplication("mojo:prediction_service",
+                              mojo::GetProxy(&prediction_service_provider),
+                              nullptr);
+  mojo::ConnectToService(prediction_service_provider.get(),
+                         &prediction_service_impl_);
+  suggestion_keys_.clear();
+}
+
+Predictor::~Predictor() {
+}
+
+void Predictor::SetSuggestionKeys(
+    std::vector<KeyLayout::Key*> suggestion_keys) {
+  size_t old_size = suggestion_keys_.size();
+  size_t new_size = suggestion_keys.size();
+  size_t keyloop_size = std::min(old_size, new_size);
+  for (size_t i = 0; i < keyloop_size; i++) {
+    if (old_size != 0) {
+      static_cast<TextUpdateKey*>(suggestion_keys[i])
+          ->ChangeText(suggestion_keys_[i]->ToText());
+      suggestion_keys_[i] = suggestion_keys[i];
+    } else {
+      suggestion_keys_.push_back(suggestion_keys[i]);
+    }
+  }
+  if (new_size < old_size) {
+    suggestion_keys_.erase(suggestion_keys_.begin() + new_size,
+                           suggestion_keys_.end());
+  } else if (old_size < new_size) {
+    suggestion_keys_.insert(suggestion_keys_.end(),
+                            suggestion_keys.begin() + old_size,
+                            suggestion_keys.end());
+  }
+}
+
+void Predictor::SetUpdateCallback(base::Callback<void()> on_update_callback) {
+  on_update_callback_ = on_update_callback;
+}
+
+void Predictor::StoreCurWord(std::string new_word) {
+  if (new_word == " ") {
+    previous_words_.push_back(current_word_);
+    current_word_ = "";
+    Predictor::ShowEmptySuggestion();
+  } else {
+    current_word_ += new_word;
+    Predictor::GetSuggestion();
+  }
+}
+
+int Predictor::ChooseSuggestedWord(std::string suggested) {
+  int old_size = static_cast<int>(current_word_.size());
+  // split suggested by space into a vector
+  std::istringstream sug(suggested);
+  std::istream_iterator<std::string> beg(sug), end;
+  std::vector<std::string> sugs(beg, end);
+  previous_words_.insert(previous_words_.end(), sugs.begin(), sugs.end());
+  current_word_ = "";
+  Predictor::ShowEmptySuggestion();
+  return old_size;
+}
+
+void Predictor::DeleteCharInCurWord() {
+  if (!current_word_.empty()) {
+    current_word_.erase(current_word_.end() - 1);
+    if (current_word_.empty()) {
+      Predictor::ShowEmptySuggestion();
+    } else {
+      Predictor::GetSuggestion();
+    }
+  } else if (!previous_words_.empty()) {
+    current_word_ = previous_words_.back();
+    previous_words_.pop_back();
+    if (!current_word_.empty())
+      Predictor::GetSuggestion();
+  }
+}
+
+void Predictor::ShowEmptySuggestion() {
+  for (size_t i = 0; i < suggestion_keys_.size(); i++) {
+    static_cast<TextUpdateKey*>(suggestion_keys_[i])->ChangeText("");
+  }
+  on_update_callback_.Run();
+}
+
+void Predictor::GetSuggestion() {
+  prediction::PredictionInfoPtr prediction_info =
+      prediction::PredictionInfo::New();
+  // we are not using bigram atm
+  prediction_info->previous_words =
+      mojo::Array<prediction::PrevWordInfoPtr>::New(0).Pass();
+  prediction_info->current_word = mojo::String(current_word_);
+
+  prediction_service_impl_->GetPredictionList(
+      prediction_info.Pass(),
+      base::Bind(&Predictor::GetPredictionListAndEnd, base::Unretained(this)));
+}
+
+void Predictor::GetPredictionListAndEnd(
+    const mojo::Array<mojo::String>& input_list) {
+  for (size_t i = 0; i < suggestion_keys_.size(); i++) {
+    std::string change_text;
+    if (i < input_list.size()) {
+      change_text = std::string(input_list[i].data());
+    } else {
+      change_text = "";
+    }
+    static_cast<TextUpdateKey*>(suggestion_keys_[i])->ChangeText(change_text);
+  }
+  on_update_callback_.Run();
+}
+
+}  // namespace keyboard