Add spellcheck and word suggestion to the prediction service

examples/keyboard_client/keyboard_client.cc

 // 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 "base/bind.h"
 #include "base/macros.h"
 #include "mojo/application/application_runner_chromium.h"
 #include "mojo/gpu/gl_texture.h"
 #include "mojo/gpu/texture_cache.h"
 #include "mojo/gpu/texture_uploader.h"
@@ skipping 201 matching lines @@
   void CommitCompletion(keyboard::CompletionDataPtr completion) override {
     DrawText();
   }
 
   void CommitCorrection(keyboard::CorrectionDataPtr correction) override {
     DrawText();
   }
 
   void CommitText(const mojo::String& text,
                   int32_t new_cursor_position) override {
-    std::string combined(text_[1]);
-    combined.append(text);
-    SkRect bounds;
-    text_paint_.measureText(combined.data(), combined.size(), &bounds);
-    if (bounds.width() > text_view_->bounds().width) {
-      text_[0] = text_[1];
-      text_[1] = text;
-    } else {
-      text_[1].append(text);
-    }
+    text_.append(text);
     DrawText();
   }
 
   void DeleteSurroundingText(int32_t before_length,
                              int32_t after_length) override {
     // treat negative and zero |before_length| values as no-op.
     if (before_length > 0) {
-      if (before_length > static_cast<int32_t>(text_[1].size())) {
-        before_length = text_[1].size();
+      if (before_length > static_cast<int32_t>(text_.size())) {
+        before_length = text_.size();
       }
-      text_[1].erase(text_[1].end() - before_length, text_[1].end());
+      text_.erase(text_.end() - before_length, text_.end());
     }
     DrawText();
   }
 
   void SetComposingRegion(int32_t start, int32_t end) override { DrawText(); }
 
   void SetComposingText(const mojo::String& text,
                         int32_t new_cursor_position) override {
     DrawText();
   }
@@ skipping 56 matching lines @@
     if (text_view_texture_uploader_) {
       text_view_texture_uploader_->Draw(text_view_surface_id_);
     }
   }
 
   void DrawTextView(SkCanvas* canvas) {
     canvas->clear(SK_ColorRED);
 
     float row_height = text_view_height_ / 2.0f;
     float text_baseline_offset = row_height / 5.0f;
+    if (!text_.empty()) {
+      SkRect sk_rect;
+      text_paint_.measureText((const void*)(text_.c_str()),
+                              strlen(text_.c_str()), &sk_rect);
 
-    if (!text_[0].empty()) {
-      canvas->drawText(text_[0].data(), text_[0].size(), 0.0f,
-                       row_height - text_baseline_offset, text_paint_);
-    }
+      if (sk_rect.width() > text_view_->bounds().width) {
+        char reverse_text[text_.length() + 1];
+        for (unsigned int i = 0; i < text_.length(); i++) {
+          reverse_text[i] = text_[text_.length() - i - 1];

[APW, 2015/07/31 22:36:43]

use either a reverse iterator or create a copy of the string and std::reverse()
it.  Also this should be a string not a char array - char array is scary

[riajiang, 2015/08/01 01:23:08]

Done.

+        }
+        reverse_text[text_.length()] = '\0';
 
-    if (!text_[1].empty()) {
-      canvas->drawText(text_[1].data(), text_[1].size(), 0.0f,
-                       (2.0f * row_height) - text_baseline_offset, text_paint_);
+        size_t processed1 = text_paint_.breakText((const void*)(reverse_text),
+                                                  strlen(reverse_text),
+                                                  text_view_->bounds().width);
+        size_t processed2 = text_paint_.breakText(
+            (const void*)(reverse_text + processed1),
+            strlen(reverse_text) - processed1, text_view_->bounds().width);
+        if (processed1 + processed2 < text_.length()) {
+          canvas->drawText(
+              text_.data() + (text_.length() - processed1), processed1, 0.0f,
+              (2.0f * row_height) - text_baseline_offset, text_paint_);
+          canvas->drawText(
+              text_.data() + (text_.length() - processed1 - processed2),
+              processed2, 0.0f, row_height - text_baseline_offset, text_paint_);
+        } else {
+          size_t processed3 = text_paint_.breakText(
+              (const void*)(text_.c_str()), strlen(text_.c_str()),
+              text_view_->bounds().width);
+          canvas->drawText(text_.data(), processed3, 0.0f,
+                           row_height - text_baseline_offset, text_paint_);
+          canvas->drawText(
+              text_.data() + processed3, strlen(text_.c_str()) - processed3,
+              0.0f, (2.0f * row_height) - text_baseline_offset, text_paint_);
+        }
+      } else {
+        canvas->drawText(text_.data(), text_.size(), 0.0f,

[APW, 2015/07/31 22:36:43]

just to make things a bit easier to understand, can you make functions for
drawing the first line and the second line?

[riajiang, 2015/08/01 01:23:08]

Done.

+                         (2.0f * row_height) - text_baseline_offset,
+                         text_paint_);
+      }
     }
 
     canvas->flush();
   }
 
   void DrawRootView(SkCanvas* canvas) {
     canvas->clear(SK_ColorDKGRAY);
     canvas->flush();
   }
 
  private:
   mojo::Binding<keyboard::KeyboardClient> binding_;
   keyboard::KeyboardServicePtr keyboard_;
   scoped_ptr<mojo::ViewManagerClientFactory> view_manager_client_factory_;
   mojo::Shell* shell_;
   mojo::View* keyboard_view_;
   mojo::View* text_view_;
   mojo::View* root_view_;
   uint32_t root_view_surface_id_;
   uint32_t text_view_surface_id_;
   uint32_t id_namespace_;
   base::WeakPtr<mojo::GLContext> gl_context_;
   mojo::SurfacePtr surface_;
   scoped_ptr<mojo::TextureCache> texture_cache_;
   scoped_ptr<ViewTextureUploader> text_view_texture_uploader_;
   scoped_ptr<ViewTextureUploader> root_view_texture_uploader_;
   int text_view_height_;
-  std::string text_[2];
+  std::string text_;
   SkPaint text_paint_;
   base::WeakPtrFactory<KeyboardDelegate> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyboardDelegate);
 };
 
 }  // namespace examples
 
 MojoResult MojoMain(MojoHandle application_request) {
   mojo::ApplicationRunnerChromium runner(new examples::KeyboardDelegate);
   return runner.Run(application_request);
 }