ppapi/examples/ime/ime.cc - chromium/src - Git at Google

 // Copyright (c) 2012 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 <stddef.h>
 #include <stdint.h>

 #include <algorithm>
 #include <string>
 #include <utility>
 #include <vector>

 #include "ppapi/c/dev/ppb_cursor_control_dev.h"
 #include "ppapi/c/ppb_console.h"
 #include "ppapi/cpp/completion_callback.h"
 #include "ppapi/cpp/graphics_2d.h"
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/input_event.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/rect.h"
 #include "ppapi/cpp/size.h"
 #include "ppapi/cpp/text_input_controller.h"
 #include "ppapi/cpp/trusted/browser_font_trusted.h"

 namespace {

 // Extracted from: ui/events/keycodes/keyboard_codes.h
 enum {
   VKEY_BACK = 0x08,
   VKEY_SHIFT = 0x10,
   VKEY_DELETE = 0x2E,
   VKEY_LEFT = 0x25,
   VKEY_UP = 0x26,
   VKEY_RIGHT = 0x27,
   VKEY_DOWN = 0x28,
 };

 const uint32_t kTextfieldBgColor = 0xffffffff;
 const uint32_t kTextfieldTextColor = 0xff000000;
 const uint32_t kTextfieldCaretColor = 0xff000000;
 const uint32_t kTextfieldPreeditTextColor = 0xffff0000;
 const uint32_t kTextfieldSelectionBackgroundColor = 0xffeecccc;
 const uint32_t kTextfieldUnderlineColorMain = 0xffff0000;
 const uint32_t kTextfieldUnderlineColorSub = 0xffddaaaa;

 void FillRect(pp::ImageData* image,
               int left, int top, int width, int height,
               uint32_t color) {
   for (int y = std::max(0, top);
        y < std::min(image->size().height() - 1, top + height);
        ++y) {
     for (int x = std::max(0, left);
          x < std::min(image->size().width() - 1, left + width);
          ++x)
       *image->GetAddr32(pp::Point(x, y)) = color;
   }
 }

 void FillRect(pp::ImageData* image, const pp::Rect& rect, uint32_t color) {
   FillRect(image, rect.x(), rect.y(), rect.width(), rect.height(), color);
 }

 size_t GetPrevCharOffsetUtf8(const std::string& str, size_t current_pos) {
   size_t i = current_pos;
   if (i > 0) {
     do {
       --i;
     } while (i > 0 && (str[i] & 0xc0) == 0x80);
   }
   return i;
 }

 size_t GetNextCharOffsetUtf8(const std::string& str, size_t current_pos) {
   size_t i = current_pos;
   if (i < str.size()) {
     do {
       ++i;
     } while (i < str.size() && (str[i] & 0xc0) == 0x80);
   }
   return i;
 }

 size_t GetNthCharOffsetUtf8(const std::string& str, size_t n) {
   size_t i = 0;
   for (size_t step = 0; step < n; ++step)
     i = GetNextCharOffsetUtf8(str, i);
   return i;
 }

 }  // namespace

 class TextFieldStatusHandler {
  public:
   virtual ~TextFieldStatusHandler() {}
   virtual void FocusIn(const pp::Rect& caret) {}
   virtual void FocusOut() {}
   virtual void UpdateSelection(const std::string& text) {}
 };

 class TextFieldStatusNotifyingHandler : public TextFieldStatusHandler {
  public:
   explicit TextFieldStatusNotifyingHandler(pp::Instance* instance)
       : textinput_control_(instance) {
   }

  protected:
   // Implement TextFieldStatusHandler.
   virtual void FocusIn(const pp::Rect& caret) {
     textinput_control_.SetTextInputType(PP_TEXTINPUT_TYPE_TEXT);
     textinput_control_.UpdateCaretPosition(caret);
   }
   virtual void FocusOut() {
     textinput_control_.CancelCompositionText();
     textinput_control_.SetTextInputType(PP_TEXTINPUT_TYPE_NONE);
   }
   virtual void UpdateSelection(const std::string& text) {
     textinput_control_.UpdateSurroundingText(
         text, 0, static_cast<uint32_t>(text.size()));
   }

  private:
   pp::TextInputController textinput_control_;
 };

 // Hand-made text field for demonstrating text input API.
 class MyTextField {
  public:
   MyTextField(pp::Instance* instance, TextFieldStatusHandler* handler,
               int x, int y, int width, int height)
       : instance_(instance),
         status_handler_(handler),
         area_(x, y, width, height),
         font_size_(height - 2),
         caret_pos_(std::string::npos),
         anchor_pos_(std::string::npos),
         target_segment_(0) {
     pp::BrowserFontDescription desc;
     desc.set_family(PP_BROWSERFONT_TRUSTED_FAMILY_SANSSERIF);
     desc.set_size(font_size_);
     font_ = pp::BrowserFont_Trusted(instance_, desc);
   }

   // Paint on the specified ImageData.
   void PaintOn(pp::ImageData* image, pp::Rect clip) {
     clip = clip.Intersect(area_);
     FillRect(image, clip, kTextfieldBgColor);

     if (caret_pos_ != std::string::npos) {
       int offset = area_.x();
       // selection (for the case without composition text)
       if (composition_.empty() && HasSelection()) {
         int left_x = font_.MeasureSimpleText(
             utf8_text_.substr(0, SelectionLeft()));
         int right_x = font_.MeasureSimpleText(
             utf8_text_.substr(0, SelectionRight()));
         FillRect(image, offset + left_x, area_.y(), right_x - left_x,
                  area_.height(), kTextfieldSelectionBackgroundColor);
       }
       // before caret
       {
         std::string str = utf8_text_.substr(0, caret_pos_);
         font_.DrawTextAt(
             image,
             pp::BrowserFontTextRun(str.c_str(), false, false),
             pp::Point(offset, area_.y() + font_size_),
             kTextfieldTextColor,
             clip,
             false);
         offset += font_.MeasureSimpleText(str);
       }
       // composition
       {
         const std::string& str = composition_;
         // selection
         if (composition_selection_.first != composition_selection_.second) {
           int left_x = font_.MeasureSimpleText(
               str.substr(0, composition_selection_.first));
           int right_x = font_.MeasureSimpleText(
               str.substr(0, composition_selection_.second));
           FillRect(image, offset + left_x, area_.y(), right_x - left_x,
                    area_.height(), kTextfieldSelectionBackgroundColor);
         }
         // composition text
         font_.DrawTextAt(
             image,
             pp::BrowserFontTextRun(str.c_str(), false, false),
             pp::Point(offset, area_.y() + font_size_),
             kTextfieldPreeditTextColor,
             clip,
             false);
         for (size_t i = 0; i < segments_.size(); ++i) {
           size_t l = segments_[i].first;
           size_t r = segments_[i].second;
           if (l != r) {
             int lx = font_.MeasureSimpleText(str.substr(0, l));
             int rx = font_.MeasureSimpleText(str.substr(0, r));
             FillRect(image,
                      offset + lx + 2, area_.y() + font_size_ + 1,
                      rx - lx - 4, 2,
                      i == static_cast<size_t>(target_segment_) ?
                          kTextfieldUnderlineColorMain :
                          kTextfieldUnderlineColorSub);
           }
         }
         // caret
         int caretx = font_.MeasureSimpleText(
             str.substr(0, composition_selection_.first));
         FillRect(image,
                  pp::Rect(offset + caretx, area_.y(), 2, area_.height()),
                  kTextfieldCaretColor);
         offset += font_.MeasureSimpleText(str);
       }
       // after caret
       {
         std::string str = utf8_text_.substr(caret_pos_);
         font_.DrawTextAt(
             image,
             pp::BrowserFontTextRun(str.c_str(), false, false),
             pp::Point(offset, area_.y() + font_size_),
             kTextfieldTextColor,
             clip,
             false);
       }
     } else {
       font_.DrawTextAt(
           image,
           pp::BrowserFontTextRun(utf8_text_.c_str(), false, false),
           pp::Point(area_.x(), area_.y() + font_size_),
           kTextfieldTextColor,
           clip,
           false);
     }
   }

   // Update current composition text.
   void SetComposition(
       const std::string& text,
       const std::vector< std::pair<uint32_t, uint32_t> >& segments,
       int32_t target_segment,
       const std::pair<uint32_t, uint32_t>& selection) {
     if (HasSelection() && !text.empty())
       InsertText(std::string());
     composition_ = text;
     segments_ = segments;
     target_segment_ = target_segment;
     composition_selection_ = selection;
     CaretPosChanged();
   }

   // Is the text field focused?
   bool Focused() const {
     return caret_pos_ != std::string::npos;
   }

   // Does the coordinate (x,y) is contained inside the edit box?
   bool Contains(int x, int y) const {
     return area_.Contains(x, y);
   }

   // Resets the content text.
   void SetText(const std::string& text) {
     utf8_text_ = text;
     if (Focused()) {
       caret_pos_ = anchor_pos_ = text.size();
       CaretPosChanged();
     }
   }

   // Inserts a text at the current caret position.
   void InsertText(const std::string& text) {
     if (!Focused())
       return;
     utf8_text_.replace(SelectionLeft(), SelectionRight() - SelectionLeft(),
                        text);
     caret_pos_ = anchor_pos_ = SelectionLeft() + text.size();
     CaretPosChanged();
   }

   // Handles mouse click event and changes the focus state.
   bool RefocusByMouseClick(int x, int y) {
     if (!Contains(x, y)) {
       // The text field is unfocused.
       caret_pos_ = anchor_pos_ = std::string::npos;
       return false;
     }

     // The text field is focused.
     size_t n = font_.CharacterOffsetForPixel(
         pp::BrowserFontTextRun(utf8_text_.c_str()), x - area_.x());
     caret_pos_ = anchor_pos_ = GetNthCharOffsetUtf8(utf8_text_, n);
     CaretPosChanged();
     return true;
   }

   void MouseDrag(int x, int y) {
     if (!Focused())
       return;
     size_t n = font_.CharacterOffsetForPixel(
         pp::BrowserFontTextRun(utf8_text_.c_str()), x - area_.x());
     caret_pos_ = GetNthCharOffsetUtf8(utf8_text_, n);
   }

   void MouseUp(int x, int y) {
     if (!Focused())
       return;
     CaretPosChanged();
   }

   void KeyLeft(bool shift) {
     if (!Focused())
       return;
     // Move caret to the head of the selection or to the previous character.
     if (!shift && HasSelection())
       caret_pos_ = SelectionLeft();
     else
       caret_pos_ = GetPrevCharOffsetUtf8(utf8_text_, caret_pos_);
     // Move the anchor if the shift key is not pressed.
     if (!shift)
       anchor_pos_ = caret_pos_;
     CaretPosChanged();
   }

   void KeyRight(bool shift) {
     if (!Focused())
       return;
     // Move caret to the end of the selection or to the next character.
     if (!shift && HasSelection())
       caret_pos_ = SelectionRight();
     else
       caret_pos_ = GetNextCharOffsetUtf8(utf8_text_, caret_pos_);
     // Move the anchor if the shift key is not pressed.
     if (!shift)
       anchor_pos_ = caret_pos_;
     CaretPosChanged();
   }

   void KeyDelete() {
     if (!Focused())
       return;
     if (HasSelection()) {
       InsertText(std::string());
     } else {
       size_t i = GetNextCharOffsetUtf8(utf8_text_, caret_pos_);
       utf8_text_.erase(caret_pos_, i - caret_pos_);
       CaretPosChanged();
     }
   }

   void KeyBackspace() {
     if (!Focused())
       return;
     if (HasSelection()) {
       InsertText(std::string());
     } else if (caret_pos_ != 0) {
       size_t i = GetPrevCharOffsetUtf8(utf8_text_, caret_pos_);
       utf8_text_.erase(i, caret_pos_ - i);
       caret_pos_ = anchor_pos_ = i;
       CaretPosChanged();
     }
   }

  private:
   // Notify the plugin instance that the caret position has changed.
   void CaretPosChanged() {
     if (Focused()) {
       std::string str = utf8_text_.substr(0, caret_pos_);
       if (!composition_.empty())
         str += composition_.substr(0, composition_selection_.first);
       int px = font_.MeasureSimpleText(str);
       pp::Rect caret(area_.x() + px, area_.y(), 0, area_.height() + 2);
       status_handler_->FocusIn(caret);
       status_handler_->UpdateSelection(
           utf8_text_.substr(SelectionLeft(),
                             SelectionRight() - SelectionLeft()));
     }
   }
   size_t SelectionLeft() const {
     return std::min(caret_pos_, anchor_pos_);
   }
   size_t SelectionRight() const {
     return std::max(caret_pos_, anchor_pos_);
   }
   bool HasSelection() const {
     return caret_pos_ != anchor_pos_;
   }

   pp::Instance* instance_;
   TextFieldStatusHandler* status_handler_;

   pp::Rect area_;
   int font_size_;
   pp::BrowserFont_Trusted font_;
   std::string utf8_text_;
   size_t caret_pos_;
   size_t anchor_pos_;
   std::string composition_;
   std::vector< std::pair<uint32_t, uint32_t> > segments_;
   std::pair<uint32_t, uint32_t> composition_selection_;
   int target_segment_;
 };

 class MyInstance : public pp::Instance {
  public:
   explicit MyInstance(PP_Instance instance)
       : pp::Instance(instance),
         status_handler_(new TextFieldStatusHandler),
         dragging_(false) {
   }

   ~MyInstance() {
     delete status_handler_;
   }

   virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
     RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE);
     RequestFilteringInputEvents(PP_INPUTEVENT_CLASS_KEYBOARD);

     for (uint32_t i = 0; i < argc; ++i) {
       if (argn[i] == std::string("ime")) {
         if (argv[i] == std::string("no")) {
           // Example of NO-IME plugins (e.g., games).
           //
           // When a plugin never wants to accept text input, at initialization
           // explicitly turn off the text input feature by calling:
           pp::TextInputController(this).SetTextInputType(
               PP_TEXTINPUT_TYPE_NONE);
         } else if (argv[i] == std::string("unaware")) {
           // Demonstrating the behavior of IME-unaware plugins.
           // Never call any text input related APIs.
           //
           // In such a case, the plugin is assumed to always accept text input.
           // For example, when the plugin is focused in touch devices a virtual
           // keyboard may pop up, or in environment IME is used, users can type
           // text via IME on the plugin. The characters are delivered to the
           // plugin via PP_INPUTEVENT_TYPE_CHAR events.
         } else if (argv[i] == std::string("caretmove")) {
           // Demonstrating the behavior of plugins with limited IME support.
           //
           // It uses SetTextInputType() and UpdateCaretPosition() API to notify
           // text input status to the browser, but unable to handle inline
           // compositions. By using the notified information. the browser can,
           // say, show virtual keyboards or IMEs only at appropriate timing
           // that the plugin does need to accept text input.
           delete status_handler_;
           status_handler_ = new TextFieldStatusNotifyingHandler(this);
         } else if (argv[i] == std::string("full")) {
           // Demonstrating the behavior of plugins fully supporting IME.
           //
           // It notifies updates of caret positions to the browser,
           // and handles all text input events by itself.
           delete status_handler_;
           status_handler_ = new TextFieldStatusNotifyingHandler(this);
           RequestInputEvents(PP_INPUTEVENT_CLASS_IME);
         }
         break;
       }
     }

     textfield_.push_back(MyTextField(this, status_handler_,
                                      10, 10, 300, 20));
     textfield_.back().SetText("Hello");
     textfield_.push_back(MyTextField(this, status_handler_,
                                      30, 100, 300, 20));
     textfield_.back().SetText("World");
     return true;
   }

  protected:
   virtual bool HandleInputEvent(const pp::InputEvent& event) {
     bool ret = false;
     switch (event.GetType()) {
       case PP_INPUTEVENT_TYPE_MOUSEDOWN: {
         const pp::MouseInputEvent mouseEvent(event);
         ret = OnMouseDown(mouseEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_MOUSEMOVE: {
         const pp::MouseInputEvent mouseEvent(event);
         ret = OnMouseMove(mouseEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_MOUSEUP: {
         const pp::MouseInputEvent mouseEvent(event);
         ret = OnMouseUp(mouseEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_KEYDOWN: {
         Log("Keydown");
         const pp::KeyboardInputEvent keyEvent(event);
         ret = OnKeyDown(keyEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_CHAR: {
         const pp::KeyboardInputEvent keyEvent(event);
         Log("Char [" + keyEvent.GetCharacterText().AsString() + "]");
         ret = OnChar(keyEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_IME_COMPOSITION_START: {
         const pp::IMEInputEvent imeEvent(event);
         Log("CompositionStart [" + imeEvent.GetText().AsString() + "]");
         ret = true;
         break;
       }
       case PP_INPUTEVENT_TYPE_IME_COMPOSITION_UPDATE: {
         const pp::IMEInputEvent imeEvent(event);
         Log("CompositionUpdate [" + imeEvent.GetText().AsString() + "]");
         ret = OnCompositionUpdate(imeEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_IME_COMPOSITION_END: {
         const pp::IMEInputEvent imeEvent(event);
         Log("CompositionEnd [" + imeEvent.GetText().AsString() + "]");
         ret = OnCompositionEnd(imeEvent);
         break;
       }
       case PP_INPUTEVENT_TYPE_IME_TEXT: {
         const pp::IMEInputEvent imeEvent(event);
         Log("ImeText [" + imeEvent.GetText().AsString() + "]");
         ret = OnImeText(imeEvent);
         break;
       }
       default:
         break;
     }
     if (ret && (dragging_ || event.GetType() != PP_INPUTEVENT_TYPE_MOUSEMOVE))
       Paint();
     return ret;
   }

   virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip) {
     if (position.size() == last_size_)
       return;
     last_size_ = position.size();
     Paint();
   }

  private:
   bool OnCompositionUpdate(const pp::IMEInputEvent& ev) {
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->Focused()) {
         std::vector< std::pair<uint32_t, uint32_t> > segs;
         for (uint32_t i = 0; i < ev.GetSegmentNumber(); ++i)
           segs.push_back(std::make_pair(ev.GetSegmentOffset(i),
                                         ev.GetSegmentOffset(i + 1)));
         uint32_t selection_start;
         uint32_t selection_end;
         ev.GetSelection(&selection_start, &selection_end);
         it->SetComposition(ev.GetText().AsString(),
                            segs,
                            ev.GetTargetSegment(),
                            std::make_pair(selection_start, selection_end));
         return true;
       }
     }
     return false;
   }

   bool OnCompositionEnd(const pp::IMEInputEvent& ev) {
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->Focused()) {
         it->SetComposition(std::string(),
                            std::vector<std::pair<uint32_t, uint32_t> >(),
                            0,
                            std::make_pair(0, 0));
         return true;
       }
     }
     return false;
   }

   bool OnMouseDown(const pp::MouseInputEvent& ev) {
     dragging_ = true;

     bool anyone_focused = false;
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->RefocusByMouseClick(ev.GetPosition().x(),
                                   ev.GetPosition().y())) {
         anyone_focused = true;
       }
     }
     if (!anyone_focused)
       status_handler_->FocusOut();
     return true;
   }

   bool OnMouseMove(const pp::MouseInputEvent& ev) {
     const PPB_CursorControl_Dev* cursor_control =
         reinterpret_cast<const PPB_CursorControl_Dev*>(
             pp::Module::Get()->GetBrowserInterface(
                 PPB_CURSOR_CONTROL_DEV_INTERFACE));
     if (!cursor_control)
       return false;

     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->Contains(ev.GetPosition().x(),
                        ev.GetPosition().y())) {
         cursor_control->SetCursor(pp_instance(), PP_CURSORTYPE_IBEAM,
                                   0, NULL);
         if (it->Focused() && dragging_)
           it->MouseDrag(ev.GetPosition().x(), ev.GetPosition().y());
         return true;
       }
     }
     cursor_control->SetCursor(pp_instance(), PP_CURSORTYPE_POINTER,
                               0, NULL);
     return true;
   }

   bool OnMouseUp(const pp::MouseInputEvent& ev) {
     dragging_ = false;
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it)
       if (it->Focused())
         it->MouseUp(ev.GetPosition().x(), ev.GetPosition().y());
     return false;
   }

   bool OnKeyDown(const pp::KeyboardInputEvent& ev) {
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->Focused()) {
         bool shift = ev.GetModifiers() & PP_INPUTEVENT_MODIFIER_SHIFTKEY;
         switch (ev.GetKeyCode()) {
           case VKEY_LEFT:
             it->KeyLeft(shift);
             break;
           case VKEY_RIGHT:
             it->KeyRight(shift);
             break;
           case VKEY_DELETE:
             it->KeyDelete();
             break;
           case VKEY_BACK:
             it->KeyBackspace();
             break;
         }
         return true;
       }
     }
     return false;
   }

   bool OnChar(const pp::KeyboardInputEvent& ev) {
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->Focused()) {
         std::string str = ev.GetCharacterText().AsString();
         if (str != "\r" && str != "\n")
           it->InsertText(str);
         return true;
       }
     }
     return false;
   }

   bool OnImeText(const pp::IMEInputEvent ev) {
     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       if (it->Focused()) {
         it->InsertText(ev.GetText().AsString());
         return true;
       }
     }
     return false;
   }

   void Paint() {
     pp::Rect clip(0, 0, last_size_.width(), last_size_.height());
     PaintClip(clip);
   }

   void PaintClip(const pp::Rect& clip) {
     pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, last_size_, true);
     pp::Graphics2D device(this, last_size_, false);
     BindGraphics(device);

     for (std::vector<MyTextField>::iterator it = textfield_.begin();
          it != textfield_.end();
          ++it) {
       it->PaintOn(&image, clip);
     }

     device.PaintImageData(image, pp::Point(0, 0));
     device.Flush(pp::CompletionCallback(&OnFlush, this));
   }

   static void OnFlush(void* user_data, int32_t result) {}

   // Prints a debug message.
   void Log(const pp::Var& value) {
     const PPB_Console* console = reinterpret_cast<const PPB_Console*>(
         pp::Module::Get()->GetBrowserInterface(PPB_CONSOLE_INTERFACE));
     if (!console)
       return;
     console->Log(pp_instance(), PP_LOGLEVEL_LOG, value.pp_var());
   }

   // IME Control interface.
   TextFieldStatusHandler* status_handler_;

   // Remembers the size of this instance.
   pp::Size last_size_;

   // Holds instances of text fields.
   std::vector<MyTextField> textfield_;

   // Whether or not during a drag operation.
   bool dragging_;
 };

 class MyModule : public pp::Module {
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new MyInstance(instance);
   }
 };

 namespace pp {

 Module* CreateModule() {
   return new MyModule();
 }

 }  // namespace pp
	// Copyright (c) 2012 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 <stddef.h>
	#include <stdint.h>

	#include <algorithm>
	#include <string>
	#include <utility>
	#include <vector>

	#include "ppapi/c/dev/ppb_cursor_control_dev.h"
	#include "ppapi/c/ppb_console.h"
	#include "ppapi/cpp/completion_callback.h"
	#include "ppapi/cpp/graphics_2d.h"
	#include "ppapi/cpp/image_data.h"
	#include "ppapi/cpp/input_event.h"
	#include "ppapi/cpp/instance.h"
	#include "ppapi/cpp/module.h"
	#include "ppapi/cpp/rect.h"
	#include "ppapi/cpp/size.h"
	#include "ppapi/cpp/text_input_controller.h"
	#include "ppapi/cpp/trusted/browser_font_trusted.h"

	namespace {

	// Extracted from: ui/events/keycodes/keyboard_codes.h
	enum {
	VKEY_BACK = 0x08,
	VKEY_SHIFT = 0x10,
	VKEY_DELETE = 0x2E,
	VKEY_LEFT = 0x25,
	VKEY_UP = 0x26,
	VKEY_RIGHT = 0x27,
	VKEY_DOWN = 0x28,
	};

	const uint32_t kTextfieldBgColor = 0xffffffff;
	const uint32_t kTextfieldTextColor = 0xff000000;
	const uint32_t kTextfieldCaretColor = 0xff000000;
	const uint32_t kTextfieldPreeditTextColor = 0xffff0000;
	const uint32_t kTextfieldSelectionBackgroundColor = 0xffeecccc;
	const uint32_t kTextfieldUnderlineColorMain = 0xffff0000;
	const uint32_t kTextfieldUnderlineColorSub = 0xffddaaaa;

	void FillRect(pp::ImageData* image,
	int left, int top, int width, int height,
	uint32_t color) {
	for (int y = std::max(0, top);
	y < std::min(image->size().height() - 1, top + height);
	++y) {
	for (int x = std::max(0, left);
	x < std::min(image->size().width() - 1, left + width);
	++x)
	*image->GetAddr32(pp::Point(x, y)) = color;
	}
	}

	void FillRect(pp::ImageData* image, const pp::Rect& rect, uint32_t color) {
	FillRect(image, rect.x(), rect.y(), rect.width(), rect.height(), color);
	}

	size_t GetPrevCharOffsetUtf8(const std::string& str, size_t current_pos) {
	size_t i = current_pos;
	if (i > 0) {
	do {
	--i;
	} while (i > 0 && (str[i] & 0xc0) == 0x80);
	}
	return i;
	}

	size_t GetNextCharOffsetUtf8(const std::string& str, size_t current_pos) {
	size_t i = current_pos;
	if (i < str.size()) {
	do {
	++i;
	} while (i < str.size() && (str[i] & 0xc0) == 0x80);
	}
	return i;
	}

	size_t GetNthCharOffsetUtf8(const std::string& str, size_t n) {
	size_t i = 0;
	for (size_t step = 0; step < n; ++step)
	i = GetNextCharOffsetUtf8(str, i);
	return i;
	}

	} // namespace

	class TextFieldStatusHandler {
	public:
	virtual ~TextFieldStatusHandler() {}
	virtual void FocusIn(const pp::Rect& caret) {}
	virtual void FocusOut() {}
	virtual void UpdateSelection(const std::string& text) {}
	};

	class TextFieldStatusNotifyingHandler : public TextFieldStatusHandler {
	public:
	explicit TextFieldStatusNotifyingHandler(pp::Instance* instance)
	: textinput_control_(instance) {
	}

	protected:
	// Implement TextFieldStatusHandler.
	virtual void FocusIn(const pp::Rect& caret) {
	textinput_control_.SetTextInputType(PP_TEXTINPUT_TYPE_TEXT);
	textinput_control_.UpdateCaretPosition(caret);
	}
	virtual void FocusOut() {
	textinput_control_.CancelCompositionText();
	textinput_control_.SetTextInputType(PP_TEXTINPUT_TYPE_NONE);
	}
	virtual void UpdateSelection(const std::string& text) {
	textinput_control_.UpdateSurroundingText(
	text, 0, static_cast<uint32_t>(text.size()));
	}

	private:
	pp::TextInputController textinput_control_;
	};

	// Hand-made text field for demonstrating text input API.
	class MyTextField {
	public:
	MyTextField(pp::Instance* instance, TextFieldStatusHandler* handler,
	int x, int y, int width, int height)
	: instance_(instance),
	status_handler_(handler),
	area_(x, y, width, height),
	font_size_(height - 2),
	caret_pos_(std::string::npos),
	anchor_pos_(std::string::npos),
	target_segment_(0) {
	pp::BrowserFontDescription desc;
	desc.set_family(PP_BROWSERFONT_TRUSTED_FAMILY_SANSSERIF);
	desc.set_size(font_size_);
	font_ = pp::BrowserFont_Trusted(instance_, desc);
	}

	// Paint on the specified ImageData.
	void PaintOn(pp::ImageData* image, pp::Rect clip) {
	clip = clip.Intersect(area_);
	FillRect(image, clip, kTextfieldBgColor);

	if (caret_pos_ != std::string::npos) {
	int offset = area_.x();
	// selection (for the case without composition text)
	if (composition_.empty() && HasSelection()) {
	int left_x = font_.MeasureSimpleText(
	utf8_text_.substr(0, SelectionLeft()));
	int right_x = font_.MeasureSimpleText(
	utf8_text_.substr(0, SelectionRight()));
	FillRect(image, offset + left_x, area_.y(), right_x - left_x,
	area_.height(), kTextfieldSelectionBackgroundColor);
	}
	// before caret
	{
	std::string str = utf8_text_.substr(0, caret_pos_);
	font_.DrawTextAt(
	image,
	pp::BrowserFontTextRun(str.c_str(), false, false),
	pp::Point(offset, area_.y() + font_size_),
	kTextfieldTextColor,
	clip,
	false);
	offset += font_.MeasureSimpleText(str);
	}
	// composition
	{
	const std::string& str = composition_;
	// selection
	if (composition_selection_.first != composition_selection_.second) {
	int left_x = font_.MeasureSimpleText(
	str.substr(0, composition_selection_.first));
	int right_x = font_.MeasureSimpleText(
	str.substr(0, composition_selection_.second));
	FillRect(image, offset + left_x, area_.y(), right_x - left_x,
	area_.height(), kTextfieldSelectionBackgroundColor);
	}
	// composition text
	font_.DrawTextAt(
	image,
	pp::BrowserFontTextRun(str.c_str(), false, false),
	pp::Point(offset, area_.y() + font_size_),
	kTextfieldPreeditTextColor,
	clip,
	false);
	for (size_t i = 0; i < segments_.size(); ++i) {
	size_t l = segments_[i].first;
	size_t r = segments_[i].second;
	if (l != r) {
	int lx = font_.MeasureSimpleText(str.substr(0, l));
	int rx = font_.MeasureSimpleText(str.substr(0, r));
	FillRect(image,
	offset + lx + 2, area_.y() + font_size_ + 1,
	rx - lx - 4, 2,
	i == static_cast<size_t>(target_segment_) ?
	kTextfieldUnderlineColorMain :
	kTextfieldUnderlineColorSub);
	}
	}
	// caret
	int caretx = font_.MeasureSimpleText(
	str.substr(0, composition_selection_.first));
	FillRect(image,
	pp::Rect(offset + caretx, area_.y(), 2, area_.height()),
	kTextfieldCaretColor);
	offset += font_.MeasureSimpleText(str);
	}
	// after caret
	{
	std::string str = utf8_text_.substr(caret_pos_);
	font_.DrawTextAt(
	image,
	pp::BrowserFontTextRun(str.c_str(), false, false),
	pp::Point(offset, area_.y() + font_size_),
	kTextfieldTextColor,
	clip,
	false);
	}
	} else {
	font_.DrawTextAt(
	image,
	pp::BrowserFontTextRun(utf8_text_.c_str(), false, false),
	pp::Point(area_.x(), area_.y() + font_size_),
	kTextfieldTextColor,
	clip,
	false);
	}
	}

	// Update current composition text.
	void SetComposition(
	const std::string& text,
	const std::vector< std::pair<uint32_t, uint32_t> >& segments,
	int32_t target_segment,
	const std::pair<uint32_t, uint32_t>& selection) {
	if (HasSelection() && !text.empty())
	InsertText(std::string());
	composition_ = text;
	segments_ = segments;
	target_segment_ = target_segment;
	composition_selection_ = selection;
	CaretPosChanged();
	}

	// Is the text field focused?
	bool Focused() const {
	return caret_pos_ != std::string::npos;
	}

	// Does the coordinate (x,y) is contained inside the edit box?
	bool Contains(int x, int y) const {
	return area_.Contains(x, y);
	}

	// Resets the content text.
	void SetText(const std::string& text) {
	utf8_text_ = text;
	if (Focused()) {
	caret_pos_ = anchor_pos_ = text.size();
	CaretPosChanged();
	}
	}

	// Inserts a text at the current caret position.
	void InsertText(const std::string& text) {
	if (!Focused())
	return;
	utf8_text_.replace(SelectionLeft(), SelectionRight() - SelectionLeft(),
	text);
	caret_pos_ = anchor_pos_ = SelectionLeft() + text.size();
	CaretPosChanged();
	}

	// Handles mouse click event and changes the focus state.
	bool RefocusByMouseClick(int x, int y) {
	if (!Contains(x, y)) {
	// The text field is unfocused.
	caret_pos_ = anchor_pos_ = std::string::npos;
	return false;
	}

	// The text field is focused.
	size_t n = font_.CharacterOffsetForPixel(
	pp::BrowserFontTextRun(utf8_text_.c_str()), x - area_.x());
	caret_pos_ = anchor_pos_ = GetNthCharOffsetUtf8(utf8_text_, n);
	CaretPosChanged();
	return true;
	}

	void MouseDrag(int x, int y) {
	if (!Focused())
	return;
	size_t n = font_.CharacterOffsetForPixel(
	pp::BrowserFontTextRun(utf8_text_.c_str()), x - area_.x());
	caret_pos_ = GetNthCharOffsetUtf8(utf8_text_, n);
	}

	void MouseUp(int x, int y) {
	if (!Focused())
	return;
	CaretPosChanged();
	}

	void KeyLeft(bool shift) {
	if (!Focused())
	return;
	// Move caret to the head of the selection or to the previous character.
	if (!shift && HasSelection())
	caret_pos_ = SelectionLeft();
	else
	caret_pos_ = GetPrevCharOffsetUtf8(utf8_text_, caret_pos_);
	// Move the anchor if the shift key is not pressed.
	if (!shift)
	anchor_pos_ = caret_pos_;
	CaretPosChanged();
	}

	void KeyRight(bool shift) {
	if (!Focused())
	return;
	// Move caret to the end of the selection or to the next character.
	if (!shift && HasSelection())
	caret_pos_ = SelectionRight();
	else
	caret_pos_ = GetNextCharOffsetUtf8(utf8_text_, caret_pos_);
	// Move the anchor if the shift key is not pressed.
	if (!shift)
	anchor_pos_ = caret_pos_;
	CaretPosChanged();
	}

	void KeyDelete() {
	if (!Focused())
	return;
	if (HasSelection()) {
	InsertText(std::string());
	} else {
	size_t i = GetNextCharOffsetUtf8(utf8_text_, caret_pos_);
	utf8_text_.erase(caret_pos_, i - caret_pos_);
	CaretPosChanged();
	}
	}

	void KeyBackspace() {
	if (!Focused())
	return;
	if (HasSelection()) {
	InsertText(std::string());
	} else if (caret_pos_ != 0) {
	size_t i = GetPrevCharOffsetUtf8(utf8_text_, caret_pos_);
	utf8_text_.erase(i, caret_pos_ - i);
	caret_pos_ = anchor_pos_ = i;
	CaretPosChanged();
	}
	}

	private:
	// Notify the plugin instance that the caret position has changed.
	void CaretPosChanged() {
	if (Focused()) {
	std::string str = utf8_text_.substr(0, caret_pos_);
	if (!composition_.empty())
	str += composition_.substr(0, composition_selection_.first);
	int px = font_.MeasureSimpleText(str);
	pp::Rect caret(area_.x() + px, area_.y(), 0, area_.height() + 2);
	status_handler_->FocusIn(caret);
	status_handler_->UpdateSelection(
	utf8_text_.substr(SelectionLeft(),
	SelectionRight() - SelectionLeft()));
	}
	}
	size_t SelectionLeft() const {
	return std::min(caret_pos_, anchor_pos_);
	}
	size_t SelectionRight() const {
	return std::max(caret_pos_, anchor_pos_);
	}
	bool HasSelection() const {
	return caret_pos_ != anchor_pos_;
	}

	pp::Instance* instance_;
	TextFieldStatusHandler* status_handler_;

	pp::Rect area_;
	int font_size_;
	pp::BrowserFont_Trusted font_;
	std::string utf8_text_;
	size_t caret_pos_;
	size_t anchor_pos_;
	std::string composition_;
	std::vector< std::pair<uint32_t, uint32_t> > segments_;
	std::pair<uint32_t, uint32_t> composition_selection_;
	int target_segment_;
	};

	class MyInstance : public pp::Instance {
	public:
	explicit MyInstance(PP_Instance instance)
	: pp::Instance(instance),
	status_handler_(new TextFieldStatusHandler),
	dragging_(false) {
	}

	~MyInstance() {
	delete status_handler_;
	}

	virtual bool Init(uint32_t argc, const char* argn[], const char* argv[]) {
	RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE);
	RequestFilteringInputEvents(PP_INPUTEVENT_CLASS_KEYBOARD);

	for (uint32_t i = 0; i < argc; ++i) {
	if (argn[i] == std::string("ime")) {
	if (argv[i] == std::string("no")) {
	// Example of NO-IME plugins (e.g., games).
	//
	// When a plugin never wants to accept text input, at initialization
	// explicitly turn off the text input feature by calling:
	pp::TextInputController(this).SetTextInputType(
	PP_TEXTINPUT_TYPE_NONE);
	} else if (argv[i] == std::string("unaware")) {
	// Demonstrating the behavior of IME-unaware plugins.
	// Never call any text input related APIs.
	//
	// In such a case, the plugin is assumed to always accept text input.
	// For example, when the plugin is focused in touch devices a virtual
	// keyboard may pop up, or in environment IME is used, users can type
	// text via IME on the plugin. The characters are delivered to the
	// plugin via PP_INPUTEVENT_TYPE_CHAR events.
	} else if (argv[i] == std::string("caretmove")) {
	// Demonstrating the behavior of plugins with limited IME support.
	//
	// It uses SetTextInputType() and UpdateCaretPosition() API to notify
	// text input status to the browser, but unable to handle inline
	// compositions. By using the notified information. the browser can,
	// say, show virtual keyboards or IMEs only at appropriate timing
	// that the plugin does need to accept text input.
	delete status_handler_;
	status_handler_ = new TextFieldStatusNotifyingHandler(this);
	} else if (argv[i] == std::string("full")) {
	// Demonstrating the behavior of plugins fully supporting IME.
	//
	// It notifies updates of caret positions to the browser,
	// and handles all text input events by itself.
	delete status_handler_;
	status_handler_ = new TextFieldStatusNotifyingHandler(this);
	RequestInputEvents(PP_INPUTEVENT_CLASS_IME);
	}
	break;
	}
	}

	textfield_.push_back(MyTextField(this, status_handler_,
	10, 10, 300, 20));
	textfield_.back().SetText("Hello");
	textfield_.push_back(MyTextField(this, status_handler_,
	30, 100, 300, 20));
	textfield_.back().SetText("World");
	return true;
	}

	protected:
	virtual bool HandleInputEvent(const pp::InputEvent& event) {
	bool ret = false;
	switch (event.GetType()) {
	case PP_INPUTEVENT_TYPE_MOUSEDOWN: {
	const pp::MouseInputEvent mouseEvent(event);
	ret = OnMouseDown(mouseEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_MOUSEMOVE: {
	const pp::MouseInputEvent mouseEvent(event);
	ret = OnMouseMove(mouseEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_MOUSEUP: {
	const pp::MouseInputEvent mouseEvent(event);
	ret = OnMouseUp(mouseEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_KEYDOWN: {
	Log("Keydown");
	const pp::KeyboardInputEvent keyEvent(event);
	ret = OnKeyDown(keyEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_CHAR: {
	const pp::KeyboardInputEvent keyEvent(event);
	Log("Char [" + keyEvent.GetCharacterText().AsString() + "]");
	ret = OnChar(keyEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_IME_COMPOSITION_START: {
	const pp::IMEInputEvent imeEvent(event);
	Log("CompositionStart [" + imeEvent.GetText().AsString() + "]");
	ret = true;
	break;
	}
	case PP_INPUTEVENT_TYPE_IME_COMPOSITION_UPDATE: {
	const pp::IMEInputEvent imeEvent(event);
	Log("CompositionUpdate [" + imeEvent.GetText().AsString() + "]");
	ret = OnCompositionUpdate(imeEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_IME_COMPOSITION_END: {
	const pp::IMEInputEvent imeEvent(event);
	Log("CompositionEnd [" + imeEvent.GetText().AsString() + "]");
	ret = OnCompositionEnd(imeEvent);
	break;
	}
	case PP_INPUTEVENT_TYPE_IME_TEXT: {
	const pp::IMEInputEvent imeEvent(event);
	Log("ImeText [" + imeEvent.GetText().AsString() + "]");
	ret = OnImeText(imeEvent);
	break;
	}
	default:
	break;
	}
	if (ret && (dragging_ \|\| event.GetType() != PP_INPUTEVENT_TYPE_MOUSEMOVE))
	Paint();
	return ret;
	}

	virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip) {
	if (position.size() == last_size_)
	return;
	last_size_ = position.size();
	Paint();
	}

	private:
	bool OnCompositionUpdate(const pp::IMEInputEvent& ev) {
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->Focused()) {
	std::vector< std::pair<uint32_t, uint32_t> > segs;
	for (uint32_t i = 0; i < ev.GetSegmentNumber(); ++i)
	segs.push_back(std::make_pair(ev.GetSegmentOffset(i),
	ev.GetSegmentOffset(i + 1)));
	uint32_t selection_start;
	uint32_t selection_end;
	ev.GetSelection(&selection_start, &selection_end);
	it->SetComposition(ev.GetText().AsString(),
	segs,
	ev.GetTargetSegment(),
	std::make_pair(selection_start, selection_end));
	return true;
	}
	}
	return false;
	}

	bool OnCompositionEnd(const pp::IMEInputEvent& ev) {
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->Focused()) {
	it->SetComposition(std::string(),
	std::vector<std::pair<uint32_t, uint32_t> >(),
	0,
	std::make_pair(0, 0));
	return true;
	}
	}
	return false;
	}

	bool OnMouseDown(const pp::MouseInputEvent& ev) {
	dragging_ = true;

	bool anyone_focused = false;
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->RefocusByMouseClick(ev.GetPosition().x(),
	ev.GetPosition().y())) {
	anyone_focused = true;
	}
	}
	if (!anyone_focused)
	status_handler_->FocusOut();
	return true;
	}

	bool OnMouseMove(const pp::MouseInputEvent& ev) {
	const PPB_CursorControl_Dev* cursor_control =
	reinterpret_cast<const PPB_CursorControl_Dev*>(
	pp::Module::Get()->GetBrowserInterface(
	PPB_CURSOR_CONTROL_DEV_INTERFACE));
	if (!cursor_control)
	return false;

	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->Contains(ev.GetPosition().x(),
	ev.GetPosition().y())) {
	cursor_control->SetCursor(pp_instance(), PP_CURSORTYPE_IBEAM,
	0, NULL);
	if (it->Focused() && dragging_)
	it->MouseDrag(ev.GetPosition().x(), ev.GetPosition().y());
	return true;
	}
	}
	cursor_control->SetCursor(pp_instance(), PP_CURSORTYPE_POINTER,
	0, NULL);
	return true;
	}

	bool OnMouseUp(const pp::MouseInputEvent& ev) {
	dragging_ = false;
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it)
	if (it->Focused())
	it->MouseUp(ev.GetPosition().x(), ev.GetPosition().y());
	return false;
	}

	bool OnKeyDown(const pp::KeyboardInputEvent& ev) {
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->Focused()) {
	bool shift = ev.GetModifiers() & PP_INPUTEVENT_MODIFIER_SHIFTKEY;
	switch (ev.GetKeyCode()) {
	case VKEY_LEFT:
	it->KeyLeft(shift);
	break;
	case VKEY_RIGHT:
	it->KeyRight(shift);
	break;
	case VKEY_DELETE:
	it->KeyDelete();
	break;
	case VKEY_BACK:
	it->KeyBackspace();
	break;
	}
	return true;
	}
	}
	return false;
	}

	bool OnChar(const pp::KeyboardInputEvent& ev) {
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->Focused()) {
	std::string str = ev.GetCharacterText().AsString();
	if (str != "\r" && str != "\n")
	it->InsertText(str);
	return true;
	}
	}
	return false;
	}

	bool OnImeText(const pp::IMEInputEvent ev) {
	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	if (it->Focused()) {
	it->InsertText(ev.GetText().AsString());
	return true;
	}
	}
	return false;
	}

	void Paint() {
	pp::Rect clip(0, 0, last_size_.width(), last_size_.height());
	PaintClip(clip);
	}

	void PaintClip(const pp::Rect& clip) {
	pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, last_size_, true);
	pp::Graphics2D device(this, last_size_, false);
	BindGraphics(device);

	for (std::vector<MyTextField>::iterator it = textfield_.begin();
	it != textfield_.end();
	++it) {
	it->PaintOn(&image, clip);
	}

	device.PaintImageData(image, pp::Point(0, 0));
	device.Flush(pp::CompletionCallback(&OnFlush, this));
	}

	static void OnFlush(void* user_data, int32_t result) {}

	// Prints a debug message.
	void Log(const pp::Var& value) {
	const PPB_Console* console = reinterpret_cast<const PPB_Console*>(
	pp::Module::Get()->GetBrowserInterface(PPB_CONSOLE_INTERFACE));
	if (!console)
	return;
	console->Log(pp_instance(), PP_LOGLEVEL_LOG, value.pp_var());
	}

	// IME Control interface.
	TextFieldStatusHandler* status_handler_;

	// Remembers the size of this instance.
	pp::Size last_size_;

	// Holds instances of text fields.
	std::vector<MyTextField> textfield_;

	// Whether or not during a drag operation.
	bool dragging_;
	};

	class MyModule : public pp::Module {
	virtual pp::Instance* CreateInstance(PP_Instance instance) {
	return new MyInstance(instance);
	}
	};

	namespace pp {

	Module* CreateModule() {
	return new MyModule();
	}

	} // namespace pp