Implement Pepper IME API.

ppapi/examples/ime/ime.cc

Index: ppapi/examples/ime/ime.cc
diff --git a/ppapi/examples/ime/ime.cc b/ppapi/examples/ime/ime.cc
new file mode 100644
index 0000000000000000000000000000000000000000..86e07d2b9680848016334acb9aa00fa761dc0f1b
--- /dev/null
+++ b/ppapi/examples/ime/ime.cc
@@ -0,0 +1,601 @@
+// Copyright (c) 2011 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 <string>
+#include <utility>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "ppapi/c/dev/ppb_console_dev.h"
+#include "ppapi/c/dev/ppb_cursor_control_dev.h"
+#include "ppapi/cpp/completion_callback.h"
+#include "ppapi/cpp/dev/font_dev.h"
+#include "ppapi/cpp/dev/ime_input_event_dev.h"
+#include "ppapi/cpp/dev/text_input_dev.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 "ui/base/keycodes/keyboard_codes.h"
+
+namespace {
+
+static const uint32_t TEXTFIELD_BG_COLOR = 0xffffffff;

[kochi, 2011/10/04 08:52:45]

I don't think you need 'static' for these consts.

[kinaba, 2011/10/05 04:43:19]

Done. Also changed the names to kThisWay.

+static const uint32_t TEXTFIELD_TEXT_COLOR = 0xff000000;
+static const uint32_t TEXTFIELD_CARET_COLOR = 0xff000000;
+static const uint32_t TEXTFIELD_PREEDIT_TEXT_COLOR = 0xffff0000;
+static const uint32_t TEXTFIELD_UNDERLINE_COLOR_MAIN = 0xffff0000;
+static const uint32_t TEXTFIELD_UNDERLINE_COLOR_SUB = 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 utf8_prev(const std::string& str, size_t i) {

[yzshen1, 2011/10/03 18:28:10]

Please use FunctionNameLikeThis. (Line 60 has the same issue.)

[kinaba, 2011/10/05 04:43:19]

Done. Thanks for pointing out these style nits. I hope I have cleaned them up...

+  if (i > 0) {
+    do
+      --i;
+    while ((str[i] & 0xC0) == 0x80 && i > 0);

[kochi, 2011/10/04 08:52:45]

minor nit: why uppercase 0xC0? (same for line 65)

[kinaba, 2011/10/05 04:43:19]

Done.

+  }
+  return i;
+}
+
+size_t utf8_next(const std::string& str, size_t i, size_t n) {
+  for (size_t step = 0; step < n; ++step) {

[yzshen1, 2011/10/03 18:28:10]

Would you please show me why this loop is necessary?

[kinaba, 2011/10/05 04:43:19]

Because I use it for moving n characters forward in RefocusByMouseClick().
To avoid confusion, I've updated here to split the function into Utf8Next (for
advancing 1 character) and Utf8NextN (n characters). 

+    if (i < str.size()) {
+      do
+        ++i;
+      while ((str[i] & 0xC0) == 0x80 && i < str.size());
+    }
+  }
+  return i;
+}
+
+}  // namespace
+
+class TextFieldStatusHandler {
+ public:
+  virtual ~TextFieldStatusHandler() {}
+  virtual void focusIn(const pp::Rect& caret, const pp::Rect& bounding_box) {}

[yzshen1, 2011/10/03 18:28:10]

Please use MethodNameLikeThis. (There are quite a few places below that have the
same problem. Please fix them all.)

[kinaba, 2011/10/05 04:43:19]

Done.

+  virtual void focusOut() {}
+};
+
+class TextFieldStatusNotifyingHanlder : public TextFieldStatusHandler {
+ public:
+  explicit TextFieldStatusNotifyingHanlder(pp::Instance* instance)
+      : instance_(instance),
+        textinput_control_(instance) {}
+
+ protected:
+  virtual void focusIn(const pp::Rect& caret, const pp::Rect& bounding_box) {
+    textinput_control_.SetTextInputType(PP_TEXTINPUT_TYPE_TEXT);
+    textinput_control_.UpdateCaretPosition(caret, bounding_box);
+  }
+  virtual void focusOut() {
+    textinput_control_.CancelCompositionText();
+    textinput_control_.SetTextInputType(PP_TEXTINPUT_TYPE_NONE);
+  }
+
+ private:
+  pp::Instance* instance_;
+  pp::TextInput_Dev 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),

[yzshen1, 2011/10/03 18:28:10]

Spaces around '-', please. (There are quite a few places below have the same
problem, please fix them all.)

[kinaba, 2011/10/05 04:43:19]

Done.

+      caret_pos_(std::string::npos) {
+    pp::FontDescription_Dev desc;
+    desc.set_family(PP_FONTFAMILY_SANSSERIF);
+    desc.set_size(font_size_);
+    font_ = pp::Font_Dev(instance_, desc);
+  }
+
+  // Paint on the specified ImageData.
+  void PaintOn(pp::ImageData* image, pp::Rect clip) {
+    clip = clip.Intersect(area_);
+    FillRect(image, clip, TEXTFIELD_BG_COLOR);
+
+    if (caret_pos_ != std::string::npos) {
+      int offset = area_.x();
+      // before caret
+      {
+        std::string str = utf8_text_.substr(0, caret_pos_);
+        font_.DrawTextAt(
+            image,
+            pp::TextRun_Dev(str.c_str(), false, false),
+            pp::Point(offset, area_.y()+font_size_),
+            TEXTFIELD_TEXT_COLOR,
+            clip,
+            false);
+        offset += font_.MeasureSimpleText(str);
+      }
+      // composition
+      {
+        const std::string& str = composition_;
+        font_.DrawTextAt(
+            image,
+            pp::TextRun_Dev(str.c_str(), false, false),
+            pp::Point(offset, area_.y()+font_size_),
+            TEXTFIELD_PREEDIT_TEXT_COLOR,
+            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>(targetSegment_) ?
+                         TEXTFIELD_UNDERLINE_COLOR_MAIN :
+                         TEXTFIELD_UNDERLINE_COLOR_SUB);
+          }
+        }
+        // caret
+        int caretx = font_.MeasureSimpleText(str.substr(0, selection_.first));
+        FillRect(image,
+                 pp::Rect(offset+caretx, area_.y(), 2, area_.height()),
+                 TEXTFIELD_CARET_COLOR);
+        offset += font_.MeasureSimpleText(str);
+      }
+      // after caret
+      {
+        std::string str = utf8_text_.substr(caret_pos_);
+        font_.DrawTextAt(
+            image,
+            pp::TextRun_Dev(str.c_str(), false, false),
+            pp::Point(offset, area_.y()+font_size_),
+            TEXTFIELD_TEXT_COLOR,
+            clip,
+            false);
+      }
+    } else {
+      font_.DrawTextAt(
+          image,
+          pp::TextRun_Dev(utf8_text_.c_str(), false, false),
+          pp::Point(area_.x(), area_.y()+font_size_),
+          TEXTFIELD_TEXT_COLOR,
+          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) {
+    composition_ = text;
+    segments_ = segments;
+    targetSegment_ = target_segment;
+    selection_ = selection;
+    caretPosChanged();
+  }
+
+  // Am I 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);
+  }
+

[yzshen1, 2011/10/03 18:28:10]

Please use sentence, with capital initial and '.' at the end. (Multiple
occurrences.)

[kinaba, 2011/10/05 04:43:19]

Done.

+  // reset the content text
+  void set_text(const std::string& text) {
+    utf8_text_ = text;
+    if (focused()) {
+      caret_pos_ = text.size();
+      caretPosChanged();
+    }
+  }
+
+  // insert the text at the caret position
+  void insert_text(const std::string& text) {
+    if (!focused())
+      return;
+    utf8_text_.insert(caret_pos_, text);
+    if (focused()) {
+      caret_pos_ += text.size();
+      caretPosChanged();
+    }
+  }
+
+  // event handling
+  bool refocusByMouseClick(int x, int y) {
+    if (!contains(x, y)) {
+      // unfocus
+      caret_pos_ = std::string::npos;
+      return false;
+    }
+
+    // focus
+    size_t n = font_.CharacterOffsetForPixel(
+        pp::TextRun_Dev(utf8_text_.c_str()), x-area_.x());
+    caret_pos_ = utf8_next(utf8_text_, 0, n);
+    caretPosChanged();
+    return true;
+  }
+
+  void keyLeft() {
+    if (!focused())
+      return;
+    caret_pos_ = utf8_prev(utf8_text_, caret_pos_);
+    caretPosChanged();
+  }
+
+  void keyRight() {
+    if (!focused())
+      return;
+    caret_pos_ = utf8_next(utf8_text_, caret_pos_, 1);
+    caretPosChanged();
+  }
+
+  void keyDelete() {
+    if (!focused())
+      return;
+    size_t i = utf8_next(utf8_text_, caret_pos_, 1);
+    utf8_text_.erase(caret_pos_, i-caret_pos_);
+    caretPosChanged();
+  }
+
+  void keyBackspace() {
+    if (!focused() || caret_pos_ == 0)
+      return;
+    keyLeft();
+    keyDelete();
+  }
+
+ 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, selection_.first);
+      int px = font_.MeasureSimpleText(str);
+      pp::Rect caret(area_.x()+px, area_.y(), 0, area_.height()+2);
+      status_handler_->focusIn(caret, area_);
+    }
+  }
+
+  pp::Instance* instance_;
+  TextFieldStatusHandler* status_handler_;
+
+  pp::Rect area_;
+  int font_size_;
+  pp::Font_Dev font_;
+  std::string utf8_text_;
+  size_t caret_pos_;
+  std::string composition_;
+  std::vector< std::pair<uint32_t, uint32_t> > segments_;
+  std::pair<uint32_t, uint32_t> selection_;
+  int targetSegment_;
+};
+
+class MyInstance : public pp::Instance {
+ public:
+  explicit MyInstance(PP_Instance instance)
+      : pp::Instance(instance),
+        status_handler_(new TextFieldStatusHandler) {
+  }
+
+  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::TextInput_Dev(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.
+          status_handler_.reset(new TextFieldStatusNotifyingHanlder(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.
+          status_handler_.reset(new TextFieldStatusNotifyingHanlder(this));
+          RequestInputEvents(PP_INPUTEVENT_CLASS_IME);
+        }
+        break;
+      }
+    }
+
+    textfield_.push_back(MyTextField(this, status_handler_.get(),
+                                     10, 10, 300, 20));
+    textfield_.back().set_text("Hello");
+    textfield_.push_back(MyTextField(this, status_handler_.get(),
+                                     30, 100, 300, 20));
+    textfield_.back().set_text("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_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_Dev imeEvent(event);
+        Log("CompositionStart ["+imeEvent.GetText().AsString()+"]");
+        ret = true;
+        break;
+      }
+      case PP_INPUTEVENT_TYPE_IME_COMPOSITION_UPDATE: {
+        const pp::IMEInputEvent_Dev imeEvent(event);
+        Log("CompositionUpdate ["+imeEvent.GetText().AsString()+"]");
+        ret = onCompositionUpdate(imeEvent);
+        break;
+      }
+      case PP_INPUTEVENT_TYPE_IME_COMPOSITION_END: {
+        const pp::IMEInputEvent_Dev imeEvent(event);
+        Log("CompositionEnd ["+imeEvent.GetText().AsString()+"]");
+        ret = onCompositionEnd(imeEvent);
+        break;
+      }
+      case PP_INPUTEVENT_TYPE_IME_TEXT: {
+        const pp::IMEInputEvent_Dev imeEvent(event);
+        Log("ImeText ["+imeEvent.GetText().AsString()+"]");
+        ret = onImeText(imeEvent);
+        break;
+      }
+      default:
+        break;
+    }
+    if (ret && 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_Dev ev) {

[yzshen1, 2011/10/03 18:28:10]

May consider to use const & (and also line 446).

[kinaba, 2011/10/05 04:43:19]

Done.

+    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)) );
+        it->setComposition(ev.GetText().AsString(),
+                           segs,
+                           ev.GetTargetSegment(),
+                           ev.GetSelection());
+        return true;
+      }
+    }
+    return false;
+  }
+
+  bool onCompositionEnd(const pp::IMEInputEvent_Dev ev) {
+    for (std::vector<MyTextField>::iterator it = textfield_.begin();
+         it != textfield_.end();
+         ++it) {
+      if (it->focused()) {
+        it->setComposition("", std::vector< std::pair<uint32_t, uint32_t> >(),
+                           0, std::make_pair(0, 0));
+        return true;
+      }
+    }
+    return false;
+  }
+
+  bool onMouseDown(const pp::MouseInputEvent& ev) {
+    bool anyoneFocused = false;

[yzshen1, 2011/10/03 18:28:10]

Please use variable_name_like_this.

[kinaba, 2011/10/05 04:43:19]

Done.

+    for (std::vector<MyTextField>::iterator it = textfield_.begin();
+         it != textfield_.end();
+         ++it) {
+      if (it->refocusByMouseClick(ev.GetPosition().x(),
+                                  ev.GetPosition().y())) {
+        anyoneFocused = true;
+      }
+    }
+    if (!anyoneFocused)
+      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);
+        return true;
+      }
+    }
+    cursor_control->SetCursor(pp_instance(), PP_CURSORTYPE_POINTER,
+                              0, NULL);
+    return true;
+  }
+
+  bool onKeyDown(const pp::KeyboardInputEvent& ev) {
+    for (std::vector<MyTextField>::iterator it = textfield_.begin();
+         it != textfield_.end();
+         ++it) {
+      if (it->focused()) {
+        switch (ev.GetKeyCode()) {
+          case ui::VKEY_LEFT:
+            it->keyLeft();
+            break;
+          case ui::VKEY_RIGHT:
+            it->keyRight();
+            break;
+          case ui::VKEY_DELETE:
+            it->keyDelete();
+            break;
+          case ui::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->insert_text(str);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  bool onImeText(const pp::IMEInputEvent_Dev ev) {
+    for (std::vector<MyTextField>::iterator it = textfield_.begin();
+         it != textfield_.end();
+         ++it) {
+      if (it->focused()) {
+        it->insert_text(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) {}
+
+  // For debugging purpose.
+  void Log(const pp::Var& value) {
+    const PPB_Console_Dev* console = reinterpret_cast<const PPB_Console_Dev*>(
+        pp::Module::Get()->GetBrowserInterface(PPB_CONSOLE_DEV_INTERFACE));
+    if (!console)
+      return;
+    console->Log(pp_instance(), PP_LOGLEVEL_LOG, value.pp_var());
+  }
+
+  // IME Control interface.
+  scoped_ptr<TextFieldStatusHandler> status_handler_;
+
+  // Remembers the size of this instance.
+  pp::Size last_size_;
+
+  // Holds instances of text fields.
+  std::vector<MyTextField> textfield_;
+};
+
+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