[KeyEvent Mac] Move WebInputEventFactory into chromium.

content/browser/renderer_host/input/web_input_event_builders_mac.mm

+// 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.
+
+/*
+ * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
+ * Copyright (C) 2006-2009 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "content/browser/renderer_host/input/web_input_event_builders_mac.h"
+
+#import <ApplicationServices/ApplicationServices.h>
+#import <AvailabilityMacros.h>
+#import <Cocoa/Cocoa.h>
+
+#include "base/mac/sdk_forward_declarations.h"
+#include "base/strings/string_util.h"
+#include "content/browser/renderer_host/input/web_input_event_util.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+#include "ui/events/keycodes/keyboard_code_conversion.h"
+#include "ui/events/keycodes/keyboard_code_conversion_mac.h"
+
+namespace content {
+
+namespace {
+
+// Return true if the target modifier key is up. OS X has an "official" flag
+// to test whether either left or right versions of a modifier key are held,
+// and "unofficial" flags for the left and right versions independently. This
+// function verifies that |targetKeyMask| and |otherKeyMask| (which should be
+// the left and right versions of a modifier) are consistent with with the
+// state of |eitherKeyMask| (which should be the corresponding ""official"
+// flag). If they are consistent, it tests |targetKeyMask|; otherwise it tests
+// |eitherKeyMask|.
+inline bool IsModifierKeyUp(unsigned int flags,
+                            unsigned int target_key_mask,
+                            unsigned int other_key_mask,
+                            unsigned int either_key_mask) {
+  bool either_key_down = (flags & either_key_mask) != 0;
+  bool target_key_down = (flags & target_key_mask) != 0;
+  bool other_key_down = (flags & other_key_mask) != 0;
+  if (either_key_down != (target_key_down || other_key_down))
+    return !either_key_down;
+  return !target_key_down;
+}
+
+bool IsKeyUpEvent(NSEvent* event) {
+  if ([event type] != NSFlagsChanged)
+    return [event type] == NSKeyUp;
+
+  // Unofficial bit-masks for left- and right-hand versions of modifier keys.
+  // These values were determined empirically.
+  const unsigned int kLeftControlKeyMask = 1 << 0;
+  const unsigned int kLeftShiftKeyMask = 1 << 1;
+  const unsigned int kRightShiftKeyMask = 1 << 2;
+  const unsigned int kLeftCommandKeyMask = 1 << 3;
+  const unsigned int kRightCommandKeyMask = 1 << 4;
+  const unsigned int kLeftAlternateKeyMask = 1 << 5;
+  const unsigned int kRightAlternateKeyMask = 1 << 6;
+  const unsigned int kRightControlKeyMask = 1 << 13;
+
+  switch ([event keyCode]) {
+    case 54:  // Right Command
+      return IsModifierKeyUp([event modifierFlags], kRightCommandKeyMask,
+                             kLeftCommandKeyMask, NSCommandKeyMask);
+    case 55:  // Left Command
+      return IsModifierKeyUp([event modifierFlags], kLeftCommandKeyMask,
+                             kRightCommandKeyMask, NSCommandKeyMask);
+
+    case 57:  // Capslock
+      return ([event modifierFlags] & NSAlphaShiftKeyMask) == 0;
+
+    case 56:  // Left Shift
+      return IsModifierKeyUp([event modifierFlags], kLeftShiftKeyMask,
+                             kRightShiftKeyMask, NSShiftKeyMask);
+    case 60:  // Right Shift
+      return IsModifierKeyUp([event modifierFlags], kRightShiftKeyMask,
+                             kLeftShiftKeyMask, NSShiftKeyMask);
+
+    case 58:  // Left Alt
+      return IsModifierKeyUp([event modifierFlags], kLeftAlternateKeyMask,
+                             kRightAlternateKeyMask, NSAlternateKeyMask);
+    case 61:  // Right Alt
+      return IsModifierKeyUp([event modifierFlags], kRightAlternateKeyMask,
+                             kLeftAlternateKeyMask, NSAlternateKeyMask);
+
+    case 59:  // Left Ctrl
+      return IsModifierKeyUp([event modifierFlags], kLeftControlKeyMask,
+                             kRightControlKeyMask, NSControlKeyMask);
+    case 62:  // Right Ctrl
+      return IsModifierKeyUp([event modifierFlags], kRightControlKeyMask,
+                             kLeftControlKeyMask, NSControlKeyMask);
+
+    case 63:  // Function
+      return ([event modifierFlags] & NSFunctionKeyMask) == 0;
+  }
+  return false;
+}
+
+inline NSString* TextFromEvent(NSEvent* event) {
+  if ([event type] == NSFlagsChanged)
+    return @"";
+  return [event characters];
+}
+
+inline NSString* UnmodifiedTextFromEvent(NSEvent* event) {
+  if ([event type] == NSFlagsChanged)
+    return @"";
+  return [event charactersIgnoringModifiers];
+}
+
+NSString* KeyIdentifierForKeyEvent(NSEvent* event) {
+  if ([event type] == NSFlagsChanged) {
+    switch ([event keyCode]) {
+      case 54:  // Right Command
+      case 55:  // Left Command
+        return @"Meta";
+
+      case 57:  // Capslock
+        return @"CapsLock";
+
+      case 56:  // Left Shift
+      case 60:  // Right Shift
+        return @"Shift";
+
+      case 58:  // Left Alt
+      case 61:  // Right Alt
+        return @"Alt";
+
+      case 59:  // Left Ctrl
+      case 62:  // Right Ctrl
+        return @"Control";
+
+      // Begin non-Apple addition/modification
+      // --------------------------------------
+      case 63:  // Function
+        return @"Function";
+
+      default:  // Unknown, but this may be a strange/new keyboard.
+        return @"Unidentified";
+        // End non-Apple addition/modification
+        // ----------------------------------------
+    }
+  }
+
+  NSString* s = [event charactersIgnoringModifiers];
+  if ([s length] != 1)
+    return @"Unidentified";
+
+  unichar c = [s characterAtIndex:0];
+  switch (c) {
+    // Each identifier listed in the DOM spec is listed here.
+    // Many are simply commented out since they do not appear on standard
+    // Macintosh keyboards
+    // or are on a key that doesn't have a corresponding character.
+
+    // "Accept"
+    // "AllCandidates"
+
+    // "Alt"
+    case NSMenuFunctionKey:
+      return @"Alt";
+
+    // "Apps"
+    // "BrowserBack"
+    // "BrowserForward"
+    // "BrowserHome"
+    // "BrowserRefresh"
+    // "BrowserSearch"
+    // "BrowserStop"
+    // "CapsLock"
+
+    // "Clear"
+    case NSClearLineFunctionKey:
+      return @"Clear";
+
+    // "CodeInput"
+    // "Compose"
+    // "Control"
+    // "Crsel"
+    // "Convert"
+    // "Copy"
+    // "Cut"
+
+    // "Down"
+    case NSDownArrowFunctionKey:
+      return @"Down";
+    // "End"
+    case NSEndFunctionKey:
+      return @"End";
+    // "Enter"
+    case 0x3:
+    case 0xA:
+    case 0xD:  // Macintosh calls the one on the main keyboard Return, but
+               // Windows calls it Enter, so we'll do the same for the DOM
+      return @"Enter";
+
+    // "EraseEof"
+
+    // "Execute"
+    case NSExecuteFunctionKey:
+      return @"Execute";
+
+    // "Exsel"
+
+    // "F1"
+    case NSF1FunctionKey:
+      return @"F1";
+    // "F2"
+    case NSF2FunctionKey:
+      return @"F2";
+    // "F3"
+    case NSF3FunctionKey:
+      return @"F3";
+    // "F4"
+    case NSF4FunctionKey:
+      return @"F4";
+    // "F5"
+    case NSF5FunctionKey:
+      return @"F5";
+    // "F6"
+    case NSF6FunctionKey:
+      return @"F6";
+    // "F7"
+    case NSF7FunctionKey:
+      return @"F7";
+    // "F8"
+    case NSF8FunctionKey:
+      return @"F8";
+    // "F9"
+    case NSF9FunctionKey:
+      return @"F9";
+    // "F10"
+    case NSF10FunctionKey:
+      return @"F10";
+    // "F11"
+    case NSF11FunctionKey:
+      return @"F11";
+    // "F12"
+    case NSF12FunctionKey:
+      return @"F12";
+    // "F13"
+    case NSF13FunctionKey:
+      return @"F13";
+    // "F14"
+    case NSF14FunctionKey:
+      return @"F14";
+    // "F15"
+    case NSF15FunctionKey:
+      return @"F15";
+    // "F16"
+    case NSF16FunctionKey:
+      return @"F16";
+    // "F17"
+    case NSF17FunctionKey:
+      return @"F17";
+    // "F18"
+    case NSF18FunctionKey:
+      return @"F18";
+    // "F19"
+    case NSF19FunctionKey:
+      return @"F19";
+    // "F20"
+    case NSF20FunctionKey:
+      return @"F20";
+    // "F21"
+    case NSF21FunctionKey:
+      return @"F21";
+    // "F22"
+    case NSF22FunctionKey:
+      return @"F22";
+    // "F23"
+    case NSF23FunctionKey:
+      return @"F23";
+    // "F24"
+    case NSF24FunctionKey:
+      return @"F24";
+
+    // "FinalMode"
+
+    // "Find"
+    case NSFindFunctionKey:
+      return @"Find";
+
+    // "FullWidth"
+    // "HalfWidth"
+    // "HangulMode"
+    // "HanjaMode"
+
+    // "Help"
+    case NSHelpFunctionKey:
+      return @"Help";
+
+    // "Hiragana"
+
+    // "Home"
+    case NSHomeFunctionKey:
+      return @"Home";
+    // "Insert"
+    case NSInsertFunctionKey:
+      return @"Insert";
+
+    // "JapaneseHiragana"
+    // "JapaneseKatakana"
+    // "JapaneseRomaji"
+    // "JunjaMode"
+    // "KanaMode"
+    // "KanjiMode"
+    // "Katakana"
+    // "LaunchApplication1"
+    // "LaunchApplication2"
+    // "LaunchMail"
+
+    // "Left"
+    case NSLeftArrowFunctionKey:
+      return @"Left";
+
+    // "Meta"
+    // "MediaNextTrack"
+    // "MediaPlayPause"
+    // "MediaPreviousTrack"
+    // "MediaStop"
+
+    // "ModeChange"
+    case NSModeSwitchFunctionKey:
+      return @"ModeChange";
+
+    // "Nonconvert"
+    // "NumLock"
+
+    // "PageDown"
+    case NSPageDownFunctionKey:
+      return @"PageDown";
+    // "PageUp"
+    case NSPageUpFunctionKey:
+      return @"PageUp";
+
+    // "Paste"
+
+    // "Pause"
+    case NSPauseFunctionKey:
+      return @"Pause";
+
+    // "Play"
+    // "PreviousCandidate"
+
+    // "PrintScreen"
+    case NSPrintScreenFunctionKey:
+      return @"PrintScreen";
+
+    // "Process"
+    // "Props"
+
+    // "Right"
+    case NSRightArrowFunctionKey:
+      return @"Right";
+
+    // "RomanCharacters"
+
+    // "Scroll"
+    case NSScrollLockFunctionKey:
+      return @"Scroll";
+    // "Select"
+    case NSSelectFunctionKey:
+      return @"Select";
+
+    // "SelectMedia"
+    // "Shift"
+
+    // "Stop"
+    case NSStopFunctionKey:
+      return @"Stop";
+    // "Up"
+    case NSUpArrowFunctionKey:
+      return @"Up";
+    // "Undo"
+    case NSUndoFunctionKey:
+      return @"Undo";
+
+    // "VolumeDown"
+    // "VolumeMute"
+    // "VolumeUp"
+    // "Win"
+    // "Zoom"
+
+    // More function keys, not in the key identifier specification.
+    case NSF25FunctionKey:
+      return @"F25";
+    case NSF26FunctionKey:
+      return @"F26";
+    case NSF27FunctionKey:
+      return @"F27";
+    case NSF28FunctionKey:
+      return @"F28";
+    case NSF29FunctionKey:
+      return @"F29";
+    case NSF30FunctionKey:
+      return @"F30";
+    case NSF31FunctionKey:
+      return @"F31";
+    case NSF32FunctionKey:
+      return @"F32";
+    case NSF33FunctionKey:
+      return @"F33";
+    case NSF34FunctionKey:
+      return @"F34";
+    case NSF35FunctionKey:
+      return @"F35";
+
+    // Turn 0x7F into 0x08, because backspace needs to always be 0x08.
+    case 0x7F:
+      return @"U+0008";
+    // Standard says that DEL becomes U+007F.
+    case NSDeleteFunctionKey:
+      return @"U+007F";
+
+    // Always use 0x09 for tab instead of AppKit's backtab character.
+    case NSBackTabCharacter:
+      return @"U+0009";
+
+    case NSBeginFunctionKey:
+    case NSBreakFunctionKey:
+    case NSClearDisplayFunctionKey:
+    case NSDeleteCharFunctionKey:
+    case NSDeleteLineFunctionKey:
+    case NSInsertCharFunctionKey:
+    case NSInsertLineFunctionKey:
+    case NSNextFunctionKey:
+    case NSPrevFunctionKey:
+    case NSPrintFunctionKey:
+    case NSRedoFunctionKey:
+    case NSResetFunctionKey:
+    case NSSysReqFunctionKey:
+    case NSSystemFunctionKey:
+    case NSUserFunctionKey:
+    // FIXME: We should use something other than the vendor-area Unicode values
+    // for the above keys.
+    // For now, just fall through to the default.
+    default:
+      return [NSString stringWithFormat:@"U+%04X", base::ToUpperASCII(c)];
+  }
+}
+
+// End Apple code.
+// ----------------------------------------------------------------------------
+
+int ModifiersFromEvent(NSEvent* event) {
+  int modifiers = 0;
+
+  if ([event modifierFlags] & NSControlKeyMask)
+    modifiers |= blink::WebInputEvent::ControlKey;
+  if ([event modifierFlags] & NSShiftKeyMask)
+    modifiers |= blink::WebInputEvent::ShiftKey;
+  if ([event modifierFlags] & NSAlternateKeyMask)
+    modifiers |= blink::WebInputEvent::AltKey;
+  if ([event modifierFlags] & NSCommandKeyMask)
+    modifiers |= blink::WebInputEvent::MetaKey;
+  if ([event modifierFlags] & NSAlphaShiftKeyMask)
+    modifiers |= blink::WebInputEvent::CapsLockOn;
+
+  // The return value of 1 << 0 corresponds to the left mouse button,
+  // 1 << 1 corresponds to the right mouse button,
+  // 1 << n, n >= 2 correspond to other mouse buttons.
+  NSUInteger pressed_buttons = [NSEvent pressedMouseButtons];
+
+  if (pressed_buttons & (1 << 0))
+    modifiers |= blink::WebInputEvent::LeftButtonDown;
+  if (pressed_buttons & (1 << 1))
+    modifiers |= blink::WebInputEvent::RightButtonDown;
+  if (pressed_buttons & (1 << 2))
+    modifiers |= blink::WebInputEvent::MiddleButtonDown;
+
+  return modifiers;
+}
+
+void SetWebEventLocationFromEventInView(blink::WebMouseEvent* result,
+                                        NSEvent* event,
+                                        NSView* view) {
+  NSPoint window_local = [event locationInWindow];
+
+  NSPoint screen_local = [[view window] convertBaseToScreen:window_local];
+  result->globalX = screen_local.x;
+  // Flip y.
+  NSScreen* primary_screen = ([[NSScreen screens] count] > 0)
+                                 ? [[NSScreen screens] objectAtIndex:0]
+                                 : nil;
+  if (primary_screen)
+    result->globalY = [primary_screen frame].size.height - screen_local.y;
+  else
+    result->globalY = screen_local.y;
+
+  NSPoint content_local = [view convertPoint:window_local fromView:nil];
+  result->x = content_local.x;
+  result->y = [view frame].size.height - content_local.y;  // Flip y.
+
+  result->windowX = result->x;
+  result->windowY = result->y;
+
+  result->movementX = [event deltaX];
+  result->movementY = [event deltaY];
+}
+
+bool IsSystemKeyEvent(const blink::WebKeyboardEvent& event) {
+  // Windows and Linux set |isSystemKey| if alt is down. Blink looks at this
+  // flag to decide if it should handle a key or not. E.g. alt-left/right
+  // shouldn't be used by Blink to scroll the current page, because we want
+  // to get that key back for it to do history navigation. Hence, the
+  // corresponding situation on OS X is to set this for cmd key presses.
+  // cmd-b and and cmd-i are system wide key bindings that OS X doesn't
+  // handle for us, so the editor handles them.
+  return event.modifiers & blink::WebInputEvent::MetaKey &&
+         event.windowsKeyCode != ui::VKEY_B &&
+         event.windowsKeyCode != ui::VKEY_I;
+}
+
+blink::WebMouseWheelEvent::Phase PhaseForNSEventPhase(
+    NSEventPhase event_phase) {
+  uint32_t phase = blink::WebMouseWheelEvent::PhaseNone;
+  if (event_phase & NSEventPhaseBegan)
+    phase |= blink::WebMouseWheelEvent::PhaseBegan;
+  if (event_phase & NSEventPhaseStationary)
+    phase |= blink::WebMouseWheelEvent::PhaseStationary;
+  if (event_phase & NSEventPhaseChanged)
+    phase |= blink::WebMouseWheelEvent::PhaseChanged;
+  if (event_phase & NSEventPhaseEnded)
+    phase |= blink::WebMouseWheelEvent::PhaseEnded;
+  if (event_phase & NSEventPhaseCancelled)
+    phase |= blink::WebMouseWheelEvent::PhaseCancelled;
+  if (event_phase & NSEventPhaseMayBegin)
+    phase |= blink::WebMouseWheelEvent::PhaseMayBegin;
+  return static_cast<blink::WebMouseWheelEvent::Phase>(phase);
+}
+
+blink::WebMouseWheelEvent::Phase PhaseForEvent(NSEvent* event) {
+  if (![event respondsToSelector:@selector(phase)])
+    return blink::WebMouseWheelEvent::PhaseNone;
+
+  NSEventPhase event_phase = [event phase];
+  return PhaseForNSEventPhase(event_phase);
+}
+
+blink::WebMouseWheelEvent::Phase MomentumPhaseForEvent(NSEvent* event) {
+  if (![event respondsToSelector:@selector(momentumPhase)])
+    return blink::WebMouseWheelEvent::PhaseNone;
+
+  NSEventPhase event_momentum_phase = [event momentumPhase];
+  return PhaseForNSEventPhase(event_momentum_phase);
+}
+
+}  // namespace
+
+blink::WebKeyboardEvent WebKeyboardEventBuilder::Build(NSEvent* event) {
+  blink::WebKeyboardEvent result;
+
+  result.type = IsKeyUpEvent(event) ? blink::WebInputEvent::KeyUp
+                                    : blink::WebInputEvent::RawKeyDown;
+
+  result.modifiers = ModifiersFromEvent(event);
+
+  if (([event type] != NSFlagsChanged) && [event isARepeat])
+    result.modifiers |= blink::WebInputEvent::IsAutoRepeat;
+
+  ui::DomCode dom_code = ui::CodeFromNSEvent(event);
+  result.windowsKeyCode =
+      ui::LocatedToNonLocatedKeyboardCode(ui::KeyboardCodeFromNSEvent(event));
+  result.modifiers |= DomCodeToWebInputEventModifiers(dom_code);
+  result.nativeKeyCode = [event keyCode];
+  result.domCode = static_cast<int>(dom_code);
+  NSString* text_str = TextFromEvent(event);
+  NSString* unmodified_str = UnmodifiedTextFromEvent(event);
+  NSString* identifier_str = KeyIdentifierForKeyEvent(event);
+
+  // Begin Apple code, copied from KeyEventMac.mm
+
+  // Always use 13 for Enter/Return -- we don't want to use AppKit's
+  // different character for Enter.
+  if (result.windowsKeyCode == '\r') {
+    text_str = @"\r";
+    unmodified_str = @"\r";
+  }
+
+  // The adjustments below are only needed in backward compatibility mode,
+  // but we cannot tell what mode we are in from here.
+
+  // Turn 0x7F into 8, because backspace needs to always be 8.
+  if ([text_str isEqualToString:@"\x7F"])
+    text_str = @"\x8";
+  if ([unmodified_str isEqualToString:@"\x7F"])
+    unmodified_str = @"\x8";
+  // Always use 9 for tab -- we don't want to use AppKit's different character
+  // for shift-tab.
+  if (result.windowsKeyCode == 9) {
+    text_str = @"\x9";
+    unmodified_str = @"\x9";
+  }
+
+  // End Apple code.
+
+  if ([text_str length] < blink::WebKeyboardEvent::textLengthCap &&
+      [unmodified_str length] < blink::WebKeyboardEvent::textLengthCap) {
+    [text_str getCharacters:&result.text[0]];
+    [unmodified_str getCharacters:&result.unmodifiedText[0]];
+  } else
+    NOTIMPLEMENTED();
+
+  [identifier_str getCString:&result.keyIdentifier[0]
+                   maxLength:sizeof(result.keyIdentifier)
+                    encoding:NSASCIIStringEncoding];
+
+  result.timeStampSeconds = [event timestamp];
+  result.isSystemKey = IsSystemKeyEvent(result);
+
+  return result;
+}
+
+// WebMouseEvent --------------------------------------------------------------
+
+blink::WebMouseEvent WebMouseEventBuilder::Build(NSEvent* event, NSView* view) {
+  blink::WebMouseEvent result;
+
+  result.clickCount = 0;
+
+  switch ([event type]) {
+    case NSMouseExited:
+      result.type = blink::WebInputEvent::MouseLeave;
+      result.button = blink::WebMouseEvent::ButtonNone;
+      break;
+    case NSLeftMouseDown:
+      result.type = blink::WebInputEvent::MouseDown;
+      result.clickCount = [event clickCount];
+      result.button = blink::WebMouseEvent::ButtonLeft;
+      break;
+    case NSOtherMouseDown:
+      result.type = blink::WebInputEvent::MouseDown;
+      result.clickCount = [event clickCount];
+      result.button = blink::WebMouseEvent::ButtonMiddle;
+      break;
+    case NSRightMouseDown:
+      result.type = blink::WebInputEvent::MouseDown;
+      result.clickCount = [event clickCount];
+      result.button = blink::WebMouseEvent::ButtonRight;
+      break;
+    case NSLeftMouseUp:
+      result.type = blink::WebInputEvent::MouseUp;
+      result.clickCount = [event clickCount];
+      result.button = blink::WebMouseEvent::ButtonLeft;
+      break;
+    case NSOtherMouseUp:
+      result.type = blink::WebInputEvent::MouseUp;
+      result.clickCount = [event clickCount];
+      result.button = blink::WebMouseEvent::ButtonMiddle;
+      break;
+    case NSRightMouseUp:
+      result.type = blink::WebInputEvent::MouseUp;
+      result.clickCount = [event clickCount];
+      result.button = blink::WebMouseEvent::ButtonRight;
+      break;
+    case NSMouseMoved:
+    case NSMouseEntered:
+      result.type = blink::WebInputEvent::MouseMove;
+      break;
+    case NSLeftMouseDragged:
+      result.type = blink::WebInputEvent::MouseMove;
+      result.button = blink::WebMouseEvent::ButtonLeft;
+      break;
+    case NSOtherMouseDragged:
+      result.type = blink::WebInputEvent::MouseMove;
+      result.button = blink::WebMouseEvent::ButtonMiddle;
+      break;
+    case NSRightMouseDragged:
+      result.type = blink::WebInputEvent::MouseMove;
+      result.button = blink::WebMouseEvent::ButtonRight;
+      break;
+    default:
+      NOTIMPLEMENTED();
+  }
+
+  SetWebEventLocationFromEventInView(&result, event, view);
+
+  result.modifiers = ModifiersFromEvent(event);
+
+  result.timeStampSeconds = [event timestamp];
+
+  return result;
+}
+
+// WebMouseWheelEvent ---------------------------------------------------------
+
+blink::WebMouseWheelEvent WebMouseWheelEventBuilder::Build(
+    NSEvent* event,
+    NSView* view,
+    bool can_rubberband_left,
+    bool can_rubberband_right) {
+  blink::WebMouseWheelEvent result;
+
+  result.type = blink::WebInputEvent::MouseWheel;
+  result.button = blink::WebMouseEvent::ButtonNone;
+
+  result.modifiers = ModifiersFromEvent(event);
+
+  SetWebEventLocationFromEventInView(&result, event, view);
+
+  result.canRubberbandLeft = can_rubberband_left;
+  result.canRubberbandRight = can_rubberband_right;
+
+  // Of Mice and Men
+  // ---------------
+  //
+  // There are three types of scroll data available on a scroll wheel CGEvent.
+  // Apple's documentation ([1]) is rather vague in their differences, and not
+  // terribly helpful in deciding which to use. This is what's really going on.
+  //
+  // First, these events behave very differently depending on whether a standard
+  // wheel mouse is used (one that scrolls in discrete units) or a
+  // trackpad/Mighty Mouse is used (which both provide continuous scrolling).
+  // You must check to see which was used for the event by testing the
+  // kCGScrollWheelEventIsContinuous field.
+  //
+  // Second, these events refer to "axes". Axis 1 is the y-axis, and axis 2 is
+  // the x-axis.
+  //
+  // Third, there is a concept of mouse acceleration. Scrolling the same amount
+  // of physical distance will give you different results logically depending on
+  // whether you scrolled a little at a time or in one continuous motion. Some
+  // fields account for this while others do not.
+  //
+  // Fourth, for trackpads there is a concept of chunkiness. When scrolling
+  // continuously, events can be delivered in chunks. That is to say, lots of
+  // scroll events with delta 0 will be delivered, and every so often an event
+  // with a non-zero delta will be delivered, containing the accumulated deltas
+  // from all the intermediate moves. [2]
+  //
+  // For notchy wheel mice (kCGScrollWheelEventIsContinuous == 0)
+  // ------------------------------------------------------------
+  //
+  // kCGScrollWheelEventDeltaAxis*
+  //   This is the rawest of raw events. For each mouse notch you get a value of
+  //   +1/-1. This does not take acceleration into account and thus is less
+  //   useful for building UIs.
+  //
+  // kCGScrollWheelEventPointDeltaAxis*
+  //   This is smarter. In general, for each mouse notch you get a value of
+  //   +1/-1, but this _does_ take acceleration into account, so you will get
+  //   larger values on longer scrolls. This field would be ideal for building
+  //   UIs except for one nasty bug: when the shift key is pressed, this set of
+  //   fields fails to move the value into the axis2 field (the other two types
+  //   of data do). This wouldn't be so bad except for the fact that while the
+  //   number of axes is used in the creation of a CGScrollWheelEvent, there is
+  //   no way to get that information out of the event once created.
+  //
+  // kCGScrollWheelEventFixedPtDeltaAxis*
+  //   This is a fixed value, and for each mouse notch you get a value of
+  //   +0.1/-0.1 (but, like above, scaled appropriately for acceleration). This
+  //   value takes acceleration into account, and in fact is identical to the
+  //   results you get from -[NSEvent delta*]. (That is, if you linked on Tiger
+  //   or greater; see [2] for details.)
+  //
+  // A note about continuous devices
+  // -------------------------------
+  //
+  // There are two devices that provide continuous scrolling events (trackpads
+  // and Mighty Mouses) and they behave rather differently. The Mighty Mouse
+  // behaves a lot like a regular mouse. There is no chunking, and the
+  // FixedPtDelta values are the PointDelta values multiplied by 0.1. With the
+  // trackpad, though, there is chunking. While the FixedPtDelta values are
+  // reasonable (they occur about every fifth event but have values five times
+  // larger than usual) the Delta values are unreasonable. They don't appear to
+  // accumulate properly.
+  //
+  // For continuous devices (kCGScrollWheelEventIsContinuous != 0)
+  // -------------------------------------------------------------
+  //
+  // kCGScrollWheelEventDeltaAxis*
+  //   This provides values with no acceleration. With a trackpad, these values
+  //   are chunked but each non-zero value does not appear to be cumulative.
+  //   This seems to be a bug.
+  //
+  // kCGScrollWheelEventPointDeltaAxis*
+  //   This provides values with acceleration. With a trackpad, these values are
+  //   not chunked and are highly accurate.
+  //
+  // kCGScrollWheelEventFixedPtDeltaAxis*
+  //   This provides values with acceleration. With a trackpad, these values are
+  //   chunked but unlike Delta events are properly cumulative.
+  //
+  // Summary
+  // -------
+  //
+  // In general the best approach to take is: determine if the event is
+  // continuous. If it is not, then use the FixedPtDelta events (or just stick
+  // with Cocoa events). They provide both acceleration and proper horizontal
+  // scrolling. If the event is continuous, then doing pixel scrolling with the
+  // PointDelta is the way to go. In general, avoid the Delta events. They're
+  // the oldest (dating back to 10.4, before CGEvents were public) but they lack
+  // acceleration and precision, making them useful only in specific edge cases.
+  //
+  // References
+  // ----------
+  //
+  // [1]
+  // <http://developer.apple.com/documentation/Carbon/Reference/QuartzEventServicesRef/Reference/reference.html>
+  // [2] <http://developer.apple.com/releasenotes/Cocoa/AppKitOlderNotes.html>
+  //     Scroll to the section headed "NSScrollWheel events".
+  //
+  // P.S. The "smooth scrolling" option in the system preferences is utterly
+  // unrelated to any of this.
+
+  CGEventRef cg_event = [event CGEvent];
+  DCHECK(cg_event);
+
+  // Wheel ticks are supposed to be raw, unaccelerated values, one per physical
+  // mouse wheel notch. The delta event is perfect for this (being a good
+  // "specific edge case" as mentioned above). Trackpads, unfortunately, do
+  // event chunking, and sending mousewheel events with 0 ticks causes some
+  // websites to malfunction. Therefore, for all continuous input devices we use
+  // the point delta data instead, since we cannot distinguish trackpad data
+  // from data from any other continuous device.
+
+  // Conversion between wheel delta amounts and number of pixels to scroll.
+  static const double kScrollbarPixelsPerCocoaTick = 40.0;
+
+  if (CGEventGetIntegerValueField(cg_event, kCGScrollWheelEventIsContinuous)) {
+    result.deltaX = CGEventGetIntegerValueField(
+        cg_event, kCGScrollWheelEventPointDeltaAxis2);
+    result.deltaY = CGEventGetIntegerValueField(
+        cg_event, kCGScrollWheelEventPointDeltaAxis1);
+    result.wheelTicksX = result.deltaX / kScrollbarPixelsPerCocoaTick;
+    result.wheelTicksY = result.deltaY / kScrollbarPixelsPerCocoaTick;
+    result.hasPreciseScrollingDeltas = true;
+  } else {
+    result.deltaX = [event deltaX] * kScrollbarPixelsPerCocoaTick;
+    result.deltaY = [event deltaY] * kScrollbarPixelsPerCocoaTick;
+    result.wheelTicksY =
+        CGEventGetIntegerValueField(cg_event, kCGScrollWheelEventDeltaAxis1);
+    result.wheelTicksX =
+        CGEventGetIntegerValueField(cg_event, kCGScrollWheelEventDeltaAxis2);
+  }
+
+  result.timeStampSeconds = [event timestamp];
+
+  result.phase = PhaseForEvent(event);
+  result.momentumPhase = MomentumPhaseForEvent(event);
+
+  return result;
+}
+
+blink::WebGestureEvent WebGestureEventBuilder::Build(NSEvent* event,
+                                                     NSView* view) {
+  blink::WebGestureEvent result;
+
+  // Use a temporary WebMouseEvent to get the location.
+  blink::WebMouseEvent temp;
+
+  SetWebEventLocationFromEventInView(&temp, event, view);
+  result.x = temp.x;
+  result.y = temp.y;
+  result.globalX = temp.globalX;
+  result.globalY = temp.globalY;
+
+  result.modifiers = ModifiersFromEvent(event);
+  result.timeStampSeconds = [event timestamp];
+
+  result.sourceDevice = blink::WebGestureDeviceTouchpad;
+  switch ([event type]) {
+    case NSEventTypeMagnify:
+      result.type = blink::WebInputEvent::GesturePinchUpdate;
+      result.data.pinchUpdate.scale = [event magnification] + 1.0;
+      break;
+    case NSEventTypeSmartMagnify:
+      // Map the Cocoa "double-tap with two fingers" zoom gesture to regular
+      // GestureDoubleTap, because the effect is similar to single-finger
+      // double-tap zoom on mobile platforms. Note that tapCount is set to 1
+      // because the gesture type already encodes that information.
+      result.type = blink::WebInputEvent::GestureDoubleTap;
+      result.data.tap.tapCount = 1;
+      break;
+    case NSEventTypeBeginGesture:
+    case NSEventTypeEndGesture:
+      // The specific type of a gesture is not defined when the gesture begin
+      // and end NSEvents come in. Leave them undefined. The caller will need
+      // to specify them when the gesture is differentiated.
+      result.type = blink::WebInputEvent::Undefined;
+      break;
+    default:
+      NOTIMPLEMENTED();
+      result.type = blink::WebInputEvent::Undefined;
+  }
+
+  return result;
+}
+
+}  // namespace content