WebInputEventFactory.mm [plain text]
/*
* 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
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "WebInputEventFactory.h"
#include <ApplicationServices/ApplicationServices.h>
#import <Cocoa/Cocoa.h>
#import "KeyEventCocoa.h"
#include "WebInputEvent.h"
#include <wtf/ASCIICType.h>
#if BUILDING_ON_LEOPARD || BUILDING_ON_SNOW_LEOPARD
// Additional Lion APIs.
enum {
NSEventPhaseNone = 0,
NSEventPhaseBegan = 0x1 << 0,
NSEventPhaseStationary = 0x1 << 1,
NSEventPhaseChanged = 0x1 << 2,
NSEventPhaseEnded = 0x1 << 3,
NSEventPhaseCancelled = 0x1 << 4,
NSEventPhaseMayBegin = 0x1 << 5
};
typedef NSUInteger NSEventPhase;
@interface NSEvent (LionSDKDeclarations)
- (NSEventPhase)phase;
- (NSEventPhase)momentumPhase;
@end
#endif // BUILDING_ON_LEOPARD || BUILDING_ON_SNOW_LEOPARD
#if BUILDING_ON_LEOPARD
// These are not defined in the 10.5 SDK but are defined in later SDKs inside
// a MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5 #ifdef.
enum {
NSEventTypeBeginGesture = 19,
NSEventTypeEndGesture = 20
};
#endif // BUILDING_ON_LEOPARD
namespace WebKit {
// WebKeyboardEvent -----------------------------------------------------------
// ----------------------------------------------------------------------------
// Begin Apple code, copied from KeyEventMac.mm
//
// We can share some of this code if we factored it out of KeyEventMac, but
// the main problem is that it relies on the NSString ctor on String for
// conversions, and since we're building without PLATFORM(MAC), we don't have
// that. As a result we have to use NSString here exclusively and thus tweak
// the code so it's not re-usable as-is. One possiblity would be to make the
// upstream code only use NSString, but I'm not certain how far that change
// would propagate.
static inline bool isKeyUpEvent(NSEvent* event)
{
if ([event type] != NSFlagsChanged)
return [event type] == NSKeyUp;
// FIXME: This logic fails if the user presses both Shift keys at once, for example:
// we treat releasing one of them as keyDown.
switch ([event keyCode]) {
case 54: // Right Command
case 55: // Left Command
return ([event modifierFlags] & NSCommandKeyMask) == 0;
case 57: // Capslock
return ([event modifierFlags] & NSAlphaShiftKeyMask) == 0;
case 56: // Left Shift
case 60: // Right Shift
return ([event modifierFlags] & NSShiftKeyMask) == 0;
case 58: // Left Alt
case 61: // Right Alt
return ([event modifierFlags] & NSAlternateKeyMask) == 0;
case 59: // Left Ctrl
case 62: // Right Ctrl
return ([event modifierFlags] & NSControlKeyMask) == 0;
case 63: // Function
return ([event modifierFlags] & NSFunctionKeyMask) == 0;
}
return false;
}
static bool isKeypadEvent(NSEvent* event)
{
// Check that this is the type of event that has a keyCode.
switch ([event type]) {
case NSKeyDown:
case NSKeyUp:
case NSFlagsChanged:
break;
default:
return false;
}
if ([event modifierFlags] & NSNumericPadKeyMask)
return true;
switch ([event keyCode]) {
case 71: // Clear
case 81: // =
case 75: // /
case 67: // *
case 78: // -
case 69: // +
case 76: // Enter
case 65: // .
case 82: // 0
case 83: // 1
case 84: // 2
case 85: // 3
case 86: // 4
case 87: // 5
case 88: // 6
case 89: // 7
case 91: // 8
case 92: // 9
return true;
}
return false;
}
static int windowsKeyCodeForKeyEvent(NSEvent* event)
{
int code = 0;
// There are several kinds of characters for which we produce key code from char code:
// 1. Roman letters. Windows keyboard layouts affect both virtual key codes and character codes for these,
// so e.g. 'A' gets the same keyCode on QWERTY, AZERTY or Dvorak layouts.
// 2. Keys for which there is no known Mac virtual key codes, like PrintScreen.
// 3. Certain punctuation keys. On Windows, these are also remapped depending on current keyboard layout,
// but see comment in windowsKeyCodeForCharCode().
if ([event type] == NSKeyDown || [event type] == NSKeyUp) {
// Cmd switches Roman letters for Dvorak-QWERTY layout, so try modified characters first.
NSString* s = [event characters];
code = [s length] > 0 ? WebCore::windowsKeyCodeForCharCode([s characterAtIndex:0]) : 0;
if (code)
return code;
// Ctrl+A on an AZERTY keyboard would get VK_Q keyCode if we relied on -[NSEvent keyCode] below.
s = [event charactersIgnoringModifiers];
code = [s length] > 0 ? WebCore::windowsKeyCodeForCharCode([s characterAtIndex:0]) : 0;
if (code)
return code;
}
// Map Mac virtual key code directly to Windows one for any keys not handled above.
// E.g. the key next to Caps Lock has the same Event.keyCode on U.S. keyboard ('A') and on Russian keyboard (CYRILLIC LETTER EF).
return WebCore::windowsKeyCodeForKeyCode([event keyCode]);
}
static WebInputEvent::Type gestureEventTypeForEvent(NSEvent *event)
{
switch ([event type]) {
case NSEventTypeBeginGesture:
return WebInputEvent::GestureScrollBegin;
case NSEventTypeEndGesture:
return WebInputEvent::GestureScrollEnd;
default:
ASSERT_NOT_REACHED();
return WebInputEvent::GestureScrollEnd;
}
}
static inline NSString* textFromEvent(NSEvent* event)
{
if ([event type] == NSFlagsChanged)
return @"";
return [event characters];
}
static inline NSString* unmodifiedTextFromEvent(NSEvent* event)
{
if ([event type] == NSFlagsChanged)
return @"";
return [event charactersIgnoringModifiers];
}
static 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", WTF::toASCIIUpper(c)];
}
}
// End Apple code.
// ----------------------------------------------------------------------------
static inline int modifiersFromEvent(NSEvent* event) {
int modifiers = 0;
if ([event modifierFlags] & NSControlKeyMask)
modifiers |= WebInputEvent::ControlKey;
if ([event modifierFlags] & NSShiftKeyMask)
modifiers |= WebInputEvent::ShiftKey;
if ([event modifierFlags] & NSAlternateKeyMask)
modifiers |= WebInputEvent::AltKey;
if ([event modifierFlags] & NSCommandKeyMask)
modifiers |= WebInputEvent::MetaKey;
if ([event modifierFlags] & NSAlphaShiftKeyMask)
modifiers |= WebInputEvent::CapsLockOn;
// TODO(port): Set mouse button states
return modifiers;
}
static inline void setWebEventLocationFromEventInView(WebMouseEvent* result,
NSEvent* event,
NSView* view) {
NSPoint windowLocal = [event locationInWindow];
NSPoint screenLocal = [[view window] convertBaseToScreen:windowLocal];
result->globalX = screenLocal.x;
// Flip y.
NSScreen* primaryScreen = ([[NSScreen screens] count] > 0) ?
[[NSScreen screens] objectAtIndex:0] : nil;
if (primaryScreen)
result->globalY = [primaryScreen frame].size.height - screenLocal.y;
else
result->globalY = screenLocal.y;
NSPoint contentLocal = [view convertPoint:windowLocal fromView:nil];
result->x = contentLocal.x;
result->y = [view frame].size.height - contentLocal.y; // Flip y.
result->windowX = result->x;
result->windowY = result->y;
result->movementX = [event deltaX];
result->movementY = [event deltaY];
}
WebKeyboardEvent WebInputEventFactory::keyboardEvent(NSEvent* event)
{
WebKeyboardEvent result;
result.type =
isKeyUpEvent(event) ? WebInputEvent::KeyUp : WebInputEvent::RawKeyDown;
result.modifiers = modifiersFromEvent(event);
if (isKeypadEvent(event))
result.modifiers |= WebInputEvent::IsKeyPad;
if (([event type] != NSFlagsChanged) && [event isARepeat])
result.modifiers |= WebInputEvent::IsAutoRepeat;
result.windowsKeyCode = windowsKeyCodeForKeyEvent(event);
result.nativeKeyCode = [event keyCode];
NSString* textStr = textFromEvent(event);
NSString* unmodifiedStr = unmodifiedTextFromEvent(event);
NSString* identifierStr = 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') {
textStr = @"\r";
unmodifiedStr = @"\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 ([textStr isEqualToString:@"\x7F"])
textStr = @"\x8";
if ([unmodifiedStr isEqualToString:@"\x7F"])
unmodifiedStr = @"\x8";
// Always use 9 for tab -- we don't want to use AppKit's different character
// for shift-tab.
if (result.windowsKeyCode == 9) {
textStr = @"\x9";
unmodifiedStr = @"\x9";
}
// End Apple code.
if ([textStr length] < WebKeyboardEvent::textLengthCap &&
[unmodifiedStr length] < WebKeyboardEvent::textLengthCap) {
[textStr getCharacters:&result.text[0]];
[unmodifiedStr getCharacters:&result.unmodifiedText[0]];
} else
ASSERT_NOT_REACHED();
[identifierStr getCString:&result.keyIdentifier[0]
maxLength:sizeof(result.keyIdentifier)
encoding:NSASCIIStringEncoding];
result.timeStampSeconds = [event timestamp];
// Windows and Linux set |isSystemKey| if alt is down. WebKit looks at this
// flag to decide if it should handle a key or not. E.g. alt-left/right
// shouldn't be used by WebKit 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.
if (result.modifiers & WebInputEvent::MetaKey)
result.isSystemKey = true;
return result;
}
WebKeyboardEvent WebInputEventFactory::keyboardEvent(wchar_t character,
int modifiers,
double timeStampSeconds)
{
// keyboardEvent(NSEvent*) depends on the NSEvent object and
// it is hard to use it from methods of the NSTextInput protocol. For
// such methods, this function creates a WebInputEvent::Char event without
// using a NSEvent object.
WebKeyboardEvent result;
result.type = WebKit::WebInputEvent::Char;
result.timeStampSeconds = timeStampSeconds;
result.modifiers = modifiers;
result.windowsKeyCode = character;
result.nativeKeyCode = character;
result.text[0] = character;
result.unmodifiedText[0] = character;
// Windows and Linux set |isSystemKey| if alt is down. WebKit looks at this
// flag to decide if it should handle a key or not. E.g. alt-left/right
// shouldn't be used by WebKit 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.
if (result.modifiers & WebInputEvent::MetaKey)
result.isSystemKey = true;
return result;
}
// WebMouseEvent --------------------------------------------------------------
WebMouseEvent WebInputEventFactory::mouseEvent(NSEvent* event, NSView* view)
{
WebMouseEvent result;
result.clickCount = 0;
switch ([event type]) {
case NSMouseExited:
result.type = WebInputEvent::MouseLeave;
result.button = WebMouseEvent::ButtonNone;
break;
case NSLeftMouseDown:
result.type = WebInputEvent::MouseDown;
result.clickCount = [event clickCount];
result.button = WebMouseEvent::ButtonLeft;
break;
case NSOtherMouseDown:
result.type = WebInputEvent::MouseDown;
result.clickCount = [event clickCount];
result.button = WebMouseEvent::ButtonMiddle;
break;
case NSRightMouseDown:
result.type = WebInputEvent::MouseDown;
result.clickCount = [event clickCount];
result.button = WebMouseEvent::ButtonRight;
break;
case NSLeftMouseUp:
result.type = WebInputEvent::MouseUp;
result.clickCount = [event clickCount];
result.button = WebMouseEvent::ButtonLeft;
break;
case NSOtherMouseUp:
result.type = WebInputEvent::MouseUp;
result.clickCount = [event clickCount];
result.button = WebMouseEvent::ButtonMiddle;
break;
case NSRightMouseUp:
result.type = WebInputEvent::MouseUp;
result.clickCount = [event clickCount];
result.button = WebMouseEvent::ButtonRight;
break;
case NSMouseMoved:
case NSMouseEntered:
result.type = WebInputEvent::MouseMove;
break;
case NSLeftMouseDragged:
result.type = WebInputEvent::MouseMove;
result.button = WebMouseEvent::ButtonLeft;
break;
case NSOtherMouseDragged:
result.type = WebInputEvent::MouseMove;
result.button = WebMouseEvent::ButtonMiddle;
break;
case NSRightMouseDragged:
result.type = WebInputEvent::MouseMove;
result.button = WebMouseEvent::ButtonRight;
break;
default:
ASSERT_NOT_REACHED();
}
setWebEventLocationFromEventInView(&result, event, view);
result.modifiers = modifiersFromEvent(event);
result.timeStampSeconds = [event timestamp];
return result;
}
// WebMouseWheelEvent ---------------------------------------------------------
static WebMouseWheelEvent::Phase phaseForNSEventPhase(NSEventPhase eventPhase)
{
uint32_t phase = WebMouseWheelEvent::PhaseNone;
if (eventPhase & NSEventPhaseBegan)
phase |= WebMouseWheelEvent::PhaseBegan;
if (eventPhase & NSEventPhaseStationary)
phase |= WebMouseWheelEvent::PhaseStationary;
if (eventPhase & NSEventPhaseChanged)
phase |= WebMouseWheelEvent::PhaseChanged;
if (eventPhase & NSEventPhaseEnded)
phase |= WebMouseWheelEvent::PhaseEnded;
if (eventPhase & NSEventPhaseCancelled)
phase |= WebMouseWheelEvent::PhaseCancelled;
return static_cast<WebMouseWheelEvent::Phase>(phase);
}
static WebMouseWheelEvent::Phase phaseForEvent(NSEvent *event)
{
if (![event respondsToSelector:@selector(phase)])
return WebMouseWheelEvent::PhaseNone;
NSEventPhase eventPhase = [event phase];
return phaseForNSEventPhase(eventPhase);
}
static WebMouseWheelEvent::Phase momentumPhaseForEvent(NSEvent *event)
{
if (![event respondsToSelector:@selector(momentumPhase)])
return WebMouseWheelEvent::PhaseNone;
NSEventPhase eventMomentumPhase = [event momentumPhase];
return phaseForNSEventPhase(eventMomentumPhase);
}
WebMouseWheelEvent WebInputEventFactory::mouseWheelEvent(NSEvent* event, NSView* view)
{
WebMouseWheelEvent result;
result.type = WebInputEvent::MouseWheel;
result.button = WebMouseEvent::ButtonNone;
result.modifiers = modifiersFromEvent(event);
setWebEventLocationFromEventInView(&result, event, view);
// 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 cgEvent = [event CGEvent];
ASSERT(cgEvent);
// 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 scrollbarPixelsPerCocoaTick = 40.0;
if (CGEventGetIntegerValueField(cgEvent, kCGScrollWheelEventIsContinuous)) {
result.deltaX = CGEventGetIntegerValueField(cgEvent, kCGScrollWheelEventPointDeltaAxis2);
result.deltaY = CGEventGetIntegerValueField(cgEvent, kCGScrollWheelEventPointDeltaAxis1);
result.wheelTicksX = result.deltaX / scrollbarPixelsPerCocoaTick;
result.wheelTicksY = result.deltaY / scrollbarPixelsPerCocoaTick;
result.hasPreciseScrollingDeltas = true;
} else {
result.deltaX = [event deltaX] * scrollbarPixelsPerCocoaTick;
result.deltaY = [event deltaY] * scrollbarPixelsPerCocoaTick;
result.wheelTicksY = CGEventGetIntegerValueField(cgEvent, kCGScrollWheelEventDeltaAxis1);
result.wheelTicksX = CGEventGetIntegerValueField(cgEvent, kCGScrollWheelEventDeltaAxis2);
}
result.timeStampSeconds = [event timestamp];
result.phase = phaseForEvent(event);
result.momentumPhase = momentumPhaseForEvent(event);
return result;
}
WebGestureEvent WebInputEventFactory::gestureEvent(NSEvent *event, NSView *view)
{
WebGestureEvent result;
// Use a temporary WebMouseEvent to get the location.
WebMouseEvent temp;
setWebEventLocationFromEventInView(&temp, event, view);
result.x = temp.x;
result.y = temp.y;
result.globalX = temp.globalX;
result.globalY = temp.globalY;
result.type = gestureEventTypeForEvent(event);
result.modifiers = modifiersFromEvent(event);
result.timeStampSeconds = [event timestamp];
return result;
}
} // namespace WebKit