Simplify TouchAction enum to be a simple bit flag

content/common/input/touch_action.h

 // Copyright 2013 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.
 
 #ifndef CONTENT_COMMON_INPUT_TOUCH_ACTION_H_
 #define CONTENT_COMMON_INPUT_TOUCH_ACTION_H_
 
 namespace content {
 
 // The current touch action specifies what accelerated browser operations
 // (panning and zooming) are currently permitted via touch input.
 // See http://www.w3.org/TR/pointerevents/#the-touch-action-css-property.
 enum TouchAction {

[jdduke (slow), 2015/10/29 15:40:26]

Now that we expose proper operators, should this be

enum class TouchAction : int

?

[jdduke (slow), 2015/10/29 15:41:44]

Actually, not sure if that works if the operators are used in the enum
definition. 

[tdresser, 2015/10/29 15:43:00]

It would require renaming everything, but it's likely worth it.

IE, TOUCH_ACTION_NONE -> TouchAction::NONE.

-  // All actions are pemitted (the default).
-  TOUCH_ACTION_AUTO = 0,
+  // No scrolling or zooming allowed.
+  TOUCH_ACTION_NONE = 0,
 
-  // No scrolling or zooming allowed.
-  TOUCH_ACTION_NONE = 1 << 0,
+  TOUCH_ACTION_PAN_LEFT = 1 << 0,
 
-  TOUCH_ACTION_PAN_LEFT = 1 << 1,
-
-  TOUCH_ACTION_PAN_RIGHT = 1 << 2,
+  TOUCH_ACTION_PAN_RIGHT = 1 << 1,
 
   TOUCH_ACTION_PAN_X = TOUCH_ACTION_PAN_LEFT | TOUCH_ACTION_PAN_RIGHT,
 
-  TOUCH_ACTION_PAN_UP = 1 << 3,
+  TOUCH_ACTION_PAN_UP = 1 << 2,
 
-  TOUCH_ACTION_PAN_DOWN = 1 << 4,
+  TOUCH_ACTION_PAN_DOWN = 1 << 3,
 
   TOUCH_ACTION_PAN_Y = TOUCH_ACTION_PAN_UP | TOUCH_ACTION_PAN_DOWN,
 
-  TOUCH_ACTION_PAN_X_Y = TOUCH_ACTION_PAN_X | TOUCH_ACTION_PAN_Y,
+  TOUCH_ACTION_PAN = TOUCH_ACTION_PAN_X | TOUCH_ACTION_PAN_Y,
 
-  TOUCH_ACTION_PINCH_ZOOM = 1 << 5,
+  TOUCH_ACTION_PINCH_ZOOM = 1 << 4,
 
-  TOUCH_ACTION_MANIPULATION = TOUCH_ACTION_PAN_X_Y | TOUCH_ACTION_PINCH_ZOOM,
+  TOUCH_ACTION_MANIPULATION = TOUCH_ACTION_PAN | TOUCH_ACTION_PINCH_ZOOM,
+
+  TOUCH_ACTION_DOUBLE_TAP_ZOOM = 1 << 5,
+
+  // All actions are pemitted (the default).

[tdresser, 2015/10/29 15:30:35]

pemitted -> permitted

[Rick Byers, 2015/10/29 16:56:04]

Done.

+  TOUCH_ACTION_AUTO = TOUCH_ACTION_MANIPULATION | TOUCH_ACTION_DOUBLE_TAP_ZOOM,
 
   TOUCH_ACTION_MAX = (1 << 6) - 1
 };
 
+inline TouchAction operator| (TouchAction a, TouchAction b)
+{
+  return TouchAction(int(a) | int(b));

[tdresser, 2015/10/29 15:30:35]

Use static_cast.

[dtapuska, 2015/10/29 15:38:44]

WebTouchAction also does this; and occurs in a few patterns inside blink as
well.. Guess it should be cleaned up to current standards.

[Rick Byers, 2015/10/29 16:56:04]

I think I've found them all and switched to static_cast.  This CL also let me
eliminate some bit manipulation (eg. now have a defined constant for
Manipulation, tests can be simpler).

+}
+inline TouchAction& operator|= (TouchAction& a, TouchAction b)
+{
+  return a = a | b;
+}
+inline TouchAction operator& (TouchAction a, TouchAction b)
+{
+  return TouchAction(int(a) & int(b));
+}
+inline TouchAction& operator&= (TouchAction& a, TouchAction b)
+{
+  return a = a & b;
+}
+
 }  // namespace content
 
 #endif  // CONTENT_COMMON_INPUT_TOUCH_ACTION_H_