/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_EventStates_h_

#define mozilla_EventStates_h_

#include "mozilla/Attributes.h"

#include "nsDebug.h"

namespace mozilla {

/**

 * EventStates is the class used to represent the event states of nsIContent

 * instances. These states are calculated by IntrinsicState() and

 * ContentStatesChanged() has to be called when one of them changes thus

 * informing the layout/style engine of the change.

 * Event states are associated with pseudo-classes.

 */

class EventStates

{

public:

  typedef uint64_t InternalType;

  typedef uint64_t ServoType;

  constexpr EventStates()

    : mStates(0)

  {

  }

  // NOTE: the ideal scenario would be to have the default constructor public

  // setting mStates to 0 and this constructor (without = 0) private.

  // In that case, we could be sure that only macros at the end were creating

  // EventStates instances with mStates set to something else than 0.

  // Unfortunately, this constructor is needed at at least two places now.

  explicit constexpr EventStates(InternalType aStates)

    : mStates(aStates)

  {

  }

  EventStates constexpr operator|(const EventStates& aEventStates) const

  {

    return EventStates(mStates | aEventStates.mStates);

  }

  EventStates& operator|=(const EventStates& aEventStates)

  {

    mStates |= aEventStates.mStates;

    return *this;

  }

  // NOTE: calling if (eventStates1 & eventStates2) will not build.

  // This might work correctly if operator bool() is defined

  // but using HasState, HasAllStates or HasAtLeastOneOfStates is recommended.

  EventStates constexpr operator&(const EventStates& aEventStates) const

  {

    return EventStates(mStates & aEventStates.mStates);

  }

  EventStates& operator&=(const EventStates& aEventStates)

  {

    mStates &= aEventStates.mStates;

    return *this;

  }

  bool operator==(const EventStates& aEventStates) const

  {

    return mStates == aEventStates.mStates;

  }

  bool operator!=(const EventStates& aEventStates) const

  {

    return mStates != aEventStates.mStates;

  }

  EventStates operator~() const

  {

    return EventStates(~mStates);

  }

  EventStates operator^(const EventStates& aEventStates) const

  {

    return EventStates(mStates ^ aEventStates.mStates);

  }

  EventStates& operator^=(const EventStates& aEventStates)

  {

    mStates ^= aEventStates.mStates;

    return *this;

  }

  /**

   * Returns true if the EventStates instance is empty.

   * A EventStates instance is empty if it contains no state.

   *

   * @return Whether if the object is empty.

   */

  bool IsEmpty() const

  {

    return mStates == 0;

  }

  /**

   * Returns true if the EventStates instance contains the state

   * contained in aEventStates.

   * @note aEventStates should contain only one state.

   *

   * @param aEventStates The state to check.

   *

   * @return Whether the object has the state from aEventStates

   */

  bool HasState(EventStates aEventStates) const

  {

#ifdef DEBUG

    // If aEventStates.mStates is a power of two, it contains only one state

    // (or none, but we don't really care).

    if ((aEventStates.mStates & (aEventStates.mStates - 1))) {

      NS_ERROR("When calling HasState, "

               "EventStates object has to contain only one state!");

    }

#endif // DEBUG

    return mStates & aEventStates.mStates;

  }

  /**

   * Returns true if the EventStates instance contains one of the states

   * contained in aEventStates.

   *

   * @param aEventStates The states to check.

   *

   * @return Whether the object has at least one state from aEventStates

   */

  bool HasAtLeastOneOfStates(EventStates aEventStates) const

  {

    return mStates & aEventStates.mStates;

  }

  /**

   * Returns true if the EventStates instance contains all states

   * contained in aEventStates.

   *

   * @param aEventStates The states to check.

   *

   * @return Whether the object has all states from aEventStates

   */

  bool HasAllStates(EventStates aEventStates) const

  {

    return (mStates & aEventStates.mStates) == aEventStates.mStates;

  }

  // We only need that method for InspectorUtils::GetContentState.

  // If InspectorUtils::GetContentState is removed, this method should

  // be removed.

  InternalType GetInternalValue() const {

    return mStates;

  }

  /**

   * Method used to get the appropriate state representation for Servo.

   */

  ServoType ServoValue() const

  {

    return mStates;

  }

private:

  InternalType mStates;

};

} // namespace mozilla

/**

 * The following macros are creating EventStates instance with different

 * values depending of their meaning.

 * Ideally, EventStates instance with values different than 0 should only be

 * created that way.

 */

// Helper to define a new EventStates macro.

#define NS_DEFINE_EVENT_STATE_MACRO(_val)               \

  (mozilla::EventStates(mozilla::EventStates::InternalType(1) << _val))

/*

 * In order to efficiently convert Gecko EventState values into Servo

 * ElementState values [1], we maintain the invariant that the low bits of

 * EventState can be masked off to form an ElementState (this works so

 * long as Servo never supports a state that Gecko doesn't).

 *

 * This is unfortunately rather fragile for now, but we should soon have

 * the infrastructure to statically-assert that these match up. If you

 * need to change these, please notify somebody involved with Stylo.

 *

 * [1] https://github.com/servo/servo/blob/master/components/style/element_state.rs

 */

// Mouse is down on content.

#define NS_EVENT_STATE_ACTIVE        NS_DEFINE_EVENT_STATE_MACRO(0)

// Content has focus.

#define NS_EVENT_STATE_FOCUS         NS_DEFINE_EVENT_STATE_MACRO(1)

// Mouse is hovering over content.

#define NS_EVENT_STATE_HOVER         NS_DEFINE_EVENT_STATE_MACRO(2)

// Content is enabled (and can be disabled).

#define NS_EVENT_STATE_ENABLED       NS_DEFINE_EVENT_STATE_MACRO(3)

// Content is disabled.

#define NS_EVENT_STATE_DISABLED      NS_DEFINE_EVENT_STATE_MACRO(4)

// Content is checked.

#define NS_EVENT_STATE_CHECKED       NS_DEFINE_EVENT_STATE_MACRO(5)

// Content is in the indeterminate state.

#define NS_EVENT_STATE_INDETERMINATE NS_DEFINE_EVENT_STATE_MACRO(6)

// Content shows its placeholder

#define NS_EVENT_STATE_PLACEHOLDERSHOWN NS_DEFINE_EVENT_STATE_MACRO(7)

// Content is URL's target (ref).

#define NS_EVENT_STATE_URLTARGET     NS_DEFINE_EVENT_STATE_MACRO(8)

// Content is the full screen element, or a frame containing the

// current fullscreen element.

#define NS_EVENT_STATE_FULLSCREEN    NS_DEFINE_EVENT_STATE_MACRO(9)

// Content is valid (and can be invalid).

#define NS_EVENT_STATE_VALID         NS_DEFINE_EVENT_STATE_MACRO(10)

// Content is invalid.

#define NS_EVENT_STATE_INVALID       NS_DEFINE_EVENT_STATE_MACRO(11)

// UI friendly version of :valid pseudo-class.

#define NS_EVENT_STATE_MOZ_UI_VALID NS_DEFINE_EVENT_STATE_MACRO(12)

// UI friendly version of :invalid pseudo-class.

#define NS_EVENT_STATE_MOZ_UI_INVALID NS_DEFINE_EVENT_STATE_MACRO(13)

// Content could not be rendered (image/object/etc).

#define NS_EVENT_STATE_BROKEN        NS_DEFINE_EVENT_STATE_MACRO(14)

// Content disabled by the user (images turned off, say).

#define NS_EVENT_STATE_USERDISABLED  NS_DEFINE_EVENT_STATE_MACRO(15)

// Content suppressed by the user (ad blocking, etc).

#define NS_EVENT_STATE_SUPPRESSED    NS_DEFINE_EVENT_STATE_MACRO(16)

// Content is still loading such that there is nothing to show the

// user (eg an image which hasn't started coming in yet).

#define NS_EVENT_STATE_LOADING       NS_DEFINE_EVENT_STATE_MACRO(17)

// Handler for the content has been blocked.

#define NS_EVENT_STATE_HANDLER_BLOCKED NS_DEFINE_EVENT_STATE_MACRO(18)

// Handler for the content has been disabled.

#define NS_EVENT_STATE_HANDLER_DISABLED NS_DEFINE_EVENT_STATE_MACRO(19)

// Handler for the content has crashed

#define NS_EVENT_STATE_HANDLER_CRASHED NS_DEFINE_EVENT_STATE_MACRO(20)

// Content is required.

#define NS_EVENT_STATE_REQUIRED      NS_DEFINE_EVENT_STATE_MACRO(21)

// Content is optional (and can be required).

#define NS_EVENT_STATE_OPTIONAL      NS_DEFINE_EVENT_STATE_MACRO(22)

// Element is either a defined custom element or uncustomized element.

#define NS_EVENT_STATE_DEFINED       NS_DEFINE_EVENT_STATE_MACRO(23)

// Link has been visited.

#define NS_EVENT_STATE_VISITED       NS_DEFINE_EVENT_STATE_MACRO(24)

// Link hasn't been visited.

#define NS_EVENT_STATE_UNVISITED     NS_DEFINE_EVENT_STATE_MACRO(25)

// Drag is hovering over content.

#define NS_EVENT_STATE_DRAGOVER      NS_DEFINE_EVENT_STATE_MACRO(26)

// Content value is in-range (and can be out-of-range).

#define NS_EVENT_STATE_INRANGE       NS_DEFINE_EVENT_STATE_MACRO(27)

// Content value is out-of-range.

#define NS_EVENT_STATE_OUTOFRANGE    NS_DEFINE_EVENT_STATE_MACRO(28)

// These two are temporary (see bug 302188)

// Content is read-only.

#define NS_EVENT_STATE_MOZ_READONLY  NS_DEFINE_EVENT_STATE_MACRO(29)

// Content is editable.

#define NS_EVENT_STATE_MOZ_READWRITE NS_DEFINE_EVENT_STATE_MACRO(30)

// Content is the default one (meaning depends of the context).

#define NS_EVENT_STATE_DEFAULT       NS_DEFINE_EVENT_STATE_MACRO(31)

// Content is a submit control and the form isn't valid.

#define NS_EVENT_STATE_MOZ_SUBMITINVALID NS_DEFINE_EVENT_STATE_MACRO(32)

// Content is in the optimum region.

#define NS_EVENT_STATE_OPTIMUM NS_DEFINE_EVENT_STATE_MACRO(33)

// Content is in the suboptimal region.

#define NS_EVENT_STATE_SUB_OPTIMUM NS_DEFINE_EVENT_STATE_MACRO(34)

// Content is in the sub-suboptimal region.

#define NS_EVENT_STATE_SUB_SUB_OPTIMUM NS_DEFINE_EVENT_STATE_MACRO(35)

// Element is highlighted (devtools inspector)

#define NS_EVENT_STATE_DEVTOOLS_HIGHLIGHTED NS_DEFINE_EVENT_STATE_MACRO(36)

// Element is transitioning for rules changed by style editor

#define NS_EVENT_STATE_STYLEEDITOR_TRANSITIONING NS_DEFINE_EVENT_STATE_MACRO(37)

#define NS_EVENT_STATE_INCREMENT_SCRIPT_LEVEL NS_DEFINE_EVENT_STATE_MACRO(38)

// Content has focus and should show a ring.

#define NS_EVENT_STATE_FOCUSRING     NS_DEFINE_EVENT_STATE_MACRO(39)

// Handler for click to play plugin

#define NS_EVENT_STATE_TYPE_CLICK_TO_PLAY NS_DEFINE_EVENT_STATE_MACRO(40)

// Handler for click to play plugin (vulnerable w/update)

#define NS_EVENT_STATE_VULNERABLE_UPDATABLE NS_DEFINE_EVENT_STATE_MACRO(41)

// Handler for click to play plugin (vulnerable w/no update)

#define NS_EVENT_STATE_VULNERABLE_NO_UPDATE NS_DEFINE_EVENT_STATE_MACRO(42)

// Element has focus-within.

#define NS_EVENT_STATE_FOCUS_WITHIN NS_DEFINE_EVENT_STATE_MACRO(43)

// Element is ltr (for :dir pseudo-class)

#define NS_EVENT_STATE_LTR NS_DEFINE_EVENT_STATE_MACRO(44)

// Element is rtl (for :dir pseudo-class)

#define NS_EVENT_STATE_RTL NS_DEFINE_EVENT_STATE_MACRO(45)

// States for tracking the state of the "dir" attribute for HTML elements.  We

// use these to avoid having to get "dir" attributes all the time during

// selector matching for some parts of the UA stylesheet.

//

// These states are externally managed, because we also don't want to keep

// getting "dir" attributes in IntrinsicState.

//

// Element is HTML and has a "dir" attibute.  This state might go away depending

// on how https://github.com/whatwg/html/issues/2769 gets resolved.  The value

// could be anything.

#define NS_EVENT_STATE_HAS_DIR_ATTR NS_DEFINE_EVENT_STATE_MACRO(46)

// Element is HTML, has a "dir" attribute, and the attribute's value is

// case-insensitively equal to "ltr".

#define NS_EVENT_STATE_DIR_ATTR_LTR NS_DEFINE_EVENT_STATE_MACRO(47)

// Element is HTML, has a "dir" attribute, and the attribute's value is

// case-insensitively equal to "rtl".

#define NS_EVENT_STATE_DIR_ATTR_RTL NS_DEFINE_EVENT_STATE_MACRO(48)

// Element is HTML, and is either a <bdi> element with no valid-valued "dir"

// attribute or any HTML element which has a "dir" attribute whose value is

// "auto".

#define NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO NS_DEFINE_EVENT_STATE_MACRO(49)

// Element is filled by Autofill feature.

#define NS_EVENT_STATE_AUTOFILL NS_DEFINE_EVENT_STATE_MACRO(50)

// Element is filled with preview data by Autofill feature.

#define NS_EVENT_STATE_AUTOFILL_PREVIEW NS_DEFINE_EVENT_STATE_MACRO(51)

// Event state that is used for values that need to be parsed but do nothing.

#define NS_EVENT_STATE_IGNORE NS_DEFINE_EVENT_STATE_MACRO(63)

/**

 * NOTE: do not go over 63 without updating EventStates::InternalType!

 */

#define DIRECTION_STATES (NS_EVENT_STATE_LTR | NS_EVENT_STATE_RTL)

#define DIR_ATTR_STATES (NS_EVENT_STATE_HAS_DIR_ATTR |          \

                         NS_EVENT_STATE_DIR_ATTR_LTR |          \

                         NS_EVENT_STATE_DIR_ATTR_RTL |          \

                         NS_EVENT_STATE_DIR_ATTR_LIKE_AUTO)

#define DISABLED_STATES (NS_EVENT_STATE_DISABLED | NS_EVENT_STATE_ENABLED)

#define REQUIRED_STATES (NS_EVENT_STATE_REQUIRED | NS_EVENT_STATE_OPTIONAL)

// Event states that can be added and removed through

// Element::{Add,Remove}ManuallyManagedStates.

//

// Take care when manually managing state bits.  You are responsible for

// setting or clearing the bit when an Element is added or removed from a

// document (e.g. in BindToTree and UnbindFromTree), if that is an

// appropriate thing to do for your state bit.

#define MANUALLY_MANAGED_STATES (             \

  NS_EVENT_STATE_AUTOFILL |                   \

  NS_EVENT_STATE_AUTOFILL_PREVIEW             \

)

// Event states that are managed externally to an element (by the

// EventStateManager, or by other code).  As opposed to those in

// INTRINSIC_STATES, which are are computed by the element itself

// and returned from Element::IntrinsicState.

#define EXTERNALLY_MANAGED_STATES (           \

  MANUALLY_MANAGED_STATES |                   \

  DIR_ATTR_STATES |                           \

  DISABLED_STATES |                           \

  REQUIRED_STATES |                           \

  NS_EVENT_STATE_ACTIVE |                     \

  NS_EVENT_STATE_DEFINED |                    \

  NS_EVENT_STATE_DRAGOVER |                   \

  NS_EVENT_STATE_FOCUS |                      \

  NS_EVENT_STATE_FOCUSRING |                  \

  NS_EVENT_STATE_FOCUS_WITHIN |               \

  NS_EVENT_STATE_FULLSCREEN |                 \

  NS_EVENT_STATE_HOVER |                      \

  NS_EVENT_STATE_URLTARGET                    \

)

#define INTRINSIC_STATES (~EXTERNALLY_MANAGED_STATES)

#endif // mozilla_EventStates_h_