gecko-dev/layout/base/PresShellForwards.h

/* -*- 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_PresShellForwards_h
#define mozilla_PresShellForwards_h

#include "mozilla/TypedEnumBits.h"
#include "mozilla/Maybe.h"

struct CapturingContentInfo;

namespace mozilla {

class PresShell;

// Flags to pass to PresShell::SetCapturingContent().
enum class CaptureFlags {
  None = 0,
  // When assigning capture, ignore whether capture is allowed or not.
  IgnoreAllowedState = 1 << 0,
  // Set if events should be targeted at the capturing content or its children.
  RetargetToElement = 1 << 1,
  // Set if the current capture wants drags to be prevented.
  PreventDragStart = 1 << 2,
  // Set when the mouse is pointer locked, and events are sent to locked
  // element.
  PointerLock = 1 << 3,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(CaptureFlags)

enum class ResizeReflowOptions : uint32_t {
  NoOption = 0,
  // the resulting BSize can be less than the given one, producing
  // shrink-to-fit sizing in the block dimension
  BSizeLimit = 1 << 0,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(ResizeReflowOptions)

enum class IntrinsicDirty {
  // Don't mark any intrinsic inline sizes dirty.
  None,
  // Mark intrinsic inline sizes dirty on aFrame and its ancestors.
  FrameAndAncestors,
  // Mark intrinsic inline sizes dirty on aFrame, its ancestors, and its
  // descendants.
  FrameAncestorsAndDescendants,
};

enum class ReflowRootHandling {
  PositionOrSizeChange,    // aFrame is changing position or size
  NoPositionOrSizeChange,  // ... NOT changing ...
  InferFromBitToAdd,       // is changing iff (aBitToAdd == NS_FRAME_IS_DIRTY)

  // Note:  With IntrinsicDirty::FrameAncestorsAndDescendants, these can also
  // apply to out-of-flows in addition to aFrame.
};

// Indicates where to scroll on a given axis.
struct WhereToScroll {
  // The percentage of the scroll axis that we're scrolling to.
  // Nothing() represents "scroll to nearest".
  Maybe<int16_t> mPercentage;

  // Default is nearest.
  constexpr WhereToScroll() = default;

  explicit constexpr WhereToScroll(int16_t aPercentage)
      : mPercentage(Some(aPercentage)) {}

  enum { Nearest };
  MOZ_IMPLICIT constexpr WhereToScroll(decltype(Nearest)) : WhereToScroll() {}
  enum { Start };
  MOZ_IMPLICIT constexpr WhereToScroll(decltype(Start)) : WhereToScroll(0) {}
  enum { Center };
  MOZ_IMPLICIT constexpr WhereToScroll(decltype(Center)) : WhereToScroll(50) {}
  enum { End };
  MOZ_IMPLICIT constexpr WhereToScroll(decltype(End)) : WhereToScroll(100) {}
};

// See the comment for constructor of ScrollAxis for the detail.
enum class WhenToScroll : uint8_t {
  Always,
  IfNotVisible,
  IfNotFullyVisible,
};

struct ScrollAxis final {
  /**
   * aWhere:
   *   Either a percentage or a special value. PresShell defines:
   *   * (Default) kScrollMinimum = -1: The visible area is scrolled the
   *     minimum amount to show as much as possible of the frame. This won't
   *     hide any initially visible part of the frame.
   *   * kScrollToTop = 0: The frame's upper edge is aligned with the top edge
   *     of the visible area.
   *   * kScrollToBottom = 100: The frame's bottom edge is aligned with the
   *     bottom edge of the visible area.
   *   * kScrollToLeft = 0: The frame's left edge is aligned with the left edge
   *     of the visible area.
   *   * kScrollToRight = 100: The frame's right edge is aligned* with the right
   *     edge of the visible area.
   *   * kScrollToCenter = 50: The frame is centered along the axis the
   *     ScrollAxis is used for.
   *
   *   Other values are treated as a percentage, and the point*"percent"
   *   down the frame is placed at the point "percent" down the visible area.
   *
   * aWhen:
   *   * (Default) WhenToScroll::IfNotFullyVisible: Move the frame only if it is
   *     not fully visible (including if it's not visible at all). Note that
   *     in this case if the frame is too large to fit in view, it will only
   *     be scrolled if more of it can fit than is already in view.
   *   * WhenToScroll::IfNotVisible: Move the frame only if none of it is
   *     visible.
   *   * WhenToScroll::Always: Move the frame regardless of its current
   *     visibility.
   *
   * aOnlyIfPerceivedScrollableDirection:
   *   If the direction is not a perceived scrollable direction (i.e. no
   *   scrollbar showing and less than one device pixel of scrollable
   *   distance), don't scroll. Defaults to false.
   */
  explicit ScrollAxis(WhereToScroll aWhere = WhereToScroll::Nearest,
                      WhenToScroll aWhen = WhenToScroll::IfNotFullyVisible,
                      bool aOnlyIfPerceivedScrollableDirection = false)
      : mWhereToScroll(aWhere),
        mWhenToScroll(aWhen),
        mOnlyIfPerceivedScrollableDirection(
            aOnlyIfPerceivedScrollableDirection) {}

  WhereToScroll mWhereToScroll;
  WhenToScroll mWhenToScroll;
  bool mOnlyIfPerceivedScrollableDirection : 1;
};

enum class ScrollFlags : uint8_t {
  None = 0,
  ScrollFirstAncestorOnly = 1 << 0,
  ScrollOverflowHidden = 1 << 1,
  ScrollNoParentFrames = 1 << 2,
  ScrollSmooth = 1 << 3,
  ScrollSmoothAuto = 1 << 4,
  TriggeredByScript = 1 << 5,
  // NOTE: `Anchor` means here is "scrolling to an anchor", not "CSS scroll
  // anchoring".
  AnchorScrollFlags =
      ScrollOverflowHidden | ScrollNoParentFrames | TriggeredByScript,
  ALL_BITS = (1 << 6) - 1,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(ScrollFlags)

// See comment at declaration of RenderDocument() for the detail.
enum class RenderDocumentFlags {
  None = 0,
  IsUntrusted = 1 << 0,
  IgnoreViewportScrolling = 1 << 1,
  DrawCaret = 1 << 2,
  UseWidgetLayers = 1 << 3,
  AsyncDecodeImages = 1 << 4,
  DocumentRelative = 1 << 5,
  DrawWindowNotFlushing = 1 << 6,
  UseHighQualityScaling = 1 << 7,
  ResetViewportScrolling = 1 << 8,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(RenderDocumentFlags)

// See comment at declaration of RenderSelection() for the detail.
enum class RenderImageFlags {
  None = 0,
  IsImage = 1 << 0,
  AutoScale = 1 << 1,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(RenderImageFlags)

enum class ResolutionChangeOrigin : uint8_t {
  Apz,
  Test,
  MainThreadRestore,
  MainThreadAdjustment,
};

enum class PaintFlags {
  None = 0,
  /* Sync-decode images. */
  PaintSyncDecodeImages = 1 << 1,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(PaintFlags)

enum class PaintInternalFlags {
  None = 0,
  /* Sync-decode images. */
  PaintSyncDecodeImages = 1 << 1,
  /* Composite layers to the window. */
  PaintComposite = 1 << 2,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(PaintInternalFlags)

// This is a private enum class of PresShell, but currently,
// MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS isn't available in class definition.
// Therefore, we need to put this here.
enum class RenderingStateFlags : uint8_t {
  None = 0,
  IgnoringViewportScrolling = 1 << 0,
  DrawWindowNotFlushing = 1 << 1,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(RenderingStateFlags)

// The state of the dynamic toolbar on Mobile.
enum class DynamicToolbarState {
  None,          // No dynamic toolbar, i.e. the toolbar is static or there is
                 // no available toolbar.
  Expanded,      // The dynamic toolbar is expanded to the maximum height.
  InTransition,  // The dynamic toolbar is being shown/hidden.
  Collapsed,     // The dynamic toolbar is collapsed to zero height.
};

#ifdef DEBUG

enum class VerifyReflowFlags {
  None = 0,
  On = 1 << 0,
  Noisy = 1 << 1,
  All = 1 << 2,
  DumpCommands = 1 << 3,
  NoisyCommands = 1 << 4,
  ReallyNoisyCommands = 1 << 5,
  DuringResizeReflow = 1 << 6,
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(VerifyReflowFlags)

#endif  // #ifdef DEBUG

}  // namespace mozilla

#endif  // #ifndef mozilla_PresShellForwards_h