nsScrollbarFrame.h

Enable keyboard shortcuts

/* -*- 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/. */

//

// nsScrollbarFrame

//

#ifndef nsScrollbarFrame_h__

#define nsScrollbarFrame_h__

#include "mozilla/Attributes.h"

#include "mozilla/ScrollTypes.h"

#include "nsContainerFrame.h"

#include "nsIAnonymousContentCreator.h"

class nsIScrollbarMediator;

namespace mozilla {

class PresShell;

namespace dom {

class Element;

}  // namespace mozilla

nsIFrame* NS_NewScrollbarFrame(mozilla::PresShell* aPresShell,

                               mozilla::ComputedStyle* aStyle);

class nsScrollbarFrame final : public nsContainerFrame,

                               public nsIAnonymousContentCreator {

  using Element = mozilla::dom::Element;

 public:

  explicit nsScrollbarFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)

      : nsContainerFrame(aStyle, aPresContext, kClassID) {}

  NS_DECL_QUERYFRAME

  NS_DECL_FRAMEARENA_HELPERS(nsScrollbarFrame)

#ifdef DEBUG_FRAME_DUMP

  nsresult GetFrameName(nsAString& aResult) const override {

    return MakeFrameName(u"ScrollbarFrame"_ns, aResult);

#endif

  // nsIFrame overrides

  nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,

                            int32_t aModType) override;

  NS_IMETHOD HandlePress(nsPresContext* aPresContext,

                         mozilla::WidgetGUIEvent* aEvent,

                         nsEventStatus* aEventStatus) override;

  NS_IMETHOD HandleMultiplePress(nsPresContext* aPresContext,

                                 mozilla::WidgetGUIEvent* aEvent,

                                 nsEventStatus* aEventStatus,

                                 bool aControlHeld) override;

  MOZ_CAN_RUN_SCRIPT

  NS_IMETHOD HandleDrag(nsPresContext* aPresContext,

                        mozilla::WidgetGUIEvent* aEvent,

                        nsEventStatus* aEventStatus) override;

  NS_IMETHOD HandleRelease(nsPresContext* aPresContext,

                           mozilla::WidgetGUIEvent* aEvent,

                           nsEventStatus* aEventStatus) override;

  mozilla::StyleScrollbarWidth ScrollbarWidth() const;

  nscoord ScrollbarTrackSize() const;

  nsSize ScrollbarMinSize() const;

  bool IsHorizontal() const;

  void Destroy(DestroyContext&) override;

  void Init(nsIContent* aContent, nsContainerFrame* aParent,

            nsIFrame* aPrevInFlow) override;

  void Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize,

              const ReflowInput& aReflowInput,

              nsReflowStatus& aStatus) override;

  void SetScrollbarMediatorContent(nsIContent* aMediator);

  nsIScrollbarMediator* GetScrollbarMediator();

  void WillBecomeActive();

/**

   * The following three methods set the value of mIncrement when a

   * scrollbar button is pressed.

*/

  void SetIncrementToLine(int32_t aDirection);

  void SetIncrementToPage(int32_t aDirection);

  void SetIncrementToWhole(int32_t aDirection);

/**

   * If aImplementsScrollByUnit is Yes then this uses mSmoothScroll,

   * mScrollUnit, and mDirection and calls ScrollByUnit on the

   * nsIScrollbarMediator. The return value is 0. This is better because it is

   * more modern and the scroll frame can perform the scroll via apz for

   * example. The old way below is still supported for xul trees. If

   * aImplementsScrollByUnit is No this adds mIncrement to the current

   * position and updates the curpos attribute obeying mSmoothScroll.

   * @returns The new position after clamping, in CSS Pixels

   * @note This method might destroy the frame, pres shell, and other objects.

*/

  enum class ImplementsScrollByUnit { Yes, No };

  int32_t MoveToNewPosition(ImplementsScrollByUnit aImplementsScrollByUnit);

  int32_t GetIncrement() const { return mIncrement; }

  // nsIAnonymousContentCreator

  nsresult CreateAnonymousContent(nsTArray<ContentInfo>& aElements) override;

  void AppendAnonymousContentTo(nsTArray<nsIContent*>& aElements,

                                uint32_t aFilter) override;

  void UpdateChildrenAttributeValue(nsAtom* aAttribute, bool aNotify);

  void ElementStateChanged(mozilla::dom::ElementState) override;

  bool HasBeenHovered() const { return mHasBeenHovered; }

  // If we're an horizontal scrollbar, get the vertical one, or viceversa.

  nsScrollbarFrame* GetOppositeScrollbar() const;

  void ActivityChanged(bool aIsNowActive);

 protected:

  void InvalidateForHoverChange(bool aIsNowHovered);

  // Direction and multiple to scroll

  int32_t mDirection = 0;

  // Amount to scroll, in CSSPixels

  // Ignored in favour of mScrollUnit/mDirection for regular scroll frames.

  // Trees use this though.

  int32_t mIncrement = 0;

  mozilla::ScrollUnit mScrollUnit = mozilla::ScrollUnit::DEVICE_PIXELS;

  bool mSmoothScroll = false;

  // On macOS, overlay scrollbar hover state should be sticky (remain hovered

  // while we've been hovered at least once).

  bool mHasBeenHovered = false;

 private:

  nsCOMPtr<nsIContent> mScrollbarMediator;

  nsCOMPtr<Element> mUpTopButton;

  nsCOMPtr<Element> mDownTopButton;

  nsCOMPtr<Element> mSlider;

  nsCOMPtr<Element> mThumb;

  nsCOMPtr<Element> mUpBottomButton;

  nsCOMPtr<Element> mDownBottomButton;

};  // class nsScrollbarFrame

#endif