gecko-dev/layout/xul/nsScrollbarFrame.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsBoxFrame.h"
class nsIScrollbarMediator;
nsIFrame* NS_NewScrollbarFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
class nsScrollbarFrame final : public nsBoxFrame
{
public:
explicit nsScrollbarFrame(nsStyleContext* aContext)
: nsBoxFrame(aContext, kClassID)
, mIncrement(0)
, mSmoothScroll(false)
, mScrollbarMediator(nullptr)
{}
NS_DECL_QUERYFRAME
NS_DECL_FRAMEARENA_HELPERS(nsScrollbarFrame)
#ifdef DEBUG_FRAME_DUMP
virtual nsresult GetFrameName(nsAString& aResult) const override {
return MakeFrameName(NS_LITERAL_STRING("ScrollbarFrame"), aResult);
}
#endif
// nsIFrame overrides
virtual nsresult AttributeChanged(int32_t aNameSpaceID,
nsIAtom* 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;
NS_IMETHOD HandleDrag(nsPresContext* aPresContext,
mozilla::WidgetGUIEvent* aEvent,
nsEventStatus* aEventStatus) override;
NS_IMETHOD HandleRelease(nsPresContext* aPresContext,
mozilla::WidgetGUIEvent* aEvent,
nsEventStatus* aEventStatus) override;
virtual void Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) override;
virtual void Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) override;
void SetScrollbarMediatorContent(nsIContent* aMediator);
nsIScrollbarMediator* GetScrollbarMediator();
// nsBox methods
/**
* Treat scrollbars as clipping their children; overflowing children
* will not be allowed to set an overflow rect on this
* frame. This means that when the scroll code decides to hide a
* scrollframe by setting its height or width to zero, that will
* hide the children too.
*/
virtual bool DoesClipChildren() override { return true; }
virtual nsresult GetXULMargin(nsMargin& aMargin) override;
/**
* 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);
/**
* MoveToNewPosition() adds mIncrement to the current position and
* updates the curpos attribute.
* @returns The new position after clamping, in CSS Pixels
* @note This method might destroy the frame, pres shell, and other objects.
*/
int32_t MoveToNewPosition();
int32_t GetIncrement() { return mIncrement; }
protected:
int32_t mIncrement; // Amount to scroll, in CSSPixels
bool mSmoothScroll;
private:
nsCOMPtr<nsIContent> mScrollbarMediator;
}; // class nsScrollbarFrame
#endif