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       1             : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* This Source Code Form is subject to the terms of the Mozilla Public
       3             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       4             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       5             : 
       6             : //
       7             : // nsScrollbarFrame
       8             : //
       9             : 
      10             : #ifndef nsScrollbarFrame_h__
      11             : #define nsScrollbarFrame_h__
      12             : 
      13             : #include "mozilla/Attributes.h"
      14             : #include "nsBoxFrame.h"
      15             : 
      16             : class nsIScrollbarMediator;
      17             : 
      18             : nsIFrame* NS_NewScrollbarFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
      19             : 
      20           0 : class nsScrollbarFrame final : public nsBoxFrame
      21             : {
      22             : public:
      23           4 :   explicit nsScrollbarFrame(nsStyleContext* aContext)
      24           4 :     : nsBoxFrame(aContext, kClassID)
      25             :     , mIncrement(0)
      26             :     , mSmoothScroll(false)
      27           4 :     , mScrollbarMediator(nullptr)
      28           4 :   {}
      29             : 
      30             :   NS_DECL_QUERYFRAME
      31          18 :   NS_DECL_FRAMEARENA_HELPERS(nsScrollbarFrame)
      32             : 
      33             : #ifdef DEBUG_FRAME_DUMP
      34           0 :   virtual nsresult GetFrameName(nsAString& aResult) const override {
      35           0 :     return MakeFrameName(NS_LITERAL_STRING("ScrollbarFrame"), aResult);
      36             :   }
      37             : #endif
      38             : 
      39             :   // nsIFrame overrides
      40             :   virtual nsresult AttributeChanged(int32_t aNameSpaceID,
      41             :                                     nsIAtom* aAttribute,
      42             :                                     int32_t aModType) override;
      43             : 
      44             :   NS_IMETHOD HandlePress(nsPresContext* aPresContext,
      45             :                          mozilla::WidgetGUIEvent* aEvent,
      46             :                          nsEventStatus* aEventStatus) override;
      47             : 
      48             :   NS_IMETHOD HandleMultiplePress(nsPresContext* aPresContext,
      49             :                                  mozilla::WidgetGUIEvent* aEvent,
      50             :                                  nsEventStatus* aEventStatus,
      51             :                                  bool aControlHeld) override;
      52             : 
      53             :   NS_IMETHOD HandleDrag(nsPresContext* aPresContext,
      54             :                         mozilla::WidgetGUIEvent* aEvent,
      55             :                         nsEventStatus* aEventStatus) override;
      56             : 
      57             :   NS_IMETHOD HandleRelease(nsPresContext* aPresContext,
      58             :                            mozilla::WidgetGUIEvent* aEvent,
      59             :                            nsEventStatus* aEventStatus) override;
      60             : 
      61             :   virtual void Init(nsIContent*       aContent,
      62             :                     nsContainerFrame* aParent,
      63             :                     nsIFrame*         aPrevInFlow) override;
      64             : 
      65             :   virtual void Reflow(nsPresContext*           aPresContext,
      66             :                       ReflowOutput&     aDesiredSize,
      67             :                       const ReflowInput& aReflowInput,
      68             :                       nsReflowStatus&          aStatus) override;
      69             : 
      70             :   void SetScrollbarMediatorContent(nsIContent* aMediator);
      71             :   nsIScrollbarMediator* GetScrollbarMediator();
      72             : 
      73             :   // nsBox methods
      74             : 
      75             :   /**
      76             :    * Treat scrollbars as clipping their children; overflowing children
      77             :    * will not be allowed to set an overflow rect on this
      78             :    * frame. This means that when the scroll code decides to hide a
      79             :    * scrollframe by setting its height or width to zero, that will
      80             :    * hide the children too.
      81             :    */
      82          10 :   virtual bool DoesClipChildren() override { return true; }
      83             : 
      84             :   virtual nsresult GetXULMargin(nsMargin& aMargin) override;
      85             : 
      86             :   /**
      87             :    * The following three methods set the value of mIncrement when a
      88             :    * scrollbar button is pressed.
      89             :    */
      90             :   void SetIncrementToLine(int32_t aDirection);
      91             :   void SetIncrementToPage(int32_t aDirection);
      92             :   void SetIncrementToWhole(int32_t aDirection);
      93             :   /**
      94             :    * MoveToNewPosition() adds mIncrement to the current position and
      95             :    * updates the curpos attribute.
      96             :    * @returns The new position after clamping, in CSS Pixels
      97             :    * @note This method might destroy the frame, pres shell, and other objects.
      98             :    */
      99             :   int32_t MoveToNewPosition();
     100           0 :   int32_t GetIncrement() { return mIncrement; }
     101             : 
     102             : protected:
     103             :   int32_t mIncrement; // Amount to scroll, in CSSPixels
     104             :   bool mSmoothScroll;
     105             : 
     106             : private:
     107             :   nsCOMPtr<nsIContent> mScrollbarMediator;
     108             : }; // class nsScrollbarFrame
     109             : 
     110             : #endif