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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/. */

 //

 // Eric Vaughan

 // Netscape Communications

 //

 // See documentation in associated header file

 //

 #include "nsScrollbarFrame.h"

 #include "nsScrollbarButtonFrame.h"

 #include "nsGkAtoms.h"

 #include "nsIScrollableFrame.h"

 #include "nsIScrollbarMediator.h"

 #include "mozilla/LookAndFeel.h"

 #include "nsThemeConstants.h"

 #include "nsRenderingContext.h"

 #include "nsIContent.h"

 using namespace mozilla;

 //

 // NS_NewScrollbarFrame

 //

 // Creates a new scrollbar frame and returns it

 //

 nsIFrame*

 NS_NewScrollbarFrame (nsIPresShell* aPresShell, nsStyleContext* aContext)

 {

   return new (aPresShell) nsScrollbarFrame (aPresShell, aContext);

 }

 NS_IMPL_FRAMEARENA_HELPERS(nsScrollbarFrame)

 NS_QUERYFRAME_HEAD(nsScrollbarFrame)

   NS_QUERYFRAME_ENTRY(nsScrollbarFrame)

 NS_QUERYFRAME_TAIL_INHERITING(nsBoxFrame)

 void

 nsScrollbarFrame::Init(nsIContent* aContent,

                        nsIFrame*   aParent,

                        nsIFrame*   aPrevInFlow)

 {

   nsBoxFrame::Init(aContent, aParent, aPrevInFlow);

   // We want to be a reflow root since we use reflows to move the

   // slider.  Any reflow inside the scrollbar frame will be a reflow to

   // move the slider and will thus not change anything outside of the

   // scrollbar or change the size of the scrollbar frame.

   mState |= NS_FRAME_REFLOW_ROOT;

 }

 nsresult

 nsScrollbarFrame::Reflow(nsPresContext*          aPresContext,

                          nsHTMLReflowMetrics&     aDesiredSize,

                          const nsHTMLReflowState& aReflowState,

                          nsReflowStatus&          aStatus)

 {

   nsresult rv = nsBoxFrame::Reflow(aPresContext, aDesiredSize, aReflowState, aStatus);

   NS_ENSURE_SUCCESS(rv, rv);

   // nsGfxScrollFrame may have told us to shrink to nothing. If so, make sure our

   // desired size agrees.

   if (aReflowState.AvailableWidth() == 0) {

     aDesiredSize.Width() = 0;

   }

   if (aReflowState.AvailableHeight() == 0) {

     aDesiredSize.Height() = 0;

   }

   return NS_OK;

 }

 nsIAtom*

 nsScrollbarFrame::GetType() const

 {

   return nsGkAtoms::scrollbarFrame;

 }

 nsresult

 nsScrollbarFrame::AttributeChanged(int32_t aNameSpaceID,

                                    nsIAtom* aAttribute,

                                    int32_t aModType)

 {

   nsresult rv = nsBoxFrame::AttributeChanged(aNameSpaceID, aAttribute,

                                              aModType);

   // if the current position changes, notify any nsGfxScrollFrame

   // parent we may have

   if (aAttribute != nsGkAtoms::curpos)

     return rv;

   nsIScrollableFrame* scrollable = do_QueryFrame(GetParent());

   if (!scrollable)

     return rv;

   nsCOMPtr<nsIContent> kungFuDeathGrip(mContent);

   scrollable->CurPosAttributeChanged(mContent);

   return rv;

 }

 NS_IMETHODIMP

 nsScrollbarFrame::HandlePress(nsPresContext* aPresContext,

                               WidgetGUIEvent* aEvent,

                               nsEventStatus* aEventStatus)

 {

   return NS_OK;

 }

 NS_IMETHODIMP

 nsScrollbarFrame::HandleMultiplePress(nsPresContext* aPresContext,

                                       WidgetGUIEvent* aEvent,

                                       nsEventStatus* aEventStatus,

                                       bool aControlHeld)

 {

   return NS_OK;

 }

 NS_IMETHODIMP 

 nsScrollbarFrame::HandleDrag(nsPresContext* aPresContext,

                              WidgetGUIEvent* aEvent,

                              nsEventStatus* aEventStatus)

 {

   return NS_OK;

 }

 NS_IMETHODIMP 

 nsScrollbarFrame::HandleRelease(nsPresContext* aPresContext,

                                 WidgetGUIEvent* aEvent,

                                 nsEventStatus* aEventStatus)

 {

   return NS_OK;

 }

 void

 nsScrollbarFrame::SetScrollbarMediatorContent(nsIContent* aMediator)

 {

   mScrollbarMediator = aMediator;

 }

 nsIScrollbarMediator*

 nsScrollbarFrame::GetScrollbarMediator()

 {

   if (!mScrollbarMediator)

     return nullptr;

   nsIFrame* f = mScrollbarMediator->GetPrimaryFrame();

   // check if the frame is a scroll frame. If so, get the scrollable frame

   // inside it.

   nsIScrollableFrame* scrollFrame = do_QueryFrame(f);

   if (scrollFrame) {

     f = scrollFrame->GetScrolledFrame();

   }

   nsIScrollbarMediator* sbm = do_QueryFrame(f);

   return sbm;

 }

 nsresult

 nsScrollbarFrame::GetMargin(nsMargin& aMargin)

 {

   aMargin.SizeTo(0,0,0,0);

   if (LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars) != 0) {

     nsPresContext* presContext = PresContext();

     nsITheme* theme = presContext->GetTheme();

     if (theme) {

       nsIntSize size;

       bool isOverridable;

       nsRefPtr<nsRenderingContext> rc =

         presContext->PresShell()->CreateReferenceRenderingContext();

       theme->GetMinimumWidgetSize(rc, this, NS_THEME_SCROLLBAR, &size,

                                   &isOverridable);

       if (IsHorizontal()) {

         aMargin.top = -presContext->DevPixelsToAppUnits(size.height);

       }

       else {

         if (StyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL) {

           aMargin.right = -presContext->DevPixelsToAppUnits(size.width);

         }

         else {

           aMargin.left = -presContext->DevPixelsToAppUnits(size.width);

         }

       }

       return NS_OK;

     }

   }

   return nsBox::GetMargin(aMargin);

 }