/* -*- 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/. */
#include "nsButtonFrameRenderer.h"
#include "nsCSSRendering.h"
#include "nsPresContext.h"
#include "nsGkAtoms.h"
#include "nsCSSPseudoElements.h"
#include "nsNameSpaceManager.h"
#include "nsStyleSet.h"
#include "nsDisplayList.h"
#include "nsITheme.h"
#include "nsFrame.h"
#include "mozilla/EventStates.h"
#include "mozilla/dom/Element.h"

#define ACTIVE   "active"
#define HOVER    "hover"
#define FOCUS    "focus"

using namespace mozilla::image;

nsButtonFrameRenderer::nsButtonFrameRenderer()
{
  MOZ_COUNT_CTOR(nsButtonFrameRenderer);
}

nsButtonFrameRenderer::~nsButtonFrameRenderer()
{
  MOZ_COUNT_DTOR(nsButtonFrameRenderer);

#ifdef DEBUG
  if (mInnerFocusStyle) {
    mInnerFocusStyle->FrameRelease();
  }
  if (mOuterFocusStyle) {
    mOuterFocusStyle->FrameRelease();
  }
#endif
}

void
nsButtonFrameRenderer::SetFrame(nsFrame* aFrame, nsPresContext* aPresContext)
{
  mFrame = aFrame;
  ReResolveStyles(aPresContext);
}

nsIFrame*
nsButtonFrameRenderer::GetFrame()
{
  return mFrame;
}

void
nsButtonFrameRenderer::SetDisabled(bool aDisabled, bool notify)
{
  if (aDisabled)
    mFrame->GetContent()->SetAttr(kNameSpaceID_None, nsGkAtoms::disabled, EmptyString(),
                                  notify);
  else
    mFrame->GetContent()->UnsetAttr(kNameSpaceID_None, nsGkAtoms::disabled, notify);
}

bool
nsButtonFrameRenderer::isDisabled() 
{
  return mFrame->GetContent()->AsElement()->
    State().HasState(NS_EVENT_STATE_DISABLED);
}

class nsDisplayButtonBoxShadowOuter : public nsDisplayItem {
public:
  nsDisplayButtonBoxShadowOuter(nsDisplayListBuilder* aBuilder,
                                nsButtonFrameRenderer* aRenderer)
    : nsDisplayItem(aBuilder, aRenderer->GetFrame()), mBFR(aRenderer) {
    MOZ_COUNT_CTOR(nsDisplayButtonBoxShadowOuter);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayButtonBoxShadowOuter() {
    MOZ_COUNT_DTOR(nsDisplayButtonBoxShadowOuter);
  }
#endif  
  
  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     nsRenderingContext* aCtx) override;
  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                           bool* aSnap) override;
  NS_DISPLAY_DECL_NAME("ButtonBoxShadowOuter", TYPE_BUTTON_BOX_SHADOW_OUTER)
private:
  nsButtonFrameRenderer* mBFR;
};

nsRect
nsDisplayButtonBoxShadowOuter::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
  *aSnap = false;
  return mFrame->GetVisualOverflowRectRelativeToSelf() + ToReferenceFrame();
}

void
nsDisplayButtonBoxShadowOuter::Paint(nsDisplayListBuilder* aBuilder,
                                     nsRenderingContext* aCtx) {
  nsRect frameRect = nsRect(ToReferenceFrame(), mFrame->GetSize());

  nsRect buttonRect;
  mBFR->GetButtonRect(frameRect, buttonRect);

  nsCSSRendering::PaintBoxShadowOuter(mFrame->PresContext(), *aCtx, mFrame,
                                      buttonRect, mVisibleRect);
}

class nsDisplayButtonBorderBackground : public nsDisplayItem {
public:
  nsDisplayButtonBorderBackground(nsDisplayListBuilder* aBuilder,
                                  nsButtonFrameRenderer* aRenderer)
    : nsDisplayItem(aBuilder, aRenderer->GetFrame()), mBFR(aRenderer) {
    MOZ_COUNT_CTOR(nsDisplayButtonBorderBackground);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayButtonBorderBackground() {
    MOZ_COUNT_DTOR(nsDisplayButtonBorderBackground);
  }
#endif  
  
  virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
                       HitTestState* aState,
                       nsTArray<nsIFrame*> *aOutFrames) override {
    aOutFrames->AppendElement(mFrame);
  }
  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     nsRenderingContext* aCtx) override;
  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                           bool* aSnap) override;
  virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) override;
  virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                         const nsDisplayItemGeometry* aGeometry,
                                         nsRegion *aInvalidRegion) override;
  NS_DISPLAY_DECL_NAME("ButtonBorderBackground", TYPE_BUTTON_BORDER_BACKGROUND)
private:
  nsButtonFrameRenderer* mBFR;
};

nsRect
nsDisplayButtonBorderBackground::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
  *aSnap = false;
  return aBuilder->IsForEventDelivery() ? nsRect(ToReferenceFrame(), mFrame->GetSize())
          : mFrame->GetVisualOverflowRectRelativeToSelf() + ToReferenceFrame();
}

class nsDisplayButtonForeground : public nsDisplayItem {
public:
  nsDisplayButtonForeground(nsDisplayListBuilder* aBuilder,
                            nsButtonFrameRenderer* aRenderer)
    : nsDisplayItem(aBuilder, aRenderer->GetFrame()), mBFR(aRenderer) {
    MOZ_COUNT_CTOR(nsDisplayButtonForeground);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayButtonForeground() {
    MOZ_COUNT_DTOR(nsDisplayButtonForeground);
  }
#endif  

  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     nsRenderingContext* aCtx) override;
  NS_DISPLAY_DECL_NAME("ButtonForeground", TYPE_BUTTON_FOREGROUND)
private:
  nsButtonFrameRenderer* mBFR;
};

nsDisplayItemGeometry*
nsDisplayButtonBorderBackground::AllocateGeometry(nsDisplayListBuilder* aBuilder)
{
  return new nsDisplayItemGenericImageGeometry(this, aBuilder);
}

void
nsDisplayButtonBorderBackground::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                                           const nsDisplayItemGeometry* aGeometry,
                                                           nsRegion *aInvalidRegion)
{
  auto geometry =
    static_cast<const nsDisplayItemGenericImageGeometry*>(aGeometry);

  if (aBuilder->ShouldSyncDecodeImages() &&
      geometry->ShouldInvalidateToSyncDecodeImages()) {
    bool snap;
    aInvalidRegion->Or(*aInvalidRegion, GetBounds(aBuilder, &snap));
  }

  nsDisplayItem::ComputeInvalidationRegion(aBuilder, aGeometry, aInvalidRegion);
}

void nsDisplayButtonBorderBackground::Paint(nsDisplayListBuilder* aBuilder,
                                            nsRenderingContext* aCtx)
{
  NS_ASSERTION(mFrame, "No frame?");
  nsPresContext* pc = mFrame->PresContext();
  nsRect r = nsRect(ToReferenceFrame(), mFrame->GetSize());
  
  // draw the border and background inside the focus and outline borders
  DrawResult result =
    mBFR->PaintBorderAndBackground(pc, *aCtx, mVisibleRect, r,
                                   aBuilder->GetBackgroundPaintFlags());

  nsDisplayItemGenericImageGeometry::UpdateDrawResult(this, result);
}

void nsDisplayButtonForeground::Paint(nsDisplayListBuilder* aBuilder,
                                      nsRenderingContext* aCtx)
{
  nsPresContext *presContext = mFrame->PresContext();
  const nsStyleDisplay *disp = mFrame->StyleDisplay();
  if (!mFrame->IsThemed(disp) ||
      !presContext->GetTheme()->ThemeDrawsFocusForWidget(disp->mAppearance)) {
    // draw the focus and outline borders
    nsRect r = nsRect(ToReferenceFrame(), mFrame->GetSize());
    mBFR->PaintOutlineAndFocusBorders(presContext, *aCtx, mVisibleRect, r);
  }
}

nsresult
nsButtonFrameRenderer::DisplayButton(nsDisplayListBuilder* aBuilder,
                                     nsDisplayList* aBackground,
                                     nsDisplayList* aForeground)
{
  if (mFrame->StyleBorder()->mBoxShadow) {
    aBackground->AppendNewToTop(new (aBuilder)
      nsDisplayButtonBoxShadowOuter(aBuilder, this));
  }

  // Almost all buttons draw some kind of background so there's not much
  // point in checking whether we should create this item.
  aBackground->AppendNewToTop(new (aBuilder)
    nsDisplayButtonBorderBackground(aBuilder, this));

  // Only display focus rings if we actually have them. Since at most one
  // button would normally display a focus ring, most buttons won't have them.
  if ((mOuterFocusStyle && mOuterFocusStyle->StyleBorder()->HasBorder()) ||
      (mInnerFocusStyle && mInnerFocusStyle->StyleBorder()->HasBorder())) {
    aForeground->AppendNewToTop(new (aBuilder)
      nsDisplayButtonForeground(aBuilder, this));
  }
  return NS_OK;
}

void
nsButtonFrameRenderer::PaintOutlineAndFocusBorders(nsPresContext* aPresContext,
          nsRenderingContext& aRenderingContext,
          const nsRect& aDirtyRect,
          const nsRect& aRect)
{
  // once we have all that we'll draw the focus if we have it. We will
  // need to draw 2 focuses, the inner and the outer. This is so we
  // can do any kind of look and feel. Some buttons have focus on the
  // outside like mac and motif. While others like windows have it
  // inside (dotted line).  Usually only one will be specifed. But I
  // guess you could have both if you wanted to.

  nsRect rect;

  if (mOuterFocusStyle) {
    // ---------- paint the outer focus border -------------

    GetButtonOuterFocusRect(aRect, rect);

    nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                aDirtyRect, rect, mOuterFocusStyle);
  }

  if (mInnerFocusStyle) { 
    // ---------- paint the inner focus border -------------

    GetButtonInnerFocusRect(aRect, rect);

    nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                aDirtyRect, rect, mInnerFocusStyle);
  }
}


DrawResult
nsButtonFrameRenderer::PaintBorderAndBackground(nsPresContext* aPresContext,
          nsRenderingContext& aRenderingContext,
          const nsRect& aDirtyRect,
          const nsRect& aRect,
          uint32_t aBGFlags)

{
  // get the button rect this is inside the focus and outline rects
  nsRect buttonRect;
  GetButtonRect(aRect, buttonRect);

  nsStyleContext* context = mFrame->StyleContext();

  DrawResult result =
    nsCSSRendering::PaintBackground(aPresContext, aRenderingContext, mFrame,
                                    aDirtyRect, buttonRect, aBGFlags);
  nsCSSRendering::PaintBoxShadowInner(aPresContext, aRenderingContext,
                                      mFrame, buttonRect, aDirtyRect);
  nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                              aDirtyRect, buttonRect, context);

  return result;
}


void
nsButtonFrameRenderer::GetButtonOuterFocusRect(const nsRect& aRect, nsRect& focusRect)
{
  focusRect = aRect;
}

void
nsButtonFrameRenderer::GetButtonRect(const nsRect& aRect, nsRect& r)
{
  r = aRect;
  r.Deflate(GetButtonOuterFocusBorderAndPadding());
}


void
nsButtonFrameRenderer::GetButtonInnerFocusRect(const nsRect& aRect, nsRect& focusRect)
{
  GetButtonRect(aRect, focusRect);
  focusRect.Deflate(GetButtonBorderAndPadding());
  focusRect.Deflate(GetButtonInnerFocusMargin());
}


nsMargin
nsButtonFrameRenderer::GetButtonOuterFocusBorderAndPadding()
{
  nsMargin result(0,0,0,0);

  if (mOuterFocusStyle) {
    if (!mOuterFocusStyle->StylePadding()->GetPadding(result)) {
      NS_NOTYETIMPLEMENTED("percentage padding");
    }
    result += mOuterFocusStyle->StyleBorder()->GetComputedBorder();
  }

  return result;
}

nsMargin
nsButtonFrameRenderer::GetButtonBorderAndPadding()
{
  return mFrame->GetUsedBorderAndPadding();
}

/**
 * Gets the size of the buttons border this is the union of the normal and disabled borders.
 */
nsMargin
nsButtonFrameRenderer::GetButtonInnerFocusMargin()
{
  nsMargin innerFocusMargin(0,0,0,0);

  if (mInnerFocusStyle) {
    const nsStyleMargin* margin = mInnerFocusStyle->StyleMargin();
    if (!margin->GetMargin(innerFocusMargin)) {
      NS_NOTYETIMPLEMENTED("percentage margin");
    }
  }

  return innerFocusMargin;
}

nsMargin
nsButtonFrameRenderer::GetButtonInnerFocusBorderAndPadding()
{
  nsMargin result(0,0,0,0);

  if (mInnerFocusStyle) {
    if (!mInnerFocusStyle->StylePadding()->GetPadding(result)) {
      NS_NOTYETIMPLEMENTED("percentage padding");
    }
    result += mInnerFocusStyle->StyleBorder()->GetComputedBorder();
  }

  return result;
}

// gets all the focus borders and padding that will be added to the regular border
nsMargin
nsButtonFrameRenderer::GetAddedButtonBorderAndPadding()
{
  return GetButtonOuterFocusBorderAndPadding() + GetButtonInnerFocusMargin() + GetButtonInnerFocusBorderAndPadding();
}

/**
 * Call this when styles change
 */
void
nsButtonFrameRenderer::ReResolveStyles(nsPresContext* aPresContext)
{
  // get all the styles
  nsStyleContext* context = mFrame->StyleContext();
  nsStyleSet *styleSet = aPresContext->StyleSet();

#ifdef DEBUG
  if (mInnerFocusStyle) {
    mInnerFocusStyle->FrameRelease();
  }
  if (mOuterFocusStyle) {
    mOuterFocusStyle->FrameRelease();
  }
#endif

  // style for the inner such as a dotted line (Windows)
  mInnerFocusStyle =
    styleSet->ProbePseudoElementStyle(mFrame->GetContent()->AsElement(),
                                      nsCSSPseudoElements::ePseudo_mozFocusInner,
                                      context);

  // style for outer focus like a ridged border (MAC).
  mOuterFocusStyle =
    styleSet->ProbePseudoElementStyle(mFrame->GetContent()->AsElement(),
                                      nsCSSPseudoElements::ePseudo_mozFocusOuter,
                                      context);

#ifdef DEBUG
  if (mInnerFocusStyle) {
    mInnerFocusStyle->FrameAddRef();
  }
  if (mOuterFocusStyle) {
    mOuterFocusStyle->FrameAddRef();
  }
#endif
}

nsStyleContext*
nsButtonFrameRenderer::GetStyleContext(int32_t aIndex) const
{
  switch (aIndex) {
  case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
    return mInnerFocusStyle;
  case NS_BUTTON_RENDERER_FOCUS_OUTER_CONTEXT_INDEX:
    return mOuterFocusStyle;
  default:
    return nullptr;
  }
}

void 
nsButtonFrameRenderer::SetStyleContext(int32_t aIndex, nsStyleContext* aStyleContext)
{
  switch (aIndex) {
  case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
#ifdef DEBUG
    if (mInnerFocusStyle) {
      mInnerFocusStyle->FrameRelease();
    }
#endif
    mInnerFocusStyle = aStyleContext;
    break;
  case NS_BUTTON_RENDERER_FOCUS_OUTER_CONTEXT_INDEX:
#ifdef DEBUG
    if (mOuterFocusStyle) {
      mOuterFocusStyle->FrameRelease();
    }
#endif
    mOuterFocusStyle = aStyleContext;
    break;
  }
#ifdef DEBUG
  aStyleContext->FrameAddRef();
#endif
}