gecko-dev/layout/forms/nsButtonFrameRenderer.cpp

/* -*- 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/. */
#include "nsButtonFrameRenderer.h"
#include "nsCSSRendering.h"
#include "nsPresContext.h"
#include "nsGkAtoms.h"
#include "nsCSSPseudoElements.h"
#include "nsNameSpaceManager.h"
#include "mozilla/ServoStyleSet.h"
#include "mozilla/Unused.h"
#include "nsDisplayList.h"
#include "nsITheme.h"
#include "nsFrame.h"
#include "mozilla/EventStates.h"
#include "mozilla/dom/Element.h"
#include "Layers.h"
#include "gfxPrefs.h"
#include "gfxUtils.h"
#include "mozilla/layers/WebRenderLayerManager.h"

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

using namespace mozilla;
using namespace mozilla::image;
using namespace mozilla::layers;

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

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

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

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

void
nsButtonFrameRenderer::SetDisabled(bool aDisabled, bool aNotify)
{
  Element* element = mFrame->GetContent()->AsElement();
  if (aDisabled)
    element->SetAttr(kNameSpaceID_None, nsGkAtoms::disabled, EmptyString(),
                     aNotify);
  else
    element->UnsetAttr(kNameSpaceID_None, nsGkAtoms::disabled, aNotify);
}

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()) {
    MOZ_COUNT_CTOR(nsDisplayButtonBoxShadowOuter);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayButtonBoxShadowOuter() {
    MOZ_COUNT_DTOR(nsDisplayButtonBoxShadowOuter);
  }
#endif

  virtual bool CreateWebRenderCommands(
    mozilla::wr::DisplayListBuilder& aBuilder,
    mozilla::wr::IpcResourceUpdateQueue& aResources,
    const StackingContextHelper& aSc,
    mozilla::layers::WebRenderLayerManager* aManager,
    nsDisplayListBuilder* aDisplayListBuilder) override;

  bool CanBuildWebRenderDisplayItems();

  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     gfxContext* aCtx) override;
  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                           bool* aSnap) const override;
  NS_DISPLAY_DECL_NAME("ButtonBoxShadowOuter", TYPE_BUTTON_BOX_SHADOW_OUTER)
};

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

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

  nsCSSRendering::PaintBoxShadowOuter(mFrame->PresContext(), *aCtx, mFrame,
                                      frameRect, GetPaintRect());
}

bool
nsDisplayButtonBoxShadowOuter::CanBuildWebRenderDisplayItems()
{
  nsCSSShadowArray* shadows = mFrame->StyleEffects()->mBoxShadow;
  if (!shadows) {
    return false;
  }

  bool hasBorderRadius;
  bool nativeTheme =
    nsCSSRendering::HasBoxShadowNativeTheme(mFrame, hasBorderRadius);

  // We don't support native themed things yet like box shadows around
  // input buttons.
  if (nativeTheme) {
    return false;
  }

  return true;
}

bool
nsDisplayButtonBoxShadowOuter::CreateWebRenderCommands(
  mozilla::wr::DisplayListBuilder& aBuilder,
  mozilla::wr::IpcResourceUpdateQueue& aResources,
  const StackingContextHelper& aSc,
  mozilla::layers::WebRenderLayerManager* aManager,
  nsDisplayListBuilder* aDisplayListBuilder)
{
  if (!CanBuildWebRenderDisplayItems()) {
    return false;
  }
  int32_t appUnitsPerDevPixel = mFrame->PresContext()->AppUnitsPerDevPixel();
  nsRect shadowRect = nsRect(ToReferenceFrame(), mFrame->GetSize());
  LayoutDeviceRect deviceBox =
    LayoutDeviceRect::FromAppUnits(shadowRect, appUnitsPerDevPixel);
  wr::LayoutRect deviceBoxRect = wr::ToRoundedLayoutRect(deviceBox);

  LayoutDeviceRect clipRect =
    LayoutDeviceRect::FromAppUnits(GetPaintRect(), appUnitsPerDevPixel);
  wr::LayoutRect deviceClipRect = wr::ToRoundedLayoutRect(clipRect);

  bool hasBorderRadius;
  Unused << nsCSSRendering::HasBoxShadowNativeTheme(mFrame, hasBorderRadius);

  LayoutDeviceSize zeroSize;
  wr::BorderRadius borderRadius = wr::ToBorderRadius(zeroSize, zeroSize,
                                                     zeroSize, zeroSize);
  if (hasBorderRadius) {
    mozilla::gfx::RectCornerRadii borderRadii;
    hasBorderRadius = nsCSSRendering::GetBorderRadii(
      shadowRect, shadowRect, mFrame, borderRadii);
    if (hasBorderRadius) {
      borderRadius = wr::ToBorderRadius(
        LayoutDeviceSize::FromUnknownSize(borderRadii.TopLeft()),
        LayoutDeviceSize::FromUnknownSize(borderRadii.TopRight()),
        LayoutDeviceSize::FromUnknownSize(borderRadii.BottomLeft()),
        LayoutDeviceSize::FromUnknownSize(borderRadii.BottomRight()));
    }

  }

  nsCSSShadowArray* shadows = mFrame->StyleEffects()->mBoxShadow;
  MOZ_ASSERT(shadows);

  for (uint32_t i = shadows->Length(); i > 0; i--) {
    nsCSSShadowItem* shadow = shadows->ShadowAt(i - 1);
    if (shadow->mInset) {
      continue;
    }
    float blurRadius = float(shadow->mRadius) / float(appUnitsPerDevPixel);
    gfx::Color shadowColor =
      nsCSSRendering::GetShadowColor(shadow, mFrame, 1.0);

    LayoutDevicePoint shadowOffset = LayoutDevicePoint::FromAppUnits(
        nsPoint(shadow->mXOffset, shadow->mYOffset),
        appUnitsPerDevPixel);

    float spreadRadius = float(shadow->mSpread) / float(appUnitsPerDevPixel);

    aBuilder.PushBoxShadow(deviceBoxRect,
                           deviceClipRect,
                           !BackfaceIsHidden(),
                           deviceBoxRect,
                           wr::ToLayoutVector2D(shadowOffset),
                           wr::ToColorF(shadowColor),
                           blurRadius,
                           spreadRadius,
                           borderRadius,
                           wr::BoxShadowClipMode::Outset);
  }
  return true;
}

class nsDisplayButtonBorder : public nsDisplayItem {
public:
  nsDisplayButtonBorder(nsDisplayListBuilder* aBuilder,
                                  nsButtonFrameRenderer* aRenderer)
    : nsDisplayItem(aBuilder, aRenderer->GetFrame())
    , mBFR(aRenderer)
  {
    MOZ_COUNT_CTOR(nsDisplayButtonBorder);
  }
#ifdef NS_BUILD_REFCNT_LOGGING
  virtual ~nsDisplayButtonBorder() {
    MOZ_COUNT_DTOR(nsDisplayButtonBorder);
  }
#endif
  virtual bool MustPaintOnContentSide() const override { return true; }

  virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
                       HitTestState* aState,
                       nsTArray<nsIFrame*> *aOutFrames) override {
    aOutFrames->AppendElement(mFrame);
  }
  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     gfxContext* aCtx) override;
  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                           bool* aSnap) const override;
  virtual nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) override;
  virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                         const nsDisplayItemGeometry* aGeometry,
                                         nsRegion *aInvalidRegion) const override;
  virtual bool CreateWebRenderCommands(mozilla::wr::DisplayListBuilder& aBuilder,
                                       mozilla::wr::IpcResourceUpdateQueue& aResources,
                                       const StackingContextHelper& aSc,
                                       mozilla::layers::WebRenderLayerManager* aManager,
                                       nsDisplayListBuilder* aDisplayListBuilder) override;
  NS_DISPLAY_DECL_NAME("ButtonBorderBackground", TYPE_BUTTON_BORDER_BACKGROUND)
private:
  nsButtonFrameRenderer* mBFR;
};

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

bool
nsDisplayButtonBorder::CreateWebRenderCommands(mozilla::wr::DisplayListBuilder& aBuilder,
                                               mozilla::wr::IpcResourceUpdateQueue& aResources,
                                               const StackingContextHelper& aSc,
                                               mozilla::layers::WebRenderLayerManager* aManager,
                                               nsDisplayListBuilder* aDisplayListBuilder)
{
  // This is really a combination of paint box shadow inner +
  // paint border.
  nsRect buttonRect = nsRect(ToReferenceFrame(), mFrame->GetSize());
  bool snap;
  nsRegion visible = GetBounds(aDisplayListBuilder, &snap);
  nsDisplayBoxShadowInner::CreateInsetBoxShadowWebRenderCommands(aBuilder,
                                                                 aSc,
                                                                 visible,
                                                                 mFrame,
                                                                 buttonRect);

  bool borderIsEmpty = false;
  Maybe<nsCSSBorderRenderer> br =
  nsCSSRendering::CreateBorderRenderer(mFrame->PresContext(),
                                       nullptr,
                                       mFrame,
                                       nsRect(),
                                       nsRect(ToReferenceFrame(), mFrame->GetSize()),
                                       mFrame->Style(),
                                       &borderIsEmpty,
                                       mFrame->GetSkipSides());
  if (!br) {
    return borderIsEmpty;
  }

  br->CreateWebRenderCommands(this, aBuilder, aResources, aSc);

  return true;
}

void
nsDisplayButtonBorder::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                                 const nsDisplayItemGeometry* aGeometry,
                                                 nsRegion *aInvalidRegion) const
{
  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
nsDisplayButtonBorder::Paint(nsDisplayListBuilder* aBuilder,
                             gfxContext* 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
  ImgDrawResult result =
    mBFR->PaintBorder(aBuilder, pc, *aCtx, GetPaintRect(), r);

  nsDisplayItemGenericImageGeometry::UpdateDrawResult(this, result);
}

nsRect
nsDisplayButtonBorder::GetBounds(nsDisplayListBuilder* aBuilder,
                                 bool* aSnap) const
{
  *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

  nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) override;
  void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                 const nsDisplayItemGeometry* aGeometry,
                                 nsRegion *aInvalidRegion) const override;
  virtual void Paint(nsDisplayListBuilder* aBuilder,
                     gfxContext* aCtx) override;
   virtual bool CreateWebRenderCommands(mozilla::wr::DisplayListBuilder& aBuilder,
                                        mozilla::wr::IpcResourceUpdateQueue& aResources,
                                        const StackingContextHelper& aSc,
                                        mozilla::layers::WebRenderLayerManager* aManager,
                                        nsDisplayListBuilder* aDisplayListBuilder) override;
  NS_DISPLAY_DECL_NAME("ButtonForeground", TYPE_BUTTON_FOREGROUND)
private:
  nsButtonFrameRenderer* mBFR;
};

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

void
nsDisplayButtonForeground::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
                                                     const nsDisplayItemGeometry* aGeometry,
                                                     nsRegion* aInvalidRegion) const
{
  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 nsDisplayButtonForeground::Paint(nsDisplayListBuilder* aBuilder,
                                      gfxContext* aCtx)
{
  nsPresContext *presContext = mFrame->PresContext();
  const nsStyleDisplay *disp = mFrame->StyleDisplay();
  if (!mFrame->IsThemed(disp) ||
      !presContext->GetTheme()->ThemeDrawsFocusForWidget(disp->mAppearance)) {
    nsRect r = nsRect(ToReferenceFrame(), mFrame->GetSize());

    // Draw the -moz-focus-inner border
    ImgDrawResult result =
      mBFR->PaintInnerFocusBorder(aBuilder, presContext, *aCtx, GetPaintRect(), r);

    nsDisplayItemGenericImageGeometry::UpdateDrawResult(this, result);
  }
}

bool
nsDisplayButtonForeground::CreateWebRenderCommands(mozilla::wr::DisplayListBuilder& aBuilder,
                                                   mozilla::wr::IpcResourceUpdateQueue& aResources,
                                                   const StackingContextHelper& aSc,
                                                   mozilla::layers::WebRenderLayerManager* aManager,
                                                   nsDisplayListBuilder* aDisplayListBuilder)
{
  Maybe<nsCSSBorderRenderer> br;
  bool borderIsEmpty = false;
  nsPresContext *presContext = mFrame->PresContext();
  const nsStyleDisplay *disp = mFrame->StyleDisplay();
  if (!mFrame->IsThemed(disp) ||
      !presContext->GetTheme()->ThemeDrawsFocusForWidget(disp->mAppearance)) {
    nsRect r = nsRect(ToReferenceFrame(), mFrame->GetSize());
    br = mBFR->CreateInnerFocusBorderRenderer(aDisplayListBuilder, presContext, nullptr,
                                              GetPaintRect(), r, &borderIsEmpty);
  }

  if (!br) {
    return borderIsEmpty;
  }

  br->CreateWebRenderCommands(this, aBuilder, aResources, aSc);
  return true;
}

nsresult
nsButtonFrameRenderer::DisplayButton(nsDisplayListBuilder* aBuilder,
                                     nsDisplayList* aBackground,
                                     nsDisplayList* aForeground)
{
  if (mFrame->StyleEffects()->mBoxShadow) {
    aBackground->AppendToTop(
      MakeDisplayItem<nsDisplayButtonBoxShadowOuter>(aBuilder, this));
  }

  nsRect buttonRect = mFrame->GetRectRelativeToSelf();

  nsDisplayBackgroundImage::AppendBackgroundItemsToTop(
    aBuilder, mFrame, buttonRect, aBackground);

  aBackground->AppendToTop(
    MakeDisplayItem<nsDisplayButtonBorder>(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 (mInnerFocusStyle && mInnerFocusStyle->StyleBorder()->HasBorder()) {
    aForeground->AppendToTop(
      MakeDisplayItem<nsDisplayButtonForeground>(aBuilder, this));
  }
  return NS_OK;
}

void
nsButtonFrameRenderer::GetButtonInnerFocusRect(const nsRect& aRect, nsRect& aResult)
{
  aResult = aRect;
  aResult.Deflate(mFrame->GetUsedBorderAndPadding());

  if (mInnerFocusStyle) {
    nsMargin innerFocusPadding(0,0,0,0);
    mInnerFocusStyle->StylePadding()->GetPadding(innerFocusPadding);

    nsMargin framePadding = mFrame->GetUsedPadding();

    innerFocusPadding.top = std::min(innerFocusPadding.top,
                                     framePadding.top);
    innerFocusPadding.right = std::min(innerFocusPadding.right,
                                       framePadding.right);
    innerFocusPadding.bottom = std::min(innerFocusPadding.bottom,
                                        framePadding.bottom);
    innerFocusPadding.left = std::min(innerFocusPadding.left,
                                      framePadding.left);

    aResult.Inflate(innerFocusPadding);
  }
}

ImgDrawResult
nsButtonFrameRenderer::PaintInnerFocusBorder(
  nsDisplayListBuilder* aBuilder,
  nsPresContext* aPresContext,
  gfxContext& aRenderingContext,
  const nsRect& aDirtyRect,
  const nsRect& aRect)
{
  // we draw the -moz-focus-inner border just inside the button's
  // normal border and padding, to match Windows themes.

  nsRect rect;

  PaintBorderFlags flags = aBuilder->ShouldSyncDecodeImages()
                         ? PaintBorderFlags::SYNC_DECODE_IMAGES
                         : PaintBorderFlags();

  ImgDrawResult result = ImgDrawResult::SUCCESS;

  if (mInnerFocusStyle) {
    GetButtonInnerFocusRect(aRect, rect);

    result &=
      nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                  aDirtyRect, rect, mInnerFocusStyle, flags);
  }

  return result;
}

Maybe<nsCSSBorderRenderer>
nsButtonFrameRenderer::CreateInnerFocusBorderRenderer(
  nsDisplayListBuilder* aBuilder,
  nsPresContext* aPresContext,
  gfxContext* aRenderingContext,
  const nsRect& aDirtyRect,
  const nsRect& aRect,
  bool* aBorderIsEmpty)
{
  if (mInnerFocusStyle) {
    nsRect rect;
    GetButtonInnerFocusRect(aRect, rect);

    gfx::DrawTarget* dt = aRenderingContext ? aRenderingContext->GetDrawTarget() : nullptr;
    return nsCSSRendering::CreateBorderRenderer(aPresContext,
                                                dt,
                                                mFrame,
                                                aDirtyRect,
                                                rect,
                                                mInnerFocusStyle,
                                                aBorderIsEmpty);
  }

  return Nothing();
}

ImgDrawResult
nsButtonFrameRenderer::PaintBorder(
  nsDisplayListBuilder* aBuilder,
  nsPresContext* aPresContext,
  gfxContext& aRenderingContext,
  const nsRect& aDirtyRect,
  const nsRect& aRect)
{
  // get the button rect this is inside the focus and outline rects
  nsRect buttonRect = aRect;
  ComputedStyle* context = mFrame->Style();

  PaintBorderFlags borderFlags = aBuilder->ShouldSyncDecodeImages()
                               ? PaintBorderFlags::SYNC_DECODE_IMAGES
                               : PaintBorderFlags();

  nsCSSRendering::PaintBoxShadowInner(aPresContext, aRenderingContext,
                                      mFrame, buttonRect);

  ImgDrawResult result =
    nsCSSRendering::PaintBorder(aPresContext, aRenderingContext, mFrame,
                                aDirtyRect, buttonRect, context, borderFlags);

  return result;
}

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

  // get styles assigned to -moz-focus-inner (ie dotted border on Windows)
  mInnerFocusStyle =
    styleSet->ProbePseudoElementStyle(mFrame->GetContent()->AsElement(),
                                      CSSPseudoElementType::mozFocusInner,
                                      context);
}

ComputedStyle*
nsButtonFrameRenderer::GetComputedStyle(int32_t aIndex) const
{
  switch (aIndex) {
  case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
    return mInnerFocusStyle;
  default:
    return nullptr;
  }
}

void
nsButtonFrameRenderer::SetComputedStyle(int32_t aIndex, ComputedStyle* aComputedStyle)
{
  switch (aIndex) {
  case NS_BUTTON_RENDERER_FOCUS_INNER_CONTEXT_INDEX:
    mInnerFocusStyle = aComputedStyle;
    break;
  }
}