[LayoutNG] Paint inlines from the fragment tree

third_party/WebKit/Source/core/paint/NGBoxFragmentPainter.cpp

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/paint/NGBoxFragmentPainter.h"
+
+#include "core/layout/BackgroundBleedAvoidance.h"
+#include "core/layout/ng/inline/ng_physical_line_box_fragment.h"
+#include "core/layout/ng/inline/ng_physical_text_fragment.h"
+#include "core/layout/ng/ng_physical_box_fragment.h"
+#include "core/paint/BoxBorderPainter.h"
+#include "core/paint/BoxDecorationData.h"
+#include "core/paint/NGTextFragmentPainter.h"
+#include "core/paint/PaintInfo.h"
+#include "core/paint/PaintLayer.h"
+#include "core/paint/RoundedInnerRectClipper.h"
+#include "core/style/FillLayer.h"
+#include "platform/geometry/LayoutRectOutsets.h"
+#include "platform/graphics/GraphicsContextStateSaver.h"
+#include "platform/graphics/paint/DrawingRecorder.h"
+
+namespace blink {
+
+void NGBoxFragmentPainter::Paint(const PaintInfo& paint_info,
+                                 const LayoutPoint& paint_offset) {
+  PaintChildren(paint_info, paint_offset);
+}
+
+void NGBoxFragmentPainter::PaintChildren(const PaintInfo& paint_info,
+                                         const LayoutPoint& paint_offset) {
+  PaintInfo child_info(paint_info);
+  for (const auto& child : box_fragment_->Children()) {
+    if (child->Type() == NGPhysicalBoxFragment::kFragmentLineBox) {
+      const NGPhysicalLineBoxFragment* line_box_fragment =
+          ToNGPhysicalLineBoxFragment(child.Get());
+      PaintLineBox(line_box_fragment, child_info, paint_offset);
+    }
+  }
+}
+
+void NGBoxFragmentPainter::PaintLineBox(
+    const NGPhysicalLineBoxFragment* fragment,
+    const PaintInfo& paint_info,
+    const LayoutPoint& paint_offset) {
+  // TODO: Should this check if the line boxes intersects with the dirty rect
+  // like legacy layout or do we want to change the invalidation logic?
+
+  LayoutRect overflow_rect(box_fragment_->VisualOverflowRect());
+  overflow_rect.MoveBy(paint_offset);
+
+  // TODO(eae): Should this go here, in ::Paint or in the NGTextFragmentPainter
+  // class?
+  DrawingRecorder recorder(
+      paint_info.context, *fragment,
+      DisplayItem::PaintPhaseToDrawingType(paint_info.phase),
+      PixelSnappedIntRect(overflow_rect));
+
+  for (const auto& child : fragment->Children()) {
+    if (child->Type() == NGPhysicalBoxFragment::kFragmentLineBox) {
+      CHECK(false);
+    } else if (child->Type() == NGPhysicalBoxFragment::kFragmentText) {
+      const NGPhysicalTextFragment* text_fragment =
+          ToNGPhysicalTextFragment(child.Get());
+      NGTextFragmentPainter(text_fragment)
+          .Paint(GetDocument(), paint_info, paint_offset);
+    }
+  }
+}
+
+bool IsPaintingBackgroundOfPaintContainerIntoScrollingContentsLayer(
+    const NGPhysicalFragment* fragment,
+    const PaintInfo& paint_info) {
+  // TODO(eae): Implement. Will require changing the type of
+  // PaintInfo::paint_container_ or using the NGBoxFragment container object.
+  return false;
+}
+
+void NGBoxFragmentPainter::PaintBoxDecorationBackground(
+    const PaintInfo& paint_info,
+    const LayoutPoint& paint_offset) {
+  LayoutRect paint_rect;
+  if (IsPaintingBackgroundOfPaintContainerIntoScrollingContentsLayer(
+          box_fragment_, paint_info)) {
+    // For the case where we are painting the background into the scrolling
+    // contents layer of a composited scroller we need to include the entire
+    // overflow rect.
+
+    // The background painting code assumes that the borders are part of the
+    // paintRect so we expand the paintRect by the border size when painting the
+    // background into the scrolling contents layer.
+  } else {
+    // TODO(eae): We need better converters for ng geometry types. Long term we
+    // probably want to change the paint code to take NGPhysical* but that is a
+    // much bigger change.
+    NGPhysicalSize size = box_fragment_->Size();
+    paint_rect = LayoutRect(LayoutPoint(), LayoutSize(size.width, size.height));
+  }
+
+  paint_rect.MoveBy(paint_offset);
+  PaintBoxDecorationBackgroundWithRect(paint_info, paint_offset, paint_rect);
+}
+
+void NGBoxFragmentPainter::PaintBoxDecorationBackgroundWithRect(
+    const PaintInfo& paint_info,
+    const LayoutPoint& paint_offset,
+    const LayoutRect& paint_rect) {
+  bool painting_overflow_contents =
+      IsPaintingBackgroundOfPaintContainerIntoScrollingContentsLayer(
+          box_fragment_, paint_info);
+  const ComputedStyle& style = box_fragment_->Style();
+
+  // TODO(eae): Implement support for painting overflow contents.
+  const DisplayItemClient& display_item_client = *box_fragment_;
+  if (DrawingRecorder::UseCachedDrawingIfPossible(
+          paint_info.context, display_item_client,
+          DisplayItem::kBoxDecorationBackground))
+    return;
+
+  DrawingRecorder recorder(
+      paint_info.context, display_item_client,
+      DisplayItem::kBoxDecorationBackground,
+      FloatRect(BoundsForDrawingRecorder(paint_info, paint_offset)));
+  BoxDecorationData box_decoration_data(box_fragment_);
+  GraphicsContextStateSaver state_saver(paint_info.context, false);
+
+  if (!painting_overflow_contents) {
+    // FIXME: Should eventually give the theme control over whether the box
+    // shadow should paint, since controls could have custom shadows of their
+    // own.
+    PaintNormalBoxShadow(paint_info, paint_rect, style);
+
+    if (BleedAvoidanceIsClipping(box_decoration_data.bleed_avoidance)) {
+      state_saver.Save();
+      FloatRoundedRect border = style.GetRoundedBorderFor(paint_rect);
+      paint_info.context.ClipRoundedRect(border);
+
+      if (box_decoration_data.bleed_avoidance == kBackgroundBleedClipLayer)
+        paint_info.context.BeginLayer();
+    }
+  }
+
+  // TODO(layout-dev): Support theme painting.
+
+  // TODO(eae): Support SkipRootBackground painting.
+  bool should_paint_background = true;
+  if (should_paint_background) {
+    PaintBackground(paint_info, paint_rect,
+                    box_decoration_data.background_color,
+                    box_decoration_data.bleed_avoidance);
+  }
+
+  if (!painting_overflow_contents) {
+    PaintInsetBoxShadow(paint_info, paint_rect, style);
+
+    if (box_decoration_data.has_border_decoration) {
+      PaintBorder(box_fragment_, paint_info, paint_rect, style,
+                  box_decoration_data.bleed_avoidance);
+    }
+  }
+
+  if (box_decoration_data.bleed_avoidance == kBackgroundBleedClipLayer)
+    paint_info.context.EndLayer();
+}
+
+void NGBoxFragmentPainter::PaintBackground(
+    const PaintInfo& paint_info,
+    const LayoutRect& paint_rect,
+    const Color& background_color,
+    BackgroundBleedAvoidance bleed_avoidance) {
+  // if (layout_box_.IsDocumentElement())
+  //  return;
+  // if (layout_box_.BackgroundStolenForBeingBody())
+  //  return;
+  // if (layout_box_.BackgroundIsKnownToBeObscured())
+  //  return;
+  PaintFillLayers(paint_info, background_color,
+                  box_fragment_->Style().BackgroundLayers(), paint_rect,
+                  bleed_avoidance);
+}
+
+void NGBoxFragmentPainter::PaintFillLayers(
+    const PaintInfo& paint_info,
+    const Color& c,
+    const FillLayer& fill_layer,
+    const LayoutRect& rect,
+    BackgroundBleedAvoidance avoidance,
+    SkBlendMode op,
+    const NGPhysicalFragment* bg_fragment) {
+  FillLayerOcclusionOutputList reversed_paint_list;
+  bool should_draw_background_in_separate_buffer =
+      CalculateFillLayerOcclusionCulling(reversed_paint_list, fill_layer,
+                                         GetDocument(), box_fragment_->Style());
+
+  // TODO(trchen): We can optimize out isolation group if we have a
+  // non-transparent background color and the bottom layer encloses all other
+  // layers.
+
+  GraphicsContext& context = paint_info.context;
+
+  if (should_draw_background_in_separate_buffer)
+    context.BeginLayer();
+
+  for (auto it = reversed_paint_list.rbegin(); it != reversed_paint_list.rend();
+       ++it) {
+    PaintFillLayer(box_fragment_, paint_info, c, **it, rect, avoidance, 0,
+                   LayoutSize(), op, bg_fragment);
+  }
+
+  if (should_draw_background_in_separate_buffer)
+    context.EndLayer();
+}
+
+namespace {
+
+inline bool PaintFastBottomLayer(
+    const NGPhysicalBoxFragment* fragment,
+    const PaintInfo& paint_info,
+    const BoxPainterBase::FillLayerInfo& info,
+    const FillLayer& layer,
+    const LayoutRect& rect,
+    BackgroundBleedAvoidance bleed_avoidance,
+    bool has_line_box_sibling,
+    const LayoutSize& box_size,
+    SkBlendMode op,
+    const NGPhysicalFragment* background_fragment
+    /*Optional<BackgroundImageGeometry>& geometry*/) {
+  // Painting a background image from an ancestor onto a cell is a complex case.
+  // if (obj.IsTableCell() && bg_fragment &&
+  //    !bg_fragment->IsTableCell())
+  //  return false;
+  // Complex cases not handled on the fast path.
+  // if (!info.is_bottom_layer || !info.is_border_fill ||
+  //    info.is_clipped_with_local_scrolling)
+  //  return false;
+
+  // Transparent layer, nothing to paint.
+  if (!info.should_paint_color && !info.should_paint_image)
+    return true;
+
+  // When the layer has an image, figure out whether it is covered by a single
+  // tile.
+  FloatRect image_tile;
+  if (info.should_paint_image) {
+    // TODO(layout-dev): Add support for background images.
+    return false;
+  }
+
+  // At this point we're committed to the fast path: the destination (r)rect
+  // fits within a single tile, and we can paint it using direct draw(R)Rect()
+  // calls.
+  GraphicsContext& context = paint_info.context;
+  FloatRoundedRect border =
+      info.is_rounded_fill
+          ? BoxPainterBase::BackgroundRoundedRectAdjustedForBleedAvoidance(
+                fragment->Style(), rect, bleed_avoidance, has_line_box_sibling,
+                box_size, info.include_left_edge, info.include_right_edge)
+          : FloatRoundedRect(PixelSnappedIntRect(rect));
+
+  // Optional<RoundedInnerRectClipper> clipper;
+  // if (info.is_rounded_fill && !border.IsRenderable()) {
+  // When the rrect is not renderable, we resort to clipping.
+  // RoundedInnerRectClipper handles this case via discrete, corner-wise
+  // clipping.
+  // clipper.emplace(obj, paint_info, rect, border, kApplyToContext);
+  // border.SetRadii(FloatRoundedRect::Radii());
+  //}
+
+  // Paint the color if needed.
+  if (info.should_paint_color)
+    context.FillRoundedRect(border, info.color);
+
+  return true;
+}
+
+}  // anonymous namespace
+
+void NGBoxFragmentPainter::PaintFillLayer(
+    const NGPhysicalBoxFragment* fragment,
+    const PaintInfo& paint_info,
+    const Color& color,
+    const FillLayer& bg_layer,
+    const LayoutRect& rect,
+    BackgroundBleedAvoidance avoidance,
+    const NGPhysicalFragment* box,
+    const LayoutSize& box_size,
+    SkBlendMode op,
+    const NGPhysicalFragment* bg_fragment) {
+  GraphicsContext& context = paint_info.context;
+  const ComputedStyle& style = fragment->Style();
+  if (rect.IsEmpty())
+    return;
+
+  const BoxPainterBase::FillLayerInfo info(
+      fragment->GetLayoutObject()->GetDocument(), style,
+      fragment->HasOverflowClip(), color, bg_layer, avoidance,
+      box ? (box->BorderEdges() & NGPhysicalTextFragment::kLeftBorder) : true,
+      box ? (box->BorderEdges() & NGPhysicalTextFragment::kRightBorder) : true);
+
+  // Optional<BackgroundImageGeometry> geometry;
+  // bool has_line_box_sibling = box && (box->NextLineBox() ||
+  // box->PrevLineBox());
+  bool has_line_box_sibling = false;
+
+  // Fast path for drawing simple color backgrounds.
+  if (PaintFastBottomLayer(fragment, paint_info, info, bg_layer, rect,
+                           avoidance, has_line_box_sibling, box_size, op,
+                           bg_fragment)) {
+    return;
+  }
+
+  NGPixelSnappedPhysicalBoxStrut borders = fragment->BorderWidths();
+  NGPhysicalBoxStrut paddings;  // TODO(layout-dev): Implement
+
+  Optional<RoundedInnerRectClipper> clip_to_border;
+  if (info.is_rounded_fill) {
+    FloatRoundedRect border =
+        info.is_border_fill
+            ? BackgroundRoundedRectAdjustedForBleedAvoidance(
+                  style, rect, avoidance, has_line_box_sibling, box_size,
+                  info.include_left_edge, info.include_right_edge)
+            : GetBackgroundRoundedRect(style, rect, has_line_box_sibling,
+                                       box_size, info.include_left_edge,
+                                       info.include_right_edge);
+
+    // Clip to the padding or content boxes as necessary.
+    if (bg_layer.Clip() == kContentFillBox) {
+      // TODO(layout-dev): Do we need to include the padding here?
+      LayoutRectOutsets border_inset(
+          LayoutUnit(borders.top), LayoutUnit(borders.right),
+          LayoutUnit(borders.bottom), LayoutUnit(borders.left));
+      border = style.GetRoundedInnerBorderFor(
+          LayoutRect(border.Rect()), border_inset, info.include_left_edge,
+          info.include_right_edge);
+    } else if (bg_layer.Clip() == kPaddingFillBox) {
+      border = style.GetRoundedInnerBorderFor(LayoutRect(border.Rect()),
+                                              info.include_left_edge,
+                                              info.include_right_edge);
+    }
+
+    clip_to_border.emplace(*fragment, paint_info, rect, border,
+                           kApplyToContext);
+  }
+
+  GraphicsContextStateSaver clip_with_scrolling_state_saver(
+      context, info.is_clipped_with_local_scrolling);
+  LayoutRect scrolled_paint_rect = rect;
+  if (info.is_clipped_with_local_scrolling &&
+      !IsPaintingBackgroundOfPaintContainerIntoScrollingContentsLayer(
+          fragment, paint_info)) {
+    // Clip to the overflow area.
+    // TODO(chrishtr): this should be pixel-snapped.
+    // TODO(layout-dev): We don't know the location...
+    // context.Clip(FloatRect(this_box.OverflowClipRect(rect.Location())));
+
+    // Adjust the paint rect to reflect a scrolled content box with borders at
+    // the ends.
+    // TODO(layout_dev): Support scrolling
+    // IntSize offset = this_box.ScrolledContentOffset();
+    // scrolled_paint_rect.Move(-offset);
+    // scrolled_paint_rect.SetWidth(borders.left + this_box.ScrollWidth() +
+    // borders.right);  scrolled_paint_rect.SetHeight(this_box.BorderTop() +
+    //                              this_box.ScrollHeight() +
+    //                              this_box.BorderBottom());
+  }
+
+  GraphicsContextStateSaver background_clip_state_saver(context, false);
+  IntRect mask_rect;
+
+  switch (bg_layer.Clip()) {
+    case kPaddingFillBox:
+    case kContentFillBox: {
+      if (info.is_rounded_fill)
+        break;
+
+      // Clip to the padding or content boxes as necessary.
+      bool include_padding = bg_layer.Clip() == kContentFillBox;
+      LayoutRect clip_rect(
+          scrolled_paint_rect.X() + borders.left,
+          scrolled_paint_rect.Y() + borders.top,
+          scrolled_paint_rect.Width() - borders.left - borders.right,
+          scrolled_paint_rect.Height() - borders.top - borders.bottom);
+
+      if (include_padding) {
+        clip_rect.ContractEdges(paddings.top, paddings.right, paddings.bottom,
+                                paddings.left);
+      }
+
+      background_clip_state_saver.Save();
+      // TODO(chrishtr): this should be pixel-snapped.
+      context.Clip(FloatRect(clip_rect));
+
+      break;
+    }
+    case kTextFillBox: {
+      // First figure out how big the mask has to be. It should be no bigger
+      // than what we need to actually render, so we should intersect the dirty
+      // rect with the border box of the background.
+      mask_rect = PixelSnappedIntRect(rect);
+
+      // We draw the background into a separate layer, to be later masked with
+      // yet another layer holding the text content.
+      background_clip_state_saver.Save();
+      context.Clip(mask_rect);
+      context.BeginLayer();
+
+      break;
+    }
+    case kBorderFillBox:
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+
+  // Paint the color first underneath all images, culled if background image
+  // occludes it.
+  // TODO(trchen): In the !bgLayer.hasRepeatXY() case, we could improve the
+  // culling test by verifying whether the background image covers the entire
+  // painting area.
+  if (info.is_bottom_layer && info.color.Alpha() && info.should_paint_color) {
+    IntRect background_rect(PixelSnappedIntRect(scrolled_paint_rect));
+    context.FillRect(background_rect, info.color);
+  }
+
+  // No progressive loading of the background image.
+  if (info.should_paint_image) {
+    // TODO(layout-dev): Add support for image painting.
+    DCHECK(false);
+  }
+
+  if (bg_layer.Clip() == kTextFillBox) {
+    // Create the text mask layer.
+    context.BeginLayer(1, SkBlendMode::kDstIn);
+
+    // Now draw the text into the mask. We do this by painting using a special
+    // paint phase that signals to
+    // InlineTextBoxes that they should just add their contents to the clip.
+    PaintInfo info(context, mask_rect, kPaintPhaseTextClip,
+                   kGlobalPaintNormalPhase, 0);
+    // if (box) {
+    //  const RootInlineBox& root = box->Root();
+    //  box->Paint(info,
+    //             LayoutPoint(scrolled_paint_rect.X() - box->X(),
+    //                         scrolled_paint_rect.Y() - box->Y()),
+    //             root.LineTop(), root.LineBottom());
+    //} else {
+    //  // FIXME: this should only have an effect for the line box list within
+    //  // |obj|. Change this to create a LineBoxListPainter directly.
+    //  LayoutSize local_offset =
+    //      obj.IsBox() ? ToLayoutBox(&obj)->LocationOffset() : LayoutSize();
+    //  obj.Paint(info, scrolled_paint_rect.Location() - local_offset);
+    //}
+
+    context.EndLayer();
+    context.EndLayer();
+  }
+}
+
+LayoutRect NGBoxFragmentPainter::BoundsForDrawingRecorder(
+    const PaintInfo& paint_info,
+    const LayoutPoint& adjusted_paint_offset) {
+  LayoutRect bounds = box_fragment_->VisualOverflowRect();
+  bounds.MoveBy(adjusted_paint_offset);
+  return bounds;
+}
+
+void NGBoxFragmentPainter::PaintBorder(const NGPhysicalBoxFragment* fragment,
+                                       const PaintInfo& info,
+                                       const LayoutRect& rect,
+                                       const ComputedStyle& style,
+                                       BackgroundBleedAvoidance bleed_avoidance,
+                                       bool include_logical_left_edge,
+                                       bool include_logical_right_edge) {
+  // TODO(layout-dev): Add support for image border painting.
+  const BoxBorderPainter border_painter(rect, style, bleed_avoidance,
+                                        include_logical_left_edge,
+                                        include_logical_right_edge);
+  border_painter.PaintBorder(info, rect);
+}
+
+const Document& NGBoxFragmentPainter::GetDocument() const {
+  return box_fragment_->GetLayoutObject()->GetDocument();
+}
+
+}  // namespace blink