core/paint/InlineFlowBoxPainter.cpp

// Copyright 2014 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 "config.h"
#include "core/paint/InlineFlowBoxPainter.h"

#include "core/paint/BoxPainter.h"
#include "core/rendering/InlineFlowBox.h"
#include "core/rendering/PaintInfo.h"
#include "core/rendering/RenderBlock.h"
#include "core/rendering/RenderInline.h"
#include "core/rendering/RenderLayer.h"
#include "core/rendering/RenderView.h"
#include "platform/graphics/GraphicsContextStateSaver.h"

namespace blink {

void InlineFlowBoxPainter::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset, const LayoutUnit lineTop, const LayoutUnit lineBottom)
{
    LayoutRect overflowRect(m_inlineFlowBox.visualOverflowRect(lineTop, lineBottom));
    m_inlineFlowBox.flipForWritingMode(overflowRect);
    overflowRect.moveBy(paintOffset);

    if (!paintInfo.rect.intersects(pixelSnappedIntRect(overflowRect)))
        return;

    if (paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) {
        // Add ourselves to the paint info struct's list of inlines that need to paint their
        // outlines.
        if (m_inlineFlowBox.renderer().style()->visibility() == VISIBLE && m_inlineFlowBox.renderer().style()->hasOutline() && !m_inlineFlowBox.isRootInlineBox()) {
            RenderInline& inlineFlow = toRenderInline(m_inlineFlowBox.renderer());

            RenderBlock* cb = 0;
            bool containingBlockPaintsContinuationOutline = inlineFlow.continuation() || inlineFlow.isInlineElementContinuation();
            if (containingBlockPaintsContinuationOutline) {
                // FIXME: See https://bugs.webkit.org/show_bug.cgi?id=54690. We currently don't reconnect inline continuations
                // after a child removal. As a result, those merged inlines do not get seperated and hence not get enclosed by
                // anonymous blocks. In this case, it is better to bail out and paint it ourself.
                RenderBlock* enclosingAnonymousBlock = m_inlineFlowBox.renderer().containingBlock();
                if (!enclosingAnonymousBlock->isAnonymousBlock()) {
                    containingBlockPaintsContinuationOutline = false;
                } else {
                    cb = enclosingAnonymousBlock->containingBlock();
                    for (RenderBoxModelObject* box = m_inlineFlowBox.boxModelObject(); box != cb; box = box->parent()->enclosingBoxModelObject()) {
                        if (box->hasSelfPaintingLayer()) {
                            containingBlockPaintsContinuationOutline = false;
                            break;
                        }
                    }
                }
            }

            if (containingBlockPaintsContinuationOutline) {
                // Add ourselves to the containing block of the entire continuation so that it can
                // paint us atomically.
                cb->addContinuationWithOutline(toRenderInline(m_inlineFlowBox.renderer().node()->renderer()));
            } else if (!inlineFlow.isInlineElementContinuation()) {
                paintInfo.outlineObjects()->add(&inlineFlow);
            }
        }
    } else if (paintInfo.phase == PaintPhaseMask) {
        paintMask(paintInfo, paintOffset);
        return;
    } else if (paintInfo.phase == PaintPhaseForeground) {
        // Paint our background, border and box-shadow.
        paintBoxDecorationBackground(paintInfo, paintOffset);
    }

    // Paint our children.
    if (paintInfo.phase != PaintPhaseSelfOutline) {
        PaintInfo childInfo(paintInfo);
        childInfo.phase = paintInfo.phase == PaintPhaseChildOutlines ? PaintPhaseOutline : paintInfo.phase;

        if (childInfo.paintingRoot && childInfo.paintingRoot->isDescendantOf(&m_inlineFlowBox.renderer()))
            childInfo.paintingRoot = 0;
        else
            childInfo.updatePaintingRootForChildren(&m_inlineFlowBox.renderer());

        for (InlineBox* curr = m_inlineFlowBox.firstChild(); curr; curr = curr->nextOnLine()) {
            if (curr->renderer().isText() || !curr->boxModelObject()->hasSelfPaintingLayer())
                curr->paint(childInfo, paintOffset, lineTop, lineBottom);
        }
    }
}

void InlineFlowBoxPainter::paintFillLayers(const PaintInfo& paintInfo, const Color& c, const FillLayer& fillLayer, const LayoutRect& rect, CompositeOperator op)
{
    // FIXME: This should be a for loop or similar. It's a little non-trivial to do so, however, since the layers need to be
    // painted in reverse order.
    if (fillLayer.next())
        paintFillLayers(paintInfo, c, *fillLayer.next(), rect, op);
    paintFillLayer(paintInfo, c, fillLayer, rect, op);
}

void InlineFlowBoxPainter::paintFillLayer(const PaintInfo& paintInfo, const Color& c, const FillLayer& fillLayer, const LayoutRect& rect, CompositeOperator op)
{
    StyleImage* img = fillLayer.image();
    bool hasFillImage = img && img->canRender(m_inlineFlowBox.renderer(), m_inlineFlowBox.renderer().style()->effectiveZoom());
    if ((!hasFillImage && !m_inlineFlowBox.renderer().style()->hasBorderRadius()) || (!m_inlineFlowBox.prevLineBox() && !m_inlineFlowBox.nextLineBox()) || !m_inlineFlowBox.parent()) {
        BoxPainter::paintFillLayerExtended(*m_inlineFlowBox.boxModelObject(), paintInfo, c, fillLayer, rect, BackgroundBleedNone, &m_inlineFlowBox, rect.size(), op);
    } else if (m_inlineFlowBox.renderer().style()->boxDecorationBreak() == DCLONE) {
        GraphicsContextStateSaver stateSaver(*paintInfo.context);
        paintInfo.context->clip(LayoutRect(rect.x(), rect.y(), m_inlineFlowBox.width(), m_inlineFlowBox.height()));
        BoxPainter::paintFillLayerExtended(*m_inlineFlowBox.boxModelObject(), paintInfo, c, fillLayer, rect, BackgroundBleedNone, &m_inlineFlowBox, rect.size(), op);
    } else {
        // We have a fill image that spans multiple lines.
        // We need to adjust tx and ty by the width of all previous lines.
        // Think of background painting on inlines as though you had one long line, a single continuous
        // strip. Even though that strip has been broken up across multiple lines, you still paint it
        // as though you had one single line. This means each line has to pick up the background where
        // the previous line left off.
        LayoutUnit logicalOffsetOnLine = 0;
        LayoutUnit totalLogicalWidth;
        if (m_inlineFlowBox.renderer().style()->direction() == LTR) {
            for (InlineFlowBox* curr = m_inlineFlowBox.prevLineBox(); curr; curr = curr->prevLineBox())
                logicalOffsetOnLine += curr->logicalWidth();
            totalLogicalWidth = logicalOffsetOnLine;
            for (InlineFlowBox* curr = &m_inlineFlowBox; curr; curr = curr->nextLineBox())
                totalLogicalWidth += curr->logicalWidth();
        } else {
            for (InlineFlowBox* curr = m_inlineFlowBox.nextLineBox(); curr; curr = curr->nextLineBox())
                logicalOffsetOnLine += curr->logicalWidth();
            totalLogicalWidth = logicalOffsetOnLine;
            for (InlineFlowBox* curr = &m_inlineFlowBox; curr; curr = curr->prevLineBox())
                totalLogicalWidth += curr->logicalWidth();
        }
        LayoutUnit stripX = rect.x() - (m_inlineFlowBox.isHorizontal() ? logicalOffsetOnLine : LayoutUnit());
        LayoutUnit stripY = rect.y() - (m_inlineFlowBox.isHorizontal() ? LayoutUnit() : logicalOffsetOnLine);
        LayoutUnit stripWidth = m_inlineFlowBox.isHorizontal() ? totalLogicalWidth : static_cast<LayoutUnit>(m_inlineFlowBox.width());
        LayoutUnit stripHeight = m_inlineFlowBox.isHorizontal() ? static_cast<LayoutUnit>(m_inlineFlowBox.height()) : totalLogicalWidth;

        GraphicsContextStateSaver stateSaver(*paintInfo.context);
        paintInfo.context->clip(LayoutRect(rect.x(), rect.y(), m_inlineFlowBox.width(), m_inlineFlowBox.height()));
        BoxPainter::paintFillLayerExtended(*m_inlineFlowBox.boxModelObject(), paintInfo, c, fillLayer, LayoutRect(stripX, stripY, stripWidth, stripHeight), BackgroundBleedNone, &m_inlineFlowBox, rect.size(), op);
    }
}

void InlineFlowBoxPainter::paintBoxShadow(const PaintInfo& info, RenderStyle* s, ShadowStyle shadowStyle, const LayoutRect& paintRect)
{
    if ((!m_inlineFlowBox.prevLineBox() && !m_inlineFlowBox.nextLineBox()) || !m_inlineFlowBox.parent()) {
        BoxPainter::paintBoxShadow(info, paintRect, s, shadowStyle);
    } else {
        // FIXME: We can do better here in the multi-line case. We want to push a clip so that the shadow doesn't
        // protrude incorrectly at the edges, and we want to possibly include shadows cast from the previous/following lines
        BoxPainter::paintBoxShadow(info, paintRect, s, shadowStyle, m_inlineFlowBox.includeLogicalLeftEdge(), m_inlineFlowBox.includeLogicalRightEdge());
    }
}


static LayoutRect clipRectForNinePieceImageStrip(InlineFlowBox* box, const NinePieceImage& image, const LayoutRect& paintRect)
{
    LayoutRect clipRect(paintRect);
    RenderStyle* style = box->renderer().style();
    LayoutBoxExtent outsets = style->imageOutsets(image);
    if (box->isHorizontal()) {
        clipRect.setY(paintRect.y() - outsets.top());
        clipRect.setHeight(paintRect.height() + outsets.top() + outsets.bottom());
        if (box->includeLogicalLeftEdge()) {
            clipRect.setX(paintRect.x() - outsets.left());
            clipRect.setWidth(paintRect.width() + outsets.left());
        }
        if (box->includeLogicalRightEdge())
            clipRect.setWidth(clipRect.width() + outsets.right());
    } else {
        clipRect.setX(paintRect.x() - outsets.left());
        clipRect.setWidth(paintRect.width() + outsets.left() + outsets.right());
        if (box->includeLogicalLeftEdge()) {
            clipRect.setY(paintRect.y() - outsets.top());
            clipRect.setHeight(paintRect.height() + outsets.top());
        }
        if (box->includeLogicalRightEdge())
            clipRect.setHeight(clipRect.height() + outsets.bottom());
    }
    return clipRect;
}

void InlineFlowBoxPainter::paintBoxDecorationBackground(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    ASSERT(paintInfo.phase == PaintPhaseForeground);
    if (!paintInfo.shouldPaintWithinRoot(&m_inlineFlowBox.renderer()) || m_inlineFlowBox.renderer().style()->visibility() != VISIBLE)
        return;

    // You can use p::first-line to specify a background. If so, the root line boxes for
    // a line may actually have to paint a background.
    RenderStyle* styleToUse = m_inlineFlowBox.renderer().style(m_inlineFlowBox.isFirstLineStyle());
    bool shouldPaintBoxDecorationBackground;
    if (m_inlineFlowBox.parent())
        shouldPaintBoxDecorationBackground = m_inlineFlowBox.renderer().hasBoxDecorationBackground();
    else
        shouldPaintBoxDecorationBackground = m_inlineFlowBox.isFirstLineStyle() && styleToUse != m_inlineFlowBox.renderer().style();

    if (!shouldPaintBoxDecorationBackground)
        return;

    LayoutRect frameRect = roundedFrameRectClampedToLineTopAndBottomIfNeeded();

    // Move x/y to our coordinates.
    LayoutRect localRect(frameRect);
    m_inlineFlowBox.flipForWritingMode(localRect);
    LayoutPoint adjustedPaintOffset = paintOffset + localRect.location();

    LayoutRect paintRect = LayoutRect(adjustedPaintOffset, frameRect.size());

    // Shadow comes first and is behind the background and border.
    if (!m_inlineFlowBox.boxModelObject()->boxShadowShouldBeAppliedToBackground(BackgroundBleedNone, &m_inlineFlowBox))
        paintBoxShadow(paintInfo, styleToUse, Normal, paintRect);

    Color backgroundColor = m_inlineFlowBox.renderer().resolveColor(styleToUse, CSSPropertyBackgroundColor);
    paintFillLayers(paintInfo, backgroundColor, styleToUse->backgroundLayers(), paintRect);
    paintBoxShadow(paintInfo, styleToUse, Inset, paintRect);

    // :first-line cannot be used to put borders on a line. Always paint borders with our
    // non-first-line style.
    if (m_inlineFlowBox.parent() && m_inlineFlowBox.renderer().style()->hasBorder()) {
        const NinePieceImage& borderImage = m_inlineFlowBox.renderer().style()->borderImage();
        StyleImage* borderImageSource = borderImage.image();
        bool hasBorderImage = borderImageSource && borderImageSource->canRender(m_inlineFlowBox.renderer(), styleToUse->effectiveZoom());
        if (hasBorderImage && !borderImageSource->isLoaded())
            return; // Don't paint anything while we wait for the image to load.

        // The simple case is where we either have no border image or we are the only box for this object.
        // In those cases only a single call to draw is required.
        if (!hasBorderImage || (!m_inlineFlowBox.prevLineBox() && !m_inlineFlowBox.nextLineBox())) {
            BoxPainter::paintBorder(*m_inlineFlowBox.boxModelObject(), paintInfo, paintRect, m_inlineFlowBox.renderer().style(m_inlineFlowBox.isFirstLineStyle()), BackgroundBleedNone, m_inlineFlowBox.includeLogicalLeftEdge(), m_inlineFlowBox.includeLogicalRightEdge());
        } else {
            // We have a border image that spans multiple lines.
            // We need to adjust tx and ty by the width of all previous lines.
            // Think of border image painting on inlines as though you had one long line, a single continuous
            // strip. Even though that strip has been broken up across multiple lines, you still paint it
            // as though you had one single line. This means each line has to pick up the image where
            // the previous line left off.
            // FIXME: What the heck do we do with RTL here? The math we're using is obviously not right,
            // but it isn't even clear how this should work at all.
            LayoutUnit logicalOffsetOnLine = 0;
            for (InlineFlowBox* curr = m_inlineFlowBox.prevLineBox(); curr; curr = curr->prevLineBox())
                logicalOffsetOnLine += curr->logicalWidth();
            LayoutUnit totalLogicalWidth = logicalOffsetOnLine;
            for (InlineFlowBox* curr = &m_inlineFlowBox; curr; curr = curr->nextLineBox())
                totalLogicalWidth += curr->logicalWidth();
            LayoutUnit stripX = adjustedPaintOffset.x() - (m_inlineFlowBox.isHorizontal() ? logicalOffsetOnLine : LayoutUnit());
            LayoutUnit stripY = adjustedPaintOffset.y() - (m_inlineFlowBox.isHorizontal() ? LayoutUnit() : logicalOffsetOnLine);
            LayoutUnit stripWidth = m_inlineFlowBox.isHorizontal() ? totalLogicalWidth : frameRect.width();
            LayoutUnit stripHeight = m_inlineFlowBox.isHorizontal() ? frameRect.height() : totalLogicalWidth;

            LayoutRect clipRect = clipRectForNinePieceImageStrip(&m_inlineFlowBox, borderImage, paintRect);
            GraphicsContextStateSaver stateSaver(*paintInfo.context);
            paintInfo.context->clip(clipRect);
            BoxPainter::paintBorder(*m_inlineFlowBox.boxModelObject(), paintInfo, LayoutRect(stripX, stripY, stripWidth, stripHeight), m_inlineFlowBox.renderer().style(m_inlineFlowBox.isFirstLineStyle()));
        }
    }
}

void InlineFlowBoxPainter::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (!paintInfo.shouldPaintWithinRoot(&m_inlineFlowBox.renderer()) || m_inlineFlowBox.renderer().style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
        return;

    LayoutRect frameRect = roundedFrameRectClampedToLineTopAndBottomIfNeeded();

    // Move x/y to our coordinates.
    LayoutRect localRect(frameRect);
    m_inlineFlowBox.flipForWritingMode(localRect);
    LayoutPoint adjustedPaintOffset = paintOffset + localRect.location();

    const NinePieceImage& maskNinePieceImage = m_inlineFlowBox.renderer().style()->maskBoxImage();
    StyleImage* maskBoxImage = m_inlineFlowBox.renderer().style()->maskBoxImage().image();

    // Figure out if we need to push a transparency layer to render our mask.
    bool pushTransparencyLayer = false;
    bool compositedMask = m_inlineFlowBox.renderer().hasLayer() && m_inlineFlowBox.boxModelObject()->layer()->hasCompositedMask();
    bool flattenCompositingLayers = m_inlineFlowBox.renderer().view()->frameView() && m_inlineFlowBox.renderer().view()->frameView()->paintBehavior() & PaintBehaviorFlattenCompositingLayers;
    CompositeOperator compositeOp = CompositeSourceOver;
    if (!compositedMask || flattenCompositingLayers) {
        if ((maskBoxImage && m_inlineFlowBox.renderer().style()->maskLayers().hasImage()) || m_inlineFlowBox.renderer().style()->maskLayers().next())
            pushTransparencyLayer = true;

        compositeOp = CompositeDestinationIn;
        if (pushTransparencyLayer) {
            paintInfo.context->setCompositeOperation(CompositeDestinationIn);
            paintInfo.context->beginTransparencyLayer(1.0f);
            compositeOp = CompositeSourceOver;
        }
    }

    LayoutRect paintRect = LayoutRect(adjustedPaintOffset, frameRect.size());
    paintFillLayers(paintInfo, Color::transparent, m_inlineFlowBox.renderer().style()->maskLayers(), paintRect, compositeOp);

    bool hasBoxImage = maskBoxImage && maskBoxImage->canRender(m_inlineFlowBox.renderer(), m_inlineFlowBox.renderer().style()->effectiveZoom());
    if (!hasBoxImage || !maskBoxImage->isLoaded()) {
        if (pushTransparencyLayer)
            paintInfo.context->endLayer();
        return; // Don't paint anything while we wait for the image to load.
    }

    // The simple case is where we are the only box for this object. In those
    // cases only a single call to draw is required.
    if (!m_inlineFlowBox.prevLineBox() && !m_inlineFlowBox.nextLineBox()) {
        BoxPainter::paintNinePieceImage(*m_inlineFlowBox.boxModelObject(), paintInfo.context, LayoutRect(adjustedPaintOffset, frameRect.size()), m_inlineFlowBox.renderer().style(), maskNinePieceImage, compositeOp);
    } else {
        // We have a mask image that spans multiple lines.
        // We need to adjust _tx and _ty by the width of all previous lines.
        LayoutUnit logicalOffsetOnLine = 0;
        for (InlineFlowBox* curr = m_inlineFlowBox.prevLineBox(); curr; curr = curr->prevLineBox())
            logicalOffsetOnLine += curr->logicalWidth();
        LayoutUnit totalLogicalWidth = logicalOffsetOnLine;
        for (InlineFlowBox* curr = &m_inlineFlowBox; curr; curr = curr->nextLineBox())
            totalLogicalWidth += curr->logicalWidth();
        LayoutUnit stripX = adjustedPaintOffset.x() - (m_inlineFlowBox.isHorizontal() ? logicalOffsetOnLine : LayoutUnit());
        LayoutUnit stripY = adjustedPaintOffset.y() - (m_inlineFlowBox.isHorizontal() ? LayoutUnit() : logicalOffsetOnLine);
        LayoutUnit stripWidth = m_inlineFlowBox.isHorizontal() ? totalLogicalWidth : frameRect.width();
        LayoutUnit stripHeight = m_inlineFlowBox.isHorizontal() ? frameRect.height() : totalLogicalWidth;

        LayoutRect clipRect = clipRectForNinePieceImageStrip(&m_inlineFlowBox, maskNinePieceImage, paintRect);
        GraphicsContextStateSaver stateSaver(*paintInfo.context);
        paintInfo.context->clip(clipRect);
        BoxPainter::paintNinePieceImage(*m_inlineFlowBox.boxModelObject(), paintInfo.context, LayoutRect(stripX, stripY, stripWidth, stripHeight), m_inlineFlowBox.renderer().style(), maskNinePieceImage, compositeOp);
    }

    if (pushTransparencyLayer)
        paintInfo.context->endLayer();
}

LayoutRect InlineFlowBoxPainter::roundedFrameRectClampedToLineTopAndBottomIfNeeded() const
{
    // Pixel snap rect painting.
    LayoutRect rect = m_inlineFlowBox.roundedFrameRect();

    bool noQuirksMode = m_inlineFlowBox.renderer().document().inNoQuirksMode();
    if (!noQuirksMode && !m_inlineFlowBox.hasTextChildren() && !(m_inlineFlowBox.descendantsHaveSameLineHeightAndBaseline() && m_inlineFlowBox.hasTextDescendants())) {
        const RootInlineBox& rootBox = m_inlineFlowBox.root();
        LayoutUnit logicalTop = m_inlineFlowBox.isHorizontal() ? rect.y() : rect.x();
        LayoutUnit logicalHeight = m_inlineFlowBox.isHorizontal() ? rect.height() : rect.width();
        LayoutUnit bottom = std::min(rootBox.lineBottom(), logicalTop + logicalHeight);
        logicalTop = std::max(rootBox.lineTop(), logicalTop);
        logicalHeight = bottom - logicalTop;
        if (m_inlineFlowBox.isHorizontal()) {
            rect.setY(logicalTop);
            rect.setHeight(logicalHeight);
        } else {
            rect.setX(logicalTop);
            rect.setWidth(logicalHeight);
        }
    }
    return rect;
}

} // namespace blink