/*

 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)

 *           (C) 1999 Antti Koivisto (koivisto@kde.org)

 *           (C) 2000 Dirk Mueller (mueller@kde.org)

 *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)

 *           (C) 2006 Samuel Weinig (sam.weinig@gmail.com)

 * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010 Apple Inc. All rights reserved.

 * Copyright (C) 2010 Google Inc. All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#include "config.h"

#include "RenderImage.h"

#include "Frame.h"

#include "GraphicsContext.h"

#include "HTMLAreaElement.h"

#include "HTMLCollection.h"

#include "HTMLImageElement.h"

#include "HTMLInputElement.h"

#include "HTMLMapElement.h"

#include "HTMLNames.h"

#include "HitTestResult.h"

#include "Page.h"

#include "RenderLayer.h"

#include "RenderTheme.h"

#include "RenderView.h"

#include "SelectionController.h"

#include <wtf/CurrentTime.h>

#include <wtf/UnusedParam.h>

#if ENABLE(WML)

#include "WMLImageElement.h"

#include "WMLNames.h"

#endif

using namespace std;

namespace WebCore {

using namespace HTMLNames;

RenderImage::RenderImage(Node* node)

    : RenderReplaced(node, IntSize(0, 0))

    , m_cachedImage(0)

{

    updateAltText();

    view()->frameView()->setIsVisuallyNonEmpty();

}

RenderImage::~RenderImage()

{

    if (m_cachedImage)

        m_cachedImage->removeClient(this);

}

void RenderImage::setCachedImage(CachedImage* newImage)

{

    if (m_cachedImage == newImage)

        return;

    if (m_cachedImage)

        m_cachedImage->removeClient(this);

    m_cachedImage = newImage;

    if (m_cachedImage) {

        m_cachedImage->addClient(this);

        if (m_cachedImage->errorOccurred())

            imageChanged(m_cachedImage.get());

    }

}

// If we'll be displaying either alt text or an image, add some padding.

static const unsigned short paddingWidth = 4;

static const unsigned short paddingHeight = 4;

// Alt text is restricted to this maximum size, in pixels.  These are

// signed integers because they are compared with other signed values.

static const int maxAltTextWidth = 1024;

static const int maxAltTextHeight = 256;

// Sets the image height and width to fit the alt text.  Returns true if the

// image size changed.

bool RenderImage::setImageSizeForAltText(CachedImage* newImage /* = 0 */)

{

    int imageWidth = 0;

    int imageHeight = 0;

    // If we'll be displaying either text or an image, add a little padding.

    if (!m_altText.isEmpty() || newImage) {

        imageWidth = paddingWidth;

        imageHeight = paddingHeight;

    }

    if (newImage && newImage->image()) {

        // imageSize() returns 0 for the error image.  We need the true size of the

        // error image, so we have to get it by grabbing image() directly.

        imageWidth += newImage->image()->width() * style()->effectiveZoom();

        imageHeight += newImage->image()->height() * style()->effectiveZoom();

    }

    // we have an alt and the user meant it (its not a text we invented)

    if (!m_altText.isEmpty()) {

        const Font& font = style()->font();

        imageWidth = max(imageWidth, min(font.width(TextRun(m_altText.characters(), m_altText.length())), maxAltTextWidth));

        imageHeight = max(imageHeight, min(font.height(), maxAltTextHeight));

    }

    IntSize imageSize = IntSize(imageWidth, imageHeight);

    if (imageSize == intrinsicSize())

        return false;

    setIntrinsicSize(imageSize);

    return true;

}

void RenderImage::imageChanged(WrappedImagePtr newImage, const IntRect* rect)

{

    if (documentBeingDestroyed())

        return;

    if (hasBoxDecorations() || hasMask())

        RenderReplaced::imageChanged(newImage, rect);

    if (newImage != imagePtr() || !newImage)

        return;

    bool imageSizeChanged = false;

    // Set image dimensions, taking into account the size of the alt text.

    if (errorOccurred())

        imageSizeChanged = setImageSizeForAltText(m_cachedImage.get());

    bool shouldRepaint = true;

    // Image dimensions have been changed, see what needs to be done

    if (imageSize(style()->effectiveZoom()) != intrinsicSize() || imageSizeChanged) {

        if (!errorOccurred())

            setIntrinsicSize(imageSize(style()->effectiveZoom()));

        // In the case of generated image content using :before/:after, we might not be in the

        // render tree yet.  In that case, we don't need to worry about check for layout, since we'll get a

        // layout when we get added in to the render tree hierarchy later.

        if (containingBlock()) {

            // lets see if we need to relayout at all..

            int oldwidth = width();

            int oldheight = height();

            if (!prefWidthsDirty())

                setPrefWidthsDirty(true);

            calcWidth();

            calcHeight();

            if (imageSizeChanged || width() != oldwidth || height() != oldheight) {

                shouldRepaint = false;

                if (!selfNeedsLayout())

                    setNeedsLayout(true);

            }

            setWidth(oldwidth);

            setHeight(oldheight);

        }

    }

    if (shouldRepaint) {

        IntRect repaintRect;

        if (rect) {

            // The image changed rect is in source image coordinates (pre-zooming),

            // so map from the bounds of the image to the contentsBox.

            repaintRect = enclosingIntRect(mapRect(*rect, FloatRect(FloatPoint(), imageSize(1.0f)), contentBoxRect()));

            // Guard against too-large changed rects.

            repaintRect.intersect(contentBoxRect());

        } else

            repaintRect = contentBoxRect();

        repaintRectangle(repaintRect);

#if USE(ACCELERATED_COMPOSITING)

        if (hasLayer()) {

            // Tell any potential compositing layers that the image needs updating.

            layer()->rendererContentChanged();

        }

#endif

    }

}

void RenderImage::notifyFinished(CachedResource* newImage)

{

    if (documentBeingDestroyed())

        return;

#if USE(ACCELERATED_COMPOSITING)

    if ((newImage == m_cachedImage) && hasLayer()) {

        // tell any potential compositing layers

        // that the image is done and they can reference it directly.

        layer()->rendererContentChanged();

    }

#else

    UNUSED_PARAM(newImage);

#endif

}

void RenderImage::resetAnimation()

{

    if (m_cachedImage) {

        image()->resetAnimation();

        if (!needsLayout())

            repaint();

    }

}

void RenderImage::paintReplaced(PaintInfo& paintInfo, int tx, int ty)

{

    int cWidth = contentWidth();

    int cHeight = contentHeight();

    int leftBorder = borderLeft();

    int topBorder = borderTop();

    int leftPad = paddingLeft();

    int topPad = paddingTop();

    if (document()->printing() && !view()->printImages())

        return;

    GraphicsContext* context = paintInfo.context;

    if (!hasImage() || errorOccurred()) {

        if (paintInfo.phase == PaintPhaseSelection)

            return;

        if (cWidth > 2 && cHeight > 2) {

            // Draw an outline rect where the image should be.

            context->setStrokeStyle(SolidStroke);

            context->setStrokeColor(Color::lightGray, style()->colorSpace());

            context->setFillColor(Color::transparent, style()->colorSpace());

            context->drawRect(IntRect(tx + leftBorder + leftPad, ty + topBorder + topPad, cWidth, cHeight));

            bool errorPictureDrawn = false;

            int imageX = 0;

            int imageY = 0;

            // When calculating the usable dimensions, exclude the pixels of

            // the ouline rect so the error image/alt text doesn't draw on it.

            int usableWidth = cWidth - 2;

            int usableHeight = cHeight - 2;

            if (errorOccurred() && !image()->isNull() && (usableWidth >= image()->width()) && (usableHeight >= image()->height())) {

                // Center the error image, accounting for border and padding.

                int centerX = (usableWidth - image()->width()) / 2;

                if (centerX < 0)

                    centerX = 0;

                int centerY = (usableHeight - image()->height()) / 2;

                if (centerY < 0)

                    centerY = 0;

                imageX = leftBorder + leftPad + centerX + 1;

                imageY = topBorder + topPad + centerY + 1;

                context->drawImage(image(), style()->colorSpace(), IntPoint(tx + imageX, ty + imageY));

                errorPictureDrawn = true;

            }

            if (!m_altText.isEmpty()) {

                String text = document()->displayStringModifiedByEncoding(m_altText);

                context->setFillColor(style()->visitedDependentColor(CSSPropertyColor), style()->colorSpace());

                int ax = tx + leftBorder + leftPad;

                int ay = ty + topBorder + topPad;

                const Font& font = style()->font();

                int ascent = font.ascent();

                // Only draw the alt text if it'll fit within the content box,

                // and only if it fits above the error image.

                TextRun textRun(text.characters(), text.length());

                int textWidth = font.width(textRun);

                if (errorPictureDrawn) {

                    if (usableWidth >= textWidth && font.height() <= imageY)

                        context->drawText(style()->font(), textRun, IntPoint(ax, ay + ascent));

                } else if (usableWidth >= textWidth && cHeight >= font.height())

                    context->drawText(style()->font(), textRun, IntPoint(ax, ay + ascent));

            }

        }

    } else if (hasImage() && cWidth > 0 && cHeight > 0) {

        Image* img = image(cWidth, cHeight);

        if (!img || img->isNull())

            return;

#if PLATFORM(MAC)

        if (style()->highlight() != nullAtom && !paintInfo.context->paintingDisabled())

            paintCustomHighlight(tx - x(), ty - y(), style()->highlight(), true);

#endif

        IntSize contentSize(cWidth, cHeight);

        IntRect rect(IntPoint(tx + leftBorder + leftPad, ty + topBorder + topPad), contentSize);

        paintIntoRect(context, rect);

    }

}

void RenderImage::paint(PaintInfo& paintInfo, int tx, int ty)

{

    RenderReplaced::paint(paintInfo, tx, ty);

    if (paintInfo.phase == PaintPhaseOutline)

        paintFocusRings(paintInfo, style());

}

void RenderImage::paintFocusRings(PaintInfo& paintInfo, const RenderStyle* style)

{

    // Don't draw focus rings if printing.

    if (document()->printing() || !frame()->selection()->isFocusedAndActive())

        return;

    if (paintInfo.context->paintingDisabled() && !paintInfo.context->updatingControlTints())

        return;

    HTMLMapElement* mapElement = imageMap();

    if (!mapElement)

        return;

    Document* document = mapElement->document();

    if (!document)

        return;

    Node* focusedNode = document->focusedNode();

    if (!focusedNode)

        return;

    RefPtr<HTMLCollection> areas = mapElement->areas();

    unsigned numAreas = areas->length();

    // FIXME: Clip the paths to the image bounding box.

    for (unsigned k = 0; k < numAreas; ++k) {

        HTMLAreaElement* areaElement = static_cast<HTMLAreaElement*>(areas->item(k));

        if (focusedNode != areaElement)

            continue;

        Vector<Path> focusRingPaths;

        focusRingPaths.append(areaElement->getPath(this));

        paintInfo.context->drawFocusRing(focusRingPaths, style->outlineWidth(), style->outlineOffset(), style->visitedDependentColor(CSSPropertyOutlineColor));

        break;

    }

}

void RenderImage::paintIntoRect(GraphicsContext* context, const IntRect& rect)

{

    if (!hasImage() || errorOccurred() || rect.width() <= 0 || rect.height() <= 0)

        return;

    Image* img = image(rect.width(), rect.height());

    if (!img || img->isNull())

        return;

    HTMLImageElement* imageElt = (node() && node()->hasTagName(imgTag)) ? static_cast<HTMLImageElement*>(node()) : 0;

    CompositeOperator compositeOperator = imageElt ? imageElt->compositeOperator() : CompositeSourceOver;

    bool useLowQualityScaling = shouldPaintAtLowQuality(context, this->image(), rect.size());

    context->drawImage(image(rect.width(), rect.height()), style()->colorSpace(), rect, compositeOperator, useLowQualityScaling);

}

int RenderImage::minimumReplacedHeight() const

{

    return errorOccurred() ? intrinsicSize().height() : 0;

}

HTMLMapElement* RenderImage::imageMap() const

{

    HTMLImageElement* i = node() && node()->hasTagName(imgTag) ? static_cast<HTMLImageElement*>(node()) : 0;

    return i ? i->document()->getImageMap(i->fastGetAttribute(usemapAttr)) : 0;

}

bool RenderImage::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty, HitTestAction hitTestAction)

{

    HitTestResult tempResult(result.point(), result.padding());

    bool inside = RenderReplaced::nodeAtPoint(request, tempResult, x, y, tx, ty, hitTestAction);

    if (tempResult.innerNode() && node()) {

        if (HTMLMapElement* map = imageMap()) {

            IntRect contentBox = contentBoxRect();

            float zoom = style()->effectiveZoom();

            int mapX = lroundf((x - tx - this->x() - contentBox.x()) / zoom);

            int mapY = lroundf((y - ty - this->y() - contentBox.y()) / zoom);

            if (map->mapMouseEvent(mapX, mapY, contentBox.size(), tempResult))

                tempResult.setInnerNonSharedNode(node());

        }

    }

    if (!inside && result.isRectBasedTest())

        result.append(tempResult);

    if (inside)

        result = tempResult;

    return inside;

}

void RenderImage::updateAltText()

{

    if (!node())

        return;

    if (node()->hasTagName(inputTag))

        m_altText = static_cast<HTMLInputElement*>(node())->altText();

    else if (node()->hasTagName(imgTag))

        m_altText = static_cast<HTMLImageElement*>(node())->altText();

#if ENABLE(WML)

    else if (node()->hasTagName(WMLNames::imgTag))

        m_altText = static_cast<WMLImageElement*>(node())->altText();

#endif

}

bool RenderImage::isWidthSpecified() const

{

    switch (style()->width().type()) {

        case Fixed:

        case Percent:

            return true;

        case Auto:

        case Relative: // FIXME: Shouldn't this case return true?

        case Static:

        case Intrinsic:

        case MinIntrinsic:

            return false;

    }

    ASSERT(false);

    return false;

}

bool RenderImage::isHeightSpecified() const

{

    switch (style()->height().type()) {

        case Fixed:

        case Percent:

            return true;

        case Auto:

        case Relative: // FIXME: Shouldn't this case return true?

        case Static:

        case Intrinsic:

        case MinIntrinsic:

            return false;

    }

    ASSERT(false);

    return false;

}

int RenderImage::calcReplacedWidth(bool includeMaxWidth) const

{

    if (imageHasRelativeWidth())

        if (RenderObject* cb = isPositioned() ? container() : containingBlock()) {

            if (cb->isBox())

                setImageContainerSize(IntSize(toRenderBox(cb)->availableWidth(), toRenderBox(cb)->availableHeight()));

        }

    int width;

    if (isWidthSpecified())

        width = calcReplacedWidthUsing(style()->width());

    else if (usesImageContainerSize())

        width = imageSize(style()->effectiveZoom()).width();

    else if (imageHasRelativeWidth())

        width = 0; // If the image is relatively-sized, set the width to 0 until there is a set container size.

    else

        width = calcAspectRatioWidth();

    int minW = calcReplacedWidthUsing(style()->minWidth());

    int maxW = !includeMaxWidth || style()->maxWidth().isUndefined() ? width : calcReplacedWidthUsing(style()->maxWidth());

    return max(minW, min(width, maxW));

}

int RenderImage::calcReplacedHeight() const

{

    int height;

    if (isHeightSpecified())

        height = calcReplacedHeightUsing(style()->height());

    else if (usesImageContainerSize())

        height = imageSize(style()->effectiveZoom()).height();

    else if (imageHasRelativeHeight())

        height = 0; // If the image is relatively-sized, set the height to 0 until there is a set container size.

    else

        height = calcAspectRatioHeight();

    int minH = calcReplacedHeightUsing(style()->minHeight());

    int maxH = style()->maxHeight().isUndefined() ? height : calcReplacedHeightUsing(style()->maxHeight());

    return max(minH, min(height, maxH));

}

int RenderImage::calcAspectRatioWidth() const

{

    IntSize size = intrinsicSize();

    if (!size.height())

        return 0;

    if (!hasImage() || errorOccurred())

        return size.width(); // Don't bother scaling.

    return RenderReplaced::calcReplacedHeight() * size.width() / size.height();

}

int RenderImage::calcAspectRatioHeight() const

{

    IntSize size = intrinsicSize();

    if (!size.width())

        return 0;

    if (!hasImage() || errorOccurred())

        return size.height(); // Don't bother scaling.

    return RenderReplaced::calcReplacedWidth() * size.height() / size.width();

}

void RenderImage::calcPrefWidths()

{

    ASSERT(prefWidthsDirty());

    int borderAndPadding = borderAndPaddingWidth();

    m_maxPrefWidth = calcReplacedWidth(false) + borderAndPadding;

    if (style()->maxWidth().isFixed() && style()->maxWidth().value() != undefinedLength)

        m_maxPrefWidth = min(m_maxPrefWidth, style()->maxWidth().value() + (style()->boxSizing() == CONTENT_BOX ? borderAndPadding : 0));

    if (style()->width().isPercent() || style()->height().isPercent() || 

        style()->maxWidth().isPercent() || style()->maxHeight().isPercent() ||

        style()->minWidth().isPercent() || style()->minHeight().isPercent())

        m_minPrefWidth = 0;

    else

        m_minPrefWidth = m_maxPrefWidth;