1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4 *           (C) 2000 Dirk Mueller (mueller@kde.org)
5 *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)
6 *           (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
7 * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
8 * Copyright (C) 2010 Google Inc. All rights reserved.
9 *
10 * This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Library General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * Library General Public License for more details.
19 *
20 * You should have received a copy of the GNU Library General Public License
21 * along with this library; see the file COPYING.LIB.  If not, write to
22 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
23 * Boston, MA 02110-1301, USA.
24 *
25 */
26
27#include "config.h"
28#include "RenderImage.h"
29
30#include "Frame.h"
31#include "GraphicsContext.h"
32#include "HTMLAreaElement.h"
33#include "HTMLImageElement.h"
34#include "HTMLInputElement.h"
35#include "HTMLMapElement.h"
36#include "HTMLNames.h"
37#include "HitTestResult.h"
38#include "Page.h"
39#include "RenderLayer.h"
40#include "RenderView.h"
41#include "SelectionController.h"
42#include "TextRun.h"
43#include <wtf/UnusedParam.h>
44
45#ifdef ANDROID_LAYOUT
46#include "Settings.h"
47#endif
48
49#if ENABLE(WML)
50#include "WMLImageElement.h"
51#include "WMLNames.h"
52#endif
53
54using namespace std;
55
56namespace WebCore {
57
58using namespace HTMLNames;
59
60RenderImage::RenderImage(Node* node)
61    : RenderReplaced(node, IntSize(0, 0))
62    , m_needsToSetSizeForAltText(false)
63{
64    updateAltText();
65
66    view()->frameView()->setIsVisuallyNonEmpty();
67}
68
69RenderImage::~RenderImage()
70{
71    ASSERT(m_imageResource);
72    m_imageResource->shutdown();
73}
74
75void RenderImage::setImageResource(PassOwnPtr<RenderImageResource> imageResource)
76{
77    ASSERT(!m_imageResource);
78    m_imageResource = imageResource;
79    m_imageResource->initialize(this);
80}
81
82// If we'll be displaying either alt text or an image, add some padding.
83static const unsigned short paddingWidth = 4;
84static const unsigned short paddingHeight = 4;
85
86// Alt text is restricted to this maximum size, in pixels.  These are
87// signed integers because they are compared with other signed values.
88static const float maxAltTextWidth = 1024;
89static const int maxAltTextHeight = 256;
90
91IntSize RenderImage::imageSizeForError(CachedImage* newImage) const
92{
93    ASSERT_ARG(newImage, newImage);
94    ASSERT_ARG(newImage, newImage->image());
95
96    // imageSize() returns 0 for the error image. We need the true size of the
97    // error image, so we have to get it by grabbing image() directly.
98    return IntSize(paddingWidth + newImage->image()->width() * style()->effectiveZoom(), paddingHeight + newImage->image()->height() * style()->effectiveZoom());
99}
100
101// Sets the image height and width to fit the alt text.  Returns true if the
102// image size changed.
103bool RenderImage::setImageSizeForAltText(CachedImage* newImage /* = 0 */)
104{
105    IntSize imageSize;
106    if (newImage && newImage->image())
107        imageSize = imageSizeForError(newImage);
108    else if (!m_altText.isEmpty() || newImage) {
109        // If we'll be displaying either text or an image, add a little padding.
110        imageSize = IntSize(paddingWidth, paddingHeight);
111    }
112
113    // we have an alt and the user meant it (its not a text we invented)
114    if (!m_altText.isEmpty()) {
115        const Font& font = style()->font();
116        IntSize textSize(min(font.width(TextRun(m_altText.characters(), m_altText.length())), maxAltTextWidth), min(font.fontMetrics().height(), maxAltTextHeight));
117        imageSize = imageSize.expandedTo(textSize);
118    }
119
120    if (imageSize == intrinsicSize())
121        return false;
122
123    setIntrinsicSize(imageSize);
124    return true;
125}
126
127void RenderImage::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
128{
129    RenderReplaced::styleDidChange(diff, oldStyle);
130    if (m_needsToSetSizeForAltText) {
131        if (!m_altText.isEmpty() && setImageSizeForAltText(m_imageResource->cachedImage()))
132            imageDimensionsChanged(true /* imageSizeChanged */);
133        m_needsToSetSizeForAltText = false;
134    }
135}
136
137void RenderImage::imageChanged(WrappedImagePtr newImage, const IntRect* rect)
138{
139    if (documentBeingDestroyed())
140        return;
141
142    if (hasBoxDecorations() || hasMask())
143        RenderReplaced::imageChanged(newImage, rect);
144
145    if (!m_imageResource)
146        return;
147
148    if (newImage != m_imageResource->imagePtr() || !newImage)
149        return;
150
151    bool imageSizeChanged = false;
152
153    // Set image dimensions, taking into account the size of the alt text.
154    if (m_imageResource->errorOccurred()) {
155        if (!m_altText.isEmpty() && document()->isPendingStyleRecalc()) {
156            ASSERT(node());
157            if (node()) {
158                m_needsToSetSizeForAltText = true;
159                node()->setNeedsStyleRecalc(SyntheticStyleChange);
160            }
161            return;
162        }
163        imageSizeChanged = setImageSizeForAltText(m_imageResource->cachedImage());
164    }
165
166    imageDimensionsChanged(imageSizeChanged, rect);
167}
168
169void RenderImage::imageDimensionsChanged(bool imageSizeChanged, const IntRect* rect)
170{
171    bool shouldRepaint = true;
172
173    if (m_imageResource->imageSize(style()->effectiveZoom()) != intrinsicSize() || imageSizeChanged) {
174        if (!m_imageResource->errorOccurred())
175            setIntrinsicSize(m_imageResource->imageSize(style()->effectiveZoom()));
176
177        // In the case of generated image content using :before/:after, we might not be in the
178        // render tree yet.  In that case, we don't need to worry about check for layout, since we'll get a
179        // layout when we get added in to the render tree hierarchy later.
180        if (containingBlock()) {
181            // lets see if we need to relayout at all..
182            int oldwidth = width();
183            int oldheight = height();
184            if (!preferredLogicalWidthsDirty())
185                setPreferredLogicalWidthsDirty(true);
186            computeLogicalWidth();
187            computeLogicalHeight();
188
189            if (imageSizeChanged || width() != oldwidth || height() != oldheight) {
190                shouldRepaint = false;
191                if (!selfNeedsLayout())
192                    setNeedsLayout(true);
193            }
194
195            setWidth(oldwidth);
196            setHeight(oldheight);
197        }
198    }
199
200    if (shouldRepaint) {
201        IntRect repaintRect;
202        if (rect) {
203            // The image changed rect is in source image coordinates (pre-zooming),
204            // so map from the bounds of the image to the contentsBox.
205            repaintRect = enclosingIntRect(mapRect(*rect, FloatRect(FloatPoint(), m_imageResource->imageSize(1.0f)), contentBoxRect()));
206            // Guard against too-large changed rects.
207            repaintRect.intersect(contentBoxRect());
208        } else
209            repaintRect = contentBoxRect();
210
211        repaintRectangle(repaintRect);
212
213#if USE(ACCELERATED_COMPOSITING)
214        if (hasLayer()) {
215            // Tell any potential compositing layers that the image needs updating.
216            layer()->contentChanged(RenderLayer::ImageChanged);
217        }
218#endif
219    }
220}
221
222void RenderImage::notifyFinished(CachedResource* newImage)
223{
224    if (!m_imageResource)
225        return;
226
227    if (documentBeingDestroyed())
228        return;
229
230#if USE(ACCELERATED_COMPOSITING)
231    if (newImage == m_imageResource->cachedImage() && hasLayer()) {
232        // tell any potential compositing layers
233        // that the image is done and they can reference it directly.
234        layer()->contentChanged(RenderLayer::ImageChanged);
235    }
236#else
237    UNUSED_PARAM(newImage);
238#endif
239}
240
241void RenderImage::paintReplaced(PaintInfo& paintInfo, int tx, int ty)
242{
243    int cWidth = contentWidth();
244    int cHeight = contentHeight();
245    int leftBorder = borderLeft();
246    int topBorder = borderTop();
247    int leftPad = paddingLeft();
248    int topPad = paddingTop();
249
250    GraphicsContext* context = paintInfo.context;
251
252    if (!m_imageResource->hasImage() || m_imageResource->errorOccurred()) {
253        if (paintInfo.phase == PaintPhaseSelection)
254            return;
255
256        if (cWidth > 2 && cHeight > 2) {
257            // Draw an outline rect where the image should be.
258#ifdef ANDROID_FIX // see http://b/issue?id=2052757
259            context->save();
260#endif
261            context->setStrokeStyle(SolidStroke);
262            context->setStrokeColor(Color::lightGray, style()->colorSpace());
263            context->setFillColor(Color::transparent, style()->colorSpace());
264            context->drawRect(IntRect(tx + leftBorder + leftPad, ty + topBorder + topPad, cWidth, cHeight));
265#ifdef ANDROID_FIX // see http://b/issue?id=2052757
266            context->restore();
267#endif
268
269            bool errorPictureDrawn = false;
270            int imageX = 0;
271            int imageY = 0;
272            // When calculating the usable dimensions, exclude the pixels of
273            // the ouline rect so the error image/alt text doesn't draw on it.
274            int usableWidth = cWidth - 2;
275            int usableHeight = cHeight - 2;
276
277            RefPtr<Image> image = m_imageResource->image();
278
279            if (m_imageResource->errorOccurred() && !image->isNull() && usableWidth >= image->width() && usableHeight >= image->height()) {
280                // Center the error image, accounting for border and padding.
281                int centerX = (usableWidth - image->width()) / 2;
282                if (centerX < 0)
283                    centerX = 0;
284                int centerY = (usableHeight - image->height()) / 2;
285                if (centerY < 0)
286                    centerY = 0;
287                imageX = leftBorder + leftPad + centerX + 1;
288                imageY = topBorder + topPad + centerY + 1;
289                context->drawImage(image.get(), style()->colorSpace(), IntPoint(tx + imageX, ty + imageY));
290                errorPictureDrawn = true;
291            }
292
293            if (!m_altText.isEmpty()) {
294                String text = document()->displayStringModifiedByEncoding(m_altText);
295                context->setFillColor(style()->visitedDependentColor(CSSPropertyColor), style()->colorSpace());
296                int ax = tx + leftBorder + leftPad;
297                int ay = ty + topBorder + topPad;
298                const Font& font = style()->font();
299                const FontMetrics& fontMetrics = font.fontMetrics();
300                int ascent = fontMetrics.ascent();
301
302                // Only draw the alt text if it'll fit within the content box,
303                // and only if it fits above the error image.
304                TextRun textRun(text.characters(), text.length());
305                int textWidth = font.width(textRun);
306                if (errorPictureDrawn) {
307                    if (usableWidth >= textWidth && fontMetrics.height() <= imageY)
308                        context->drawText(font, textRun, IntPoint(ax, ay + ascent));
309                } else if (usableWidth >= textWidth && cHeight >= fontMetrics.height())
310                    context->drawText(font, textRun, IntPoint(ax, ay + ascent));
311            }
312        }
313    } else if (m_imageResource->hasImage() && cWidth > 0 && cHeight > 0) {
314        RefPtr<Image> img = m_imageResource->image(cWidth, cHeight);
315        if (!img || img->isNull())
316            return;
317
318#if PLATFORM(MAC)
319        if (style()->highlight() != nullAtom && !paintInfo.context->paintingDisabled())
320            paintCustomHighlight(tx - x(), ty - y(), style()->highlight(), true);
321#endif
322
323        IntSize contentSize(cWidth, cHeight);
324        IntRect rect(IntPoint(tx + leftBorder + leftPad, ty + topBorder + topPad), contentSize);
325        paintIntoRect(context, rect);
326    }
327}
328
329void RenderImage::paint(PaintInfo& paintInfo, int tx, int ty)
330{
331    RenderReplaced::paint(paintInfo, tx, ty);
332
333    if (paintInfo.phase == PaintPhaseOutline)
334        paintAreaElementFocusRing(paintInfo);
335}
336
337void RenderImage::paintAreaElementFocusRing(PaintInfo& paintInfo)
338{
339    Document* document = this->document();
340
341    if (document->printing() || !document->frame()->selection()->isFocusedAndActive())
342        return;
343
344    if (paintInfo.context->paintingDisabled() && !paintInfo.context->updatingControlTints())
345        return;
346
347    Node* focusedNode = document->focusedNode();
348    if (!focusedNode || !focusedNode->hasTagName(areaTag))
349        return;
350
351    HTMLAreaElement* areaElement = static_cast<HTMLAreaElement*>(focusedNode);
352    if (areaElement->imageElement() != node())
353        return;
354
355    // Even if the theme handles focus ring drawing for entire elements, it won't do it for
356    // an area within an image, so we don't call RenderTheme::supportsFocusRing here.
357
358    Path path = areaElement->computePath(this);
359    if (path.isEmpty())
360        return;
361
362    // FIXME: Do we need additional code to clip the path to the image's bounding box?
363
364    RenderStyle* areaElementStyle = areaElement->computedStyle();
365    unsigned short outlineWidth = areaElementStyle->outlineWidth();
366    if (!outlineWidth)
367        return;
368
369    paintInfo.context->drawFocusRing(path, outlineWidth,
370        areaElementStyle->outlineOffset(),
371        areaElementStyle->visitedDependentColor(CSSPropertyOutlineColor));
372}
373
374void RenderImage::areaElementFocusChanged(HTMLAreaElement* element)
375{
376    ASSERT_UNUSED(element, element->imageElement() == node());
377
378    // It would be more efficient to only repaint the focus ring rectangle
379    // for the passed-in area element. That would require adding functions
380    // to the area element class.
381    repaint();
382}
383
384void RenderImage::paintIntoRect(GraphicsContext* context, const IntRect& rect)
385{
386    if (!m_imageResource->hasImage() || m_imageResource->errorOccurred() || rect.width() <= 0 || rect.height() <= 0)
387        return;
388
389    RefPtr<Image> img = m_imageResource->image(rect.width(), rect.height());
390    if (!img || img->isNull())
391        return;
392
393    HTMLImageElement* imageElt = (node() && node()->hasTagName(imgTag)) ? static_cast<HTMLImageElement*>(node()) : 0;
394    CompositeOperator compositeOperator = imageElt ? imageElt->compositeOperator() : CompositeSourceOver;
395    Image* image = m_imageResource->image().get();
396    bool useLowQualityScaling = shouldPaintAtLowQuality(context, image, image, rect.size());
397    context->drawImage(m_imageResource->image(rect.width(), rect.height()).get(), style()->colorSpace(), rect, compositeOperator, useLowQualityScaling);
398}
399
400int RenderImage::minimumReplacedHeight() const
401{
402    return m_imageResource->errorOccurred() ? intrinsicSize().height() : 0;
403}
404
405HTMLMapElement* RenderImage::imageMap() const
406{
407    HTMLImageElement* i = node() && node()->hasTagName(imgTag) ? static_cast<HTMLImageElement*>(node()) : 0;
408    return i ? i->document()->getImageMap(i->fastGetAttribute(usemapAttr)) : 0;
409}
410
411bool RenderImage::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty, HitTestAction hitTestAction)
412{
413    HitTestResult tempResult(result.point(), result.topPadding(), result.rightPadding(), result.bottomPadding(), result.leftPadding());
414    bool inside = RenderReplaced::nodeAtPoint(request, tempResult, x, y, tx, ty, hitTestAction);
415
416    if (tempResult.innerNode() && node()) {
417        if (HTMLMapElement* map = imageMap()) {
418            IntRect contentBox = contentBoxRect();
419            float zoom = style()->effectiveZoom();
420            int mapX = lroundf((x - tx - this->x() - contentBox.x()) / zoom);
421            int mapY = lroundf((y - ty - this->y() - contentBox.y()) / zoom);
422            if (map->mapMouseEvent(mapX, mapY, contentBox.size(), tempResult))
423                tempResult.setInnerNonSharedNode(node());
424        }
425    }
426
427    if (!inside && result.isRectBasedTest())
428        result.append(tempResult);
429    if (inside)
430        result = tempResult;
431    return inside;
432}
433
434void RenderImage::updateAltText()
435{
436    if (!node())
437        return;
438
439    if (node()->hasTagName(inputTag))
440        m_altText = static_cast<HTMLInputElement*>(node())->altText();
441    else if (node()->hasTagName(imgTag))
442        m_altText = static_cast<HTMLImageElement*>(node())->altText();
443#if ENABLE(WML)
444    else if (node()->hasTagName(WMLNames::imgTag))
445        m_altText = static_cast<WMLImageElement*>(node())->altText();
446#endif
447}
448
449bool RenderImage::isLogicalWidthSpecified() const
450{
451    switch (style()->logicalWidth().type()) {
452        case Fixed:
453        case Percent:
454            return true;
455        case Auto:
456        case Relative: // FIXME: Shouldn't this case return true?
457        case Intrinsic:
458        case MinIntrinsic:
459            return false;
460    }
461    ASSERT(false);
462    return false;
463}
464
465bool RenderImage::isLogicalHeightSpecified() const
466{
467    switch (style()->logicalHeight().type()) {
468        case Fixed:
469        case Percent:
470            return true;
471        case Auto:
472        case Relative: // FIXME: Shouldn't this case return true?
473        case Intrinsic:
474        case MinIntrinsic:
475            return false;
476    }
477    ASSERT(false);
478    return false;
479}
480
481int RenderImage::computeReplacedLogicalWidth(bool includeMaxWidth) const
482{
483    if (m_imageResource->imageHasRelativeWidth())
484        if (RenderObject* cb = isPositioned() ? container() : containingBlock()) {
485            if (cb->isBox())
486                m_imageResource->setImageContainerSize(IntSize(toRenderBox(cb)->availableWidth(), toRenderBox(cb)->availableHeight()));
487        }
488
489    int logicalWidth;
490    if (isLogicalWidthSpecified())
491        logicalWidth = computeReplacedLogicalWidthUsing(style()->logicalWidth());
492    else if (m_imageResource->usesImageContainerSize()) {
493        IntSize size = m_imageResource->imageSize(style()->effectiveZoom());
494        logicalWidth = style()->isHorizontalWritingMode() ? size.width() : size.height();
495    } else if (m_imageResource->imageHasRelativeWidth())
496        logicalWidth = 0; // If the image is relatively-sized, set the width to 0 until there is a set container size.
497    else
498        logicalWidth = calcAspectRatioLogicalWidth();
499
500    int minLogicalWidth = computeReplacedLogicalWidthUsing(style()->logicalMinWidth());
501    int maxLogicalWidth = !includeMaxWidth || style()->logicalMaxWidth().isUndefined() ? logicalWidth : computeReplacedLogicalWidthUsing(style()->logicalMaxWidth());
502
503#ifdef ANDROID_LAYOUT
504    logicalWidth = max(minLogicalWidth, min(logicalWidth, maxLogicalWidth));
505    // in SSR mode, we will fit the image to its container width
506    if (document()->settings()->layoutAlgorithm() == Settings::kLayoutSSR) {
507        int cw = containingBlockLogicalWidthForContent();
508        if (cw && logicalWidth > cw)
509            logicalWidth = cw;
510    }
511    return logicalWidth;
512#else
513    return max(minLogicalWidth, min(logicalWidth, maxLogicalWidth));
514#endif
515}
516
517int RenderImage::computeReplacedLogicalHeight() const
518{
519    int logicalHeight;
520    if (isLogicalHeightSpecified())
521        logicalHeight = computeReplacedLogicalHeightUsing(style()->logicalHeight());
522    else if (m_imageResource->usesImageContainerSize()) {
523        IntSize size = m_imageResource->imageSize(style()->effectiveZoom());
524        logicalHeight = style()->isHorizontalWritingMode() ? size.height() : size.width();
525    } else if (m_imageResource->imageHasRelativeHeight())
526        logicalHeight = 0; // If the image is relatively-sized, set the height to 0 until there is a set container size.
527    else
528        logicalHeight = calcAspectRatioLogicalHeight();
529
530    int minLogicalHeight = computeReplacedLogicalHeightUsing(style()->logicalMinHeight());
531    int maxLogicalHeight = style()->logicalMaxHeight().isUndefined() ? logicalHeight : computeReplacedLogicalHeightUsing(style()->logicalMaxHeight());
532
533#ifdef ANDROID_LAYOUT
534    logicalHeight = max(minLogicalHeight, min(logicalHeight, maxLogicalHeight));
535    // in SSR mode, we will fit the image to its container width
536    if (logicalHeight && document()->settings()->layoutAlgorithm() == Settings::kLayoutSSR) {
537        int logicalWidth;
538        if (isLogicalWidthSpecified())
539            logicalWidth = computeReplacedLogicalWidthUsing(style()->width());
540        else
541            logicalWidth = calcAspectRatioLogicalWidth();
542        int minLogicalWidth = computeReplacedLogicalWidthUsing(style()->minWidth());
543        int maxLogicalWidth = style()->maxWidth().value() == undefinedLength ? logicalWidth :
544            computeReplacedLogicalWidthUsing(style()->maxWidth());
545        logicalWidth = max(minLogicalWidth, min(logicalWidth, maxLogicalWidth));
546
547        int cw = containingBlockLogicalWidthForContent();
548        if (cw && logicalWidth && logicalWidth > cw)
549            logicalHeight = cw * logicalHeight / logicalWidth;   // preserve aspect ratio
550    }
551    return logicalHeight;
552#else
553    return max(minLogicalHeight, min(logicalHeight, maxLogicalHeight));
554#endif
555}
556
557int RenderImage::calcAspectRatioLogicalWidth() const
558{
559    int intrinsicWidth = intrinsicLogicalWidth();
560    int intrinsicHeight = intrinsicLogicalHeight();
561    if (!intrinsicHeight)
562        return 0;
563    if (!m_imageResource->hasImage() || m_imageResource->errorOccurred())
564        return intrinsicWidth; // Don't bother scaling.
565    return RenderBox::computeReplacedLogicalHeight() * intrinsicWidth / intrinsicHeight;
566}
567
568int RenderImage::calcAspectRatioLogicalHeight() const
569{
570    int intrinsicWidth = intrinsicLogicalWidth();
571    int intrinsicHeight = intrinsicLogicalHeight();
572    if (!intrinsicWidth)
573        return 0;
574    if (!m_imageResource->hasImage() || m_imageResource->errorOccurred())
575        return intrinsicHeight; // Don't bother scaling.
576    return RenderBox::computeReplacedLogicalWidth() * intrinsicHeight / intrinsicWidth;
577}
578
579} // namespace WebCore
580