third_party/WebKit/Source/core/html/HTMLAreaElement.cpp

   1 /*
   2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
   3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
   4  * Copyright (C) 2004, 2005, 2006, 2009, 2011 Apple Inc. All rights reserved.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include "config.h"
  23 #include "core/html/HTMLAreaElement.h"
  24
  25 #include "core/HTMLNames.h"
  26 #include "core/dom/ElementTraversal.h"
  27 #include "core/html/HTMLImageElement.h"
  28 #include "core/html/HTMLMapElement.h"
  29 #include "core/layout/HitTestResult.h"
  30 #include "core/layout/LayoutImage.h"
  31 #include "core/layout/LayoutView.h"
  32 #include "platform/LengthFunctions.h"
  33 #include "platform/graphics/Path.h"
  34 #include "platform/transforms/AffineTransform.h"
  35
  36 namespace blink {
  37
  38 using namespace HTMLNames;
  39
  40 inline HTMLAreaElement::HTMLAreaElement(Document& document)
  41     : HTMLAnchorElement(areaTag, document)
  42     , m_lastSize(-1, -1)
  43     , m_shape(Unknown)
  44 {
  45 }
  46
  47 // An explicit empty destructor should be in HTMLAreaElement.cpp, because
  48 // if an implicit destructor is used or an empty destructor is defined in
  49 // HTMLAreaElement.h, when including HTMLAreaElement.h, msvc tries to expand
  50 // the destructor and causes a compile error because of lack of blink::Path
  51 // definition.
  52 HTMLAreaElement::~HTMLAreaElement()
  53 {
  54 }
  55
  56 DEFINE_NODE_FACTORY(HTMLAreaElement)
  57
  58 void HTMLAreaElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
  59 {
  60     if (name == shapeAttr) {
  61         if (equalIgnoringCase(value, "default"))
  62             m_shape = Default;
  63         else if (equalIgnoringCase(value, "circle"))
  64             m_shape = Circle;
  65         else if (equalIgnoringCase(value, "poly"))
  66             m_shape = Poly;
  67         else if (equalIgnoringCase(value, "rect"))
  68             m_shape = Rect;
  69         invalidateCachedRegion();
  70     } else if (name == coordsAttr) {
  71         m_coords = parseHTMLAreaElementCoords(value.string());
  72         invalidateCachedRegion();
  73     } else if (name == altAttr || name == accesskeyAttr) {
  74         // Do nothing.
  75     } else {
  76         HTMLAnchorElement::parseAttribute(name, value);
  77     }
  78 }
  79
  80 void HTMLAreaElement::invalidateCachedRegion()
  81 {
  82     m_lastSize = LayoutSize(-1, -1);
  83 }
  84
  85 bool HTMLAreaElement::pointInArea(LayoutPoint location, const LayoutSize& containerSize)
  86 {
  87     if (m_lastSize != containerSize) {
  88         m_region = adoptPtr(new Path(getRegion(containerSize)));
  89         m_lastSize = containerSize;
  90     }
  91
  92     return m_region->contains(FloatPoint(location));
  93 }
  94
  95 Path HTMLAreaElement::computePath(LayoutObject* obj) const
  96 {
  97     if (!obj)
  98         return Path();
  99
 100     // FIXME: This doesn't work correctly with transforms.
 101     FloatPoint absPos = obj->localToAbsolute();
 102
 103     // Default should default to the size of the containing object.
 104     LayoutSize size = m_lastSize;
 105     if (m_shape == Default)
 106         size = obj->absoluteClippedOverflowRect().size();
 107
 108     Path p = getRegion(size);
 109     float zoomFactor = obj->style()->effectiveZoom();
 110     if (zoomFactor != 1.0f) {
 111         AffineTransform zoomTransform;
 112         zoomTransform.scale(zoomFactor);
 113         p.transform(zoomTransform);
 114     }
 115
 116     p.translate(toFloatSize(absPos));
 117     return p;
 118 }
 119
 120 LayoutRect HTMLAreaElement::computeRect(LayoutObject* obj) const
 121 {
 122     return enclosingLayoutRect(computePath(obj).boundingRect());
 123 }
 124
 125 Path HTMLAreaElement::getRegion(const LayoutSize& size) const
 126 {
 127     if (m_coords.isEmpty() && m_shape != Default)
 128         return Path();
 129
 130     LayoutUnit width = size.width();
 131     LayoutUnit height = size.height();
 132
 133     // If element omits the shape attribute, select shape based on number of coordinates.
 134     Shape shape = m_shape;
 135     if (shape == Unknown) {
 136         if (m_coords.size() == 3)
 137             shape = Circle;
 138         else if (m_coords.size() == 4)
 139             shape = Rect;
 140         else if (m_coords.size() >= 6)
 141             shape = Poly;
 142     }
 143
 144     Path path;
 145     switch (shape) {
 146     case Poly:
 147         if (m_coords.size() >= 6) {
 148             int numPoints = m_coords.size() / 2;
 149             path.moveTo(FloatPoint(minimumValueForLength(m_coords[0], width).toFloat(), minimumValueForLength(m_coords[1], height).toFloat()));
 150             for (int i = 1; i < numPoints; ++i)
 151                 path.addLineTo(FloatPoint(minimumValueForLength(m_coords[i * 2], width).toFloat(), minimumValueForLength(m_coords[i * 2 + 1], height).toFloat()));
 152             path.closeSubpath();
 153         }
 154         break;
 155     case Circle:
 156         if (m_coords.size() >= 3) {
 157             Length radius = m_coords[2];
 158             float r = std::min(minimumValueForLength(radius, width).toFloat(), minimumValueForLength(radius, height).toFloat());
 159             path.addEllipse(FloatRect(minimumValueForLength(m_coords[0], width).toFloat() - r, minimumValueForLength(m_coords[1], height).toFloat() - r, 2 * r, 2 * r));
 160         }
 161         break;
 162     case Rect:
 163         if (m_coords.size() >= 4) {
 164             float x0 = minimumValueForLength(m_coords[0], width).toFloat();
 165             float y0 = minimumValueForLength(m_coords[1], height).toFloat();
 166             float x1 = minimumValueForLength(m_coords[2], width).toFloat();
 167             float y1 = minimumValueForLength(m_coords[3], height).toFloat();
 168             path.addRect(FloatRect(x0, y0, x1 - x0, y1 - y0));
 169         }
 170         break;
 171     case Default:
 172         path.addRect(FloatRect(0, 0, width.toFloat(), height.toFloat()));
 173         break;
 174     case Unknown:
 175         break;
 176     }
 177
 178     return path;
 179 }
 180
 181 HTMLImageElement* HTMLAreaElement::imageElement() const
 182 {
 183     if (HTMLMapElement* mapElement = Traversal<HTMLMapElement>::firstAncestor(*this))
 184         return mapElement->imageElement();
 185     return nullptr;
 186 }
 187
 188 bool HTMLAreaElement::isKeyboardFocusable() const
 189 {
 190     return isFocusable();
 191 }
 192
 193 bool HTMLAreaElement::isMouseFocusable() const
 194 {
 195     return isFocusable();
 196 }
 197
 198 bool HTMLAreaElement::layoutObjectIsFocusable() const
 199 {
 200     HTMLImageElement* image = imageElement();
 201     if (!image || !image->layoutObject() || image->layoutObject()->style()->visibility() != VISIBLE)
 202         return false;
 203
 204     return supportsFocus() && Element::tabIndex() >= 0;
 205 }
 206
 207 void HTMLAreaElement::setFocus(bool shouldBeFocused)
 208 {
 209     if (focused() == shouldBeFocused)
 210         return;
 211
 212     HTMLAnchorElement::setFocus(shouldBeFocused);
 213
 214     HTMLImageElement* imageElement = this->imageElement();
 215     if (!imageElement)
 216         return;
 217
 218     LayoutObject* layoutObject = imageElement->layoutObject();
 219     if (!layoutObject || !layoutObject->isImage())
 220         return;
 221
 222     toLayoutImage(layoutObject)->areaElementFocusChanged(this);
 223 }
 224
 225 void HTMLAreaElement::updateFocusAppearance(bool restorePreviousSelection)
 226 {
 227     if (!isFocusable())
 228         return;
 229
 230     HTMLImageElement* imageElement = this->imageElement();
 231     if (!imageElement)
 232         return;
 233
 234     imageElement->updateFocusAppearance(restorePreviousSelection);
 235 }
 236
 237 }