third_party/WebKit/Source/web/FindInPageCoordinates.cpp

   1 /*
   2  * Copyright (C) 2012 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "web/FindInPageCoordinates.h"
  33
  34 #include "core/dom/Node.h"
  35 #include "core/dom/Range.h"
  36 #include "core/frame/LocalFrame.h"
  37 #include "core/layout/LayoutBlock.h"
  38 #include "core/layout/LayoutBox.h"
  39 #include "core/layout/LayoutObject.h"
  40 #include "core/layout/LayoutPart.h"
  41 #include "core/layout/LayoutView.h"
  42 #include "core/style/ComputedStyle.h"
  43 #include "platform/geometry/FloatPoint.h"
  44 #include "platform/geometry/FloatQuad.h"
  45 #include "platform/geometry/IntPoint.h"
  46
  47 namespace blink {
  48
  49 static const LayoutBlock* enclosingScrollableAncestor(const LayoutObject* layoutObject)
  50 {
  51     ASSERT(!layoutObject->isLayoutView());
  52
  53     // Trace up the containingBlocks until we reach either the layoutObject view or a scrollable object.
  54     const LayoutBlock* container = layoutObject->containingBlock();
  55     while (!container->hasOverflowClip() && !container->isLayoutView())
  56         container = container->containingBlock();
  57     return container;
  58 }
  59
  60 static FloatRect toNormalizedRect(const FloatRect& absoluteRect, const LayoutObject* layoutObject, const LayoutBlock* container)
  61 {
  62     ASSERT(layoutObject);
  63
  64     ASSERT(container || layoutObject->isLayoutView());
  65     if (!container)
  66         return FloatRect();
  67
  68     // We want to normalize by the max layout overflow size instead of only the visible bounding box.
  69     // Quads and their enclosing bounding boxes need to be used in order to keep results transform-friendly.
  70     FloatPoint scrolledOrigin;
  71
  72     // For overflow:scroll we need to get where the actual origin is independently of the scroll.
  73     if (container->hasOverflowClip())
  74         scrolledOrigin = -IntPoint(container->scrolledContentOffset());
  75
  76     FloatRect overflowRect(scrolledOrigin, FloatSize(container->maxLayoutOverflow()));
  77     FloatRect containerRect = container->localToAbsoluteQuad(FloatQuad(overflowRect)).enclosingBoundingBox();
  78
  79     if (containerRect.isEmpty())
  80         return FloatRect();
  81
  82     // Make the coordinates relative to the container enclosing bounding box.
  83     // Since we work with rects enclosing quad unions this is still transform-friendly.
  84     FloatRect normalizedRect = absoluteRect;
  85     normalizedRect.moveBy(-containerRect.location());
  86
  87     // Fixed positions do not make sense in this coordinate system, but need to leave consistent tickmarks.
  88     // So, use their position when the view is not scrolled, like an absolute position.
  89     if (layoutObject->style()->position() == FixedPosition && container->isLayoutView())
  90         normalizedRect.moveBy(-toLayoutView(container)->frameView()->scrollPosition());
  91
  92     normalizedRect.scale(1 / containerRect.width(), 1 / containerRect.height());
  93     return normalizedRect;
  94 }
  95
  96 FloatRect findInPageRectFromAbsoluteRect(const FloatRect& inputRect, const LayoutObject* baseLayoutObject)
  97 {
  98     if (!baseLayoutObject || inputRect.isEmpty())
  99         return FloatRect();
 100
 101     // Normalize the input rect to its container block.
 102     const LayoutBlock* baseContainer = enclosingScrollableAncestor(baseLayoutObject);
 103     FloatRect normalizedRect = toNormalizedRect(inputRect, baseLayoutObject, baseContainer);
 104
 105     // Go up across frames.
 106     for (const LayoutBox* layoutObject = baseContainer; layoutObject; ) {
 107
 108         // Go up the layout tree until we reach the root of the current frame (the LayoutView).
 109         while (!layoutObject->isLayoutView()) {
 110             const LayoutBlock* container = enclosingScrollableAncestor(layoutObject);
 111
 112             // Compose the normalized rects.
 113             FloatRect normalizedBoxRect = toNormalizedRect(layoutObject->absoluteBoundingBoxRect(), layoutObject, container);
 114             normalizedRect.scale(normalizedBoxRect.width(), normalizedBoxRect.height());
 115             normalizedRect.moveBy(normalizedBoxRect.location());
 116
 117             layoutObject = container;
 118         }
 119
 120         ASSERT(layoutObject->isLayoutView());
 121
 122         // Jump to the layoutObject owning the frame, if any.
 123         layoutObject = layoutObject->frame() ? layoutObject->frame()->ownerLayoutObject() : 0;
 124     }
 125
 126     return normalizedRect;
 127 }
 128
 129 FloatRect findInPageRectFromRange(Range* range)
 130 {
 131     if (!range || !range->firstNode())
 132         return FloatRect();
 133
 134     return findInPageRectFromAbsoluteRect(LayoutObject::absoluteBoundingBoxRectForRange(range), range->firstNode()->layoutObject());
 135 }
 136
 137 } // namespace blink