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/*
* Copyright (C) 2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "MarkedText.h"
#include <algorithm>
#include <wtf/HashSet.h>
namespace WebCore {
Vector<MarkedText> subdivide(const Vector<MarkedText>& markedTexts, OverlapStrategy overlapStrategy)
{
if (markedTexts.isEmpty())
return { };
struct Offset {
enum Kind { Begin, End };
Kind kind;
unsigned value; // Copy of markedText.startOffset/endOffset to avoid the need to branch based on kind.
const MarkedText* markedText;
};
// 1. Build table of all offsets.
Vector<Offset> offsets;
ASSERT(markedTexts.size() < std::numeric_limits<unsigned>::max() / 2);
unsigned numberOfMarkedTexts = markedTexts.size();
unsigned numberOfOffsets = 2 * numberOfMarkedTexts;
offsets.reserveInitialCapacity(numberOfOffsets);
for (auto& markedText : markedTexts) {
offsets.uncheckedAppend({ Offset::Begin, markedText.startOffset, &markedText });
offsets.uncheckedAppend({ Offset::End, markedText.endOffset, &markedText });
}
// 2. Sort offsets such that begin offsets are in paint order and end offsets are in reverse paint order.
std::sort(offsets.begin(), offsets.end(), [] (const Offset& a, const Offset& b) {
return a.value < b.value || (a.value == b.value && a.kind == b.kind && a.kind == Offset::Begin && a.markedText->type < b.markedText->type)
|| (a.value == b.value && a.kind == b.kind && a.kind == Offset::End && a.markedText->type > b.markedText->type);
});
// 3. Compute intersection.
Vector<MarkedText> result;
result.reserveInitialCapacity(numberOfMarkedTexts);
HashSet<const MarkedText*> processedMarkedTexts;
unsigned offsetSoFar = offsets[0].value;
for (unsigned i = 1; i < numberOfOffsets; ++i) {
if (offsets[i].value > offsets[i - 1].value) {
if (overlapStrategy == OverlapStrategy::Frontmost) {
Optional<unsigned> frontmost;
for (unsigned j = 0; j < i; ++j) {
if (!processedMarkedTexts.contains(offsets[j].markedText) && (!frontmost || offsets[j].markedText->type > offsets[*frontmost].markedText->type))
frontmost = j;
}
if (frontmost)
result.append({ offsetSoFar, offsets[i].value, offsets[*frontmost].markedText->type, offsets[*frontmost].markedText->marker, offsets[*frontmost].markedText->highlightName });
} else {
// The appended marked texts may not be in paint order. We will fix this up at the end of this function.
for (unsigned j = 0; j < i; ++j) {
if (!processedMarkedTexts.contains(offsets[j].markedText))
result.append({ offsetSoFar, offsets[i].value, offsets[j].markedText->type, offsets[j].markedText->marker, offsets[j].markedText->highlightName });
}
}
offsetSoFar = offsets[i].value;
}
if (offsets[i].kind == Offset::End)
processedMarkedTexts.add(offsets[i].markedText);
}
// Fix up; sort the marked texts so that they are in paint order.
if (overlapStrategy == OverlapStrategy::None)
std::sort(result.begin(), result.end(), [] (const MarkedText& a, const MarkedText& b) { return a.startOffset < b.startOffset || (a.startOffset == b.startOffset && a.type < b.type); });
return result;
}
}