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      1 /*
      2  * Copyright (C) 2007, 2009, 2010 Apple 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
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "core/html/TimeRanges.h"
     28 
     29 #include "bindings/v8/ExceptionMessages.h"
     30 #include "bindings/v8/ExceptionState.h"
     31 #include "bindings/v8/ExceptionStatePlaceholder.h"
     32 #include "core/dom/ExceptionCode.h"
     33 #include <math.h>
     34 
     35 using namespace WebCore;
     36 
     37 TimeRanges::TimeRanges(double start, double end)
     38 {
     39     ScriptWrappable::init(this);
     40     add(start, end);
     41 }
     42 
     43 PassRefPtr<TimeRanges> TimeRanges::create(const blink::WebTimeRanges& webRanges)
     44 {
     45     RefPtr<TimeRanges> ranges = TimeRanges::create();
     46 
     47     unsigned size = webRanges.size();
     48     for (unsigned i = 0; i < size; ++i)
     49         ranges->add(webRanges[i].start, webRanges[i].end);
     50 
     51     return ranges.release();
     52 }
     53 
     54 PassRefPtr<TimeRanges> TimeRanges::copy() const
     55 {
     56     RefPtr<TimeRanges> newSession = TimeRanges::create();
     57 
     58     unsigned size = m_ranges.size();
     59     for (unsigned i = 0; i < size; i++)
     60         newSession->add(m_ranges[i].m_start, m_ranges[i].m_end);
     61 
     62     return newSession.release();
     63 }
     64 
     65 void TimeRanges::invert()
     66 {
     67     RefPtr<TimeRanges> inverted = TimeRanges::create();
     68     double posInf = std::numeric_limits<double>::infinity();
     69     double negInf = -std::numeric_limits<double>::infinity();
     70 
     71     if (!m_ranges.size())
     72         inverted->add(negInf, posInf);
     73     else {
     74         double start = m_ranges.first().m_start;
     75         if (start != negInf)
     76             inverted->add(negInf, start);
     77 
     78         for (size_t index = 0; index + 1 < m_ranges.size(); ++index)
     79             inverted->add(m_ranges[index].m_end, m_ranges[index + 1].m_start);
     80 
     81         double end = m_ranges.last().m_end;
     82         if (end != posInf)
     83             inverted->add(end, posInf);
     84     }
     85 
     86     m_ranges.swap(inverted->m_ranges);
     87 }
     88 
     89 void TimeRanges::intersectWith(const TimeRanges* other)
     90 {
     91     ASSERT(other);
     92 
     93     if (other == this)
     94         return;
     95 
     96     RefPtr<TimeRanges> invertedOther = other->copy();
     97     invertedOther->invert();
     98 
     99     invert();
    100     unionWith(invertedOther.get());
    101     invert();
    102 }
    103 
    104 void TimeRanges::unionWith(const TimeRanges* other)
    105 {
    106     ASSERT(other);
    107     RefPtr<TimeRanges> unioned = copy();
    108     for (size_t index = 0; index < other->m_ranges.size(); ++index) {
    109         const Range& range = other->m_ranges[index];
    110         unioned->add(range.m_start, range.m_end);
    111     }
    112 
    113     m_ranges.swap(unioned->m_ranges);
    114 }
    115 
    116 double TimeRanges::start(unsigned index, ExceptionState& exceptionState) const
    117 {
    118     if (index >= length()) {
    119         exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexExceedsMaximumBound("index", index, length()));
    120         return 0;
    121     }
    122     return m_ranges[index].m_start;
    123 }
    124 
    125 double TimeRanges::end(unsigned index, ExceptionState& exceptionState) const
    126 {
    127     if (index >= length()) {
    128         exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexExceedsMaximumBound("index", index, length()));
    129         return 0;
    130     }
    131     return m_ranges[index].m_end;
    132 }
    133 
    134 void TimeRanges::add(double start, double end)
    135 {
    136     ASSERT(start <= end);
    137     unsigned overlappingArcIndex;
    138     Range addedRange(start, end);
    139 
    140     // For each present range check if we need to:
    141     // - merge with the added range, in case we are overlapping or contiguous
    142     // - Need to insert in place, we we are completely, not overlapping and not contiguous
    143     // in between two ranges.
    144     //
    145     // TODO: Given that we assume that ranges are correctly ordered, this could be optimized.
    146 
    147     for (overlappingArcIndex = 0; overlappingArcIndex < m_ranges.size(); overlappingArcIndex++) {
    148         if (addedRange.isOverlappingRange(m_ranges[overlappingArcIndex])
    149          || addedRange.isContiguousWithRange(m_ranges[overlappingArcIndex])) {
    150             // We need to merge the addedRange and that range.
    151             addedRange = addedRange.unionWithOverlappingOrContiguousRange(m_ranges[overlappingArcIndex]);
    152             m_ranges.remove(overlappingArcIndex);
    153             overlappingArcIndex--;
    154         } else {
    155             // Check the case for which there is no more to do
    156             if (!overlappingArcIndex) {
    157                 if (addedRange.isBeforeRange(m_ranges[0])) {
    158                     // First index, and we are completely before that range (and not contiguous, nor overlapping).
    159                     // We just need to be inserted here.
    160                     break;
    161                 }
    162             } else {
    163                 if (m_ranges[overlappingArcIndex - 1].isBeforeRange(addedRange)
    164                  && addedRange.isBeforeRange(m_ranges[overlappingArcIndex])) {
    165                     // We are exactly after the current previous range, and before the current range, while
    166                     // not overlapping with none of them. Insert here.
    167                     break;
    168                 }
    169             }
    170         }
    171     }
    172 
    173     // Now that we are sure we don't overlap with any range, just add it.
    174     m_ranges.insert(overlappingArcIndex, addedRange);
    175 }
    176 
    177 bool TimeRanges::contain(double time) const
    178 {
    179     for (unsigned n = 0; n < length(); n++) {
    180         if (time >= start(n, IGNORE_EXCEPTION) && time <= end(n, IGNORE_EXCEPTION))
    181             return true;
    182     }
    183     return false;
    184 }
    185 
    186 double TimeRanges::nearest(double time) const
    187 {
    188     double closest = 0;
    189     unsigned count = length();
    190     for (unsigned ndx = 0; ndx < count; ndx++) {
    191         double startTime = start(ndx, IGNORE_EXCEPTION);
    192         double endTime = end(ndx, IGNORE_EXCEPTION);
    193         if (time >= startTime && time <= endTime)
    194             return time;
    195         if (fabs(startTime - time) < closest)
    196             closest = fabs(startTime - time);
    197         else if (fabs(endTime - time) < closest)
    198             closest = fabs(endTime - time);
    199     }
    200     return closest;
    201 }
    202