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JUCE/src/containers/juce_SparseSet.h
2011-03-09 11:36:34 +00:00

300 lines
9.4 KiB
C++

/*
==============================================================================
This file is part of the JUCE library - "Jules' Utility Class Extensions"
Copyright 2004-11 by Raw Material Software Ltd.
------------------------------------------------------------------------------
JUCE can be redistributed and/or modified under the terms of the GNU General
Public License (Version 2), as published by the Free Software Foundation.
A copy of the license is included in the JUCE distribution, or can be found
online at www.gnu.org/licenses.
JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
------------------------------------------------------------------------------
To release a closed-source product which uses JUCE, commercial licenses are
available: visit www.rawmaterialsoftware.com/juce for more information.
==============================================================================
*/
#ifndef __JUCE_SPARSESET_JUCEHEADER__
#define __JUCE_SPARSESET_JUCEHEADER__
#include "juce_ArrayAllocationBase.h"
#include "../maths/juce_Range.h"
#include "../threads/juce_CriticalSection.h"
//==============================================================================
/**
Holds a set of primitive values, storing them as a set of ranges.
This container acts like an array, but can efficiently hold large continguous
ranges of values. It's quite a specialised class, mostly useful for things
like keeping the set of selected rows in a listbox.
The type used as a template paramter must be an integer type, such as int, short,
int64, etc.
*/
template <class Type>
class SparseSet
{
public:
//==============================================================================
/** Creates a new empty set. */
SparseSet()
{
}
/** Creates a copy of another SparseSet. */
SparseSet (const SparseSet<Type>& other)
: values (other.values)
{
}
//==============================================================================
/** Clears the set. */
void clear()
{
values.clear();
}
/** Checks whether the set is empty.
This is much quicker than using (size() == 0).
*/
bool isEmpty() const throw()
{
return values.size() == 0;
}
/** Returns the number of values in the set.
Because of the way the data is stored, this method can take longer if there
are a lot of items in the set. Use isEmpty() for a quick test of whether there
are any items.
*/
Type size() const
{
Type total (0);
for (int i = 0; i < values.size(); i += 2)
total += values.getUnchecked (i + 1) - values.getUnchecked (i);
return total;
}
/** Returns one of the values in the set.
@param index the index of the value to retrieve, in the range 0 to (size() - 1).
@returns the value at this index, or 0 if it's out-of-range
*/
Type operator[] (Type index) const
{
for (int i = 0; i < values.size(); i += 2)
{
const Type start (values.getUnchecked (i));
const Type len (values.getUnchecked (i + 1) - start);
if (index < len)
return start + index;
index -= len;
}
return Type();
}
/** Checks whether a particular value is in the set. */
bool contains (const Type valueToLookFor) const
{
for (int i = 0; i < values.size(); ++i)
if (valueToLookFor < values.getUnchecked(i))
return (i & 1) != 0;
return false;
}
//==============================================================================
/** Returns the number of contiguous blocks of values.
@see getRange
*/
int getNumRanges() const throw()
{
return values.size() >> 1;
}
/** Returns one of the contiguous ranges of values stored.
@param rangeIndex the index of the range to look up, between 0
and (getNumRanges() - 1)
@see getTotalRange
*/
const Range<Type> getRange (const int rangeIndex) const
{
if (isPositiveAndBelow (rangeIndex, getNumRanges()))
return Range<Type> (values.getUnchecked (rangeIndex << 1),
values.getUnchecked ((rangeIndex << 1) + 1));
else
return Range<Type>();
}
/** Returns the range between the lowest and highest values in the set.
@see getRange
*/
const Range<Type> getTotalRange() const
{
if (values.size() > 0)
{
jassert ((values.size() & 1) == 0);
return Range<Type> (values.getUnchecked (0),
values.getUnchecked (values.size() - 1));
}
return Range<Type>();
}
//==============================================================================
/** Adds a range of contiguous values to the set.
e.g. addRange (Range \<int\> (10, 14)) will add (10, 11, 12, 13) to the set.
*/
void addRange (const Range<Type>& range)
{
jassert (range.getLength() >= 0);
if (range.getLength() > 0)
{
removeRange (range);
values.addUsingDefaultSort (range.getStart());
values.addUsingDefaultSort (range.getEnd());
simplify();
}
}
/** Removes a range of values from the set.
e.g. removeRange (Range\<int\> (10, 14)) will remove (10, 11, 12, 13) from the set.
*/
void removeRange (const Range<Type>& rangeToRemove)
{
jassert (rangeToRemove.getLength() >= 0);
if (rangeToRemove.getLength() > 0
&& values.size() > 0
&& rangeToRemove.getStart() < values.getUnchecked (values.size() - 1)
&& values.getUnchecked(0) < rangeToRemove.getEnd())
{
const bool onAtStart = contains (rangeToRemove.getStart() - 1);
const Type lastValue (jmin (rangeToRemove.getEnd(), values.getLast()));
const bool onAtEnd = contains (lastValue);
for (int i = values.size(); --i >= 0;)
{
if (values.getUnchecked(i) <= lastValue)
{
while (values.getUnchecked(i) >= rangeToRemove.getStart())
{
values.remove (i);
if (--i < 0)
break;
}
break;
}
}
if (onAtStart) values.addUsingDefaultSort (rangeToRemove.getStart());
if (onAtEnd) values.addUsingDefaultSort (lastValue);
simplify();
}
}
/** Does an XOR of the values in a given range. */
void invertRange (const Range<Type>& range)
{
SparseSet newItems;
newItems.addRange (range);
int i;
for (i = getNumRanges(); --i >= 0;)
newItems.removeRange (getRange (i));
removeRange (range);
for (i = newItems.getNumRanges(); --i >= 0;)
addRange (newItems.getRange(i));
}
/** Checks whether any part of a given range overlaps any part of this set. */
bool overlapsRange (const Range<Type>& range)
{
if (range.getLength() > 0)
{
for (int i = getNumRanges(); --i >= 0;)
{
if (values.getUnchecked ((i << 1) + 1) <= range.getStart())
return false;
if (values.getUnchecked (i << 1) < range.getEnd())
return true;
}
}
return false;
}
/** Checks whether the whole of a given range is contained within this one. */
bool containsRange (const Range<Type>& range)
{
if (range.getLength() > 0)
{
for (int i = getNumRanges(); --i >= 0;)
{
if (values.getUnchecked ((i << 1) + 1) <= range.getStart())
return false;
if (values.getUnchecked (i << 1) <= range.getStart()
&& range.getEnd() <= values.getUnchecked ((i << 1) + 1))
return true;
}
}
return false;
}
//==============================================================================
bool operator== (const SparseSet<Type>& other) throw()
{
return values == other.values;
}
bool operator!= (const SparseSet<Type>& other) throw()
{
return values != other.values;
}
private:
//==============================================================================
// alternating start/end values of ranges of values that are present.
Array<Type, DummyCriticalSection> values;
void simplify()
{
jassert ((values.size() & 1) == 0);
for (int i = values.size(); --i > 0;)
if (values.getUnchecked(i) == values.getUnchecked (i - 1))
values.removeRange (--i, 2);
}
};
#endif // __JUCE_SPARSESET_JUCEHEADER__