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///////////////////////////////////////////////////////////////////////////////
//
// JTOpen (IBM Toolbox for Java - OSS version)
//
// Filename: BidiText.java
//
// The source code contained herein is licensed under the IBM Public License
// Version 1.0, which has been approved by the Open Source Initiative.
// Copyright (C) 1997-2006 International Business Machines Corporation and
// others. All rights reserved.
//
///////////////////////////////////////////////////////////////////////////////
package com.ibm.as400.access;
/**
* Bidi text is a combination of a sequence of characters and a set of
* Bidi flags which represent Bidi attributes used during Bidi Layout
* transformations.
*
* Layout transformations allow to convert a given instance of Bidi text
* into another instance with possibly different Bidi flags while
* conserving the semantics of the text.
*
* A BidiText object contains a BidiFlagSet to store the Bidi flags
* characterizing its character data.
* The characters are contained in a character array. This array may
* contain more data than the Bidi text to process. The part of the array
* to process is called the "interesting" data, and is defined by its length
* and its offset from the beginning of the character array.
*
*
Multi-threading considerations:
* Each thread must use its own instances of this class.
*
*/
public class BidiText
{
/**
* BidiFlagSet qualifying the character data
*/
public BidiFlagSet flags;
/**
* character array containing the data
*/
public char[] data;
/**
* offset of the "interesting" data within the character array
*/
public int offset;
/**
* length of the "interesting" data within the character array
*/
public int count;
/**
* Constructor with no arguments to create a flags member with
* a DEFAULT value. There is no data and no character array,
* but a default BidiFlagSet is created and referred to in "flags".
*/
public BidiText()
{
this.flags = new BidiFlagSet();
}
/**
* Constructs a BidiText object based on an existing BidiFlagSet.
* There is no data and no character array.
* @param initFlags
*/
public BidiText(BidiFlagSet initFlags)
{
this.flags = initFlags;
}
/**
* Constructs a BidiText object based on an existing
* BidiFlagSet and the data in a character array.
*
The argument flags and data are duplicated. Changing them will not
* affect the BidiText instance.
* @param initFlags The Bidi flags of the data.
* @param initData The character data.
*/
public BidiText(BidiFlagSet initFlags, char[] initData)
{
this(initFlags, initData, 0, initData.length, initData.length);
}
/**
* Constructs a BidiText object based on an existing
* BidiFlagSet and the data in part of a character array.
*
The argument flags and data are duplicated. Changing them will not
* affect the BidiText instance.
* @param initFlags The Bidi flags of the data.
* @param initData The character data.
* @param offset The offset of the "interesting" data in initData.
* @param length The length of the "interesting" data in initData.
* @param capacity The length of the created character array (may be
* larger than "length" to reserve space for
* adding more data).
*/
public BidiText(BidiFlagSet initFlags,
char[] initData,
int offset,
int length,
int capacity)
{
this.flags = new BidiFlagSet(initFlags);
this.data = new char[capacity];
System.arraycopy(initData, offset, this.data, 0, length);
this.count = length;
}
/**
* Constructs a BidiText object based on an existing
* BidiFlagSet and the data in a string.
*
The argument flags and data are duplicated. Changing them will not
* affect the BidiText instance.
* @param initFlags The Bidi flags of the data.
* @param str The character data.
*/
public BidiText(BidiFlagSet initFlags, String str)
{
this.flags = new BidiFlagSet(initFlags);
this.count = str.length();
// it would be nicer to use str.toCharArray, but it has bugs on
// Arabic NT
this.data = new char[count];
str.getChars(0, count, this.data, 0);
}
/**
* Compares two BidiText objects.
* Two BidiText objects are considered equal if they have the same Bidi flags
* and the same "interesting" character data,
* @param other The BidiText to compare to this.
* @return true if the BidiText objects are equal, false otherwise.
*/
public boolean equals(BidiText other)
{
if (other == null) return false;
if (this.count != other.count) return false;
if (this.flags.value != other.flags.value) return false;
for (int i = 0; i < this.count; i++)
{
if (this.data[this.offset + i] !=
other.data[other.offset + i]) return false;
}
return true;
}
/**
* Replaces the character data reference in the BidiText object.
* Note that the data is not duplicated, only its
* reference is written in the BidiText object.
*
This method avoids the overhead of creating a character array
* and copying the source data to it, when the source data is already
* contained in a character array.
*
This method can be used after creating a BidiText object with no
* arguments, or to reuse a BidiText object with new data.
*
This is a convenience method. It is also possible to manipulate
* directly the data, offset and count members of the BidiText instance.
* @param newData A reference to the character data.
* @param newOffset The offset of the "interesting" data in newData.
* @param newLength The length of the "interesting" data in newData.
*/
public void setCharsRef(char[] newData, int newOffset, int newLength)
{
this.data = newData;
this.offset = newOffset;
this.count = newLength;
}
/**
* Extracts the character data from a BidiText in character array format
* @return A char array containing a copy of the "interesting" data.
*/
public char[] toCharArray()
{
char[] copyChars = new char[this.count];
System.arraycopy(this.data, this.offset, copyChars, 0, count);
return copyChars;
}
/**
* Extracts the character data from a BidiText in string format
* @return A string containing a copy of the "interesting" data.
*/
public String toString()
{
return new String(this.data, this.offset, this.count);
}
/**
* Transforms the data in the "this" BidiText object and return the resulting
* BidiText object.
* The transformation is done according to the Bidi flags of the source
* BidiText and the Bidi flags specified in the argument.
*
The source BidiText is never modified by the transform.
*
The destination BidiText has its Bidi flags set to those of the
* argument.
*
A typical usage of this method could be:
*
* BidiText src = new BidiText(); // source text
* BidiFlagSet dstFlags; // Bidi flags for destination
* BidiText dst; // destination reference
* src.flags.setAllFlags( {flag values for source} );
* dstFlags.setAllFlags( {flag values for destination} );
* // assign values to src.data, src.offset, src.count
* dst = src.transform(dstFlags);
*
* @param dstFlags Bidi flags of the destination BidiText.
* @return A BidiText which is the transformation of the "this" BidiText.
*/
public BidiText transform(BidiFlagSet dstFlags)
{
BidiTransform bdx = new BidiTransform();
bdx.flags.setAllFlags(dstFlags);
return this.transform(bdx);
}
/**
* Transforms the data in the "this" BidiText object and return the resulting
* BidiText object.
* The transformation is done according to the Bidi flags of the source
* BidiText and the Bidi flags specified in the BidiTransform argument.
* The source BidiText is never modified by the transform.
*
The destination BidiText has its Bidi flags set to those of the
* argument.
*
Output fields of the BidiTransform object are set by this method.
* srcToDstMap, DstToSrcMap and propertyMap may be set by this method if the
* corresponding options have been required in BidiTransform when calling it.
*
By default, transformed output data is written to the destination
* BidiText character array but no maps are created.
*
A typical usage of this method could be:
*
* BidiTransform bdx = new BidiTransform();
* BidiText src = new BidiText(); // source text
* BidiText dst; // destination reference
* src.flags.setAllFlags( {flag values for source} );
* bdx.flags.setAllFlags( {flag values for destination} );
* // assign values to src.data, src.offset, src.count
* dst = src.transform(bdx);
*
* This method is still in construction. Currently only the default
* options are implemented. No maps are created.
* @param bdx The BidiTransform object defining the transformation.
* @return A BidiText which is the transformation of the "this" BidiText.
* If destination data is not required, a null is returned.
*/
public BidiText transform(BidiTransform bdx)
{
BidiText dst = new BidiText();
dst.flags.setAllFlags(bdx.flags);
if (bdx.myOrder == null) bdx.myOrder = new BidiOrder();
bdx.myOrder.order(this, dst, bdx);
if (this.flags.getText() != dst.flags.getText())
{
char[] sData; /* char array for shaping */
if (bdx.myShape == null)
{
bdx.myShape = new BidiShape();
bdx.flags1 = new BidiFlagSet();
bdx.flags2 = new BidiFlagSet();
}
bdx.flags1.setAllFlags(this.flags);
bdx.flags2.setAllFlags(dst.flags);
if ((dst.offset == 0) && (dst.data.length == dst.count))
sData = dst.data;
else
{
sData = new char[dst.count];
System.arraycopy(dst.data, dst.offset, sData, 0, dst.count);
}
sData = bdx.myShape.shape(bdx.flags1, bdx.flags2, sData, bdx.options);
dst.count = sData.length; /* could be changed by shaping */
if (dst.offset == 0)
dst.data = sData;
else
{
if ((dst.offset + dst.count) <= dst.data.length)
System.arraycopy(sData, 0, dst.data, dst.offset, dst.count);
else
{
char[] tmp = new char[dst.offset + dst.count];
System.arraycopy(dst.data, 0, tmp, 0, dst.offset);
System.arraycopy(sData, 0, tmp, dst.offset, dst.count);
dst.data = tmp;
}
}
}
return dst;
}
}