Android example source code file (PackedObjectVector.java)

This example Android source code file (PackedObjectVector.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, e, object, packedobjectvector, util, utilities, utils, xxx

The PackedObjectVector.java Android example source code

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.text;

import com.android.internal.util.ArrayUtils;

class PackedObjectVector<E>
{
    private int mColumns;
    private int mRows;

    private int mRowGapStart;
    private int mRowGapLength;

    private Object[] mValues;

    public
    PackedObjectVector(int columns)
    {
        mColumns = columns;
        mRows = ArrayUtils.idealIntArraySize(0) / mColumns;

        mRowGapStart = 0;
        mRowGapLength = mRows;

        mValues = new Object[mRows * mColumns];
    }

    public E
    getValue(int row, int column)
    {
        if (row >= mRowGapStart)
            row += mRowGapLength;

        Object value = mValues[row * mColumns + column];

        return (E) value;
    }

    public void
    setValue(int row, int column, E value)
    {
        if (row >= mRowGapStart)
            row += mRowGapLength;

        mValues[row * mColumns + column] = value;
    }

    public void
    insertAt(int row, E[] values)
    {
        moveRowGapTo(row);

        if (mRowGapLength == 0)
            growBuffer();

        mRowGapStart++;
        mRowGapLength--;

        if (values == null)
            for (int i = 0; i < mColumns; i++)
                setValue(row, i, null);
        else
            for (int i = 0; i < mColumns; i++)
                setValue(row, i, values[i]);
    }

    public void
    deleteAt(int row, int count)
    {
        moveRowGapTo(row + count);

        mRowGapStart -= count;
        mRowGapLength += count;

        if (mRowGapLength > size() * 2)
        {
            // dump();
            // growBuffer();
        }
    }

    public int
    size()
    {
        return mRows - mRowGapLength;
    }

    public int
    width()
    {
        return mColumns;
    }

    private void
    growBuffer()
    {
        int newsize = size() + 1;
        newsize = ArrayUtils.idealIntArraySize(newsize * mColumns) / mColumns;
        Object[] newvalues = new Object[newsize * mColumns];

        int after = mRows - (mRowGapStart + mRowGapLength);

        System.arraycopy(mValues, 0, newvalues, 0, mColumns * mRowGapStart);
        System.arraycopy(mValues, (mRows - after) * mColumns, newvalues, (newsize - after) * mColumns, after * mColumns);

        mRowGapLength += newsize - mRows;
        mRows = newsize;
        mValues = newvalues;
    }

    private void
    moveRowGapTo(int where)
    {
        if (where == mRowGapStart)
            return;

        if (where > mRowGapStart)
        {
            int moving = where + mRowGapLength - (mRowGapStart + mRowGapLength);

            for (int i = mRowGapStart + mRowGapLength; i < mRowGapStart + mRowGapLength + moving; i++)
            {
                int destrow = i - (mRowGapStart + mRowGapLength) + mRowGapStart;

                for (int j = 0; j < mColumns; j++)
                {
                    Object val = mValues[i * mColumns + j];

                    mValues[destrow * mColumns + j] = val;
                }
            }
        }
        else /* where < mRowGapStart */
        {
            int moving = mRowGapStart - where;

            for (int i = where + moving - 1; i >= where; i--)
            {
                int destrow = i - where + mRowGapStart + mRowGapLength - moving;

                for (int j = 0; j < mColumns; j++)
                {
                    Object val = mValues[i * mColumns + j];

                    mValues[destrow * mColumns + j] = val;
                }
            }
        }

        mRowGapStart = where;
    }

    public void // XXX
    dump()
    {
        for (int i = 0; i < mRows; i++)
        {
            for (int j = 0; j < mColumns; j++)
            {
                Object val = mValues[i * mColumns + j];

                if (i < mRowGapStart || i >= mRowGapStart + mRowGapLength)
                    System.out.print(val + " ");
                else
                    System.out.print("(" + val + ") ");
            }

            System.out.print(" << \n");
        }

        System.out.print("-----\n\n");
    }
}