com.ibm.wala.cast.js.translator.RangePosition.java Source code

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Here is the source code for com.ibm.wala.cast.js.translator.RangePosition.java

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/*******************************************************************************
 * Copyright (c) 2007 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package com.ibm.wala.cast.js.translator;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;

import org.apache.commons.io.IOUtils;

import com.ibm.wala.cast.tree.CAstSourcePositionMap.Position;
import com.ibm.wala.cast.tree.impl.AbstractSourcePosition;

public class RangePosition extends AbstractSourcePosition implements Position {
    private final static int TABSIZE = 4;
    private final URL url;
    private final int line;
    private final int startOffset;
    private final int endOffset;

    private int col = -1;
    private int lastLine = -1;
    private int lastCol = -1;

    public RangePosition(URL url, int line, int startOffset, int endOffset) {
        super();
        this.url = url;
        this.line = line;
        this.startOffset = startOffset;
        this.endOffset = endOffset;
    }

    @Override
    public int compareTo(Object o) {
        Position other = (Position) o;
        if (startOffset != other.getFirstOffset()) {
            return startOffset - other.getFirstOffset();
        } else {
            return endOffset - other.getLastOffset();
        }
    }

    @Override
    public int getFirstLine() {
        return line;
    }

    @Override
    public int getLastLine() {
        if (lastLine == -1) {
            String content;
            Reader reader = null;
            try {
                reader = getReader();
                content = IOUtils.toString(reader).substring(startOffset, endOffset);
                int nrOfNewlines = content.length() - content.replace("\n", "").length();
                lastLine = line + nrOfNewlines;
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                IOUtils.closeQuietly(reader);
            }
        }

        return lastLine;
    }

    @Override
    public int getFirstCol() {
        if (col == -1) {
            col = getCol(getFirstLine(), startOffset);
        }

        return col;
    }

    @Override
    public int getLastCol() {
        if (lastCol == -1) {
            lastCol = getCol(getLastLine(), endOffset);
        }

        return lastCol;
    }

    private int getCol(int line, int offset) {
        int col = -1;
        Reader reader = null;
        try {
            reader = getReader();
            col = getCol(IOUtils.toString(reader), line, offset);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            IOUtils.closeQuietly(reader);
        }

        return col;
    }

    public static int getCol(String content, int line, int offset) {
        if (line == 1) {
            return offset + 1;
        }
        int pos = -1;
        for (int i = 0; i < line - 1; i++) {
            pos = content.indexOf('\n', pos + 1);
        }

        try {
            String lineBeginning = content.substring(pos, offset);
            int nrOfTabs = lineBeginning.length() - lineBeginning.replace("\t", "").length();
            return offset - pos + (TABSIZE - 1) * nrOfTabs;
        } catch (StringIndexOutOfBoundsException e) {
            e.printStackTrace();
            return -1;
        }
    }

    @Override
    public int getFirstOffset() {
        return startOffset;
    }

    @Override
    public int getLastOffset() {
        return endOffset;
    }

    @Override
    public URL getURL() {
        return url;
    }

    @Override
    public Reader getReader() throws IOException {
        return new InputStreamReader(url.openStream());
    }
}