org.incava.analysis.DiffContextWriter Maven / Gradle / Ivy

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package org.incava.analysis;

import java.util.List;
import org.incava.ijdk.text.LocationRange;

/**
 * Writes differences with context. Actually returns the differences as strings.
 * Writing is left to the invoker.
 */
public class DiffContextWriter extends DiffWriter {
    public DiffContextWriter(List fromContents, List toContents) {
        super(fromContents, toContents);
    }

    public void printFrom(StringBuilder sb, FileDiff fdiff) {
        printLines(sb, true, fdiff, fdiff.getFirstLocation(), fromContents);
    }

    public void printTo(StringBuilder sb, FileDiff fdiff) {
        printLines(sb, false, fdiff, fdiff.getSecondLocation(), toContents);
    }

    protected String getLine(List lines, int lidx, int fromLine, int fromColumn, int toLine, int toColumn, boolean isDelete) {
        StringBuilder sb = new StringBuilder();
        sb.append("! ").append(lines.get(lidx - 1)).append(EOLN);
        return sb.toString();
    }

    protected void printLines(StringBuilder sb, boolean isDelete, FileDiff fdiff, LocationRange loc, List lines) {
        int fromLine = loc.getStart().getLine();
        int fromColumn = loc.getStart().getColumn();
        int toLine = loc.getEnd().getLine();
        int toColumn = loc.getEnd().getColumn();
        
        for (int lnum = Math.max(0, fromLine - 4); lnum < fromLine - 1; ++lnum) {
            sb.append("  ").append(lines.get(lnum));
            sb.append(EOLN);
        }

        // PMD reports columns using tabSize == 8, so we replace tabs with
        // spaces here.
        // ... I loathe tabs.

        for (int lidx = fromLine; lidx <= toLine; ++lidx) {
            String line = getLine(lines, lidx, fromLine, fromColumn, toLine, toColumn, isDelete);
            sb.append(line);
        }

        for (int lnum = toLine; lnum < Math.min(toLine + 3, lines.size()); ++lnum) {
            sb.append("  ").append(lines.get(lnum));
            sb.append(EOLN);
        }
    }

    protected void printLines(StringBuilder sb, FileDiff fdiff) {
        fdiff.printContext(this, sb);
        sb.append(DiffContextWriter.EOLN);
    }
}