org.nakedobjects.metamodel.commons.debug.DebugString Maven / Gradle / Ivy
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package org.nakedobjects.metamodel.commons.debug;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
public class DebugString {
private static final int COLUMN_SPACING = 25;
private static final int INDENT_WIDTH = 3;
private static final String LINE;
private static final int MAX_LINE_LENGTH;
private static final int MAX_SPACES_LENGTH;
private static final String SPACES = " ";
static {
LINE = "-------------------------------------------------------------------------------";
MAX_LINE_LENGTH = LINE.length();
MAX_SPACES_LENGTH = SPACES.length();
}
private int indent = 0;
private int section = 1;
private final StringBuffer string = new StringBuffer();
private boolean newLine = true;
/**
* Append the specified number within a space (number of spaces) specified by the width. E.g. "15 " where
* number is 15 and width is 4.
*/
public void append(final int number, final int width) {
appendIndent();
final int len = string.length();
string.append(number);
regularizeWidth(width, len);
}
/**
* Append the specified object by calling it toString() method.
*/
public void append(final Object object) {
if (object instanceof DebugInfo) {
indent();
appendTitle(((DebugInfo) object).debugTitle());
((DebugInfo) object).debugData(this);
unindent();
} else {
appendIndent();
string.append(object);
}
}
/**
* Append the specified object by calling its toString() method, placing it within specified
* space.
*/
public void append(final Object object, final int width) {
appendIndent();
final int len = string.length();
string.append(object);
regularizeWidth(width, len);
}
/**
* Append the specified number, displayed in hexadecimal notation, with the specified label, then start a
* new line.
*/
public void appendAsHexln(final String label, final long value) {
appendln(label, "#" + Long.toHexString(value));
}
/**
* Append the message and trace of the specified exception.
*/
public void appendException(final Exception e) {
ByteArrayOutputStream baos;
final PrintStream s = new PrintStream(baos = new ByteArrayOutputStream());
e.printStackTrace(s);
appendln(e.getMessage());
appendln(new String(baos.toByteArray()));
s.close();
}
/**
* Start a new line.
*
* @see #blankLine()
*/
public void appendln() {
string.append('\n');
newLine = true;
}
/**
* Append the specified text, then start a new line.
*/
public void appendln(final String text) {
appendIndent();
append(text);
appendln();
newLine = true;
}
/**
* Append the specified value, displayed as true or false, with the specified label, then start a new
* line.
*/
public void appendln(final String label, final boolean value) {
appendln(label, String.valueOf(value));
}
/**
* Append the specified number with the specified label, then start a new line.
*/
public void appendln(final String label, final double value) {
appendln(label, String.valueOf(value));
}
/**
* Append the specified number, displayed in hexadecimal notation, with the specified label, then start a
* new line.
*/
public void appendln(final String label, final long value) {
appendln(label, String.valueOf(value));
}
/**
* Append the specified object with the specified label, then start a new line.
*/
public void appendln(final String label, final Object object) {
appendIndent();
string.append(label);
final int spaces = COLUMN_SPACING - label.length();
string.append(": " + spaces(spaces > 0 ? spaces : 0));
string.append(object);
string.append('\n');
newLine = true;
}
/**
* Append the elements of the specified array with the specified label. Each element is appended on its
* own line, and a new line is added after the last element.
*/
public void appendln(final String label, final Object[] object) {
if (object.length == 0) {
appendln(label, "empty array");
} else {
appendln(label, object[0]);
for (int i = 1; i < object.length; i++) {
string.append(spaces(COLUMN_SPACING + 2));
string.append(object[i]);
string.append('\n');
}
newLine = true;
}
}
/**
* Append the specified title, then start a new line. A title is shown on two lines with the text on the
* first line and dashes on the second.
*/
public void appendTitle(final String title) {
appendln();
final String titleString = section++ + ". " + title;
// string.append('\n');
appendln(titleString);
// string.append('\n');
final String underline = LINE.substring(0, Math.min(MAX_LINE_LENGTH, titleString.length()));
appendln(underline);
// string.append('\n');
}
public void startSection(final String title) {
appendTitle(title);
indent();
}
public void endSection() {
appendln();
unindent();
}
/**
* Append a blank line only if there are existing lines and the previous line is not blank.
*/
public void blankLine() {
final int length = string.length();
if (length == 0) {
return;
}
final boolean hasLineEnding = string.charAt(length - 1) == '\n';
if (!hasLineEnding) {
string.append('\n');
string.append('\n');
newLine = true;
} else {
final boolean hasDoubleLineEnding = length >= 2 && string.charAt(length - 2) != '\n';
if (hasDoubleLineEnding) {
string.append('\n');
newLine = true;
}
}
}
/**
* Increase indent used when appending.
*/
public void indent() {
indent++;
}
private void appendIndent() {
if (newLine) {
final String spaces = spaces(Math.min(MAX_SPACES_LENGTH, indent * INDENT_WIDTH));
string.append(spaces);
newLine = false;
}
}
private void regularizeWidth(final int width, final int len) {
if (width > 0) {
final int textWidth = string.length() - len;
if (textWidth > width) {
string.setLength(len + width - 3);
string.append("...");
} else {
int spaces = width - textWidth;
spaces = Math.max(0, spaces);
string.append(SPACES.substring(0, spaces));
}
}
}
private String spaces(final int spaces) {
return SPACES.substring(0, spaces);
}
/**
* Return the String representation of this debug string.
*/
@Override
public String toString() {
return string.toString();
}
/**
* Decrease indent used when appending.
*/
public void unindent() {
if (indent > 0) {
indent--;
}
}
}
// Copyright (c) Naked Objects Group Ltd.