org.metawidget.statically.StaticUtils Maven / Gradle / Ivy
// Metawidget
//
// This file is dual licensed under both the LGPL
// (http://www.gnu.org/licenses/lgpl-2.1.html) and the EPL
// (http://www.eclipse.org/org/documents/epl-v10.php). As a
// recipient of Metawidget, you may choose to receive it under either
// the LGPL or the EPL.
//
// Commercial licenses are also available. See http://metawidget.org
// for details.
package org.metawidget.statically;
import java.io.IOException;
import java.io.Writer;
/**
* Utilities for working with statically generated output.
*
* @author Richard Kennard
*/
public final class StaticUtils {
//
// Public statics
//
/**
* Writer that automatically inserts indents into the written characters, based on the current
* indentation level.
*/
public static class IndentedWriter
extends Writer {
//
// Private members
//
private Writer mWriter;
private int mIndent;
private boolean mWriteIndent = true;
//
// Constructor
//
/**
* Constructs a new IndentedWriter with the given inital indent.
*
* Note the initialIndent and carriage returns are applied to every line, including the
* first and last. If this is undesirable, clients can use String.trim().
*
* @param writer
* the writer to delegate all writes to
* @param initialIndent
* the initialIndent that will be applied to every line
*/
public IndentedWriter( Writer writer, int initialIndent ) {
mWriter = writer;
mIndent = initialIndent;
}
//
// Public methods
//
/**
* Increase the indentation level for subsequent writes.
*/
public void indent() {
mIndent++;
}
/**
* Decrease the indentation level for subsequent writes.
*/
public void outdent() {
if ( mIndent == 0 ) {
return;
}
mIndent--;
}
/**
* Write the given characters, inserting indents as necessary.
*/
@Override
public void write( char[] characters, int offset, int length )
throws IOException {
// For each character...
for ( int loop = offset, end = offset + length; loop < end; loop++ ) {
// ...write indent if necessary...
if ( mWriteIndent ) {
mWriteIndent = false;
for ( int indent = 0; indent < mIndent; indent++ ) {
mWriter.write( '\t' );
}
}
// ...then write the character...
mWriter.write( characters, loop, 1 );
// ...and watch for next indent
if ( characters[loop] == '\n' ) {
mWriteIndent = true;
}
}
}
@Override
public void flush()
throws IOException {
mWriter.flush();
}
@Override
public void close()
throws IOException {
mWriter.close();
}
@Override
public String toString() {
return mWriter.toString();
}
}
/**
* Writer that automatically inserts a leading space before the first character.
*/
public static class LeadingSpaceWriter
extends Writer {
//
// Private members
//
private Writer mWriter;
private boolean mWriteLeadingSpace = true;
//
// Constructor
//
/**
* Constructs a new LeadingSpaceWriter.
*
* @param writer
* the writer to delegate all writes to
*/
public LeadingSpaceWriter( Writer writer ) {
mWriter = writer;
}
//
// Public methods
//
/**
* Write the given characters, inserting a leading space.
*/
@Override
public void write( char[] characters, int offset, int length )
throws IOException {
for ( int loop = offset, end = offset + length; loop < end; loop++ ) {
if ( mWriteLeadingSpace ) {
mWriter.write( ' ' );
mWriteLeadingSpace = false;
}
mWriter.write( characters, loop, 1 );
}
}
@Override
public void flush()
throws IOException {
mWriter.flush();
}
@Override
public void close()
throws IOException {
mWriter.close();
}
}
//
// Private constructor
//
private StaticUtils() {
// Can never be called
}
}