/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
/* $Id: TXTState.java 426576 2006-07-28 15:44:37Z jeremias $ */
package org.apache.fop.render.txt;
import java.awt.Point;
import java.awt.geom.Rectangle2D;
import java.util.Iterator;
import java.util.LinkedList;
import org.apache.fop.area.CTM;
/**
* This keeps information about the current state when writing to txt, i.e.
* manages coordinate transformation matrices for getting absolute coordinates.
*/
public class TXTState {
/** Keeps all coordinate transformation matrices during rendering. */
private LinkedList stackCTM = new LinkedList();
/**
* Current result coordinate transformation matrix. It's product of
* all matrices in order, saved in <code>stackCTM</code>.
*/
private CTM resultCTM = new CTM();
/**
* Constructs a newly allocated <code>TXTState</code> object.
*/
public TXTState() {
}
/**
* Updates result coordinate transformation matrix
* (i.e. <code>resultCTM</code>), multipliing it by given matrix.
*
* @param ctm CTM
*/
private void updateResultCTM(CTM ctm) {
resultCTM = resultCTM.multiply(ctm);
}
/**
* Recalculate current result coordinate transformation matrix.
*/
private void calcResultCTM() {
resultCTM = new CTM();
for (Iterator i = stackCTM.iterator(); i.hasNext();) {
updateResultCTM((CTM) i.next());
}
}
/**
* Push the current coordinate transformation matrix onto the stack and
* reevaluate <code>resultCTM</code>.
*
* @param ctm instance of CTM
*/
public void push(CTM ctm) {
stackCTM.addLast(ctm);
updateResultCTM(ctm);
}
/**
* Pop the coordinate transformation matrix from the stack and reevaluate
* <code>resultCTM</code>.
*/
public void pop() {
stackCTM.removeLast();
calcResultCTM();
}
/**
* Modifies coordinate transformation matrix in such a way, so
* x-shift and y-shift will be transformed in text positions.
*
* @param ctm CTM to modify
* @return instance of CTM
*/
public CTM refineCTM(CTM ctm) {
double[] da = ctm.toArray();
// refine x-shift
da[4] = Helper.roundPosition((int) da[4], TXTRenderer.CHAR_WIDTH);
// refine y-shift
da[5] = Helper.roundPosition((int) da[5], TXTRenderer.CHAR_HEIGHT);
return new CTM(da[0], da[1], da[2], da[3], da[4], da[5]);
}
/**
* Transforms <code>point</code> using <code>ctm</code>.
*
* @param p Point
* @param ctm CTM
* @return transformed Point
*/
public Point transformPoint(Point p, CTM ctm) {
Rectangle2D r = new Rectangle2D.Double(p.x, p.y, 0, 0);
CTM nctm = refineCTM(ctm);
r = nctm.transform(r);
return new Point((int) r.getX(), (int) r.getY());
}
/**
* Transforms point (x, y) using <code>resultCTM</code>.
*
* @param x x-coordinate
* @param y y-coordinate
* @return transformed Point
*/
public Point transformPoint(int x, int y) {
return transformPoint(new Point(x, y), resultCTM);
}
/**
* @return current result coordinate transformation matrix
*/
public CTM getResultCTM() {
return resultCTM;
}
}