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/*
 * Copyright (c) 2009 Piotr Piastucki
 * 
 * This file is part of Patchca CAPTCHA library.
 * 
 *  Patchca is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  
 *  Patchca is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with Patchca. If not, see .
 */
package cn.atomtool.captcha.text.renderer;


import cn.atomtool.captcha.color.ColorFactory;
import cn.atomtool.captcha.font.FontFactory;

import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;

public abstract class AbstractTextRenderer implements TextRenderer {

	protected int leftMargin;
	protected int rightMargin;
	protected int topMargin;
	protected int bottomMargin;

	protected abstract void arrangeCharacters(int width, int height, TextString ts);

	public AbstractTextRenderer() {
		leftMargin = rightMargin = 5;
		topMargin = bottomMargin = 5;
	}

	@Override
	public void setLeftMargin(int leftMargin) {
		this.leftMargin = leftMargin;
	}

	@Override
	public void setRightMargin(int rightMargin) {
		this.rightMargin = rightMargin;
	}

	@Override
	public void setTopMargin(int topMargin) {
		this.topMargin = topMargin;
	}

	@Override
	public void setBottomMargin(int bottomMargin) {
		this.bottomMargin = bottomMargin;
	}

	@Override
	public void draw(String text, BufferedImage canvas, FontFactory fontFactory, ColorFactory colorFactory) {
		Graphics2D g = (Graphics2D) canvas.getGraphics();
		TextString ts = convertToCharacters(text, g, fontFactory, colorFactory);
		arrangeCharacters(canvas.getWidth(), canvas.getHeight(), ts);
		g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		g.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
		g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
		for (TextCharacter tc : ts.getCharacters()) {
			g.setColor(tc.getColor());
			g.drawString(tc.iterator(), (float) tc.getX(), (float) tc.getY());
		}
	}

	protected TextString convertToCharacters(String text, Graphics2D g, FontFactory fontFactory, ColorFactory colorFactory) {
		TextString characters = new TextString();
		FontRenderContext frc = g.getFontRenderContext();
		double lastx = 0;
		for (int i = 0; i < text.length(); i++) {
			Font font = fontFactory.getFont(i);
			char c = text.charAt(i);
			FontMetrics fm = g.getFontMetrics(font);
			Rectangle2D bounds = font.getStringBounds(String.valueOf(c), frc);
			TextCharacter tc = new TextCharacter();
			tc.setCharacter(c);
			tc.setFont(font);
			tc.setWidth(fm.charWidth(c));
			tc.setHeight(fm.getAscent() + fm.getDescent());
			tc.setAscent(fm.getAscent());
			tc.setDescent(fm.getDescent());
			tc.setX(lastx);
			tc.setY(0);
			tc.setFont(font);
			tc.setColor(colorFactory.getColor(i));
			lastx += bounds.getWidth();
			characters.addCharacter(tc);
		}
		return characters;
	}

}