/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2020, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library 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 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 *
 */

package org.jfree.chart.text;

import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;
import org.jfree.chart.ui.Size2D;
import org.jfree.chart.ui.TextAnchor;

/**
 * A sequence of {@link TextFragment} objects that together form a line of 
 * text.  A sequence of text lines is managed by the {@link TextBlock} class.
 */
public class TextLine implements Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 7100085690160465444L;
    
    /** Storage for the text fragments that make up the line. */
    private List fragments;

    /**
     * Creates a new empty line.
     */
    public TextLine() {
        this.fragments = new java.util.ArrayList();
    }
    
    /**
     * Creates a new text line using the default font.
     * 
     * @param text  the text ({@code null} not permitted).
     */
    public TextLine(String text) {
        this(text, TextFragment.DEFAULT_FONT);   
    }
    
    /**
     * Creates a new text line.
     * 
     * @param text  the text ({@code null} not permitted).
     * @param font  the text font ({@code null} not permitted).
     */
    public TextLine(String text, Font font) {
        this.fragments = new java.util.ArrayList();
        final TextFragment fragment = new TextFragment(text, font);
        this.fragments.add(fragment);
    }
    
    /**
     * Creates a new text line.
     * 
     * @param text  the text ({@code null} not permitted).
     * @param font  the text font ({@code null} not permitted).
     * @param paint  the text color ({@code null} not permitted).
     */
    public TextLine(String text, Font font, Paint paint) {
        if (text == null) {
            throw new IllegalArgumentException("Null 'text' argument.");   
        }
        if (font == null) {
            throw new IllegalArgumentException("Null 'font' argument.");   
        }
        if (paint == null) {
            throw new IllegalArgumentException("Null 'paint' argument.");   
        }
        this.fragments = new java.util.ArrayList();
        final TextFragment fragment = new TextFragment(text, font, paint);
        this.fragments.add(fragment);
    }
    
    /**
     * Adds a text fragment to the text line.
     * 
     * @param fragment  the text fragment ({@code null} not permitted).
     */
    public void addFragment(TextFragment fragment) {
        this.fragments.add(fragment);        
    }
    
    /**
     * Removes a fragment from the line.
     * 
     * @param fragment  the fragment to remove.
     */
    public void removeFragment(TextFragment fragment) {
        this.fragments.remove(fragment);
    }
    
    /**
     * Draws the text line.
     * 
     * @param g2  the graphics device.
     * @param anchorX  the x-coordinate for the anchor point.
     * @param anchorY  the y-coordinate for the anchor point.
     * @param anchor  the point on the text line that is aligned to the anchor 
     *                point.
     * @param rotateX  the x-coordinate for the rotation point.
     * @param rotateY  the y-coordinate for the rotation point.
     * @param angle  the rotation angle (in radians).
     */
    public void draw(Graphics2D g2, float anchorX, float anchorY, 
            TextAnchor anchor, float rotateX, float rotateY, double angle) {
    
        Size2D dim = calculateDimensions(g2);
        float xAdj = 0.0f;
        if (anchor.isHorizontalCenter()) {
            xAdj = (float) -dim.getWidth() / 2.0f;
        }
        else if (anchor.isRight()) {
            xAdj = (float) -dim.getWidth();
        }
        float x = anchorX + xAdj;
        final float yOffset = calculateBaselineOffset(g2, anchor);
        final Iterator iterator = this.fragments.iterator();
        while (iterator.hasNext()) {
            final TextFragment fragment = (TextFragment) iterator.next();
            final Size2D d = fragment.calculateDimensions(g2);
            fragment.draw(g2, x, anchorY + yOffset, TextAnchor.BASELINE_LEFT, 
                    rotateX, rotateY, angle);
            x = x + (float) d.getWidth();
        }
    
    }
    
    /**
     * Calculates the width and height of the text line.
     * 
     * @param g2  the graphics device.
     * 
     * @return The width and height.
     */
    public Size2D calculateDimensions(Graphics2D g2) {
        double width = 0.0;
        double height = 0.0;
        final Iterator iterator = this.fragments.iterator();
        while (iterator.hasNext()) {
            final TextFragment fragment = (TextFragment) iterator.next();
            final Size2D dimension = fragment.calculateDimensions(g2);
            width = width + dimension.getWidth();
            height = Math.max(height, dimension.getHeight());
        }
        return new Size2D(width, height);
    }
    
    /**
     * Returns the first text fragment in the line.
     * 
     * @return The first text fragment in the line.
     */
    public TextFragment getFirstTextFragment() {
        TextFragment result = null;
        if (this.fragments.size() > 0) {
            result = (TextFragment) this.fragments.get(0);
        }    
        return result;
    }
    
    /**
     * Returns the last text fragment in the line.
     * 
     * @return The last text fragment in the line.
     */
    public TextFragment getLastTextFragment() {
        TextFragment result = null;
        if (this.fragments.size() > 0) {
            result = (TextFragment) this.fragments.get(this.fragments.size() 
                    - 1);
        }    
        return result;
    }
    
    /**
     * Calculate the offsets required to translate from the specified anchor 
     * position to the left baseline position.
     * 
     * @param g2  the graphics device.
     * @param anchor  the anchor position.
     * 
     * @return The offsets.
     */
    private float calculateBaselineOffset(Graphics2D g2, TextAnchor anchor) {
        float result = 0.0f;
        Iterator iterator = this.fragments.iterator();
        while (iterator.hasNext()) {
            TextFragment fragment = (TextFragment) iterator.next();
            result = Math.max(result, 
                    fragment.calculateBaselineOffset(g2, anchor));
        }
        return result;
    }
    
    /**
     * Tests this object for equality with an arbitrary object.
     * 
     * @param obj  the object to test against ({@code null} permitted).
     * 
     * @return A boolean.
     */
    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (obj == this) {
            return true;   
        }
        if (obj instanceof TextLine) {
            final TextLine line = (TextLine) obj;
            return this.fragments.equals(line.fragments);
        }
        return false;
    }

    /**
     * Returns a hash code for this object.
     * 
     * @return A hash code.
     */
    @Override
    public int hashCode() {
        return (this.fragments != null ? this.fragments.hashCode() : 0);
    }

}