001/*
002 * $Id: TextRenderInfo.java 4784 2011-03-15 08:33:00Z blowagie $
003 *
004 * This file is part of the iText (R) project.
005 * Copyright (c) 1998-2011 1T3XT BVBA
006 * Authors: Kevin Day, Bruno Lowagie, Paulo Soares, et al.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU Affero General Public License version 3
010 * as published by the Free Software Foundation with the addition of the
011 * following permission added to Section 15 as permitted in Section 7(a):
012 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
013 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
014 *
015 * This program is distributed in the hope that it will be useful, but
016 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
017 * or FITNESS FOR A PARTICULAR PURPOSE.
018 * See the GNU Affero General Public License for more details.
019 * You should have received a copy of the GNU Affero General Public License
020 * along with this program; if not, see http://www.gnu.org/licenses or write to
021 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
022 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
023 * http://itextpdf.com/terms-of-use/
024 *
025 * The interactive user interfaces in modified source and object code versions
026 * of this program must display Appropriate Legal Notices, as required under
027 * Section 5 of the GNU Affero General Public License.
028 *
029 * In accordance with Section 7(b) of the GNU Affero General Public License,
030 * a covered work must retain the producer line in every PDF that is created
031 * or manipulated using iText.
032 *
033 * You can be released from the requirements of the license by purchasing
034 * a commercial license. Buying such a license is mandatory as soon as you
035 * develop commercial activities involving the iText software without
036 * disclosing the source code of your own applications.
037 * These activities include: offering paid services to customers as an ASP,
038 * serving PDFs on the fly in a web application, shipping iText with a closed
039 * source product.
040 *
041 * For more information, please contact iText Software Corp. at this
042 * address: sales@itextpdf.com
043 */
044package com.itextpdf.text.pdf.parser;
045
046import java.util.ArrayList;
047import java.util.Collection;
048
049import com.itextpdf.text.pdf.BaseFont;
050import com.itextpdf.text.pdf.DocumentFont;
051
052/**
053 * Provides information and calculations needed by render listeners
054 * to display/evaluate text render operations.
055 * <br><br>
056 * This is passed between the {@link PdfContentStreamProcessor} and 
057 * {@link RenderListener} objects as text rendering operations are
058 * discovered
059 */
060public class TextRenderInfo {
061        
062    private final String text;
063    private final Matrix textToUserSpaceTransformMatrix;
064    private final GraphicsState gs;
065    /**
066     * Array containing marked content info for the text.
067     * @since 5.0.2
068     */
069    private final Collection<MarkedContentInfo> markedContentInfos;
070    
071    /**
072     * Creates a new TextRenderInfo object
073     * @param text the text that should be displayed
074     * @param gs the graphics state (note: at this time, this is not immutable, so don't cache it)
075     * @param textMatrix the text matrix at the time of the render operation
076     * @param markedContentInfo the marked content sequence, if available
077     */
078    TextRenderInfo(String text, GraphicsState gs, Matrix textMatrix, Collection<MarkedContentInfo> markedContentInfo) {
079        this.text = text;
080        this.textToUserSpaceTransformMatrix = textMatrix.multiply(gs.ctm);
081        this.gs = gs;
082        this.markedContentInfos = new ArrayList<MarkedContentInfo>(markedContentInfo);
083    }
084    
085    /**
086     * @return the text to render
087     */
088    public String getText(){ 
089        return text; 
090    }
091
092        /**
093         * Checks if the text belongs to a marked content sequence
094         * with a given mcid.
095         * @param mcid a marked content id
096         * @return true if the text is marked with this id
097         * @since 5.0.2
098         */
099        public boolean hasMcid(int mcid) {
100                for (MarkedContentInfo info : markedContentInfos) {
101            if (info.hasMcid())
102                if(info.getMcid() == mcid)
103                    return true;
104        }
105
106                return false;
107        }
108
109        /**
110     * @return the unscaled (i.e. in Text space) width of the text
111     */
112    float getUnscaledWidth(){ 
113        return getStringWidth(text); 
114    }
115    
116    /**
117     * Gets the baseline for the text (i.e. the line that the text 'sits' on)
118     * @return the baseline line segment
119     * @since 5.0.2
120     */
121    public LineSegment getBaseline(){
122        return getUnscaledBaselineWithOffset(0).transformBy(textToUserSpaceTransformMatrix);
123    }
124    
125    /**
126     * Gets the ascentline for the text (i.e. the line that represents the topmost extent that a string of the current font could have)
127     * @return the ascentline line segment
128     * @since 5.0.2
129     */
130    public LineSegment getAscentLine(){
131        float ascent = gs.getFont().getFontDescriptor(BaseFont.ASCENT, gs.getFontSize());
132        return getUnscaledBaselineWithOffset(ascent).transformBy(textToUserSpaceTransformMatrix);
133    }
134    
135    /**
136     * Gets the descentline for the text (i.e. the line that represents the bottom most extent that a string of the current font could have)
137     * @return the descentline line segment
138     * @since 5.0.2
139     */
140    public LineSegment getDescentLine(){
141        // per getFontDescription() API, descent is returned as a negative number, so we apply that as a normal vertical offset
142        float descent = gs.getFont().getFontDescriptor(BaseFont.DESCENT, gs.getFontSize());
143        return getUnscaledBaselineWithOffset(descent).transformBy(textToUserSpaceTransformMatrix);
144    }
145    
146    private LineSegment getUnscaledBaselineWithOffset(float yOffset){
147        return new LineSegment(new Vector(0, yOffset, 1), new Vector(getUnscaledWidth(), yOffset, 1));
148    }
149
150        /**
151         * Getter for the font
152         * @return the font
153         * @since iText 5.0.2
154         */
155        public DocumentFont getFont() {
156                return gs.getFont();
157        }
158    
159    /**
160     * @return The width, in user space units, of a single space character in the current font
161     */
162    public float getSingleSpaceWidth(){
163        LineSegment textSpace = new LineSegment(new Vector(0, 0, 1), new Vector(getUnscaledFontSpaceWidth(), 0, 1));
164        LineSegment userSpace = textSpace.transformBy(textToUserSpaceTransformMatrix);
165        return userSpace.getLength();
166    }
167    
168    /**
169     * @return the text render mode that should be used for the text.  From the
170     * PDF specification, this means:
171     * <ul>
172     *   <li>0 = Fill text</li>
173     *   <li>1 = Stroke text</li>
174     *   <li>2 = Fill, then stroke text</li>
175     *   <li>3 = Invisible</li>
176     *   <li>4 = Fill text and add to path for clipping</li>
177     *   <li>5 = Stroke text and add to path for clipping</li>
178     *   <li>6 = Fill, then stroke text and add to path for clipping</li>
179     *   <li>7 = Add text to padd for clipping</li>
180     * </ul>
181     * @since iText 5.0.1
182     */
183    public int getTextRenderMode(){
184        return gs.renderMode;
185    }
186    
187    /**
188     * Calculates the width of a space character.  If the font does not define
189     * a width for a standard space character \u0020, we also attempt to use
190     * the width of \u00A0 (a non-breaking space in many fonts)
191     * @return the width of a single space character in text space units
192     */
193    private float getUnscaledFontSpaceWidth(){
194        char charToUse = ' ';
195        if (gs.font.getWidth(charToUse) == 0)
196            charToUse = '\u00A0';
197        return getStringWidth(String.valueOf(charToUse));
198    }
199    
200    /**
201     * Gets the width of a String in text space units
202     * @param string    the string that needs measuring
203     * @return  the width of a String in text space units
204     */
205    private float getStringWidth(String string){
206        DocumentFont font = gs.font;
207        char[] chars = string.toCharArray();
208        float totalWidth = 0;
209        for (int i = 0; i < chars.length; i++) {
210            float w = font.getWidth(chars[i]) / 1000.0f;
211            float wordSpacing = chars[i] == 32 ? gs.wordSpacing : 0f;
212            totalWidth += (w * gs.fontSize + gs.characterSpacing + wordSpacing) * gs.horizontalScaling;
213        }
214        
215        return totalWidth;
216    }
217    
218}