Enhance the PDF glyph handling to handle advanced kerning and ligatur…

…es (#2059)

engine/org.eclipse.birt.report.engine.emitter.pdf/src/org/eclipse/birt/report/engine/emitter/pdf/PDFPage.java

@@ -20,7 +20,6 @@
 import java.awt.print.Paper;
 import java.io.ByteArrayInputStream;
 import java.io.File;
-import java.io.IOException;
 import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
@@ -599,7 +598,7 @@ private void drawText(String text, float textX, float textY, FontInfo fontInfo,
 					// PDF/A fallback font must be entered fully qualified with path and file name
 					String defaultFontPdfA = this.pageDevice.getDefaultFontPdfA();
 					if (defaultFontPdfA != null) {
-						font = BaseFont.createFont(defaultFontPdfA, BaseFont.IDENTITY_H, true);
+						font = BaseFont.createFont(defaultFontPdfA, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
 						font.setIncludeCidSet(this.pageDevice.isIncludeCidSet());
 					}
 					logger.log(Level.WARNING,

engine/org.eclipse.birt.report.engine.emitter.pdf/src/org/eclipse/birt/report/engine/emitter/pdf/PDFPageDevice.java

@@ -685,7 +685,7 @@ public void concatPDFs(List<InputStream> streamOfPDFFiles, boolean paginate) {
 			// Create a writer for the outputstream
 			PdfWriter writer = this.writer;
 
-			BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED); // TGXX
+			BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
 			PdfContentByte cb = writer.getDirectContent(); // Holds the PDF
 
 			PdfImportedPage page;

engine/org.eclipse.birt.report.engine.fonts/fontsConfig.xml

@@ -48,6 +48,9 @@
 	currently "Times-Roman", to denote a place of missing character. 
 -->
 <font>
+	<!-- font advanced kerning ligatures will be used, enabled: false/unused (default), true/used -->
+	<kerning-and-ligatures enabled="false" />
+
 <!--
 	In <font-aliases> section, you can:
 	a. Define a mapping from a generic family to a font family.

engine/org.eclipse.birt.report.engine.fonts/fontsConfig_pdf.xml

@@ -14,6 +14,8 @@
  *******************************************************************************
 -->
 <font>
+	<!-- font advanced kerning ligatures will be used, enabled: false/unused (default), true/used -->
+	<!--<kerning-and-ligatures enabled="true" />-->
 	<font-aliases>
 		<mapping name="serif" font-family="Times-Roman" />
 		<mapping name="sans-serif" font-family="Helvetica" />

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/font/FontConfigHandler.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Actuate Corporation.
+ * Copyright (c) 2008, 2025 Actuate Corporation and others
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -111,6 +111,9 @@ public ParseState startElement(String tagName) {
 	private final static String TAG_CHARACTER = "character"; //$NON-NLS-1$
 	private final static String ATTR_VALUE = "value"; //$NON-NLS-1$
 
+	private final static String TAG_FONT_KERNING = "kerning-and-ligatures"; //$NON-NLS-1$
+	private final static String ATTR_KERNING_ENABLED = "enabled"; //$NON-NLS-1$
+
 	private class RootState extends ParseState {
 
 		@Override
@@ -146,6 +149,9 @@ public ParseState startElement(String tagName) {
 			if (TAG_COMPOSITE_FONT.equals(tagValue)) {
 				return new CompositeFontState();
 			}
+			if (TAG_FONT_KERNING.equals(tagValue)) {
+				return new FontKerningState();
+			}
 			return super.startElement(tagName);
 		}
 	}
@@ -173,6 +179,17 @@ public void parseAttrs(Attributes attrs) {
 		}
 	}
 
+	private class FontKerningState extends ParseState {
+
+		@Override
+		public void parseAttrs(Attributes attrs) {
+			String kerning = getStringValue(attrs, ATTR_KERNING_ENABLED);
+			if (kerning != null) {
+				config.setFontKerning(Boolean.valueOf(kerning));
+			}
+		}
+	}
+
 	private class FontAliasesState extends ParseState {
 
 		@Override

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/font/FontConfigReader.java

@@ -25,8 +25,23 @@
 import org.xml.sax.InputSource;
 import org.xml.sax.SAXException;
 
+/**
+ * Reader to read the font configuration file (fontsConfig*.xml)
+ *
+ * @since 3.3
+ *
+ */
 public class FontConfigReader {
 
+	/**
+	 * Constructor
+	 *
+	 * @param url file url
+	 * @return the configured font mapping
+	 * @throws IOException
+	 * @throws ParserConfigurationException
+	 * @throws SAXException
+	 */
 	public FontMappingConfig parseConfig(URL url) throws IOException, ParserConfigurationException, SAXException {
 		InputStream input = url.openStream();
 		try (input) {

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/font/FontHandler.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2004,2008 Actuate Corporation.
+ * Copyright (c) 2004, 2008, 2025 Actuate Corporation and others
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -27,6 +27,7 @@
 
 import com.lowagie.text.Font;
 import com.lowagie.text.pdf.BaseFont;
+import com.lowagie.text.pdf.LayoutProcessor;
 
 /**
  * the font handler, which maps fontFamily, fontStyle, fontWeight properties to
@@ -99,6 +100,7 @@ public FontHandler(FontMappingManager fontManager, ITextContent textContent, boo
 				textContent) / PDFConstants.LAYOUT_TO_PDF_RATIO;
 
 		if (!fontSubstitution) {
+			enableKerningAndLigatures();
 			for (int i = 0; i < fontFamilies.length; i++) {
 				String fontName = fontManager.getAliasedFont(fontFamilies[i]);
 				bf = fontManager.createFont(fontName, fontStyle);
@@ -110,6 +112,14 @@ public FontHandler(FontMappingManager fontManager, ITextContent textContent, boo
 		}
 	}
 
+	/**
+	 * The constructor
+	 *
+	 * @param fontManager      font manager
+	 * @param fontFamilies     font families
+	 * @param fontStyle        font style
+	 * @param fontSubstitution font substitution
+	 */
 	public FontHandler(FontMappingManager fontManager, String fontFamilies[], int fontStyle, boolean fontSubstitution) {
 		this.fontManager = fontManager;
 
@@ -120,6 +130,7 @@ public FontHandler(FontMappingManager fontManager, String fontFamilies[], int fo
 		this.fontSize = fontSize / PDFConstants.LAYOUT_TO_PDF_RATIO;
 
 		if (!fontSubstitution) {
+			enableKerningAndLigatures();
 			for (int i = 0; i < fontFamilies.length; i++) {
 				String fontName = fontManager.getAliasedFont(fontFamilies[i]);
 				bf = fontManager.createFont(fontName, fontStyle);
@@ -192,6 +203,7 @@ public BaseFont getMappedFont(char c) {
 			}
 		}
 		// search in the font family to find one to display the character
+		enableKerningAndLigatures();
 		for (int i = 0; i < fontFamilies.length; i++) {
 			// Translate the font alias to font family
 			String fontFamily = fontManager.getAliasedFont(fontFamilies[i]);
@@ -306,4 +318,15 @@ private String getEnglishName(String[][] names) {
 
 		return tmp;
 	}
+
+	/**
+	 * Enable the font mode to handle advanced kerning and ligatures
+	 *
+	 * @since 4.19
+	 */
+	private void enableKerningAndLigatures() {
+		if (fontManager.useFontKerningAdvanced() && !LayoutProcessor.isEnabled()) {
+			LayoutProcessor.enableKernLiga();
+		}
+	}
 }

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/font/FontMappingConfig.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Actuate Corporation.
+ * Copyright (c) 2008, 2025 Actuate Corporation and others
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -45,6 +45,9 @@ public class FontMappingConfig {
 	 */
 	protected HashMap<String, CompositeFontConfig> compositeFonts = new HashMap<String, CompositeFontConfig>();
 
+	/** Usage of the advanced font kerning and ligatures */
+	protected boolean fontKerningAdvancedUsage = false;
+
 	/**
 	 * Constructor
 	 */
@@ -144,4 +147,22 @@ public void addCompositeFont(CompositeFontConfig fontConfig) {
 	public Collection<CompositeFontConfig> getAllCompositeFonts() {
 		return compositeFonts.values();
 	}
+
+	/**
+	 * Set the usage of advanced font kerning and ligatures
+	 *
+	 * @param kerning usage of advanced font kerning and ligatures
+	 */
+	public void setFontKerning(boolean kerning) {
+		fontKerningAdvancedUsage = kerning;
+	}
+
+	/**
+	 * Get the usage of advanced font kerning and ligatures
+	 *
+	 * @return the usage of advanced font kerning and ligatures
+	 */
+	public boolean getFontKerning() {
+		return fontKerningAdvancedUsage;
+	}
 }

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/font/FontMappingManager.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2004,2008 Actuate Corporation.
+ * Copyright (c) 2004, 2008, 2025 Actuate Corporation and others
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -21,6 +21,12 @@
 
 import com.lowagie.text.pdf.BaseFont;
 
+/**
+ * Manager to handle the font mapping configuration
+ *
+ * @since 3.3
+ *
+ */
 public class FontMappingManager {
 
 	/** all fonts key */
@@ -40,6 +46,9 @@ public class FontMappingManager {
 	/** The font-family replacement */
 	private Map fontAliases = new HashMap();
 
+	/** Usage of the advanced font kerning and ligatures */
+	private boolean fontKerningAdvancedUsage = false;
+
 	/**
 	 * composite fonts
 	 */
@@ -54,10 +63,14 @@ public class FontMappingManager {
 			this.fontAliases.putAll(parent.getFontAliases());
 			this.fontEncodings.putAll(parent.getFontEncodings());
 			this.compositeFonts.putAll(parent.getCompositeFonts());
+			if (!this.fontKerningAdvancedUsage)
+				this.fontKerningAdvancedUsage = parent.fontKerningAdvancedUsage;
 		}
 		this.fontEncodings.putAll(config.fontEncodings);
 		this.searchSequences.putAll(config.searchSequences);
 		this.fontAliases.putAll(config.fontAliases);
+		if (!this.fontKerningAdvancedUsage)
+			this.fontKerningAdvancedUsage = config.fontKerningAdvancedUsage;
 
 		String[] sequence = getSearchSequence(locale);
 		Iterator iter = config.compositeFonts.entrySet().iterator();
@@ -70,26 +83,60 @@ public class FontMappingManager {
 		}
 	}
 
+	/**
+	 * Get the parent font mapping manager
+	 *
+	 * @return the parent font mapping manager
+	 */
 	public FontMappingManager getParent() {
 		return parent;
 	}
 
+	/**
+	 * Get the font encodings
+	 *
+	 * @return the font encodings
+	 */
 	public Map getFontEncodings() {
 		return fontEncodings;
 	}
 
+	/**
+	 * Get the font aliases
+	 *
+	 * @return the font aliases
+	 */
 	public Map getFontAliases() {
 		return fontAliases;
 	}
 
+	/**
+	 * Get the search sequences
+	 *
+	 * @return the search sequences
+	 */
 	public Map getSearchSequences() {
 		return searchSequences;
 	}
 
+	/**
+	 * Get the composite fonts
+	 *
+	 * @return the composite fonts
+	 */
 	public Map getCompositeFonts() {
 		return compositeFonts;
 	}
 
+	/**
+	 * Get the usage of advanced font kerning and ligatures
+	 *
+	 * @return the usage of advanced font kerning and ligatures
+	 */
+	public boolean useFontKerningAdvanced() {
+		return fontKerningAdvancedUsage;
+	}
+
 	protected String[] getSearchSequence(Locale locale) {
 		StringBuilder sb = new StringBuilder();
 		String[] localeKeys = new String[3];
@@ -105,10 +152,22 @@ protected String[] getSearchSequence(Locale locale) {
 		return null;
 	}
 
+	/**
+	 * Get the composite font based at font name
+	 *
+	 * @param name font name
+	 * @return the composite font based at font name
+	 */
 	public CompositeFont getCompositeFont(String name) {
 		return (CompositeFont) compositeFonts.get(name);
 	}
 
+	/**
+	 * Get the default physical font
+	 *
+	 * @param c special character of the font
+	 * @return the default physical font
+	 */
 	public String getDefaultPhysicalFont(char c) {
 		CompositeFont compositeFont = (CompositeFont) compositeFonts.get(FONT_NAME_ALL_FONTS);
 		if (compositeFont != null) {
@@ -121,6 +180,12 @@ public String getDefaultPhysicalFont(char c) {
 		return null;
 	}
 
+	/**
+	 * Get the aliased font
+	 *
+	 * @param fontAlias font alias name
+	 * @return the aliased font
+	 */
 	public String getAliasedFont(String fontAlias) {
 		String alias = (String) fontAliases.get(fontAlias.toLowerCase());
 		if (alias != null) {
@@ -133,7 +198,7 @@ public String getAliasedFont(String fontAlias) {
 	 * Creates iText BaseFont with the given font family name.
 	 *
 	 * @param fontFamily the specified font family name.
-	 * @param style      font style
+	 * @param fontStyle  font style
 	 * @return the created BaseFont.
 	 */
 	public BaseFont createFont(String fontFamily, int fontStyle) {