Improve font selection mechanism by comparing all available font families

DEVSIX-7757

Author: vitali-pr

io/src/main/java/com/itextpdf/io/font/FontNames.java

@@ -36,8 +36,10 @@ public class FontNames {
 
     // name, ID = 4
     private String[][] fullName;
-    // name, ID = 1 or 16
+    // name, ID = 16 or 1
     private String[][] familyName;
+    // name, ID = 1
+    private String[][] familyName2;
     // name, ID = 2 or 17
     private String[][] subfamily;
     //name, ID = 6
@@ -82,6 +84,15 @@ public String[][] getFamilyName() {
         return familyName;
     }
 
+    /**
+     * Get extra family name if exists.
+     *
+     * @return extra family name if exists in the font, {@code null} otherwise.
+     */
+    public String[][] getFamilyName2() {
+        return familyName2;
+    }
+
     public String getStyle() {
         return style;
     }
@@ -176,6 +187,15 @@ protected void setFamilyName(String[][] familyName) {
         this.familyName = familyName;
     }
 
+    /**
+     * Set extra family name used for better fonts match.
+     *
+     * @param familyName2 family name to set.
+     */
+    protected void setFamilyName2(String[][] familyName2) {
+        this.familyName2 = familyName2;
+    }
+
     protected void setFamilyName(String familyName) {
         this.familyName = new String[][]{new String[]{"", "", "", familyName}};
     }

io/src/main/java/com/itextpdf/io/font/FontProgramDescriptor.java

@@ -37,6 +37,7 @@ public class FontProgramDescriptor {
     private final String fullNameLowerCase;
     private final String fontNameLowerCase;
     private final String familyNameLowerCase;
+    private final String familyName2LowerCase;
 
     private final String style;
     private final int macStyle;
@@ -63,7 +64,14 @@ public class FontProgramDescriptor {
         this.fontName = fontNames.getFontName();
         this.fontNameLowerCase = this.fontName.toLowerCase();
         this.fullNameLowerCase = fontNames.getFullName()[0][3].toLowerCase();
-        this.familyNameLowerCase = fontNames.getFamilyName() != null && fontNames.getFamilyName()[0][3] != null ? fontNames.getFamilyName()[0][3].toLowerCase() : null;
+        this.familyNameLowerCase = fontNames.getFamilyName() != null && fontNames.getFamilyName()[0][3] != null ?
+                fontNames.getFamilyName()[0][3].toLowerCase() : null;
+        // For font family2 let's take the last element in array. The family in the 1st element has high chance
+        // to be the same as returned by getFamilyName. Ideally we should take different families based on OS
+        // but it breaks the compatibility, produces different results on different OSs etc.
+        String[][] familyName2 = fontNames.getFamilyName2();
+        this.familyName2LowerCase = familyName2 != null && familyName2[familyName2.length - 1][3] != null ?
+                familyName2[familyName2.length - 1][3].toLowerCase() : null;
         this.style = fontNames.getStyle();
         this.weight = fontNames.getFontWeight();
         this.macStyle = fontNames.getMacStyle();
@@ -118,6 +126,15 @@ public String getFamilyNameLowerCase() {
         return familyNameLowerCase;
     }
 
+    /**
+     * Get extra family name if exists.
+     *
+     * @return extra family name if exists in the font, {@code null} otherwise.
+     */
+    public String getFamilyName2LowerCase() {
+        return familyName2LowerCase;
+    }
+
     public Set<String> getFullNameAllLangs() { return fullNamesAllLangs; }
 
     public Set<String> getFullNamesEnglishOpenType() { return fullNamesEnglishOpenType; }

io/src/main/java/com/itextpdf/io/font/OpenTypeParser.java

@@ -271,10 +271,12 @@ public FontNames getFontNames() {
         fontNames.setFontName(getPsFontName());
         fontNames.setFullName(fontNames.getNames(4));
         String[][] otfFamilyName = fontNames.getNames(16);
+        String[][] familyName = fontNames.getNames(1);
+        fontNames.setFamilyName2(familyName);
         if (otfFamilyName != null) {
             fontNames.setFamilyName(otfFamilyName);
         } else {
-            fontNames.setFamilyName(fontNames.getNames(1));
+            fontNames.setFamilyName(familyName);
         }
         String[][] subfamily = fontNames.getNames(2);
         if (subfamily != null) {

layout/src/main/java/com/itextpdf/layout/font/FontSelector.java

@@ -117,8 +117,16 @@ public int compare(FontInfo o1, FontInfo o2) {
                     fc.setMonospaceFlag(true);
                 }
                 boolean isLastFontFamilyToBeProcessed = i == fontFamilies.size() - 1;
-                res = characteristicsSimilarity(fontFamily, fc, o2, isLastFontFamilyToBeProcessed) - characteristicsSimilarity(fontFamily, fc, o1, isLastFontFamilyToBeProcessed);
+                res = characteristicsSimilarity(fontFamily, fc, o2, isLastFontFamilyToBeProcessed) -
+                        characteristicsSimilarity(fontFamily, fc, o1, isLastFontFamilyToBeProcessed);
+                // This method is a fallback to compare family2 field if the main method wasn't able to prioritize
+                // the fonts. We don't want to add this into scoring in the main method (characteristicsSimilarity)
+                // not to break anything for existing solutions.
+                if (res == 0) {
+                    res = family2Similarity(fontFamily, fc, o2) - family2Similarity(fontFamily, fc, o1);
+                }
             }
+
             return res;
         }
 
@@ -227,5 +235,19 @@ private static int characteristicsSimilarity(String fontFamily, FontCharacterist
 
             return score;
         }
+
+        /**
+         * This method is a fallback to compare family2 field if the main method wasn't able to prioritize the fonts.
+         */
+        private static int family2Similarity(String fontFamily, FontCharacteristics fc, FontInfo fontInfo) {
+            FontProgramDescriptor fontDescriptor = fontInfo.getDescriptor();
+            if (!fc.isMonospace() && null == fontInfo.getAlias() &&
+                    null != fontDescriptor.getFamilyName2LowerCase() &&
+                    fontDescriptor.getFamilyName2LowerCase().equals(fontFamily)) {
+                return 1;
+            }
+
+            return 0;
+        }
     }
 }

layout/src/test/java/com/itextpdf/layout/FontSelectorTest.java

@@ -647,7 +647,7 @@ public void openSansFontSetIncorrectNameTest01() {
         fc = new FontCharacteristics();
         fc.setFontStyle("italic");
         fc.setFontWeight((short) 500);
-        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-LightItalic");
+        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-Italic");
 
         fc = new FontCharacteristics();
         fc.setFontStyle("oblique");
@@ -742,7 +742,7 @@ public void openSansFontSetRegularTest01() {
         fc = new FontCharacteristics();
         fc.setFontStyle("italic");
         fc.setFontWeight((short) 500);
-        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-LightItalic");
+        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-Italic");
 
         fc = new FontCharacteristics();
         fc.setFontStyle("oblique");
@@ -838,7 +838,7 @@ public void openSansFontSetLightTest01() {
         fc = new FontCharacteristics();
         fc.setFontStyle("italic");
         fc.setFontWeight((short) 500);
-        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-LightItalic");
+        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-Italic");
 
         fc = new FontCharacteristics();
         fc.setFontStyle("oblique");
@@ -934,7 +934,7 @@ public void openSansFontSetExtraBoldTest01() {
         fc = new FontCharacteristics();
         fc.setFontStyle("italic");
         fc.setFontWeight((short) 500);
-        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-LightItalic");
+        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-Italic");
 
         fc = new FontCharacteristics();
         fc.setFontStyle("oblique");
@@ -963,6 +963,19 @@ public void openSansFontSetExtraBoldTest01() {
         assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-ExtraBoldItalic");
     }
 
+    @Test
+    public void openSansLightTest() {
+        FontSet set = getOpenSansFontSet();
+        addTimesFonts(set);
+        Collection<FontInfo> fontInfoCollection = set.getFonts();
+        List<String> fontFamilies = new ArrayList<>();
+        fontFamilies.add("Open Sans Light");
+
+        FontCharacteristics fc = new FontCharacteristics();
+        fc.setFontWeight((short) 500);
+        assertSelectedFont(fontInfoCollection, fontFamilies, fc, "OpenSans-Light");
+    }
+
     @Test
     public void openSansFontWeightBoldRenderingTest() throws Exception {
         String outFileName = destinationFolder + "openSansFontWeightBoldRendering.pdf";
@@ -1108,6 +1121,24 @@ public void monospaceFontIsNotSelectedInPreferenceToTestFamilyTest() {
                 new FontSelector(set.getFonts(), fontFamilies, fc).bestMatch().getDescriptor().getFontName());
     }
 
+    @Test
+    public void family2UsedToSortFontsTest() {
+        FontSet set = new FontSet();
+        set.addFont(fontsFolder + "Lato/Lato-Black.ttf");
+        set.addFont(fontsFolder + "Lato/Lato-Regular.ttf");
+        set.addFont(fontsFolder + "Lato/Lato-Italic.ttf");
+        set.addFont(fontsFolder + "Lato/Lato-Hairline.ttf");
+
+        List<String> fontFamilies = new ArrayList<>();
+        fontFamilies.add("Lato Hairline");
+
+        FontCharacteristics fc = new FontCharacteristics();
+        fc.setFontWeight((short) 300); // Between hairline (200) and regular (400)
+
+        Assert.assertEquals("Lato-Hairline",
+                new FontSelector(set.getFonts(), fontFamilies, fc).bestMatch().getDescriptor().getFontName());
+    }
+
     private void checkSelector(Collection<FontInfo> fontInfoCollection, String fontFamily,
                                String expectedNormal, String expectedBold, String expectedItalic, String expectedBoldItalic) {
         List<String> fontFamilies = new ArrayList<>();

layout/src/test/resources/com/itextpdf/layout/fonts/Lato/Lato-Black.ttf

@@ -0,0 +1,93 @@
+Copyright (c) 2011, TypeTogether (www.type-together.com),
+with Reserved Font Names "Abril" and "Abril Fatface"
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
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+OTHER DEALINGS IN THE FONT SOFTWARE.