utils for characters such as getting width and determining if space

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@194618 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/org/apache/fop/util/CharUtilities.java b/src/org/apache/fop/util/CharUtilities.java
new file mode 100644 (file)
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--- /dev/null
+++ b/src/org/apache/fop/util/CharUtilities.java
@@ -0,0 +1,117 @@
+/*
+ * $Id$
+ * Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
+ * For details on use and redistribution please refer to the
+ * LICENSE file included with these sources.
+ */
+
+package org.apache.fop.util;
+
+import org.apache.fop.layout.FontState;
+
+/**
+ */
+public class CharUtilities {
+
+    /**
+     * Helper method for getting the width of a unicode char
+     * from the current fontstate.
+     * This also performs some guessing on widths on various
+     * versions of space that might not exists in the font.
+     */
+    public static int getCharWidth(char c, FontState fs) {
+        int width = fs.width(fs.mapChar(c));
+        if (width <= 0) {
+            // Estimate the width of spaces not represented in
+            // the font
+            int em = fs.width(fs.mapChar('m'));
+            int en = fs.width(fs.mapChar('n'));
+            if (em <= 0)
+                em = 500 * fs.getFontSize();
+            if (en <= 0)
+                en = em - 10;
+
+            if (c == ' ')
+                width = em;
+            if (c == '\u2000')
+                width = en;
+            if (c == '\u2001')
+                width = em;
+            if (c == '\u2002')
+                width = em / 2;
+            if (c == '\u2003')
+                width = fs.getFontSize();
+            if (c == '\u2004')
+                width = em / 3;
+            if (c == '\u2005')
+                width = em / 4;
+            if (c == '\u2006')
+                width = em / 6;
+            if (c == '\u2007')
+                width = getCharWidth(' ', fs);
+            if (c == '\u2008')
+                width = getCharWidth('.', fs);
+            if (c == '\u2009')
+                width = em / 5;
+            if (c == '\u200A')
+                width = 5;
+            if (c == '\u200B')
+                width = 100;
+            if (c == '\u00A0')
+                width = getCharWidth(' ', fs);
+            if (c == '\u202F')
+                width = getCharWidth(' ', fs) / 2;
+            if (c == '\u3000')
+                width = getCharWidth(' ', fs) * 2;
+            if ((c == '\n') || (c == '\r') || (c == '\t'))
+                width = getCharWidth(' ', fs);
+        }
+
+        return width;
+    }
+
+    /**
+     * Helper method to determine if the character is a
+     * space with normal behaviour. Normal behaviour means that
+     * it's not non-breaking
+     */
+    public static boolean isSpace(char c) {
+        if (c == ' ' || c == '\u2000' ||    // en quad
+        c == '\u2001' ||                    // em quad
+        c == '\u2002' ||                    // en space
+        c == '\u2003' ||                    // em space
+        c == '\u2004' ||                    // three-per-em space
+        c == '\u2005' ||                    // four--per-em space
+        c == '\u2006' ||                    // six-per-em space
+        c == '\u2007' ||                    // figure space
+        c == '\u2008' ||                    // punctuation space
+        c == '\u2009' ||                    // thin space
+        c == '\u200A' ||                    // hair space
+        c == '\u200B')                      // zero width space
+            return true;
+        else
+            return false;
+    }
+
+    /**
+     * Method to determine if the character is a nonbreaking
+     * space.
+     */
+    public static boolean isNBSP(char c) {
+        if (c == '\u00A0' || c == '\u202F' ||    // narrow no-break space
+        c == '\u3000' ||                    // ideographic space
+        c == '\uFEFF') {                    // zero width no-break space
+            return true;
+        } else
+            return false;
+    }
+
+    /**
+     * @return true if the character represents any kind of space
+     */
+    public static boolean isAnySpace(char c) {
+        boolean ret = (isSpace(c) || isNBSP(c));
+        return ret;
+    }
+}
+