Changeset 8994 in josm for trunk/src/org/openstreetmap/josm/tools

Timestamp:

2015-11-07T13:24:20+01:00 (9 years ago)

Author:

bastiK

Message:

fixed #12025 - text along line rendering for bi-directional text

File:

• trunk/src/org/openstreetmap/josm/tools/Utils.java (modified) (4 diffs)

trunk/src/org/openstreetmap/josm/tools/Utils.java

@@ -6 +6 @@
 
 import java.awt.Color;
+import java.awt.Font;
 import java.awt.Toolkit;
 import java.awt.datatransfer.Clipboard;
@@ -13 +14 @@
 import java.awt.datatransfer.Transferable;
 import java.awt.datatransfer.UnsupportedFlavorException;
+import java.awt.font.FontRenderContext;
+import java.awt.font.GlyphVector;
 import java.io.BufferedReader;
 import java.io.ByteArrayOutputStream;
@@ -34 +37 @@
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.text.Bidi;
 import java.text.MessageFormat;
 import java.util.AbstractCollection;
@@ -1493 +1497 @@
         return hashMapInitialCapacity(nEntries, 0.75f);
     }
+
+    /**
+     * Utility class to save a string along with its rendering direction
+     * (left-to-right or right-to-left).
+     */
+    private static class DirectionString {
+        public int direction;
+        public String str;
+
+        public DirectionString(int direction, String str) {
+            this.direction = direction;
+            this.str = str;
+        }
+    }
+
+    /**
+     * Convert a string to a list of {@link GlyphVector}s. The string may contain
+     * bi-directional text. The result will be in correct visual order.
+     * Each element of the resulting list corresponds to one section of the
+     * string with consistent writing direction (left-to-right or right-to-left).
+     *
+     * @param string the string to render
+     * @param font the font
+     * @param frc a FontRenderContext object
+     * @return a list of GlyphVectors
+     */
+    public static List<GlyphVector> getGlyphVectorsBidi(String string, Font font, FontRenderContext frc) {
+        List<GlyphVector> gvs = new ArrayList<>();
+        Bidi bidi = new Bidi(string, Bidi.DIRECTION_DEFAULT_LEFT_TO_RIGHT);
+        byte[] levels = new byte[bidi.getRunCount()];
+        DirectionString[] dirStrings = new DirectionString[levels.length];
+        for (int i = 0; i < levels.length; ++i) {
+            levels[i] = (byte) bidi.getRunLevel(i);
+            String substr = string.substring(bidi.getRunStart(i), bidi.getRunLimit(i));
+            int dir = levels[i] % 2 == 0 ? Bidi.DIRECTION_LEFT_TO_RIGHT : Bidi.DIRECTION_RIGHT_TO_LEFT;
+            dirStrings[i] = new DirectionString(dir, substr);
+        }
+        Bidi.reorderVisually(levels, 0, dirStrings, 0, levels.length);
+        for (int i = 0; i < dirStrings.length; ++i) {
+            char[] chars = dirStrings[i].str.toCharArray();
+            gvs.add(font.layoutGlyphVector(frc, chars, 0, chars.length, dirStrings[i].direction));
+        }
+        return gvs;
+    }
+
 }