Merge "Introduce font variation settings parser"

2 files changed, 177 insertions, 4 deletions

diff --git a/graphics/java/android/graphics/FontListParser.java b/graphics/java/android/graphics/FontListParser.java
index 7871aa81dded..069f81b75b32 100644
--- a/graphics/java/android/graphics/FontListParser.java
+++ b/graphics/java/android/graphics/FontListParser.java
@@ -21,6 +21,8 @@ import android.util.Xml;
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 
+import com.android.internal.annotations.VisibleForTesting;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
@@ -99,6 +101,67 @@ public class FontListParser {
         }
     }
 
+    // Note that a well-formed variation contains a four-character tag and a float as styleValue,
+    // with spacers in between. The tag is enclosd either by double quotes or single quotes.
+    @VisibleForTesting
+    public static Axis[] parseFontVariationSettings(String settings) {
+        String[] settingList = settings.split(",");
+        ArrayList<Axis> axisList = new ArrayList<>();
+        settingLoop:
+        for (String setting : settingList) {
+            int pos = 0;
+            while (pos < setting.length()) {
+                char c = setting.charAt(pos);
+                if (c == '\'' || c == '"') {
+                    break;
+                } else if (!isSpacer(c)) {
+                    continue settingLoop;  // Only spacers are allowed before tag appeared.
+                }
+                pos++;
+            }
+            if (pos + 7 > setting.length()) {
+                continue;  // 7 is the minimum length of tag-style value pair text.
+            }
+            if (setting.charAt(pos) != setting.charAt(pos + 5)) {
+                continue;  // Tag should be wrapped with double or single quote.
+            }
+            String tagString = setting.substring(pos + 1, pos + 5);
+            if (!TAG_PATTERN.matcher(tagString).matches()) {
+                continue;  // Skip incorrect format tag.
+            }
+            pos += 6;
+            while (pos < setting.length()) {
+                if (!isSpacer(setting.charAt(pos++))) {
+                    break;  // Skip spacers between the tag and the styleValue.
+                }
+            }
+            // Skip invalid styleValue
+            float styleValue;
+            String valueString = setting.substring(pos - 1);
+            if (!STYLE_VALUE_PATTERN.matcher(valueString).matches()) {
+                continue;  // Skip incorrect format styleValue.
+            }
+            try {
+                styleValue = Float.parseFloat(valueString);
+            } catch (NumberFormatException e) {
+                continue;  // ignoreing invalid number format
+            }
+            int tag = makeTag(tagString.charAt(0), tagString.charAt(1), tagString.charAt(2),
+                    tagString.charAt(3));
+            axisList.add(new Axis(tag, styleValue));
+        }
+        return axisList.toArray(new Axis[axisList.size()]);
+    }
+
+    @VisibleForTesting
+    public static int makeTag(char c1, char c2, char c3, char c4) {
+        return (c1 << 24) + (c2 << 16) + (c3 << 8) + c4;
+    }
+
+    private static boolean isSpacer(char c) {
+        return c == ' ' || c == '\r' || c == '\t' || c == '\n';
+    }
+
     private static Config readFamilies(XmlPullParser parser)
             throws XmlPullParserException, IOException {
         Config config = new Config();
@@ -179,10 +242,7 @@ public class FontListParser {
         int tag = 0;
         String tagStr = parser.getAttributeValue(null, "tag");
         if (tagStr != null && TAG_PATTERN.matcher(tagStr).matches()) {
-            tag = (tagStr.charAt(0) << 24) +
-                  (tagStr.charAt(1) << 16) +
-                  (tagStr.charAt(2) <<  8) +
-                  (tagStr.charAt(3)      );
+            tag = makeTag(tagStr.charAt(0), tagStr.charAt(1), tagStr.charAt(2), tagStr.charAt(3));
         } else {
             throw new XmlPullParserException("Invalid tag attribute value.", parser, null);
         }
diff --git a/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java b/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java
new file mode 100644
index 000000000000..e4d6aa8b64f5
--- /dev/null
+++ b/graphics/tests/graphicstests/src/android/graphics/VariationParserTest.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.graphics;
+
+import android.test.suitebuilder.annotation.SmallTest;
+import junit.framework.TestCase;
+
+
+public class VariationParserTest extends TestCase {
+
+    @SmallTest
+    public void testParseFontVariationSetting() {
+        int tag = FontListParser.makeTag('w', 'd', 't', 'h');
+        FontListParser.Axis[] axis = FontListParser.parseFontVariationSettings("'wdth' 1");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(1.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("\"wdth\" 100");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(100.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("   'wdth' 100");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(100.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("\t'wdth' 0.5");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(0.5f, axis[0].styleValue);
+
+        tag = FontListParser.makeTag('A', 'X', ' ', ' ');
+        axis = FontListParser.parseFontVariationSettings("'AX  ' 1");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(1.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("'AX  '\t1");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(1.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("'AX  '\n1");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(1.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("'AX  '\r1");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(1.0f, axis[0].styleValue);
+
+        axis = FontListParser.parseFontVariationSettings("'AX  '\r\t\n 1");
+        assertEquals(tag, axis[0].tag);
+        assertEquals(1.0f, axis[0].styleValue);
+
+        // Test for invalid input
+        axis = FontListParser.parseFontVariationSettings("");
+        assertEquals(0, axis.length);
+        axis = FontListParser.parseFontVariationSettings("invalid_form");
+        assertEquals(0, axis.length);
+
+        // Test with invalid tag
+        axis = FontListParser.parseFontVariationSettings("'' 1");
+        assertEquals(0, axis.length);
+        axis = FontListParser.parseFontVariationSettings("'invalid' 1");
+        assertEquals(0, axis.length);
+
+        // Test with invalid styleValue
+        axis = FontListParser.parseFontVariationSettings("'wdth' ");
+        assertEquals(0, axis.length);
+        axis = FontListParser.parseFontVariationSettings("'wdth' x");
+        assertEquals(0, axis.length);
+        axis = FontListParser.parseFontVariationSettings("'wdth' \t");
+        assertEquals(0, axis.length);
+        axis = FontListParser.parseFontVariationSettings("'wdth' \n\r");
+        assertEquals(0, axis.length);
+    }
+
+    @SmallTest
+    public void testParseFontVariationStyleSettings() {
+        FontListParser.Axis[] axis =
+                FontListParser.parseFontVariationSettings("'wdth' 10,'AX  '\r1");
+        int tag1 = FontListParser.makeTag('w', 'd', 't', 'h');
+        int tag2 = FontListParser.makeTag('A', 'X', ' ', ' ');
+        assertEquals(tag1, axis[0].tag);
+        assertEquals(10.0f, axis[0].styleValue);
+        assertEquals(tag2, axis[1].tag);
+        assertEquals(1.0f, axis[1].styleValue);
+
+        // Test only spacers are allowed before tag
+        axis = FontListParser.parseFontVariationSettings("     'wdth' 10,ab'wdth' 1");
+        tag1 = FontListParser.makeTag('w', 'd', 't', 'h');
+        assertEquals(tag1, axis[0].tag);
+        assertEquals(10.0f, axis[0].styleValue);
+        assertEquals(1, axis.length);
+    }
+
+    @SmallTest
+    public void testMakeTag() {
+      assertEquals(0x77647468, FontListParser.makeTag('w', 'd', 't', 'h'));
+      assertEquals(0x41582020, FontListParser.makeTag('A', 'X', ' ', ' '));
+      assertEquals(0x20202020, FontListParser.makeTag(' ', ' ', ' ', ' '));
+    }
+}
\ No newline at end of file