Make SnippetFormatter support other styles

An alternative approach would be to pass in the formatter; see
google#251.

Author: Stephan202

core/src/main/java/com/google/googlejavaformat/java/SnippetFormatter.java

@@ -20,6 +20,7 @@
 import com.google.common.collect.Range;
 import com.google.common.collect.RangeSet;
 import com.google.common.collect.TreeRangeSet;
+import com.google.googlejavaformat.java.JavaFormatterOptions.Style;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -56,16 +57,26 @@ public void closeBraces(int initialIndent) {
     }
   }
 
-  private static final int INDENTATION_SIZE = 2;
-  private final Formatter formatter = new Formatter();
   private static final CharMatcher NOT_WHITESPACE = CharMatcher.whitespace().negate();
 
+  private final Formatter formatter;
+  private final int indentationSize;
+
+  public SnippetFormatter() {
+	 this(Style.GOOGLE);
+  }
+
+  public SnippetFormatter(Style style) {
+	 this.formatter = new Formatter(JavaFormatterOptions.builder().style(style).build());
+	 this.indentationSize = 2 * style.indentationMultiplier();
+  }
+
   public String createIndentationString(int indentationLevel) {
     Preconditions.checkArgument(
         indentationLevel >= 0,
         "Indentation level cannot be less than zero. Given: %s",
         indentationLevel);
-    int spaces = indentationLevel * INDENTATION_SIZE;
+    int spaces = indentationLevel * indentationSize;
     StringBuilder buf = new StringBuilder(spaces);
     for (int i = 0; i < spaces; i++) {
       buf.append(' ');

core/src/test/java/com/google/googlejavaformat/java/SnippetFormatterTest.java

@@ -18,6 +18,7 @@
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Range;
+import com.google.googlejavaformat.java.JavaFormatterOptions.Style;
 import com.google.googlejavaformat.java.SnippetFormatter.SnippetKind;
 import java.util.List;
 import org.junit.Test;
@@ -104,4 +105,36 @@ public void compilationWithComments() throws FormatterException {
         .containsExactly(
             Replacement.create(Range.closedOpen(0, 24), "/** a b */\nclass Test {}\n"));
   }
+
+  @Test
+  public void classWithMethodGoogleStyle() throws FormatterException {
+    String input = "class Test {\nvoid f() {}\n}";
+    List<Replacement> replacements =
+        new SnippetFormatter(Style.GOOGLE)
+            .format(
+                SnippetKind.COMPILATION_UNIT,
+                input,
+                ImmutableList.of(Range.closedOpen(0, input.length())),
+                4,
+                true);
+    assertThat(replacements)
+        .containsExactly(
+            Replacement.create(Range.closedOpen(0, 26), "class Test {\n  void f() {}\n}\n"));
+  }
+
+  @Test
+  public void classWithMethodAospStyle() throws FormatterException {
+    String input = "class Test {\nvoid f() {}\n}";
+    List<Replacement> replacements =
+        new SnippetFormatter(Style.AOSP)
+            .format(
+                SnippetKind.COMPILATION_UNIT,
+                input,
+                ImmutableList.of(Range.closedOpen(0, input.length())),
+                4,
+                true);
+    assertThat(replacements)
+        .containsExactly(
+            Replacement.create(Range.closedOpen(0, 26), "class Test {\n    void f() {}\n}\n"));
+  }
 }