Java: Implements union generation.

mojo/public/tools/bindings/generators/mojom_java_generator.py

Index: mojo/public/tools/bindings/generators/mojom_java_generator.py
diff --git a/mojo/public/tools/bindings/generators/mojom_java_generator.py b/mojo/public/tools/bindings/generators/mojom_java_generator.py
index 2320dbaf983cb7431fa54599e638a65b6e8f5162..554db742aa085fca26985b6b01b841c7a5bb76c2 100644
--- a/mojo/public/tools/bindings/generators/mojom_java_generator.py
+++ b/mojo/public/tools/bindings/generators/mojom_java_generator.py
@@ -346,7 +346,13 @@ def IsPointerArrayKind(kind):
   if not mojom.IsArrayKind(kind):
     return False
   sub_kind = kind.kind
-  return mojom.IsObjectKind(sub_kind)
+  return mojom.IsObjectKind(sub_kind) and not mojom.IsUnionKind(sub_kind)
+
+def IsUnionArrayKind(kind):
+  if not mojom.IsArrayKind(kind):
+    return False
+  sub_kind = kind.kind
+  return mojom.IsUnionKind(sub_kind)
 
 def GetConstantsMainEntityName(module):
   if module.attributes and 'JavaConstantsClassName' in module.attributes:
@@ -408,12 +414,14 @@ class Generator(generator.Generator):
     'is_pointer_array_kind': IsPointerArrayKind,
     'is_reference_kind': mojom.IsReferenceKind,
     'is_struct_kind': mojom.IsStructKind,
+    'is_union_array_kind': IsUnionArrayKind,
     'is_union_kind': mojom.IsUnionKind,
     'java_true_false': GetJavaTrueFalse,
     'java_type': GetJavaType,
     'method_ordinal_name': GetMethodOrdinalName,
     'name': GetNameForElement,
     'new_array': NewArray,
+    'ucc': lambda x: UpperCamelCase(x.name),
   }
 
   def GetJinjaExports(self):
@@ -438,6 +446,12 @@ class Generator(generator.Generator):
     exports.update({'struct': struct})
     return exports
 
+  @UseJinja('java_templates/union.java.tmpl', filters=java_filters)
+  def GenerateUnionSource(self, union):
+    exports = self.GetJinjaExports()
+    exports.update({'union': union})
+    return exports
+
   @UseJinja('java_templates/interface.java.tmpl', filters=java_filters)
   def GenerateInterfaceSource(self, interface):
     return self.GetJinjaExportsForInterface(interface)
@@ -462,6 +476,10 @@ class Generator(generator.Generator):
       self.Write(self.GenerateStructSource(struct),
                  '%s.java' % GetNameForElement(struct))
 
+    for union in self.module.unions:
+      self.Write(self.GenerateUnionSource(union),
+                 '%s.java' % GetNameForElement(union))
+
     for enum in self.module.enums:
       self.Write(self.GenerateEnumSource(enum),
                  '%s.java' % GetNameForElement(enum))