base/android/jni_generator/codegen/proxy_impl_java.py

# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.


def Generate(jni_obj, *, gen_jni_class, script_name):
  visibility = 'public ' if jni_obj.proxy_interface.is_public else ''
  interface_name = jni_obj.proxy_interface.name_with_dots
  impl_name = f'{jni_obj.java_class.name}Jni'
  gen_jni = gen_jni_class.name

  sb = []
  sb.append(f"""\
//
// This file was generated by {script_name}
//
package {jni_obj.java_class.package_with_dots};

import org.chromium.build.annotations.CheckDiscard;
import org.chromium.base.JniStaticTestMocker;
import org.chromium.base.NativeLibraryLoadedStatus;
import {gen_jni_class.full_name_with_dots};
""")

  # Copy over all imports (some will be unused, but oh well).
  for java_class in jni_obj.type_resolver.imports:
    sb.append(f'import {java_class.full_name_with_dots};\n')

  sb.append(f"""
@CheckDiscard("crbug.com/993421")
{visibility}class {impl_name} implements {interface_name} {{
  private static {interface_name} testInstance;

  public static final JniStaticTestMocker<{interface_name}> TEST_HOOKS =
      new JniStaticTestMocker<{interface_name}>() {{
    @Override
    public void setInstanceForTesting({interface_name} instance) {{
      if (!{gen_jni}.TESTING_ENABLED) {{
        throw new RuntimeException(
            "Tried to set a JNI mock when mocks aren't enabled!");
      }}
      testInstance = instance;
    }}
  }};
""")

  for native in jni_obj.proxy_natives:
    call_params = ', '.join(p.name for p in native.params)
    sig_params = ', '.join(f'{p.datatype} {p.name}' for p in native.params)
    return_prefix = ''
    if native.return_type != 'void':
      return_prefix = f'return ({native.return_type}) '

    sb.append(f"""
  @Override
  public {native.return_type} {native.name}({sig_params}) {{
    {return_prefix}{gen_jni}.{native.proxy_name}({call_params});
  }}
""")

  sb.append(f"""
  public static {interface_name} get() {{
    if ({gen_jni}.TESTING_ENABLED) {{
      if (testInstance != null) {{
        return testInstance;
      }}
      if ({gen_jni}.REQUIRE_MOCK) {{
        throw new UnsupportedOperationException(
            "No mock found for the native implementation of {interface_name}. "
            + "The current configuration requires implementations be mocked.");
      }}
    }}
    NativeLibraryLoadedStatus.checkLoaded();
    return new {impl_name}();
  }}
}}
""")
  return ''.join(sb)