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/*
* Copyright (C) 2017 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.testing;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.withSettings;
import android.content.Context;
import android.content.res.Resources;
import android.util.Log;
import android.util.SparseArray;
import org.mockito.invocation.InvocationOnMock;
/**
* Provides a version of Resources that defaults to all existing resources, but can have ids
* changed to return specific values.
* <p>
* TestableResources are lazily initialized, be sure to call
* {@link TestableContext#ensureTestableResources} before your tested code has an opportunity
* to cache {@link Context#getResources}.
* </p>
*/
public class TestableResources {
private static final String TAG = "TestableResources";
private final Resources mResources;
private final SparseArray<Object> mOverrides = new SparseArray<>();
/** Creates a TestableResources instance that calls through to the given real Resources. */
public TestableResources(Resources realResources) {
mResources = mock(Resources.class, withSettings()
.spiedInstance(realResources)
.defaultAnswer(this::answer));
}
/**
* Gets the implementation of Resources that will return overridden values when called.
*/
public Resources getResources() {
return mResources;
}
/**
* Sets the return value for the specified resource id.
* <p>
* Since resource ids are unique there is a single addOverride that will override the value
* whenever it is gotten regardless of which method is used (i.e. getColor or getDrawable).
* </p>
* @param id The resource id to be overridden
* @param value The value of the resource, null to cause a {@link Resources.NotFoundException}
* when gotten.
*/
public void addOverride(int id, Object value) {
mOverrides.put(id, value);
}
/**
* Removes the override for the specified id.
* <p>
* This should be called over addOverride(id, null), because specifying a null value will
* cause a {@link Resources.NotFoundException} whereas removing the override will actually
* switch back to returning the default/real value of the resource.
* </p>
* @param id
*/
public void removeOverride(int id) {
mOverrides.remove(id);
}
private Object answer(InvocationOnMock invocationOnMock) throws Throwable {
try {
int id = invocationOnMock.getArgument(0);
int index = mOverrides.indexOfKey(id);
if (index >= 0) {
Object value = mOverrides.valueAt(index);
if (value == null) throw new Resources.NotFoundException();
return value;
}
} catch (Resources.NotFoundException e) {
// Let through NotFoundException.
throw e;
} catch (Throwable t) {
// Generic catching for the many things that can go wrong, fall back to
// the real implementation.
Log.i(TAG, "Falling back to default resources call " + t);
}
return invocationOnMock.callRealMethod();
}
}