/*
* Copyright 2023 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 androidx.wear.protolayout.expression.pipeline;
import androidx.annotation.NonNull;
import androidx.wear.protolayout.expression.PlatformDataKey;
import java.util.Set;
import java.util.concurrent.Executor;
/**
* This interface is used by platform data providers to yield dynamic data for their supported data
* keys.
*
* <p>It's up to the implementations to check if the expression provider has the required permission
* before sending data with {@link PlatformDataReceiver#onData}. If a required permission is not
* granted or is revoked they should stop sending more data and call {@link
* PlatformDataReceiver#onInvalidated(Set)} instead.
*/
public interface PlatformDataProvider {
/**
* Sets the receiver for receiving the platform data from this provider.
*
* <p>Each provider is expected to have only one receiver. When a receiver has already been set,
* the implementation should throw an exception.
*
* <p>The implementation should periodically send the dynamic data values for the set of {@link
* PlatformDataKey}s specified when registering this {@link PlatformDataProvider} in {@link
* DynamicTypeEvaluator.Config.Builder#addPlatformDataProvider}
*
* @param executor The executor to run the {@link PlatformDataReceiver#onData} or {@link
* PlatformDataReceiver#onInvalidated(Set)} on.
* @param receiver The {@link PlatformDataReceiver} to receive the new dynamic values or to be
* notified that the current data has been invalidated for the registered keys.
*/
void setReceiver(@NonNull Executor executor, @NonNull PlatformDataReceiver receiver);
/** Clears the receiver from the provider. */
void clearReceiver();
}