StateBuilders.java
/*
* Copyright 2022 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;
import static androidx.wear.protolayout.expression.Preconditions.checkNotNull;
import android.annotation.SuppressLint;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import androidx.wear.protolayout.expression.AppDataKey;
import androidx.wear.protolayout.expression.DynamicBuilders.DynamicType;
import androidx.wear.protolayout.expression.DynamicDataBuilders;
import androidx.wear.protolayout.expression.DynamicDataBuilders.DynamicDataValue;
import androidx.wear.protolayout.expression.Fingerprint;
import androidx.wear.protolayout.expression.proto.DynamicDataProto;
import androidx.wear.protolayout.proto.StateProto;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
/** Builders for state of a layout. */
public final class StateBuilders {
private StateBuilders() {}
/**
* {@link State} information.
*
* @since 1.0
*/
public static final class State {
private final StateProto.State mImpl;
@Nullable private final Fingerprint mFingerprint;
private static final int MAX_STATE_ENTRY_COUNT = 30;
State(StateProto.State impl, @Nullable Fingerprint fingerprint) {
this.mImpl = impl;
this.mFingerprint = fingerprint;
}
/**
* Returns the maximum number for state entries that can be added to the {@link State} using
* {@link Builder#addKeyToValueMapping(AppDataKey, DynamicDataValue)}.
*
* <p>The ProtoLayout state model is not designed to handle large volumes of layout provided
* state. So we limit the number of state entries to keep the on-the-wire size and state
* store update times manageable.
*/
public static int getMaxStateEntryCount() {
return MAX_STATE_ENTRY_COUNT;
}
/**
* Gets the ID of the clickable that was last clicked.
*
* @since 1.0
*/
@NonNull
public String getLastClickableId() {
return mImpl.getLastClickableId();
}
/**
* Gets any shared state between the provider and renderer.
*
* @since 1.2
*/
@NonNull
public Map<AppDataKey<?>, DynamicDataValue<?>> getKeyToValueMapping() {
Map<AppDataKey<?>, DynamicDataValue<?>> map = new HashMap<>();
for (Entry<String, DynamicDataProto.DynamicDataValue> entry :
mImpl.getIdToValueMap().entrySet()) {
map.put(
new AppDataKey<>(entry.getKey()),
DynamicDataBuilders.dynamicDataValueFromProto(entry.getValue()));
}
return Collections.unmodifiableMap(map);
}
/** Get the fingerprint for this object, or null if unknown. */
@RestrictTo(Scope.LIBRARY_GROUP)
@Nullable
public Fingerprint getFingerprint() {
return mFingerprint;
}
/** Creates a new wrapper instance from the proto. */
@RestrictTo(Scope.LIBRARY_GROUP)
@NonNull
public static State fromProto(
@NonNull StateProto.State proto, @Nullable Fingerprint fingerprint) {
return new State(proto, fingerprint);
}
/**
* Creates a new wrapper instance from the proto. Intended for testing purposes only. An
* object created using this method can't be added to any other wrapper.
*/
@RestrictTo(Scope.LIBRARY_GROUP)
@NonNull
public static State fromProto(@NonNull StateProto.State proto) {
return fromProto(proto, null);
}
/** Returns the internal proto instance. */
@RestrictTo(Scope.LIBRARY_GROUP)
@NonNull
public StateProto.State toProto() {
return mImpl;
}
@Override
@NonNull
public String toString() {
return "State{"
+ "lastClickableId="
+ getLastClickableId()
+ ", keyToValueMapping="
+ getKeyToValueMapping()
+ "}";
}
/** Builder for {@link State} */
public static final class Builder {
private final StateProto.State.Builder mImpl = StateProto.State.newBuilder();
private final Fingerprint mFingerprint = new Fingerprint(-688813584);
/** Creates an instance of {@link Builder}. */
public Builder() {}
/**
* Adds an entry into any shared state between the provider and renderer.
*
* @throws IllegalStateException if adding the new key/value will make the state larger
* than the allowed limit ({@link #getMaxStateEntryCount()}).
* @since 1.2
*/
@SuppressLint("MissingGetterMatchingBuilder")
@NonNull
public <T extends DynamicType> Builder addKeyToValueMapping(
@NonNull AppDataKey<T> sourceKey, @NonNull DynamicDataValue<T> value) {
if (mImpl.getIdToValueMap().size() >= getMaxStateEntryCount()) {
throw new IllegalStateException(
String.format(
"Can't add more entries to the state. It is already at its "
+ "maximum allowed size of %d.",
getMaxStateEntryCount()));
}
mImpl.putIdToValue(sourceKey.getKey(), value.toDynamicDataValueProto());
mFingerprint.recordPropertyUpdate(
sourceKey.getKey().hashCode(),
checkNotNull(value.getFingerprint()).aggregateValueAsInt());
return this;
}
/**
* Builds an instance from accumulated values.
*
* @throws IllegalStateException if number of key/value pairs are greater than {@link
* #getMaxStateEntryCount()}.
*/
@NonNull
public State build() {
if (mImpl.getIdToValueMap().size() > getMaxStateEntryCount()) {
throw new IllegalStateException(
String.format(
"State size is too large: %d. "
+ "Maximum allowed state size is %d.",
mImpl.getIdToValueMap().size(), getMaxStateEntryCount()));
}
return new State(mImpl.build(), mFingerprint);
}
}
}
}