TriggerBuilders.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 androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import androidx.wear.protolayout.expression.DynamicBuilders;
import androidx.wear.protolayout.expression.DynamicBuilders.DynamicBool;
import androidx.wear.protolayout.expression.Fingerprint;
import androidx.wear.protolayout.expression.RequiresSchemaVersion;
import androidx.wear.protolayout.proto.TriggerProto;

/** Builders for triggers that can be used to start an animation. */
public final class TriggerBuilders {
    private TriggerBuilders() {}

    /** Creates a {@link Trigger} that fires immediately when the layout is loaded / reloaded. */
    @NonNull
    public static Trigger createOnLoadTrigger() {
        return new OnLoadTrigger.Builder().build();
    }

    /**
     * Creates a {@link Trigger} that fires *every time* the condition switches from false to true.
     * If the condition is true initially, that will fire the trigger on load.
     */
    @NonNull
    public static Trigger createOnConditionMetTrigger(@NonNull DynamicBool dynamicBool) {
        return new OnConditionMetTrigger.Builder().setCondition(dynamicBool).build();
    }

    /** Triggers immediately when the layout is loaded / reloaded. */
    @RequiresSchemaVersion(major = 1, minor = 200)
    static final class OnLoadTrigger implements Trigger {
        private final TriggerProto.OnLoadTrigger mImpl;
        @Nullable private final Fingerprint mFingerprint;

        OnLoadTrigger(TriggerProto.OnLoadTrigger impl, @Nullable Fingerprint fingerprint) {
            this.mImpl = impl;
            this.mFingerprint = fingerprint;
        }

        @Override
        @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 OnLoadTrigger fromProto(
                @NonNull TriggerProto.OnLoadTrigger proto, @Nullable Fingerprint fingerprint) {
            return new OnLoadTrigger(proto, fingerprint);
        }

        @NonNull
        static OnLoadTrigger fromProto(@NonNull TriggerProto.OnLoadTrigger proto) {
            return fromProto(proto, null);
        }

        /** Returns the internal proto instance. */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        TriggerProto.OnLoadTrigger toProto() {
            return mImpl;
        }

        @Override
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public TriggerProto.Trigger toTriggerProto() {
            return TriggerProto.Trigger.newBuilder().setOnLoadTrigger(mImpl).build();
        }

        @Override
        @NonNull
        public String toString() {
            return "OnLoadTrigger";
        }

        /** Builder for {@link OnLoadTrigger}. */
        public static final class Builder implements Trigger.Builder {
            private final TriggerProto.OnLoadTrigger.Builder mImpl =
                    TriggerProto.OnLoadTrigger.newBuilder();
            private final Fingerprint mFingerprint = new Fingerprint(-1262805599);

            /** Creates an instance of {@link Builder}. */
            public Builder() {}

            /** Builds an instance from accumulated values. */
            @Override
            @NonNull
            public OnLoadTrigger build() {
                return new OnLoadTrigger(mImpl.build(), mFingerprint);
            }
        }
    }

    /**
     * Triggers *every time* the condition switches from false to true. If the condition is true
     * initially, that will fire the trigger on load.
     */
    @RequiresSchemaVersion(major = 1, minor = 200)
    static final class OnConditionMetTrigger implements Trigger {
        private final TriggerProto.OnConditionMetTrigger mImpl;
        @Nullable private final Fingerprint mFingerprint;

        OnConditionMetTrigger(
                TriggerProto.OnConditionMetTrigger impl, @Nullable Fingerprint fingerprint) {
            this.mImpl = impl;
            this.mFingerprint = fingerprint;
        }

        /** Gets dynamic boolean used as trigger. */
        @RequiresSchemaVersion(major = 1, minor = 200)
        @Nullable
        public DynamicBool getCondition() {
            if (mImpl.hasCondition()) {
                return DynamicBuilders.dynamicBoolFromProto(mImpl.getCondition());
            } else {
                return null;
            }
        }

        @Override
        @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 OnConditionMetTrigger fromProto(
                @NonNull TriggerProto.OnConditionMetTrigger proto,
                @Nullable Fingerprint fingerprint) {
            return new OnConditionMetTrigger(proto, fingerprint);
        }

        @NonNull
        static OnConditionMetTrigger fromProto(@NonNull TriggerProto.OnConditionMetTrigger proto) {
            return fromProto(proto, null);
        }

        /** Returns the internal proto instance. */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        TriggerProto.OnConditionMetTrigger toProto() {
            return mImpl;
        }

        @Override
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        public TriggerProto.Trigger toTriggerProto() {
            return TriggerProto.Trigger.newBuilder().setOnConditionMetTrigger(mImpl).build();
        }

        @Override
        @NonNull
        public String toString() {
            return "OnConditionMetTrigger{" + "condition=" + getCondition() + "}";
        }

        /** Builder for {@link OnConditionMetTrigger}. */
        public static final class Builder implements Trigger.Builder {
            private final TriggerProto.OnConditionMetTrigger.Builder mImpl =
                    TriggerProto.OnConditionMetTrigger.newBuilder();
            private final Fingerprint mFingerprint = new Fingerprint(756642641);

            /** Creates an instance of {@link Builder}. */
            public Builder() {}

            /** Sets dynamic boolean used as trigger. */
            @RequiresSchemaVersion(major = 1, minor = 200)
            @NonNull
            public Builder setCondition(@NonNull DynamicBool condition) {
                mImpl.setCondition(condition.toDynamicBoolProto());
                mFingerprint.recordPropertyUpdate(
                        1, checkNotNull(condition.getFingerprint()).aggregateValueAsInt());
                return this;
            }

            /** Builds an instance from accumulated values. */
            @Override
            @NonNull
            public OnConditionMetTrigger build() {
                return new OnConditionMetTrigger(mImpl.build(), mFingerprint);
            }
        }
    }

    /**
     * Interface defining the triggers that can be fired. These triggers can be used to allow acting
     * on events. For example some animations can be set to start based on a trigger.
     */
    @RequiresSchemaVersion(major = 1, minor = 200)
    public interface Trigger {
        /** Get the protocol buffer representation of this object. */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @NonNull
        TriggerProto.Trigger toTriggerProto();

        /** Get the fingerprint for this object or null if unknown. */
        @RestrictTo(Scope.LIBRARY_GROUP)
        @Nullable
        Fingerprint getFingerprint();

        /** Builder to create {@link Trigger} objects. */
        @RestrictTo(Scope.LIBRARY_GROUP)
        interface Builder {

            /** Builds an instance with values accumulated in this Builder. */
            @NonNull
            Trigger build();
        }
    }

    /** Creates a new wrapper instance from the proto. */
    @RestrictTo(Scope.LIBRARY_GROUP)
    @NonNull
    public static Trigger triggerFromProto(
            @NonNull TriggerProto.Trigger proto, @Nullable Fingerprint fingerprint) {
        if (proto.hasOnLoadTrigger()) {
            return OnLoadTrigger.fromProto(proto.getOnLoadTrigger(), fingerprint);
        }
        if (proto.hasOnConditionMetTrigger()) {
            return OnConditionMetTrigger.fromProto(proto.getOnConditionMetTrigger(), fingerprint);
        }
        throw new IllegalStateException("Proto was not a recognised instance of Trigger");
    }

    @NonNull
    static Trigger triggerFromProto(@NonNull TriggerProto.Trigger proto) {
        return triggerFromProto(proto, null);
    }
}