src/com/android/quicksearchbox/QueryTask.kt

/*
 * Copyright (C) 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 com.android.quicksearchbox

import android.os.Handler
import android.util.Log
import com.android.quicksearchbox.util.Consumer
import com.android.quicksearchbox.util.Consumers
import com.android.quicksearchbox.util.NamedTask
import com.android.quicksearchbox.util.NamedTaskExecutor

/**
 * A task that gets suggestions from a corpus.
 */
class QueryTask<C : SuggestionCursor?>(
    private val mQuery: String?,
    private val mQueryLimit: Int,
    private val mProvider: SuggestionCursorProvider<C>?,
    handler: Handler?,
    consumer: Consumer<C>?
) : NamedTask {

    private val mHandler: Handler?

    private val mConsumer: Consumer<C>?

    @get:Override
    override val name: String?
        get() = mProvider?.name

    @Override
    override fun run() {
        val cursor = mProvider?.getSuggestions(mQuery, mQueryLimit)
        if (DBG) Log.d(
            TAG,
            "Suggestions from $mProvider = $cursor"
        )
        Consumers.consumeCloseableAsync(mHandler, mConsumer, cursor)
    }

    @Override
    override fun toString(): String {
        return "$mProvider[$mQuery]"
    }

    companion object {
        private const val TAG = "QSB.QueryTask"
        private const val DBG = false

        @JvmStatic
        fun <C : SuggestionCursor?> startQuery(
            query: String?,
            maxResults: Int,
            provider: SuggestionCursorProvider<C>?,
            executor: NamedTaskExecutor, handler: Handler?,
            consumer: Consumer<C>?
        ) {
            val task = QueryTask(
                query, maxResults, provider, handler,
                consumer
            )
            executor.execute(task)
        }
    }

    /**
     * Creates a new query task.
     *
     * @param query Query to run.
     * @param queryLimit The number of suggestions to ask each provider for.
     * @param provider The provider to ask for suggestions.
     * @param handler Handler that [Consumer.consume] will
     * get called on. If null, the method is called on the query thread.
     * @param consumer Consumer to notify when the suggestions have been returned.
     */
    init {
        mHandler = handler
        mConsumer = consumer
    }
}