src/com/android/calculator2/EvaluatorStateUtils.java


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/*
 * Copyright (C) 2016 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.calculator2;

/**
 * Utils class to get the state of the passed-in Evaluator.
 */

public class EvaluatorStateUtils {
    public static boolean isDisplayEmpty(Evaluator evaluator) {
        if (evaluator != null) {
            final CalculatorExpr mainExpr = evaluator.getExpr(Evaluator.MAIN_INDEX);
            return mainExpr == null || mainExpr.isEmpty();
        } else {
            return true;
        }
    }
}