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Diffstat (limited to 'common/src/com/android/tv/common/SoftPreconditions.java')
| -rw-r--r-- | common/src/com/android/tv/common/SoftPreconditions.java | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/common/src/com/android/tv/common/SoftPreconditions.java b/common/src/com/android/tv/common/SoftPreconditions.java new file mode 100644 index 00000000..9b7713f6 --- /dev/null +++ b/common/src/com/android/tv/common/SoftPreconditions.java @@ -0,0 +1,164 @@ +/* + * Copyright (C) 2015 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.tv.common; + +import android.content.Context; +import android.text.TextUtils; +import android.util.Log; + +import com.android.tv.common.BuildConfig; +import com.android.tv.common.feature.Feature; + +/** + * Simple static methods to be called at the start of your own methods to verify + * correct arguments and state. + * + * <p>{@code checkXXX} methods throw exceptions when {@link BuildConfig#ENG} is true, and + * logs a warning when it is false. + * + * <p>This is based on com.android.internal.util.Preconditions. + */ +public final class SoftPreconditions { + private static final String TAG = "SoftPreconditions"; + + /** + * Throws or logs if an expression involving the parameter of the calling + * method is not true. + * + * @param expression a boolean expression + * @param tag Used to identify the source of a log message. It usually + * identifies the class or activity where the log call occurs. + * @param msg The message you would like logged. + * @throws IllegalArgumentException if {@code expression} is true + */ + public static void checkArgument(final boolean expression, String tag, String msg) { + if (!expression) { + warn(tag, "Illegal argument", msg, new IllegalArgumentException(msg)); + } + } + + /** + * Throws or logs if an expression involving the parameter of the calling + * method is not true. + * + * @param expression a boolean expression + * @throws IllegalArgumentException if {@code expression} is true + */ + public static void checkArgument(final boolean expression) { + checkArgument(expression, null, null); + } + + /** + * Throws or logs if an and object is null. + * + * @param reference an object reference + * @param tag Used to identify the source of a log message. It usually + * identifies the class or activity where the log call occurs. + * @param msg The message you would like logged. + * @return true if the object is null + * @throws NullPointerException if {@code reference} is null + */ + public static <T> T checkNotNull(final T reference, String tag, String msg) { + if (reference == null) { + warn(tag, "Null Pointer", msg, new NullPointerException(msg)); + } + return reference; + } + + /** + * Throws or logs if an and object is null. + * + * @param reference an object reference + * @return true if the object is null + * @throws NullPointerException if {@code reference} is null + */ + public static <T> T checkNotNull(final T reference) { + return checkNotNull(reference, null, null); + } + + /** + * Throws or logs if an expression involving the state of the calling + * instance, but not involving any parameters to the calling method is not true. + * + * @param expression a boolean expression + * @param tag Used to identify the source of a log message. It usually + * identifies the class or activity where the log call occurs. + * @param msg The message you would like logged. + * @throws IllegalStateException if {@code expression} is true + */ + public static void checkState(final boolean expression, String tag, String msg) { + if (!expression) { + warn(tag, "Illegal State", msg, new IllegalStateException(msg)); + } + } + + /** + * Throws or logs if an expression involving the state of the calling + * instance, but not involving any parameters to the calling method is not true. + * + * @param expression a boolean expression + * @throws IllegalStateException if {@code expression} is true + */ + public static void checkState(final boolean expression) { + checkState(expression, null, null); + } + + /** + * Throws or logs if the Feature is not enabled + * + * @param context an android context + * @param feature the required feature + * @param tag used to identify the source of a log message. It usually + * identifies the class or activity where the log call occurs + * @throws IllegalStateException if {@code feature} is not enabled + */ + public static void checkFeatureEnabled(Context context, Feature feature, String tag) { + checkState(feature.isEnabled(context), tag, feature.toString()); + } + + /** + * Throws a {@link RuntimeException} if {@link BuildConfig#ENG} is true, else log a warning. + * + * @param tag Used to identify the source of a log message. It usually + * identifies the class or activity where the log call occurs. + * @param msg The message you would like logged + * @param e The exception to wrap with a RuntimeException when thrown. + */ + public static void warn(String tag, String prefix, String msg, Exception e) + throws RuntimeException { + if (TextUtils.isEmpty(tag)) { + tag = TAG; + } + String logMessage; + if (TextUtils.isEmpty(msg)) { + logMessage = prefix; + } else if (TextUtils.isEmpty(prefix)) { + logMessage = msg; + } else { + logMessage = prefix + ": " + msg; + } + + if (BuildConfig.ENG) { + throw new RuntimeException(msg, e); + } else { + Log.w(tag, logMessage, e); + } + } + + private SoftPreconditions() { + } +} |