/*
* 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.tools.klint.checks;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.tools.klint.client.api.JavaEvaluator;
import com.android.tools.klint.detector.api.Category;
import com.android.tools.klint.detector.api.ConstantEvaluator;
import com.android.tools.klint.detector.api.Detector;
import com.android.tools.klint.detector.api.Implementation;
import com.android.tools.klint.detector.api.Issue;
import com.android.tools.klint.detector.api.JavaContext;
import com.android.tools.klint.detector.api.Scope;
import com.android.tools.klint.detector.api.Severity;
import org.jetbrains.uast.UCallExpression;
import org.jetbrains.uast.UExpression;
import org.jetbrains.uast.UMethod;
import org.jetbrains.uast.visitor.UastVisitor;
import java.util.Collections;
import java.util.List;
/**
* Makes sure that alarms are handled correctly
*/
public class AlarmDetector extends Detector implements Detector.UastScanner {
private static final Implementation IMPLEMENTATION = new Implementation(
AlarmDetector.class,
Scope.JAVA_FILE_SCOPE);
/** Alarm set too soon/frequently */
public static final Issue ISSUE = Issue.create(
"ShortAlarm", //$NON-NLS-1$
"Short or Frequent Alarm",
"Frequent alarms are bad for battery life. As of API 22, the `AlarmManager` " +
"will override near-future and high-frequency alarm requests, delaying the alarm " +
"at least 5 seconds into the future and ensuring that the repeat interval is at " +
"least 60 seconds.\n" +
"\n" +
"If you really need to do work sooner than 5 seconds, post a delayed message " +
"or runnable to a Handler.",
Category.CORRECTNESS,
6,
Severity.WARNING,
IMPLEMENTATION);
/** Constructs a new {@link AlarmDetector} check */
public AlarmDetector() {
}
// ---- Implements JavaScanner ----
@Override
public List<String> getApplicableMethodNames() {
return Collections.singletonList("setRepeating");
}
@Override
public void visitMethod(@NonNull JavaContext context, @Nullable UastVisitor visitor,
@NonNull UCallExpression node, @NonNull UMethod method) {
JavaEvaluator evaluator = context.getEvaluator();
if (evaluator.isMemberInClass(method, "android.app.AlarmManager") &&
evaluator.getParameterCount(method) == 4) {
ensureAtLeast(context, node, 1, 5000L);
ensureAtLeast(context, node, 2, 60000L);
}
}
private static void ensureAtLeast(@NonNull JavaContext context,
@NonNull UCallExpression node, int parameter, long min) {
UExpression argument = node.getValueArguments().get(parameter);
long value = getLongValue(context, argument);
if (value < min) {
String message = String.format("Value will be forced up to %1$d as of Android 5.1; "
+ "don't rely on this to be exact", min);
context.report(ISSUE, argument, context.getUastLocation(argument), message);
}
}
private static long getLongValue(
@NonNull JavaContext context,
@NonNull UExpression argument) {
Object value = ConstantEvaluator.evaluate(context, argument);
if (value instanceof Number) {
return ((Number)value).longValue();
}
return Long.MAX_VALUE;
}
}