| /* |
| * Copyright (C) 2012 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.lint.checks; |
| |
| import com.android.annotations.NonNull; |
| import com.android.annotations.Nullable; |
| import com.android.tools.lint.detector.api.Category; |
| import com.android.tools.lint.detector.api.Context; |
| import com.android.tools.lint.detector.api.Detector; |
| import com.android.tools.lint.detector.api.Implementation; |
| import com.android.tools.lint.detector.api.Issue; |
| import com.android.tools.lint.detector.api.JavaContext; |
| import com.android.tools.lint.detector.api.Scope; |
| import com.android.tools.lint.detector.api.Severity; |
| |
| import java.io.File; |
| import java.util.Collections; |
| import java.util.List; |
| |
| import lombok.ast.AstVisitor; |
| import lombok.ast.Expression; |
| import lombok.ast.ForwardingAstVisitor; |
| import lombok.ast.IntegralLiteral; |
| import lombok.ast.MethodInvocation; |
| import lombok.ast.Node; |
| import lombok.ast.Return; |
| import lombok.ast.StrictListAccessor; |
| |
| /** Detector looking for Toast.makeText() without a corresponding show() call */ |
| public class ToastDetector extends Detector implements Detector.JavaScanner { |
| /** The main issue discovered by this detector */ |
| public static final Issue ISSUE = Issue.create( |
| "ShowToast", //$NON-NLS-1$ |
| "Toast created but not shown", |
| |
| "`Toast.makeText()` creates a `Toast` but does *not* show it. You must call " + |
| "`show()` on the resulting object to actually make the `Toast` appear.", |
| |
| Category.CORRECTNESS, |
| 6, |
| Severity.WARNING, |
| new Implementation( |
| ToastDetector.class, |
| Scope.JAVA_FILE_SCOPE)); |
| |
| |
| /** Constructs a new {@link ToastDetector} check */ |
| public ToastDetector() { |
| } |
| |
| @Override |
| public boolean appliesTo(@NonNull Context context, @NonNull File file) { |
| return true; |
| } |
| |
| |
| // ---- Implements JavaScanner ---- |
| |
| @Override |
| public List<String> getApplicableMethodNames() { |
| return Collections.singletonList("makeText"); //$NON-NLS-1$ |
| } |
| |
| @Override |
| public void visitMethod(@NonNull JavaContext context, @Nullable AstVisitor visitor, |
| @NonNull MethodInvocation node) { |
| assert node.astName().astValue().equals("makeText"); |
| if (node.astOperand() == null) { |
| // "makeText()" in the code with no operand |
| return; |
| } |
| |
| String operand = node.astOperand().toString(); |
| if (!(operand.equals("Toast") || operand.endsWith(".Toast"))) { |
| return; |
| } |
| |
| // Make sure you pass the right kind of duration: it's not a delay, it's |
| // LENGTH_SHORT or LENGTH_LONG |
| // (see http://code.google.com/p/android/issues/detail?id=3655) |
| StrictListAccessor<Expression, MethodInvocation> args = node.astArguments(); |
| if (args.size() == 3) { |
| Expression duration = args.last(); |
| if (duration instanceof IntegralLiteral) { |
| context.report(ISSUE, duration, context.getLocation(duration), |
| "Expected duration `Toast.LENGTH_SHORT` or `Toast.LENGTH_LONG`, a custom " + |
| "duration value is not supported"); |
| } |
| } |
| |
| Node method = JavaContext.findSurroundingMethod(node.getParent()); |
| if (method == null) { |
| return; |
| } |
| |
| ShowFinder finder = new ShowFinder(node); |
| method.accept(finder); |
| if (!finder.isShowCalled()) { |
| context.report(ISSUE, node, context.getLocation(node), |
| "Toast created but not shown: did you forget to call `show()` ?"); |
| } |
| } |
| |
| private static class ShowFinder extends ForwardingAstVisitor { |
| /** The target makeText call */ |
| private final MethodInvocation mTarget; |
| /** Whether we've found the show method */ |
| private boolean mFound; |
| /** Whether we've seen the target makeText node yet */ |
| private boolean mSeenTarget; |
| |
| private ShowFinder(MethodInvocation target) { |
| mTarget = target; |
| } |
| |
| @Override |
| public boolean visitMethodInvocation(MethodInvocation node) { |
| if (node == mTarget) { |
| mSeenTarget = true; |
| } else if ((mSeenTarget || node.astOperand() == mTarget) |
| && "show".equals(node.astName().astValue())) { //$NON-NLS-1$ |
| // TODO: Do more flow analysis to see whether we're really calling show |
| // on the right type of object? |
| mFound = true; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public boolean visitReturn(Return node) { |
| if (node.astValue() == mTarget) { |
| // If you just do "return Toast.makeText(...) don't warn |
| mFound = true; |
| } |
| return super.visitReturn(node); |
| } |
| |
| boolean isShowCalled() { |
| return mFound; |
| } |
| } |
| } |