/*
* Copyright (C) 2011 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 static com.android.SdkConstants.ATTR_CLASS;
import static com.android.SdkConstants.ATTR_ID;
import static com.android.SdkConstants.DOT_JAVA;
import static com.android.SdkConstants.ID_PREFIX;
import static com.android.SdkConstants.NEW_ID_PREFIX;
import static com.android.SdkConstants.VIEW_TAG;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.resources.ResourceFolderType;
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.Issue;
import com.android.tools.lint.detector.api.JavaContext;
import com.android.tools.lint.detector.api.LintUtils;
import com.android.tools.lint.detector.api.ResourceXmlDetector;
import com.android.tools.lint.detector.api.Scope;
import com.android.tools.lint.detector.api.Severity;
import com.android.tools.lint.detector.api.Speed;
import com.android.tools.lint.detector.api.XmlContext;
import com.google.common.base.Joiner;
import org.w3c.dom.Attr;
import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import lombok.ast.AstVisitor;
import lombok.ast.Cast;
import lombok.ast.Expression;
import lombok.ast.MethodInvocation;
import lombok.ast.Select;
import lombok.ast.StrictListAccessor;
/** Detector for finding inconsistent usage of views and casts */
public class ViewTypeDetector extends ResourceXmlDetector implements Detector.JavaScanner {
/** Mismatched view types */
public static final Issue ISSUE = Issue.create("WrongViewCast", //$NON-NLS-1$
"Looks for incorrect casts to views that according to the XML are of a different type",
"Keeps track of the view types associated with ids and if it finds a usage of " +
"the id in the Java code it ensures that it is treated as the same type.",
Category.CORRECTNESS,
9,
Severity.ERROR,
ViewTypeDetector.class,
EnumSet.of(Scope.ALL_RESOURCE_FILES, Scope.ALL_JAVA_FILES));
private Map<String, Object> mIdToViewTag = new HashMap<String, Object>(50);
@Override
public @NonNull Speed getSpeed() {
return Speed.SLOW;
}
@Override
public boolean appliesTo(@NonNull ResourceFolderType folderType) {
return folderType == ResourceFolderType.LAYOUT;
}
@Override
public boolean appliesTo(@NonNull Context context, @NonNull File file) {
if (LintUtils.endsWith(file.getName(), DOT_JAVA)) {
return true;
}
return super.appliesTo(context, file);
}
@Override
public Collection<String> getApplicableAttributes() {
return Collections.singletonList(ATTR_ID);
}
@Override
public void visitAttribute(@NonNull XmlContext context, @NonNull Attr attribute) {
String view = attribute.getOwnerElement().getTagName();
String value = attribute.getValue();
String id = null;
if (value.startsWith(ID_PREFIX)) {
id = value.substring(ID_PREFIX.length());
} else if (value.startsWith(NEW_ID_PREFIX)) {
id = value.substring(NEW_ID_PREFIX.length());
} // else: could be @android id
if (id != null) {
if (view.equals(VIEW_TAG)) {
view = attribute.getOwnerElement().getAttribute(ATTR_CLASS);
}
Object existing = mIdToViewTag.get(id);
if (existing == null) {
mIdToViewTag.put(id, view);
} else if (existing instanceof String) {
String existingString = (String) existing;
if (!existingString.equals(view)) {
// Convert to list
List<String> list = new ArrayList<String>(2);
list.add((String) existing);
list.add(view);
mIdToViewTag.put(id, list);
}
} else if (existing instanceof List<?>) {
@SuppressWarnings("unchecked")
List<String> list = (List<String>) existing;
if (!list.contains(view)) {
list.add(view);
}
}
}
}
// ---- Implements Detector.JavaScanner ----
@Override
public List<String> getApplicableMethodNames() {
return Collections.singletonList("findViewById"); //$NON-NLS-1$
}
@Override
public void visitMethod(@NonNull JavaContext context, @Nullable AstVisitor visitor,
@NonNull MethodInvocation node) {
assert node.astName().getDescription().equals("findViewById");
if (node.getParent() instanceof Cast) {
Cast cast = (Cast) node.getParent();
String castType = cast.astTypeReference().getTypeName();
StrictListAccessor<Expression, MethodInvocation> args = node.astArguments();
if (args.size() == 1) {
Expression first = args.first();
// TODO: Do flow analysis as in the StringFormatDetector in order
// to handle variable references too
if (first instanceof Select) {
String resource = first.toString();
if (resource.startsWith("R.id.")) { //$NON-NLS-1$
String id = ((Select) first).astIdentifier().astValue();
Object types = mIdToViewTag.get(id);
if (types instanceof String) {
String layoutType = (String) types;
checkCompatible(context, castType, layoutType, null, cast);
} else if (types instanceof List<?>) {
@SuppressWarnings("unchecked")
List<String> layoutTypes = (List<String>) types;
checkCompatible(context, castType, null, layoutTypes, cast);
}
}
}
}
}
}
/** Check if the view and cast type are compatible */
private void checkCompatible(JavaContext context, String castType, String layoutType,
List<String> layoutTypes, Cast node) {
assert layoutType == null || layoutTypes == null; // Should only specify one or the other
boolean compatible = true;
if (layoutType != null) {
if (!layoutType.equals(castType)
&& !context.getSdkInfo().isSubViewOf(castType, layoutType)) {
compatible = false;
}
} else {
compatible = false;
assert layoutTypes != null;
for (String type : layoutTypes) {
if (type.equals(castType)
|| context.getSdkInfo().isSubViewOf(castType, type)) {
compatible = true;
break;
}
}
}
if (!compatible) {
if (layoutType == null) {
layoutType = Joiner.on("|").join(layoutTypes);
}
String message = String.format(
"Unexpected cast to %1$s: layout tag was %2$s",
castType, layoutType);
context.report(ISSUE, node, context.parser.getLocation(context, node), message,
null);
}
}
}