Java tutorial
/* * 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 static com.android.SdkConstants.ATTR_NAME; import static com.android.SdkConstants.ATTR_TYPE; import static com.android.SdkConstants.TAG_ITEM; import static com.android.utils.SdkUtils.getResourceFieldName; import com.android.annotations.NonNull; import com.android.annotations.Nullable; import com.android.ide.common.resources.ResourceUrl; import com.android.resources.ResourceFolderType; import com.android.resources.ResourceType; import com.android.tools.lint.detector.api.Category; import com.android.tools.lint.detector.api.Context; import com.android.tools.lint.detector.api.Implementation; import com.android.tools.lint.detector.api.Issue; import com.android.tools.lint.detector.api.LintUtils; import com.android.tools.lint.detector.api.Location; import com.android.tools.lint.detector.api.Location.Handle; 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.TextFormat; import com.android.tools.lint.detector.api.XmlContext; import com.android.utils.Pair; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import org.w3c.dom.Attr; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import java.io.File; import java.util.Collection; import java.util.Collections; import java.util.List; import java.util.Map; import java.util.Set; /** * This detector identifies cases where a resource is defined multiple times in the * same resource folder */ public class DuplicateResourceDetector extends ResourceXmlDetector { /** The main issue discovered by this detector */ @SuppressWarnings("unchecked") public static final Issue ISSUE = Issue.create("DuplicateDefinition", //$NON-NLS-1$ "Duplicate definitions of resources", "You can define a resource multiple times in different resource folders; that's how " + "string translations are done, for example. However, defining the same resource " + "more than once in the same resource folder is likely an error, for example " + "attempting to add a new resource without realizing that the name is already used, " + "and so on.", Category.CORRECTNESS, 6, Severity.ERROR, new Implementation(DuplicateResourceDetector.class, // We should be able to do this incrementally! Scope.ALL_RESOURCES_SCOPE, Scope.RESOURCE_FILE_SCOPE)); /** Wrong resource value type */ public static final Issue TYPE_MISMATCH = Issue.create("ReferenceType", //$NON-NLS-1$ "Incorrect reference types", "When you generate a resource alias, the resource you are pointing to must be " + "of the same type as the alias", Category.CORRECTNESS, 8, Severity.FATAL, new Implementation(DuplicateResourceDetector.class, Scope.RESOURCE_FILE_SCOPE)); private static final String PRODUCT = "product"; //$NON-NLS-1$ private Map<ResourceType, Set<String>> mTypeMap; private Map<ResourceType, List<Pair<String, Location.Handle>>> mLocations; private File mParent; /** Constructs a new {@link DuplicateResourceDetector} */ public DuplicateResourceDetector() { } @NonNull @Override public Speed getSpeed() { return Speed.NORMAL; } @Override @Nullable public Collection<String> getApplicableAttributes() { return Collections.singletonList(ATTR_NAME); } @Override public boolean appliesTo(@NonNull ResourceFolderType folderType) { return folderType == ResourceFolderType.VALUES; } @Override public void beforeCheckFile(@NonNull Context context) { File parent = context.file.getParentFile(); if (!parent.equals(mParent)) { mParent = parent; mTypeMap = Maps.newEnumMap(ResourceType.class); mLocations = Maps.newEnumMap(ResourceType.class); } } @Override public void visitAttribute(@NonNull XmlContext context, @NonNull Attr attribute) { Element element = attribute.getOwnerElement(); if (element.hasAttribute(PRODUCT)) { return; } String tag = element.getTagName(); String typeString = tag; if (tag.equals(TAG_ITEM)) { typeString = element.getAttribute(ATTR_TYPE); if (typeString == null || typeString.isEmpty()) { if (element.getParentNode().getNodeName().equals(ResourceType.STYLE.getName()) && isFirstElementChild(element)) { checkUniqueNames(context, (Element) element.getParentNode()); } return; } } ResourceType type = ResourceType.getEnum(typeString); if (type == null) { return; } if (type == ResourceType.ATTR && element.getParentNode().getNodeName().equals(ResourceType.DECLARE_STYLEABLE.getName())) { if (isFirstElementChild(element)) { checkUniqueNames(context, (Element) element.getParentNode()); } return; } NodeList children = element.getChildNodes(); int childCount = children.getLength(); for (int i = 0; i < childCount; i++) { Node child = children.item(i); if (child.getNodeType() == Node.TEXT_NODE) { String text = child.getNodeValue(); for (int j = 0, length = text.length(); j < length; j++) { char c = text.charAt(j); if (c == '@') { if (!text.regionMatches(false, j + 1, typeString, 0, typeString.length()) && context.isEnabled(TYPE_MISMATCH)) { ResourceUrl url = ResourceUrl.parse(text.trim()); if (url != null && url.type != type && // colors and mipmaps can apparently be used as drawables !(type == ResourceType.DRAWABLE && (url.type == ResourceType.COLOR || url.type == ResourceType.MIPMAP))) { String message = "Unexpected resource reference type; " + "expected value of type `@" + type + "/`"; context.report(TYPE_MISMATCH, element, context.getLocation(child), message); } } break; } else if (!Character.isWhitespace(c)) { break; } } break; } } Set<String> names = mTypeMap.get(type); if (names == null) { names = Sets.newHashSetWithExpectedSize(40); mTypeMap.put(type, names); } String name = attribute.getValue(); String originalName = name; // AAPT will flatten the namespace, turning dots, dashes and colons into _ name = getResourceFieldName(name); if (names.contains(name)) { String message = String.format("`%1$s` has already been defined in this folder", name); if (!name.equals(originalName)) { message += " (`" + name + "` is equivalent to `" + originalName + "`)"; } Location location = context.getLocation(attribute); List<Pair<String, Handle>> list = mLocations.get(type); for (Pair<String, Handle> pair : list) { if (name.equals(pair.getFirst())) { Location secondary = pair.getSecond().resolve(); secondary.setMessage("Previously defined here"); location.setSecondary(secondary); } } context.report(ISSUE, attribute, location, message); } else { names.add(name); List<Pair<String, Handle>> list = mLocations.get(type); if (list == null) { list = Lists.newArrayList(); mLocations.put(type, list); } Location.Handle handle = context.createLocationHandle(attribute); list.add(Pair.of(name, handle)); } } private static void checkUniqueNames(XmlContext context, Element parent) { List<Element> items = LintUtils.getChildren(parent); if (items.size() > 1) { Set<String> names = Sets.newHashSet(); for (Element item : items) { Attr nameNode = item.getAttributeNode(ATTR_NAME); if (nameNode != null) { String name = nameNode.getValue(); if (names.contains(name) && context.isEnabled(ISSUE)) { Location location = context.getLocation(nameNode); for (Element prevItem : items) { Attr attribute = item.getAttributeNode(ATTR_NAME); if (attribute != null && name.equals(attribute.getValue())) { assert prevItem != item; Location prev = context.getLocation(prevItem); prev.setMessage("Previously defined here"); location.setSecondary(prev); break; } } String message = String.format("`%1$s` has already been defined in this `<%2$s>`", name, parent.getTagName()); context.report(ISSUE, nameNode, location, message); } names.add(name); } } } } private static boolean isFirstElementChild(Node node) { node = node.getPreviousSibling(); while (node != null) { if (node.getNodeType() == Node.ELEMENT_NODE) { return false; } node = node.getPreviousSibling(); } return true; } /** * Returns the resource type expected for a {@link #TYPE_MISMATCH} error reported by * this lint detector. Intended for IDE quickfix implementations. * * @param message the error message created by this lint detector * @param format the format of the error message */ public static String getExpectedType(@NonNull String message, @NonNull TextFormat format) { return LintUtils.findSubstring(format.toText(message), "value of type @", "/"); } }