| /* |
| * 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.ANDROID_URI; |
| import static com.android.SdkConstants.ATTR_CONTENT_DESCRIPTION; |
| import static com.android.SdkConstants.ATTR_HINT; |
| import static com.android.SdkConstants.ATTR_ID; |
| import static com.android.SdkConstants.ATTR_LABEL_FOR; |
| import static com.android.SdkConstants.ATTR_TEXT; |
| import static com.android.SdkConstants.AUTO_COMPLETE_TEXT_VIEW; |
| import static com.android.SdkConstants.EDIT_TEXT; |
| import static com.android.SdkConstants.ID_PREFIX; |
| import static com.android.SdkConstants.MULTI_AUTO_COMPLETE_TEXT_VIEW; |
| import static com.android.SdkConstants.NEW_ID_PREFIX; |
| import static com.android.SdkConstants.TEXT_VIEW; |
| import static com.android.tools.lint.detector.api.Lint.stripIdPrefix; |
| |
| 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.Implementation; |
| import com.android.tools.lint.detector.api.Issue; |
| import com.android.tools.lint.detector.api.LayoutDetector; |
| import com.android.tools.lint.detector.api.LintFix; |
| import com.android.tools.lint.detector.api.Location; |
| import com.android.tools.lint.detector.api.Scope; |
| import com.android.tools.lint.detector.api.Severity; |
| import com.android.tools.lint.detector.api.XmlContext; |
| import com.google.common.collect.Sets; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Set; |
| import org.w3c.dom.Attr; |
| import org.w3c.dom.Element; |
| |
| /** Detector which finds unlabeled text fields */ |
| public class LabelForDetector extends LayoutDetector { |
| /** The main issue discovered by this detector */ |
| public static final Issue ISSUE = |
| Issue.create( |
| "LabelFor", |
| "Missing accessibility label", |
| "Editable text fields should provide an `android:hint` or, provided your " |
| + "`minSdkVersion` is at least 17, they may be referenced by a view " |
| + "with a `android:labelFor` attribute.\n" |
| + "\n" |
| + "When using `android:labelFor`, be sure to provide an `android:text` or an " |
| + "`android:contentDescription`.\n" |
| + "\n" |
| + "If your view is labeled but by a label in a different layout which " |
| + "includes this one, just suppress this warning from lint.", |
| Category.A11Y, |
| 2, |
| Severity.WARNING, |
| new Implementation(LabelForDetector.class, Scope.RESOURCE_FILE_SCOPE)); |
| |
| private static final String PREFIX = "Missing accessibility label"; |
| |
| private static final String PROVIDE_HINT = |
| "where minSdk < 17, you should provide an `android:hint`"; |
| |
| private static final String PROVIDE_LABEL_FOR_OR_HINT = |
| "provide either a view with an " |
| + "`android:labelFor` that references this view or provide an `android:hint`"; |
| |
| private Set<String> mLabels; |
| private List<Element> mEditableTextFields; |
| |
| /** Constructs a new {@link LabelForDetector} */ |
| public LabelForDetector() {} |
| |
| @Override |
| @Nullable |
| public Collection<String> getApplicableAttributes() { |
| return Collections.singletonList(ATTR_LABEL_FOR); |
| } |
| |
| @Override |
| public Collection<String> getApplicableElements() { |
| return Arrays.asList(EDIT_TEXT, AUTO_COMPLETE_TEXT_VIEW, MULTI_AUTO_COMPLETE_TEXT_VIEW); |
| } |
| |
| @Override |
| public void afterCheckFile(@NonNull Context context) { |
| if (mEditableTextFields != null) { |
| if (mLabels == null) { |
| mLabels = Collections.emptySet(); |
| } |
| |
| for (Element element : mEditableTextFields) { |
| String id = element.getAttributeNS(ANDROID_URI, ATTR_ID); |
| |
| boolean hintProvided = element.hasAttributeNS(ANDROID_URI, ATTR_HINT); |
| boolean labelForProvided = false; |
| |
| if (mLabels.contains(id)) { |
| labelForProvided = true; |
| } else if (id.startsWith(NEW_ID_PREFIX)) { |
| labelForProvided = mLabels.contains(ID_PREFIX + stripIdPrefix(id)); |
| } else if (id.startsWith(ID_PREFIX)) { |
| labelForProvided = mLabels.contains(NEW_ID_PREFIX + stripIdPrefix(id)); |
| } |
| |
| XmlContext xmlContext = (XmlContext) context; |
| String message = ""; |
| Location location = xmlContext.getElementLocation(element); |
| int minSdk = context.getMainProject().getMinSdk(); |
| |
| if (hintProvided && labelForProvided) { |
| // Note: labelFor no-ops below 17. |
| if (minSdk >= 17) { |
| message = PROVIDE_LABEL_FOR_OR_HINT + ", but not both"; |
| } |
| } else if (!hintProvided && !labelForProvided) { |
| if (minSdk < 17) { |
| message = PROVIDE_HINT; |
| } else { |
| message = PROVIDE_LABEL_FOR_OR_HINT; |
| } |
| } else { |
| // Note: if only android:hint is provided, no need for a warning. |
| |
| if (labelForProvided) { |
| if (minSdk < 17) { |
| message = PROVIDE_HINT; |
| } |
| } |
| } |
| |
| if (!message.isEmpty()) { |
| xmlContext.report(ISSUE, element, location, messageWithPrefix(message)); |
| } |
| } |
| } |
| |
| mLabels = null; |
| mEditableTextFields = null; |
| } |
| |
| @Override |
| public void visitAttribute(@NonNull XmlContext context, @NonNull Attr attribute) { |
| |
| assert (attribute.getLocalName().equals(ATTR_LABEL_FOR)); |
| |
| Element element = attribute.getOwnerElement(); |
| |
| if (mLabels == null) { |
| mLabels = Sets.newHashSet(); |
| } |
| mLabels.add(attribute.getValue()); |
| |
| // Unlikely this is anything other than a TextView. If it is, bail. |
| if (!element.getLocalName().equals(TEXT_VIEW)) { |
| return; |
| } |
| |
| Attr textAttributeNode = element.getAttributeNodeNS(ANDROID_URI, ATTR_TEXT); |
| Attr contentDescriptionNode = |
| element.getAttributeNodeNS(ANDROID_URI, ATTR_CONTENT_DESCRIPTION); |
| |
| if ((textAttributeNode == null || textAttributeNode.getValue().isEmpty()) |
| && (contentDescriptionNode == null |
| || contentDescriptionNode.getValue().isEmpty())) { |
| LintFix fix = |
| fix().alternatives( |
| fix().set().todo(ANDROID_URI, ATTR_TEXT).build(), |
| fix().set() |
| .todo(ANDROID_URI, ATTR_CONTENT_DESCRIPTION) |
| .build()); |
| |
| context.report( |
| ISSUE, |
| element, |
| context.getElementLocation(element, null, ANDROID_URI, ATTR_LABEL_FOR), |
| messageWithPrefix( |
| "when using `android:labelFor`, you must also define an " |
| + "`android:text` or an `android:contentDescription`"), |
| fix); |
| } |
| } |
| |
| @Override |
| public void visitElement(@NonNull XmlContext context, @NonNull Element element) { |
| if (element.hasAttributeNS(ANDROID_URI, ATTR_HINT)) { |
| Attr hintAttributeNode = element.getAttributeNodeNS(ANDROID_URI, ATTR_HINT); |
| if (hintAttributeNode.getValue().isEmpty()) { |
| context.report( |
| ISSUE, |
| hintAttributeNode, |
| context.getLocation(hintAttributeNode), |
| "Empty `android:hint` attribute"); |
| } |
| } |
| if (mEditableTextFields == null) { |
| mEditableTextFields = new ArrayList<>(); |
| } |
| mEditableTextFields.add(element); |
| } |
| |
| private static String messageWithPrefix(String message) { |
| return PREFIX + ": " + message; |
| } |
| } |
