Java tutorial
/* * Copyright (C) 2014 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.CLASS_VIEW; import static com.android.SdkConstants.CLASS_VIEWGROUP; import static com.android.SdkConstants.DOT_LAYOUT_PARAMS; import static com.android.SdkConstants.R_STYLEABLE_PREFIX; import com.android.annotations.NonNull; import com.android.annotations.Nullable; import com.android.tools.lint.client.api.JavaParser.ResolvedClass; import com.android.tools.lint.client.api.JavaParser.ResolvedNode; 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 com.android.tools.lint.detector.api.Speed; import com.google.common.collect.Iterators; import java.io.File; import java.util.Collections; import java.util.List; import lombok.ast.AstVisitor; import lombok.ast.ClassDeclaration; import lombok.ast.Expression; import lombok.ast.ExpressionStatement; import lombok.ast.MethodInvocation; import lombok.ast.StrictListAccessor; /** * Makes sure that custom views use a declare styleable that matches * the name of the custom view */ public class CustomViewDetector extends Detector implements Detector.JavaScanner { private static final Implementation IMPLEMENTATION = new Implementation(CustomViewDetector.class, Scope.JAVA_FILE_SCOPE); /** Mismatched style and class names */ public static final Issue ISSUE = Issue.create("CustomViewStyleable", //$NON-NLS-1$ "Mismatched Styleable/Custom View Name", "The convention for custom views is to use a `declare-styleable` whose name " + "matches the custom view class name. The IDE relies on this convention such that " + "for example code completion can be offered for attributes in a custom view " + "in layout XML resource files.\n" + "\n" + "(Similarly, layout parameter classes should use the suffix `_Layout`.)", Category.CORRECTNESS, 6, Severity.WARNING, IMPLEMENTATION); private static final String OBTAIN_STYLED_ATTRIBUTES = "obtainStyledAttributes"; //$NON-NLS-1$ /** Constructs a new {@link com.android.tools.lint.checks.CustomViewDetector} check */ public CustomViewDetector() { } @Override public boolean appliesTo(@NonNull Context context, @NonNull File file) { return true; } @NonNull @Override public Speed getSpeed() { return Speed.FAST; } // ---- Implements JavaScanner ---- @Override public List<String> getApplicableMethodNames() { return Collections.singletonList(OBTAIN_STYLED_ATTRIBUTES); } @Override public void visitMethod(@NonNull JavaContext context, @Nullable AstVisitor visitor, @NonNull MethodInvocation node) { if (node.getParent() instanceof ExpressionStatement) { if (!context.isContextMethod(node)) { return; } StrictListAccessor<Expression, MethodInvocation> expressions = node.astArguments(); int size = expressions.size(); // Which parameter contains the styleable (attrs) ? int parameterIndex; if (size == 1) { // obtainStyledAttributes(int[] attrs) parameterIndex = 0; } else { // obtainStyledAttributes(int resid, int[] attrs) // obtainStyledAttributes(AttributeSet set, int[] attrs) // obtainStyledAttributes(AttributeSet set, int[] attrs, int defStyleAttr, int defStyleRes) parameterIndex = 1; } Expression expression = Iterators.get(node.astArguments().iterator(), parameterIndex, null); if (expression == null) { return; } String s = expression.toString(); if (!s.startsWith(R_STYLEABLE_PREFIX)) { return; } String styleableName = s.substring(R_STYLEABLE_PREFIX.length()); ClassDeclaration cls = JavaContext.findSurroundingClass(node); if (cls == null) { return; } ResolvedNode resolved = context.resolve(cls); if (!(resolved instanceof ResolvedClass)) { return; } String className = cls.astName().astValue(); ResolvedClass resolvedClass = (ResolvedClass) resolved; if (resolvedClass.isSubclassOf(CLASS_VIEW, false)) { if (!styleableName.equals(className)) { String message = String .format("By convention, the custom view (`%1$s`) and the declare-styleable (`%2$s`) " + "should have the same name (various editor features rely on " + "this convention)", className, styleableName); context.report(ISSUE, node, context.getLocation(expression), message); } } else if (resolvedClass.isSubclassOf(CLASS_VIEWGROUP + DOT_LAYOUT_PARAMS, false)) { ClassDeclaration outer = JavaContext.findSurroundingClass(cls.getParent()); if (outer == null) { return; } String layoutClassName = outer.astName().astValue(); String expectedName = layoutClassName + "_Layout"; if (!styleableName.equals(expectedName)) { String message = String.format( "By convention, the declare-styleable (`%1$s`) for a layout parameter " + "class (`%2$s`) is expected to be the surrounding " + "class (`%3$s`) plus \"`_Layout`\", e.g. `%4$s`. " + "(Various editor features rely on this convention.)", styleableName, className, layoutClassName, expectedName); context.report(ISSUE, node, context.getLocation(expression), message); } } } } }