写个更牛逼的Transform | Plugin 进阶教程

package com.kronos.plugin.base

interface TransformCallBack {
    fun process(className: String, classBytes: ByteArray?): ByteArray?
}

public class DoubleTapPlugin implements Plugin<Project> {

    private static final String EXT_NAME = "doubleTab";

    @Override
    public void apply(Project project) {
        boolean isApp = project.getPlugins().hasPlugin(AppPlugin.class);
        project.getExtensions().create(EXT_NAME, DoubleTabConfig.class);
        project.afterEvaluate(project1 -> {
            DoubleTabConfig config = (DoubleTabConfig) project1.getExtensions().findByName(EXT_NAME);
            if (config == null) {
                config = new DoubleTabConfig();
            }
            config.transform();
        });
        if (isApp) {
            AppExtension appExtension = project.getExtensions().getByType(AppExtension.class);
            appExtension.registerTransform(new DoubleTapAppTransform());

            return;
        }
        if (project.getPlugins().hasPlugin("com.android.library")) {
            LibraryExtension libraryExtension = project.getExtensions().getByType(LibraryExtension.class);
            libraryExtension.registerTransform(new DoubleTapLibraryTransform());
        }
    }
}

class DoubleTapLibraryTransform : DoubleTapTransform() {

    override fun getScopes(): MutableSet<in QualifiedContent.Scope> {
        return ImmutableSet.of(
            QualifiedContent.Scope.PROJECT
        )
    }

    override fun getInputTypes(): Set<QualifiedContent.ContentType>? {
        return TransformManager.CONTENT_CLASS
    }
}

class AutoTrackHelper : AsmHelper {

    private val classNodeMap = hashMapOf<String, ClassNode>()

    @Throws(IOException::class)
    override fun modifyClass(srcClass: ByteArray): ByteArray {
        val classNode = ClassNode(ASM5)
        val classReader = ClassReader(srcClass)
        //1 将读入的字节转为classNode
        classReader.accept(classNode, 0)
        classNodeMap[classNode.name] = classNode
        // 判断当前类是否实现了OnClickListener接口
        classNode.interfaces?.forEach {
            if (it == "android/view/View\$OnClickListener") {
                val field = classNode.getField()
                classNode.methods?.forEach { method ->
                    // 找到onClick 方法
                    insertTrack(classNode, method, field)
                }
            }
        }
        //调用Fragment的onHiddenChange方法
        visitFragment(classNode)
        val classWriter = ClassWriter(0)
        //3  将classNode转为字节数组
        classNode.accept(classWriter)
        return classWriter.toByteArray()
    }


    private fun insertTrack(node: ClassNode, method: MethodNode, field: FieldNode?) {
        // 判断方法名和方法描述
        if (method.name == "onClick" && method.desc == "(Landroid/view/View;)V") {
            val className = node.outerClass
            val parentNode = classNodeMap[className]
            // 根据outClassName 获取到外部类的Node
            val parentField = field ?: parentNode?.getField()
            val instructions = method.instructions
            instructions?.iterator()?.forEach {
                // 判断是不是代码的截止点
                if ((it.opcode >= Opcodes.IRETURN && it.opcode <= Opcodes.RETURN) || it.opcode == Opcodes.ATHROW) {
                    instructions.insertBefore(it, VarInsnNode(Opcodes.ALOAD, 1))
                    instructions.insertBefore(it, VarInsnNode(Opcodes.ALOAD, 1))
                    // 获取到数据参数 
                    if (parentField != null) {
                        parentField.apply {
                            instructions.insertBefore(it, VarInsnNode(Opcodes.ALOAD, 0))
                            instructions.insertBefore(
                                    it, FieldInsnNode(Opcodes.GETFIELD, node.name, parentField.name, parentField.desc)
                            )
                        }
                    } else {
                        instructions.insertBefore(it, LdcInsnNode("1234"))
                    }
                    instructions.insertBefore(
                            it, MethodInsnNode(
                            Opcodes.INVOKESTATIC,
                            "com/wallstreetcn/sample/ToastHelper",
                            "toast",
                            "(Ljava/lang/Object;Landroid/view/View;Ljava/lang/Object;)V",
                            false
                    )
                    )
                }
            }
        }
    }
    // 判断Field是否包含注解
    private fun ClassNode.getField(): FieldNode? {
        return fields?.firstOrNull { field ->
            var hasAnnotation = false
            field?.visibleAnnotations?.forEach { annotation ->
                if (annotation.desc == "Lcom/wallstreetcn/sample/adapter/Test;") {
                    hasAnnotation = true
                }
            }
            hasAnnotation
        }
    }
}