Android-DataBinding分析

分析基于 androidx.databinding 4.1.3版本进行

源码&编译

源码地址

git clone https://android.googlesource.com/platform/tools/buildSrc

git clone https://android.googlesource.com/platform/frameworks/data-binding

基于分支 studio-main

分析用源xml文件 fragment_test_db.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>

        <import type="java.util.HashMap" />

        <import type="com.example.behaviordemo.bindingadapter.ShapeBuilder" />

        <import type="android.graphics.Color" />

        <variable
            name="text"
            type="String" />

        <variable
            name="map"
            type="HashMap&lt;String,String>" />

    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/tv_txt"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{text, default = 23456}"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            setShape="@{ShapeBuilder.create().setCornerRadius(10).setColors(Color.RED).setShapeType(0)}"
            android:layout_width="100dp"
            android:layout_height="50dp"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            android:layout_width="100dp"
            android:layout_height="50dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            android:background='@{"#00ff00"}'/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{tvTxt.text}"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>

    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

@BindingAdapter("setShape")
fun setShape(view: View, builder: ShapeBuilder) {
    view.background = builder.mGradientDrawable
}

@BindingAdapter("setShape1")
fun setShape1(view: View, builder: ShapeBuilder) {
    view.background = builder.mGradientDrawable
}

@BindingAdapter(
    value = ["android:beforeTextChanged", "android:onTextChanged", "android:afterTextChanged", "android:textAttrChanged"],
    requireAll = false
)
fun setTextChange(
    view: TextView,
    before: TextViewBindingAdapter.BeforeTextChanged,
    on: TextViewBindingAdapter.OnTextChanged,
    after: TextViewBindingAdapter.AfterTextChanged,
    textAttrChanged: InverseBindingListener
) {

}

@BindingConversion
fun colorToDrawable(color: String): ColorDrawable {
    val colorInt = Color.parseColor(color)
    return ColorDrawable(colorInt)
}

用于分析生成后的文件

核心模块

• compiler

  APT模块，负责layout下xml文件解析以及生成DataBinding所需文件
  对应artifactId databinding-compiler

• compilerCommon

  与compiler功能保持一致，有些许的差别
  对应artifactId databinding-compiler-common

• baseLibrary(支持androidX)/baseLibrarySuppor(支持support)

  对外提供DataBinding相关注解
  对应artifactId databinding-common

• extensions/baseAdapters

  封装相关View的属性改变方法，与实际View进行隔离
  对应artifactId databinding-adapters

• extensions/library

  提供可被观察的对象，例如ObservableXX
  对应artifactId databinding-runtime

其他模块

• extensions/viewbinding

  ViewBinding相关实现
  对应artifactId viewbinding

• extensions/databindingKtx

  ViewBinding Ktx拓展函数实现
  对应artifiactId databinding-ktx

DataBinding Plugin——解析XML及生成相关文件

//分析置于如下文章

Android-DataBinding-GradlePlugin分析

DataBinding 源码解析

Android-DataBinding-Library分析

相关小结

ViewBinding与DataBinding区别？

新建Xml后DataBinding文件如何生成？不需要通过build去生成

https://cs.android.com/android-studio/platform/tools/adt/idea/+/mirror-goog-studio-main:android/src/com/android/tools/idea/databinding/
Android Studio 提供了DataBinding相关的文件生成与解析，待后续理解AS相关源码分析

DataBinding针对ViewStub的处理

DataBinding编译错误及临时解决方案记录

资源无法下载

在各个build.gradle添加如下配置

buildscript{
  XXX
  repositories {  
    google()  
    jcenter()  
    mavenCentral()  
  }
}

找不到addRemoteRepos参数

修改propLoader.gradle

//def addRemoteRepos = getBooleanValue(project, "addRemoteRepos", false)  
ext.dataBindingConfig.addRemoteRepos = true

修改settings.gradle

include ':dataBinding:baseLibrary'  
project(':dataBinding:baseLibrary').projectDir = new File("baseLibrary")  
include ':dataBinding:baseLibrarySupport'  
project(':dataBinding:baseLibrarySupport').projectDir = new File("baseLibrarySupport")  
include ':dataBinding:compiler'  
project(':dataBinding:compiler').projectDir = new File("compiler")  
//include ':dataBinding:compilationTests'  
//project(':dataBinding:compilationTests').projectDir = new File("compilationTests")  
include ':dataBinding:compilerCommon'  
project(':dataBinding:compilerCommon').projectDir = new File("compilerCommon")  
//include ':dataBinding:exec'  
//project(':dataBinding:exec').projectDir = new File("exec")

注释掉的内容并不影响data-binding相关源码分析及查看

参考链接

DataBinding注解详解

DataBinding数据绑定

todo

ViewStub加载分析

关键步骤的流程图补充

xmind总结