使用Android databinding进行动态布局

Google 最近公布了Android mvvm架构，可以使用databinding做些赋值和渲染界面的操作。

了解到Jsp中使用EL表达式，可以做些简单的赋值和表达式运算。

然后我写一个简单的库，可以使用Android的Databinding进行动态布局，布局的大小可以通过表达式来计算。

比如一个view的高度是屏幕宽度的三分之一，然后再减10dp。可以这样使用。

width = "@{dimen.screenWidth/3 - dimen.dp(10)}"

下面是Github连接

AndroidSizeUtil

下面是文档：

AndroidSizeUtil

Desc

AndroidSizeUtil is use android mvvm(databinding) architecture.

It is easy to compose layout, like html. Use percentage or expression in xml file to compose layout.

Usage

#1

Your app project must use android mvvm(databinding) architecture.

Android mvvm doc

#2

Gradle compile

repositories {
maven {
url "https://raw.githubusercontent.com/LiushuiXiaoxia/AndroidSizeUtil/master/repo/"
}
}
compile 'cn.mycommons:androidsizeutil:1.0.0'

#3

Init AndroidSizeUtil in android Application or Activity.

public class AppContext extends Application {

@Override
public void onCreate() {
super.onCreate();

AndroidSizeUtil.init(this);
}
}

#4

Improt AndroidSizeUtil in 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"

xmlns:tools="http://schemas.android.com/tools">

<data>

<variable
name="dimen"
type="cn.mycommons.androidsizeutil.DimenUtil" />
</data>
</layout>

#5

Use dimen to compose view or layout like this.

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_height="@{dimen.csh/3}"
app:layout_marginLeft="@{dimen.csw/3}"
app:layout_marginTop="@{0}"
app:layout_width="@{dimen.csw*2/3}" />

#6

Use databind in activity.

ContentMainBinding is generate java file by android databinding.

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

ContentMainBinding.bind(findViewById(R.id.content_main)).setDimen(AndroidSizeUtil.newDimenUtil());
}
}

Api

Attributes set width, height, paddding, margin. The unit is px.

app:layout_width // set view width
app:layout_height // set view height

android:paddingLeft // set view paddingLeft
android:paddingRight // set view paddingRight
android:paddingTop // set view paddingTop
android:paddingBottom // set view paddingBottom

app:paddingLeft // set view paddingLeft
app:paddingRight // set view paddingRight
app:paddingTop // set view paddingTop
app:paddingBottom // set view paddingBottom

android:layout_marginLeft // set view layout_marginLeft
android:layout_marginRight // set view layout_marginRight
android:layout_marginTop // set view layout_marginTop
android:layout_marginBottom // set view layout_marginBottom

app:layout_marginLeft // set view layout_marginLeft
app:layout_marginRight // set view layout_marginRight
app:layout_marginTop // set view layout_marginTop
app:layout_marginBottom // set view layout_marginBottom

Expression to set size.

// 100% screen width
app:layout_width="@{dimen.sw}"
app:layout_width="@{dimen.screenWidth}"

// 1/2 screen height
app:layout_height="@{dimen.sh/2}"
app:layout_height="@{dimen.screenHeight/2}"

// 100px
app:layout_width="@{100}"
app:layout_width="@{dimen.px(100)}"

// 100dp
app:layout_width="@{dimen.dp(100)}"

// 100dp - 10px
app:layout_width="@{dimen.dp(100)-10}"

Set view or layout size.

// 100dp * 100dp
app:size="@{dimen.sizeDp(100,100)}"

// 100px * 100px
app:size="@{dimen.size(100,100)}"

// 100dp * 100px
app:size="@{dimen.size(dimen.dp(100),100)}"

// screenWidth * 100px
app:size="@{dimen.size(dimen.screenWidth,100)}"

Java api.

DimenUtil.java

LayoutUtil.java

Demo

<?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"

xmlns:tools="http://schemas.android.com/tools">

<data>

<variable
name="dimen"
type="cn.mycommons.androidsizeutil.DimenUtil" />
</data>

<RelativeLayout
android:id="@+id/content_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
tools:showIn="@layout/activity_main">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#faa"
android:gravity="center"
android:text="1"
app:size="@{dimen.size(dimen.csw/3,dimen.csh/3)}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#f00"
android:gravity="center"
android:text="2"
app:layout_height="@{dimen.csh/3}"
app:layout_marginLeft="@{dimen.csw/3}"
app:layout_marginTop="@{0}"
app:layout_width="@{dimen.csw*2/3}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#f0f"
android:gravity="center"
android:text="3"
app:layout_height="@{dimen.csh*2/3}"
app:layout_marginLeft="@{0}"
app:layout_marginTop="@{dimen.csh/3}"
app:layout_width="@{dimen.csw/3}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#ff0"
android:gravity="center"
android:text="4"
app:layout_height="@{dimen.csh*2/3}"
app:layout_marginLeft="@{dimen.csw/3}"
app:layout_marginTop="@{dimen.csh/3}"
app:layout_width="@{dimen.csw*2/3}" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#0f0"
android:gravity="center"
android:text="5"
app:layout_marginLeft="@{dimen.csw/3-dimen.dp(50)}"
app:layout_marginTop="@{dimen.csh/3-dimen.dp(50)}"
app:size="@{dimen.sizeDp(100,100)}" />
</RelativeLayout>
</layout>

Gradle

repositories {
maven {
url "https://raw.githubusercontent.com/LiushuiXiaoxia/AndroidSizeUtil/master/repo/"
}
}

compile 'cn.mycommons:androidsizeutil:1.0.0'