Generally, when writing a page, everyone writes the layout through xml, and loads the xml layout into memory through set contentView or LayoutInflater.from(context).inflate method.
- Good maintainability
- Support instant preview
- Clear code structure
- Reading xml is time consuming
- Recursive parsing xml is time consuming
- The time it takes to generate an object is more than three times that of new.
Our team has also explored many solutions on this issue. Once it reached the other extreme, completely abandoning xml, all controls are new through java, even directly in the canvas, so although the performance is indeed improved, but the code is gone. A little bit of readability and maintainability. We later reflected on the code to see the machine, or to show it? ? Maybe X2C has given us an answer.
In order to preserve the advantages of xml and solve the performance problems it brings, we developed the X2C solution. That is, during the compilation and generation of the APK, the translation of the layout that needs to be translated generates the corresponding java file, so that the developer writes the layout or writes the original xml, but for the program, the runtime loads the corresponding java file. We use APT (Annotation Processor Tool) + JavaPoet technology to complete the operation of the whole process during the compilation [Annotation] -> [Resolve] -> [Translate xml] -> [Generate java].
After the development integration, we did a simple test, the performance comparison is as follows
| Loading method | frequency | Average load time |
|---|---|---|
| XML | 100 | 30 |
| X2C | 100 | 11 |
Add dependencies in the build.gradle file of the module
annotationProcessor 'com.zhangyue.we:x2c-apt:1.1.2'
implementation 'com.zhangyue.we:x2c-lib:1.0.6'Add annotations to any java class or method that uses the layout.
@Xml(layouts = "activity_main")Create an X2C_CONFIG.xml file under the module, which defines the mapping between attributes and methods. If the receiver is a view, write the view. Otherwise fill in params.
<x2c-config>
<attr name="app:mixColor" toFunc="view.setMixColor(int)" />
<attr name="android:layout_marginTop" toFunc="params.topMargin=int" />
</x2c-config>
Replace where you originally used set content view or inflate, as follows:
this.setContentView(R.layout.activity_main); --> X2C.setContentView(this, R.layout.activity_main);LayoutInflater.from(this).inflate(R.layout.activity_main,null); --> X2C.inflate(this,R.layout.activity_main,null);<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="10dp">
<include
android:id="@+id/head"
layout="@layout/head"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true" />
<ImageView
android:id="@+id/ccc"
style="@style/bb"
android:layout_below="@id/head" />
</RelativeLayout>/**
* WARN!!! dont edit this file
* translate from {@link com.zhangyue.we.x2c.demo.R.layout.activity_main}
* autho chengwei
* email [email protected]
*/
public class X2C_2131296281_Activity_Main implements IViewCreator {
@Override
public View createView(Context ctx, int layoutId) {
Resources res = ctx.getResources();
RelativeLayout relativeLayout0 = new RelativeLayout(ctx);
relativeLayout0.setPadding((int)(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,10,res.getDisplayMetrics())),0,0,0);
View view1 =(View) new X2C_2131296283_Head().createView(ctx,0);
RelativeLayout.LayoutParams layoutParam1 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
view1.setLayoutParams(layoutParam1);
relativeLayout0.addView(view1);
view1.setId(R.id.head);
layoutParam1.addRule(RelativeLayout.CENTER_HORIZONTAL,RelativeLayout.TRUE);
ImageView imageView2 = new ImageView(ctx);
RelativeLayout.LayoutParams layoutParam2 = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,(int)(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,1,res.getDisplayMetrics())));
imageView2.setLayoutParams(layoutParam2);
relativeLayout0.addView(imageView2);
imageView2.setId(R.id.ccc);
layoutParam2.addRule(RelativeLayout.BELOW,R.id.head);
return relativeLayout0;
}
}/**
* WARN!!! don't edit this file
*
* author chengwei
* email [email protected]
*/
public class X2C127_activity implements IViewCreator {
@Override
public View createView(Context context) {
View view = null ;
int sdk = Build.VERSION.SDK_INT;
int orientation = context.getResources().getConfiguration().orientation;
boolean isLandscape = orientation == Configuration.ORIENTATION_LANDSCAPE;
if (isLandscape) {
view = new com.zhangyue.we.x2c.layouts.land.X2C127_Activity().createView(context);
} else if (sdk >= 27) {
view = new com.zhangyue.we.x2c.layouts.v27.X2C127_Activity().createView(context);
} else if (sdk >= 21) {
view = new com.zhangyue.we.x2c.layouts.v21.X2C127_Activity().createView(context);
} else {
view = new com.zhangyue.we.x2c.layouts.X2C127_Activity().createView(context);
}
return view;
}
}- The merge tag cannot determine the parent of the xml during compilation, so it cannot be supported.
- System style, only the style list of the application can be found during compilation, and the system style cannot be queried, so only the in-app style is supported.
- ButterKnifer
- DataBinding
- android widget
- customView
- include tag
- viewStub tag
- fragment label
- Application style
- Custom attribute
- System attribute
| Attribute name | Attribute name |
|---|---|
| android:textSize | app:layout_constraintRight_toLeftOf |
| android:textColor | app:layout_constraintBottom_toTopOf |
| android:text | app:layout_constraintTop_toTopOf |
| android:background | app:layout_constrainedHeight |
| view all |
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