Why checkbox of android is so slow？

Question

Today, I used an Android machine with poor performance. I found the checkbox loading is very slow. For example:

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        long t1 = System.currentTimeMillis();
        setContentView(R.layout.activity_main);
        System.out.println("main cost: " + (System.currentTimeMillis()  - t1));
    }
}

There is only one Checkbox in the page, this will cost 200ms. If there are 3 or 5 checkbox in activity_main.xml, will cost 1s. What happend?

I compared Switch to Checkbox. Obviously Switch is very very better than Checkbox. If i want to keep to use Checkbox, what should i do?

Answer 1

Why does it happen ?

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This is happening because the Checkbox class is very complicated(too much code ?).

What is the solution ?

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1. You can create a custom layout.
2. You can use a library.

How to implement ?

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1.Custom layout

• First create a LinearLayout with horizontal orientation.
• Add an ImageView and a TextView in the xml.
• Code reference

<LinearLayout
        android:id="@+id/checkbox"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="7dp">
        
        <ImageView
            android:id="@+id/checkImageView"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:src="@drawable/checked"/>
        
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="This is the text for checkbox."
            android:layout_gravity="center_vertical"
            android:layout_marginStart="15dp"/>
        
</LinearLayout>

• Now the code for it to work.

In your class add this

boolean isChecked = true

Now it will function like this

LinearLayout checkBox = findViewById( R.id.checkbox );
        ImageView checkBoxImage = findViewById( R.id.checkImageView );
        checkBox.setOnClickListener( v -> {
            final Bitmap bmap = ((BitmapDrawable)checkBoxImage.getDrawable()).getBitmap();
            Drawable myDrawable = getResources().getDrawable(R.drawable.checked);
            final Bitmap myLogo = ((BitmapDrawable) myDrawable).getBitmap();
            if (bmap.sameAs(myLogo)){
                //it is checked
                isChecked = false;
                checkBoxImage.setImageResource( R.drawable.unchecked );
            }else {
                isChecked = true;
                checkBoxImage.setImageResource( R.drawable.checked );
            }
        } );

---

2.Using a library

• Use this library.

Sample usage

setChecked(boolean checked); //by default, it's wthout animation
setChecked(boolean checked, boolean animate);  //pass true to animate

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sample);

    final CustomCheckBox scb = (CustomCheckBox) findViewById(R.id.scb);
    scb.setOnCheckedChangeListener(new CustomCheckBox.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CustomCheckBox checkBox, boolean isChecked) {
            Log.d("CustomCheckBox", String.valueOf(isChecked));
        }
    });
}

Attributes

Attr	Type	Description
duration	integer	Animation Duration
stroke_width	dimension	The border width when unchecked
color_tick	color	Tick color (visible only when checked)
color_checked	color	Fill color when selected
color_unchecked	color	Fill color when unchecked
color_unchecked_stroke	color	Border color when unchecked

References

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Github

Edit 1 (27/1/22)

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Because of the comment received by Decent Dabbler , I now remember what it forgot. I actually forgot to mention that the file that takes too long to load is the xml file.This can be proved as we do not always use the class right? Just the view in the xml. If you open the xml file of the checkbox, you find it too big.