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Why checkbox of android is so slow？

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?

Why does it happen ?
This is happening because the Checkbox class is very complicated(too much code 😠).
What is the solution ?
You can create a custom layout.
You can use a library.
How to implement ?
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
Github
Edit 1 (27/1/22)
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.

Center crop dont work in gridlayoutmaneger Android

I have grid view which is using GridLayoutManager and the RecyclerView
grid has 3 rows which are working fine as you see,[![enter image description here][1]][1]
but for some reason, image views scale type won't work on any of the items and those items you see work fine because the resolution already is square mean 512*512 but if you see the last item that has low resolution it have white space in left and right.
that's my code from a setup list
int getori = getResources().getConfiguration().orientation;
if (getori == Configuration.ORIENTATION_PORTRAIT) {
gl = new GridLayoutManager(getBaseContext(), 3);
} else if (getori == Configuration.ORIENTATION_LANDSCAPE){
gl = new GridLayoutManager(getBaseContext(), 6);
}
gg.setHasFixedSize(true);
gg.setFitsSystemWindows(true);
gg.setLayoutManager(gl);
gg.setAdapter(startpostsystem);
that's my grid adapter code
#Override
public void onBindViewHolder(Grid_view holder, final int position) {
holder.im.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String getfiledop = fall[position].getAbsolutePath();
Intent is = new Intent(cm,Open_post_item.class);
is.putExtra("req",12);
cm.startActivity(is);
and this is my grid view items layout code.
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="140dp">
<ImageView
android:id="#+id/imageView18"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:adjustViewBounds="true"
app:srcCompat="#drawable/sunbow100" />
I tried to use :
android:scaleType="centerCrop"
android:adjustViewBounds="true"
or fitxy it make it worse
view bounds won't work either.
if i add more images like 800*400 or ... it will have white space
so where is problem where I do wrong.

try using android:src in place of app:srcCompat
<ImageView
android:id="#+id/imageView18"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:adjustViewBounds="true"
android:src="#drawable/sunbow100" />

Ripple animation of ListView item won't work by click on containing TextView

I have a custom adapter set for my ListView. I have also set the default item selection ripple animation to appear when an item is selected (android:background="?android:selectableItemBackground").
However, the animation won't appear when I tap the TextViews. Here's a video.
What I've tried, to no avail:
setting the parent LinearLayout's descendantFocusability="blocksDescendants"
adding clickable &
focusable="false" to the TextViews
Here's my list_item.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawSelectorOnTop="true"
android:background="?android:selectableItemBackground"
android:orientation="vertical"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="16dp">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ellipsize="end"
android:maxLines="1"
android:textSize="18sp"
android:textStyle="bold" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ellipsize="end"
android:maxLines="1" />
</LinearLayout>
(Edit) And in getView() method in Adapter class I have these before return convertView:
holder.title.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((ListView) parent).performItemClick(v, position, 0); // Let the event be handled in onItemClick()
}
});
holder.text.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((ListView) parent).performItemClick(v, position, 0); // Let the event be handled in onItemClick()
}
});
convertView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((ListView) parent).performItemClick(v, position, 0);
}
});
...to allow onItemClick in MainActivity (if I press the text or the linear layout, it opens up the same thing).

I have a solution to your problem: Try this in your getView():
final RippleDrawable rippleDrawable = (RippleDrawable) convertView.getBackground();
final View finalParent = parent;
final int finalPosition = position;
View.OnTouchListener listener = new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()) {
case MotionEvent.ACTION_DOWN:
rippleDrawable.setHotspot(motionEvent.getX(), motionEvent.getY());
rippleDrawable.setState(new int[] {android.R.attr.state_pressed, android.R.attr.state_enabled});
return true;
case MotionEvent.ACTION_UP:
rippleDrawable.setState(new int[0]);
((ListView)finalParent).performItemClick(view, finalPosition, 0);
return true;
}
return false;
}
};
The first line gets the RippleDrawable of the ListView item which holds the touched TextView.
When the TextView gets touched, you get the coordinates of the touch and set them to the RippleDrawable with setHotSpot, to specify the starting point of the ripple effect.
After that you trigger the ripple effect by setting an int array holding the states android.R.attr.state_pressed and android.R.attr.state_enabled to the RippleDrawable using setState().
When the touch ends, you set the state to an empty int array, the stop the ripple.
It should work!

Android numberpicker getting stuck

I have a numberpicker dialog to select hours and minutes (15 minutes interval). It works fine on large screens but on small screens and older devices it gets stuck if I try to scroll using touch.
I am extending the android.widget.NumberPicker and reducing the font size which helps on some devices.
public class TimerNumberPicker extends android.widget.NumberPicker {
public TimerNumberPicker(Context context) {
super(context);
}
public TimerNumberPicker(Context context, AttributeSet attrs){
super(context,attrs);
}
#Override
public void addView(View child) {
super.addView(child);
updateView(child);
}
#Override
public void addView(View child, ViewGroup.LayoutParams params) {
super.addView(child, params);
updateView(child);
}
#Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
super.addView(child, index, params);
updateView(child);
}
private void updateView(View view) {
if(view instanceof EditText){
((EditText) view).setTextSize(TypedValue.COMPLEX_UNIT_SP,16);
view.setTag(FontUtil.TAG_CONDENSED_LIGHT);
FontUtil.getInstence(getContext()).setFontByTag(view);
}
}
}
What makes it more complicated is that the minutes have only values (0, 15, 30, 45) and I have to setWrapSelectorWheel to false?
I am thinking if it will be possible to always show the up and down arrows and then disabling scroll.

Change it to an Edittext with the type of number, and use a Toast if the client put a number upper or below of your range. It's more elegant visually, and that will not give you any problem at all

you can use Fantastic PickView library
See PickView
This is a helper lib for us to pick date or province like IOS system WheelView widget.

Maybe you could solve it using a TimePicker.
This could be the layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:padding="8dp"
android:layout_height="wrap_content">
<ScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TimePicker
android:id="#+id/time_picker"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<Button
android:id="#+id/date_time_set"
android:layout_width="match_parent"
android:text="Set"
android:layout_height="wrap_content" />
</LinearLayout>
</ScrollView>
While the dialog could be included in a normal alert:
private void showTimePicker(){
final View dialogView = View.inflate(getActivity(), <time_picker_container_layout_id>, null);
final AlertDialog alertDialog = new AlertDialog.Builder(getActivity()).create();
dialogView.findViewById(R.id.date_time_set).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
TimePicker timePicker = (TimePicker) dialogView.findViewById(R.id.time_picker);
String time = timePicker.getCurrentHour()+":"+timePicker.getCurrentMinute());
dateTime.setText(time);
alertDialog.dismiss();
}});
TimePicker timePicker = (TimePicker) dialogView.findViewById(R.id.time_picker);
timePicker.setCurrentHour(<default_hour>);
timePicker.setCurrentMinute(<default_minute>);
alertDialog.setView(dialogView);
alertDialog.show();
}
If you need to show just the 15', you can round the picked minutes to the closest valid value.
The scrollView in the layout will reduce problems related the picker size.
I hope it helped.

Scroll a RelativeLayout when it contains custom Views

I'm trying to make scrollable RelativeLayout, that contains some custom Views. This is the plan of cinema hall, i have x, y coordinates of places and it's width and height (that are just rectangales, actually). I just put it into this RelativeLayout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:padding="10px">
<ScrollView
android:layout_height="wrap_content"
android:layout_width="fill_parent">
<RelativeLayout android:id="#+id/scrollable_places"
android:layout_height="wrap_content"
android:layout_width="wrap_content">
</RelativeLayout>
</ScrollView>
I put it like this:
RelativeLayout layout = (RelativeLayout) context.findViewById(R.id.scrollable_places);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(place.getWidth(),
place.getHeight());
params.leftMargin = place.getX();
params.topMargin = place.getY();
layout.addView(new Seat(context, place), params);
Seat class looks like this:
public class Seat extends View {
private Place place;
private boolean isRed = false;
public Seat(Context context, Place place) {
super(context);
this.place = place;
setOnClickListener(new OnSeatClickListener());
}
#Override
protected void onDraw(Canvas canvas) {
if (!isRed)
canvas.drawColor(Color.GREEN);
else
canvas.drawColor(Color.RED);
}
protected void setRed() {
isRed = true;
}
private class OnSeatClickListener implements OnClickListener {
#Override
public void onClick(View view) {
((Seat) view).setRed();
view.invalidate();
}
}
}
Views are drawing perfectly. But I have ann array of views, and when some of them go out of the screen, scrollView didn't work, there is no scroll on the screen. Have you any ideas how can I make this layout scroll?

You should try following xml file. It will work on all the devices.
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:fillViewport="true"
android:padding="10px"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<RelativeLayout android:id="#+id/scrollable_places"
android:layout_height="wrap_content"
android:layout_width="wrap_content">
</RelativeLayout>
</ScrollView>
Thanks.

In scroll view you have written android:layout_height="wrap_content" instead of using wrap_content five specific height size eg android:layout_height="100dip"
Thanks
Deepak