onTouchListener warning: onTouch should call View#performClick when a click is detected
I have created a onTouchListener
. Unfortunately onTouch() method throws
me a warning:
com/calculator/activitys/Calculator$1#onTouch should call View#performClick when a click is detected
What does it mean? I have not found any information about this warn. Here is the full code:
LinearLayout llCalculatorContent = (LinearLayout) fragmentView.findViewById(R.id.calculator_content);
llCalculatorContent.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
Tools.hideKeyboard(getActivity(), getView());
getView().clearFocus();
return false;
}
});
Solution 1:
Here you go:
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//some code....
break;
case MotionEvent.ACTION_UP:
v.performClick();
break;
default:
break;
}
return true;
}
Solution 2:
onTouch should call View#performClick when a click is detected
You can suppress the Lint
@SuppressLint("ClickableViewAccessibility")
You should call performClick()
inside onTouchEvent()
.
@Override
public boolean onTouchEvent(MotionEvent event) {
//Logic
performClick();
return super.onTouchEvent(event);
}
or
findViewById(R.id.view1).setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
v.performClick();
return v.onTouchEvent(event);
}
});
OnTouch
flow
Read more here
Solution 3:
In case you're not using a Custom View
which explicitly overrides onPerformClick
, the warning won't get removed by just following Secko's answer.
In addition to his answer, for doing the same on classes like android.widget.Button
or Button
you need to make a simple custom view which extends the target view.
Example :
The Custom View Class:
public class UselessButton extends AppCompatButton {
public UselessButton(Context context) {
super(context);
}
public UselessButton(Context context, AttributeSet attrs) {
super(context, attrs);
}
public UselessButton(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean performClick() {
return super.performClick();
}
}
XML :
<stackoverflow.onEarth.UselessButton
android:id="@+id/left"
android:layout_width="60dp"
android:layout_height="60dp"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"
android:background="@drawable/left"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.16"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBaseline_toBaselineOf="@+id/right"
app:layout_constraintVertical_bias="0.5" />
Java :
left.setOnTouchListener((v, event) -> {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
enLeft = 1;
enRight = 0;
return true;
} else if (event.getAction() == MotionEvent.ACTION_UP) {
enLeft = 0;
v.performClick();
return false;
} else {
return false;
}
});
Current problems : Warning gets resolved by IDE, but can't see this practically performing click action on a real Android Device.
EDIT: Fixed getting the click event : Use View.setPressed(boolean)
down.setOnTouchListener((v, event) -> {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
enFront = 0;
enBack = 1;
left.setPressed(true);
return true;
} else if (event.getAction() == MotionEvent.ACTION_UP) {
enBack = 0;
v.performClick();
v.setPressed(false);
return false;
} else {
return false;
}
Solution 4:
just call performClick method, like this:
@Override
public boolean onTouch(View v, MotionEvent event) {
v.performClick();
Tools.hideKeyboard(getActivity(), getView());
getView().clearFocus();
return false;
}
Solution 5:
I solved this warning by using Kotlin Extensions
First create the extension (Eg. ViewExtensions.kt)
fun Button.onTouch(touch: (view: View, motionEvent: MotionEvent) -> Unit) {
setOnTouchListener { v, event ->
touch(v,event)
v.performClick()
true
}
}
Second, in your Fragment or activity create a function
private fun onTouchButton(v: View, event: MotionEvent) {
/* My Amazing implementation */
}
Finally, use the extension
myButton.onTouch { v, event ->
onTouchButton(v, event)
}