There are two very important ways to View Touch

There are two very important ways to View Touch

• dispatchTouchEvent event event distribution

//Default is false
boolean result = false;
// ListenerInfo li = mListenerInfo;
ListenerInfo li = mListenerInfo;

//True if enabled and the touch event returns true
 if (li != null && li.mOnTouchListener != null
                    && (mViewFlags & ENABLED_MASK) == ENABLED
                    && li.mOnTouchListener.onTouch(this, event)) {
                result = true;
 }
 //If the result is false, the onTouchEvent method is executed; if the onTouchEvent is true, the result is true
if (!result && onTouchEvent(event)) {
       result = true;
  }

• onTouchEvent method (usually copied by us)

test
Customize view first

public class TouchView extends View {
    public TouchView(Context context) {
        super(context);
    }

    public TouchView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public TouchView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        Log.e("TAG", "onTouchEvent--->" + event.getAction());
        return super.onTouchEvent(event);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        Log.e("TAG", "dispatchTouchEvent--->" + event.getAction());
        return super.dispatchTouchEvent(event);
    }
}

Use custom view

    View view = findViewById(R.id.touch_view);
        view.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                Log.e("TAG","onTouch-->"+event.getAction());
                return false;
            }
        });
        view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.e("TAG","onClick");
            }
        });

Analysis (0 for down, 1 for up, 2 for move)

The first scenario: OnTouchListener ontouchevent dispatchtouchevent onclicklistener if all four of them have the premise that OnTouchListener returns false

Result:
dispatchTouchEvent—>0
onTouch–>0
onTouchEvent—>0
dispatchTouchEvent—>2
onTouch–>2
onTouchEvent—>2
dispatchTouchEvent—>1
onTouch–>1
onTouchEvent—>1
onClick

The second scenario: OnTouchListener ontouchevent dispatchtouchevent onclicklistener. In all four cases, the precondition is that OnTouchListener returns true, and others do not move

View view = findViewById(R.id.touch_view);
            view.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                Log.e("TAG","onTouch-->"+event.getAction());
                return true;
            }
});

At this time, if the li.mentouchlistener.ontouch (this, event)) method returns true, the ontoucheevent method will not be executed

Result
dispatchTouchEvent—>0
onTouch–>0
dispatchTouchEvent—>2
onTouch–>2
dispatchTouchEvent—>1
onTouch–>1

The third scenario: OnTouchEvent dispatchtouchevent onclicklistener
OnTouchEvent returns true when clicked by default

Result
dispatchTouchEvent—>0
onTouchEvent—>0
dispatchTouchEvent—>2
onTouchEvent—>2
dispatchTouchEvent—>2
dispatchTouchEvent—>1
onTouchEvent—>1

return super.onTouchEvent(event) is different from return true. When it is set to true, there will be no onClick method, and the default value will
Reason: when set to true, the onTouchEvent method in view will not be entered

The fourth scenario: ontouchlistener ontouchevent dispatchTouchEvent onclicklistener: set the dispatchTouchEvent to true when there are four cases, and other cases return the same

 @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        Log.e("TAG", "dispatchTouchEvent--->" + event.getAction());
        return true;
    }

Result
dispatchTouchEvent—>0
dispatchTouchEvent—>2
dispatchTouchEvent—>1

view's dispatch method will not be executed