This is a simple apk help you to understand how the Android TouchEvent works.
There are 5 views in this apk. "--1--" is the root view and contains "--2--", and "--2--" contains "--3--", same as the others.
In the top is the control panel, you can control the views how to act in onInterceptTouchEvent(拦截) and onTouchEvent(处理). With the checkbox checked, that means its will return true in these method, otherwise means false.
The middle area is the result panel, when you touch the bottom area, this panel will shows you how does the touch transfer(see the number in the small square), and how does views act when hit ACTION_DOWN and ACTION_MOVE and ACTION_UP.
The bottom area is the touch area.
No views to eat this touch, after ACTION_DOWN, ACTION_MOVE and ACTION_UP will not come, because there are no touch target view find.
No views to intercept(拦截) this touch, and 3 views want to eat(处理) this touch, and the "--5--" view eat this touch successfully, and next time during the ACTION_MOVE and ACTION_UP, "--5--" view's onInterceptTouchEvent will not be called, the touch event will be transfer from "--5--" view's dispatchTouchEvent to onTouchEvent(处理) directly.
One view intercept(拦截) this touch, so "--5--" can not reach this touch, and this touch was eat by the "--3--". And after ACTION_DOWN, the "--4--" view will not get touch again, because we found "--3--" is the touch target, so we just directly pass the touch to "--3--".
You also can see the below log output to help you to study.
There are many duplicate outputs during the ACTION_MOVE, so I had just cut all the duplicate logs. If you want to open it, you can modified LogUtils.java.
