User input i. Detect common gestures

  • 2021-01-22 05:23:11
  • OfStack

Effects: 1 finger implementation (all gesture events) and (partial events);

A. All gestures

activity_main.xml


<TextView 
android:id="@+id/gesture" 
android:layout_width="match_parent" 
android:layout_height="150dp" 
android:gravity="center" 
android:text=" Click Gesture Change " /><TextView 
android:id="@+id/doubleTap" 
android:layout_width="match_parent" 
android:layout_height="150dp" 
android:gravity="center" 
android:text=" Double-click gesture change " /> 

MainActivity.java


public class MainActivity extends Activity
{ 
private static final String LOG_TAG = "HelloGesture"; 
private GestureDetector mGestureDetector = null; 
private TextView mGestureTextView = null; 
private TextView mDoubleTapTextView = null; 
@Override 
protected void onCreate(Bundle savedInstanceState) 
{ 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_main); 
mGestureTextView = (TextView) findViewById(R.id.gesture); 
mDoubleTapTextView = (TextView) findViewById(R.id.doubleTap); 
//  structure GestureDetector Object passed in the listener object  
mGestureDetector = new GestureDetector(this, mOnGestureListener); 
//  Pass in the double-click listener object  
mGestureDetector.setOnDoubleTapListener(mDoubleTapListener); 
} 
@Override public boolean onTouchEvent(MotionEvent event) 
{ 
//  in onTouchEvent Method passes the event to the gesture listener object, otherwise the callback function in the gesture listener object will not be called  
mGestureDetector.onTouchEvent(event); 
return super.onTouchEvent(event); 
} 
private OnGestureListener mOnGestureListener = new OnGestureListener()
{ 
@Override 
public boolean onSingleTapUp(MotionEvent e) 
{ 
Log.i(LOG_TAG, "onSingleTapUp: " + e.toString()); 
mGestureTextView.setText("onSingleTapUp: "); 
return false; 
} 
@Override 
public void onShowPress(MotionEvent e) 
{ 
Log.i(LOG_TAG, "onShowPress: " + e.toString()); 
mGestureTextView.setText("onShowPress: "); 
} 
@Override 
public boolean onScroll(MotionEvent e1, MotionEvent e2, 
float distanceX, float distanceY)
{ 
Log.i(LOG_TAG, "onScroll: " + e1.toString() + ", " + e2.toString()); 
mGestureTextView.setText("onScroll "); 
return false; 
} @Override 
public void onLongPress(MotionEvent e)
{ 
Log.i(LOG_TAG, "onLongPress: " + e.toString()); 
mGestureTextView.setText("onLongPress: "); 
} 
@Override 
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, 
float velocityY) 
{ 
Log.i(LOG_TAG, "onFling: " + e1.toString() + ", " + e2.toString()); 
mGestureTextView.setText("onFling "); 
return false; 
} 
@Override 
public boolean onDown(MotionEvent e) 
{ 
Log.i(LOG_TAG, "onDown: " + e.toString()); 
mGestureTextView.setText("onDown: "); 
return false; 
} 
}; private OnDoubleTapListener mDoubleTapListener = new OnDoubleTapListener() 
{ 
@Override 
public boolean onSingleTapConfirmed(MotionEvent e) 
{ 
Log.i("LOG_TAG", "onSingleTapConfirmed: " + e.toString()); 
mDoubleTapTextView.setText("onSingleTapConfirmed: "); 
return false; 
} 
@Override 
public boolean onDoubleTapEvent(MotionEvent e) 
{ 
Log.i("LOG_TAG", "onDoubleTapEvent: " + e.toString()); 
mDoubleTapTextView.setText("onDoubleTapEvent: "); 
return false; 
} 
@Override 
public boolean onDoubleTap(MotionEvent e) 
{ 
Log.i("LOG_TAG", "onDoubleTap: " + e.toString()); 
mDoubleTapTextView.setText("onDoubleTap: "); 
return false; 
} 
};} 

B. Partial gestures

If you only want to handle a few gestures, you can choose to inherit the GestureDetector. SimpleOnGestureListener class instead of implementing it
GestureDetector OnGestureListener interface

MainActivity.java


public class MainActivity extends Activity 
{ 
private GestureDetector mGestureDetector = null; 
private TextView mGestureTextView = null; 
private TextView mDoubleTapTextView = null; 
@Override 
protected void onCreate(Bundle savedInstanceState) 
{ 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_main); 
mGestureTextView = (TextView) findViewById(R.id.gesture); 
mDoubleTapTextView = (TextView) findViewById(R.id.doubleTap); 
//  structure GestureDetector Object passed in the listener object  
mGestureDetector = new GestureDetector(this, new MyGestureListener()); 
//  Pass in the double-click listener object  
} 
@Override 
public boolean onTouchEvent(MotionEvent event) 
{ 
//  in onTouchEvent Method passes the event to the gesture listener object, otherwise the callback function in the gesture listener object will not be called  
this.mGestureDetector.onTouchEvent(event); 
return super.onTouchEvent(event); 
} 
class MyGestureListener extends GestureDetector.SimpleOnGestureListener 
{ 
private static final String DEBUG_TAG = "Gestures"; 
@Override 
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, 
float velocityY) 
{ 
Log.d(DEBUG_TAG, "onFling: " + e1.toString() + ", " + e2.toString()); 
mGestureTextView.setText("onFling "); 
return false; 
} 
@Override 
public boolean onDown(MotionEvent e)
{ 
Log.d(DEBUG_TAG, "onDown: " + e.toString()); 
mGestureTextView.setText("onDown: "); 
return false; 
} 
}} 


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