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;
}
}}