Android Custom View Realization of Automatic Adsorption Function
- 2021-11-14 07:13:51
- OfStack
In this paper, we share the specific code of Android to realize automatic adsorption function for your reference. The specific contents are as follows
1. Brief introduction
In the recent development of app, it is necessary to realize the automatic adsorption function after dragging view, so it is necessary to customize view to use animation in onTouchEvent to realize this function
2. Function code section
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.animation.DecelerateInterpolator;
import android.widget.ImageView;
public class AdsorbentViews extends ImageView {
private int maxWidth;
private int maxHeight;
private int viewWidth;
private int viewHeight;
private float downx;
private float downy;
private Context mContext;
public CustomViews(Context context) {
this(context, null);
}
public CustomViews(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CustomViews(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
mContext = context;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
DisplayMetrics outMetrics = new DisplayMetrics();
WindowManager windowManager = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
windowManager.getDefaultDisplay().getRealMetrics(outMetrics);
// Width of screen
maxWidth = outMetrics.widthPixels;
// Height of screen
maxHeight = outMetrics.heightPixels;
/**
* Width and height of the control
*/
viewWidth = canvas.getWidth();
viewHeight = canvas.getHeight();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
clearAnimation();
downx = event.getX();
downy = event.getY();
return true;
case MotionEvent.ACTION_MOVE:
float moveX = event.getRawX() - downx;
float moveY = event.getRawY() - downy;
moveX = moveX < 0 ? 0 : (moveX + viewWidth > maxWidth) ? (maxWidth - viewWidth) : moveX;
moveY = moveY < 0 ? 0 : (moveY + viewHeight) > maxHeight ? (maxHeight - viewHeight) : moveY;
this.setY(moveY);
this.setX(moveX);
return true;
case MotionEvent.ACTION_UP:
// Do adsorption effect
float centerX = getX() + viewWidth / 2;
if (centerX > maxWidth/2){
// Right side adsorption
animate().setInterpolator(new DecelerateInterpolator())
.setDuration(500)
.x(maxWidth-viewWidth)
.y(maxHeight-viewHeight)
.start();
}else {
animate().setInterpolator(new DecelerateInterpolator())
.setDuration(500)
.x(0)
.y(maxHeight-viewHeight)
.start();
}
return true;
default:
return super.onTouchEvent(event);
}
}
}