import android.os.Bundle;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.DragEvent;
import android.view.Menu;
import android.view.View;
import android.view.View.DragShadowBuilder;
import android.view.View.OnDragListener;
import android.view.View.OnLongClickListener;

public class MainActivity extends Activity {
	private View ViewD;
	private View ViewP;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		findById();
		setListener();
	}
	
	private void setListener() {
		//設定監聽器,長按後拖動
		ViewD.setOnLongClickListener(new OnLongClickListener() {
			@Override
			public boolean onLongClick(View view) {
				ViewD.startDrag(null, new DragShadowBuilder(view), view, 0);
				return true;
			}
		});
		//開始拖動時回撥的函式,setOnDragListener
		ViewP.setOnDragListener(new OnDragListener() {
			@Override
			public boolean onDrag(View mDropview, DragEvent event) {
				boolean result=false;
				switch (event.getAction()) {
				//開始拖動時
				case DragEvent.ACTION_DRAG_STARTED:{
					Log.e("Dragging", "View開始被拖動");
					result=true;
					break;
				}
				//被拖動的額物件進入當前view物件時
				case DragEvent.ACTION_DRAG_ENTERED:{
					Log.e("Dragging", "被拖動的View物件進入當前的View");
					break;
				}
				//被拖動的View進入當前的View後,位置改變時回撥
				case DragEvent.ACTION_DRAG_LOCATION:{
					Log.e("Dragging", "被拖動的view進入當前view");
					break;
				}
				//拖動的View被放入當前的View時回撥
				case DragEvent.ACTION_DROP:{
					Log.e("Dragging", "拖動的View被放入當前View");
					View mDragView=(View) event.getLocalState();
					//得到拖動檢視的背景
					Drawable mDragViewBackGround=mDragView.getBackground();
					mDragView.setBackgroundDrawable(mDropview.getBackground());
					mDropview.setBackgroundDrawable(mDragViewBackGround);
					break;
				}
				//拖動結束時
				case DragEvent.ACTION_DRAG_ENDED:{
					Log.e("Dragging", "View拖動結束");
					break;
				}
				//拖動完成時
				case DragEvent.ACTION_DRAG_EXITED:{
					Log.e("Dragging", "View拖動退出");
					break;
				}
				default :{
					break;
				}
				}
				return result;
			}
		});
	}

	private void findById() {
		ViewD=findViewById(R.id.ViewD);
		ViewP=findViewById(R.id.ViewP);
	}
}