Android解析---DragGridView长按动态排序
曾经项目需求，要实现一个类似以前ZAKER新闻阅读的DragGridView特效。不过，没要求实现横向跨屏，而是竖向跨屏。网上资源也很多，有实现横向跨屏的，可是没有找到竖向的。后来只好结合人家代码，修改一二。
贴代码！
/**
* @blog http://blog.csdn.net/xiaanming
*
* @author xiaanming&&wangxuanao
*
*/
public class DragGridView extends GridView {
/**
* DragGridView的item长按响应的时间， 默认是1000毫秒，也可以自行设置。目前没有用到延迟。
*/
private long dragResponseMS = 1000;
/**
* 是否可以拖拽，默认不可以
*/
private boolean isDrag = false;
private int mDownX;
private int mDownY;
private int moveX;
private int moveY;
private int nColumns = 2;
/**
* 是否计算状态栏的高度在内，涉及到镜像的起始位置y
*/
private boolean isContainStatusHeight = false;
private boolean isMoving = false;
/**
* 正在拖拽的position
*/
private int mDragPosition;
/**
* 刚开始拖拽的item对应的View
*/
private View mStartDragItemView = null;
/**
* 用于拖拽的镜像，这里直接用一个ImageView
*/
private ImageView mDragImageView;
/**
* 震动器
*/
private Vibrator mVibrator;
private WindowManager mWindowManager;
/**
* item镜像的布局参数
*/
private WindowManager.LayoutParams mWindowLayoutParams;
/**
* 我们拖拽的item对应的Bitmap
*/
private Bitmap mDragBitmap;
/**
* 按下的点到所在item的上边缘的距离
*/
private int mPoint2ItemTop;
/**
* 按下的点到所在item的左边缘的距离
*/
private int mPoint2ItemLeft;
/**
* DragGridView距离屏幕顶部的偏移量
*/
private int mOffset2Top;
/**
* DragGridView距离屏幕左边的偏移量
*/
private int mOffset2Left;
/**
* 状态栏的高度
*/
private int mStatusHeight;
/**
* DragGridView自动向下滚动的边界值
*/
private int mDownScrollBorder;
/**
* DragGridView自动向上滚动的边界值
*/
private int mUpScrollBorder;
/**
* DragGridView自动滚动的速度
*/
private static final int speed = 20;
public DragGridView(Context context) {
this(context, null);
}
public DragGridView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public DragGridView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mVibrator = (Vibrator) context
.getSystemService(Context.VIBRATOR_SERVICE);
mWindowManager = (WindowManager) context
.getSystemService(Context.WINDOW_SERVICE);
mStatusHeight = getStatusHeight(context); // 获取状态栏的高度
}
private Handler mHandler = new Handler();
// 用来处理是否为长按的Runnable
private Runnable mLongClickRunnable = new Runnable() {
@Override
public void run() {
isDrag = true; // 设置可以拖拽
isMoving = false;
mVibrator.vibrate(50); // 震动一下
mStartDragItemView.setVisibility(View.INVISIBLE);// 隐藏该item
// 根据我们按下的点显示item镜像
createDragImage(mDragBitmap, mDownX, mDownY);
}
};
/**
* 设置响应拖拽的毫秒数，默认是1000毫秒
*
* @param dragResponseMS
*/
public void setDragResponseMS(long dragResponseMS) {
this.dragResponseMS = dragResponseMS;
}
/**
* 长按检测事件
*
* @author wangxuanao
*/
public boolean setOnItemLongClickListener(final MotionEvent ev) {
this.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView arg0, View arg1,
int arg2, long arg3) {
// arg2和arg3一直是相等的。及点击的item的position
Log.e("LOG", "int arg2=" + arg2 + " long arg3=" + arg3);
mDownX = (int) ev.getX();
mDownY = (int) ev.getY();
// 获取所点击item的position
mDragPosition = arg2;
if (mDragPosition == AdapterView.INVALID_POSITION) {
Log.e("tag====onItemLongClick", "INVALID_POSITION");
return true;
}
// 根据position获取该item所对应的View
mStartDragItemView = getChildAt(mDragPosition
- getFirstVisiblePosition());
// 下面这几个距离大家可以参考我的博客上面的图来理解下
mPoint2ItemTop = mDownY - mStartDragItemView.getTop();
mPoint2ItemLeft = mDownX - mStartDragItemView.getLeft();
mOffset2Top = (int) (ev.getRawY() - mDownY);
mOffset2Left = (int) (ev.getRawX() - mDownX);
// 获取DragGridView自动向上滚动的偏移量，小于这个值，DragGridView向下滚动
mDownScrollBorder = getHeight() / 4;
// 获取DragGridView自动向下滚动的偏移量，大于这个值，DragGridView向上滚动
mUpScrollBorder = getHeight() * 3 / 4;
// 开启mDragItemView绘图缓存
mStartDragItemView.setDrawingCacheEnabled(true);
// 获取mDragItemView在缓存中的Bitmap对象
mDragBitmap = Bitmap.createBitmap(mStartDragItemView
.getDrawingCache());
// 这一步很关键，释放绘图缓存，避免出现重复的镜像
mStartDragItemView.destroyDrawingCache();
// 使用Handler延迟dragResponseMS执行mLongClickRunnable
// mHandler.postDelayed(mLongClickRunnable, dragResponseMS);
// 不延迟加载
mHandler.post(mLongClickRunnable);
return false;
}
});
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
return setOnItemLongClickListener(ev);
}
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// Log.e("LOG", "=========onTouchEvent=======");
if (isDrag && mDragImageView != null) {
switch (ev.getAction()) {
case MotionEvent.ACTION_MOVE:
moveX = (int) ev.getX();
moveY = (int) ev.getY();
// 拖动item
onDragItem(moveX, moveY);
break;
case MotionEvent.ACTION_UP:
onStopDrag();
isDrag = false;
mHandler.removeCallbacks(mLongClickRunnable); // 线程结束
mHandler.removeCallbacks(mScrollRunnable);
break;
}
return true;
}
return super.onTouchEvent(ev);
}
/**
* 创建拖动的镜像
*
* @param bitmap
* @param downX
* 按下的点相对父控件的X坐标
* @param downY
* 按下的点相对父控件的X坐标
*/
private void createDragImage(Bitmap bitmap, int downX, int downY) {
DragAdapter adapter = (DragAdapter) this.getAdapter();
adapter.showDropItem(false);
mWindowLayoutParams = new WindowManager.LayoutParams();
mWindowLayoutParams.format = PixelFormat.TRANSLUCENT; // 图片之外的其他地方透明
mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT;
mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left;
if (isContainStatusHeight) {
mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top
- mStatusHeight; // 状态栏高度 可选
} else {
mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top;
}
Log.e("tag", "mWindowLayoutParams x=" + mWindowLayoutParams.x
+ " y=" + mWindowLayoutParams.y);
mWindowLayoutParams.alpha = 0.55f; // 透明度
mWindowLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
mWindowLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
mWindowLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
mDragImageView = new ImageView(getContext());
mDragImageView.setImageBitmap(bitmap);
mWindowManager.addView(mDragImageView, mWindowLayoutParams);
}
/**
* 从界面上面移动拖动镜像
*/
private void removeDragImage() {
if (mDragImageView != null) {
mWindowManager.removeView(mDragImageView);
mDragImageView = null;
}
}
/**
* 拖动item，在里面实现了item镜像的位置更新，item的相互交换以及GridView的自行滚动
*
* @param x
* @param y
*/
private void onDragItem(int moveX, int moveY) {
mWindowLayoutParams.x = moveX - mPoint2ItemLeft + mOffset2Left;
if (isContainStatusHeight) {
mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top
- mStatusHeight;// 状态栏高度 可选
} else {
mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top;
}
mWindowManager.updateViewLayout(mDragImageView, mWindowLayoutParams); // 更新镜像的位置
onSwapItem(moveX, moveY);
// GridView自动滚动
mHandler.post(mScrollRunnable);
}
/**
* 当moveY的值大于向上滚动的边界值，触发GridView自动向上滚动 当moveY的值小于向下滚动的边界值，触犯GridView自动向下滚动
* 否则不进行滚动
*/
private Runnable mScrollRunnable = new Runnable() {
@Override
public void run() {
int scrollY;
if (moveY > mUpScrollBorder) {
scrollY = speed;
mHandler.postDelayed(mScrollRunnable, 25);
} else if (moveY < mDownScrollBorder) {
scrollY = -speed;
mHandler.postDelayed(mScrollRunnable, 25);
} else {
scrollY = 0;
mHandler.removeCallbacks(mScrollRunnable);
}
// 当我们的手指到达GridView向上或者向下滚动的偏移量的时候，可能我们手指没有移动，但是DragGridView在自动的滚动
// 所以我们在这里调用下onSwapItem()方法来交换item
onSwapItem(moveX, moveY);
smoothScrollBy(scrollY, 10);
}
};
/**
* 交换item,并且控制item之间的显示与隐藏效果
*
* @param moveX
* @param moveY
*/
private void onSwapItem(int moveX, int moveY) {
// 获取我们手指移动到的那个item的position
final int tempPosition = pointToPosition(moveX, moveY);
// 假如tempPosition 改变了并且tempPosition不等于-1,则进行交换
if (tempPosition != mDragPosition
&& tempPosition != AdapterView.INVALID_POSITION) {
// getChildAt(tempPosition -
// getFirstVisiblePosition()).setVisibility(
// View.INVISIBLE);// 拖动到了新的item,新的item隐藏掉
//
// getChildAt(mDragPosition - getFirstVisiblePosition())
// .setVisibility(View.VISIBLE);// 之前的item显示出来
if (!isMoving) {
final int dropPosition = tempPosition
- getFirstVisiblePosition();
int dragPosition = mDragPosition - getFirstVisiblePosition();
final int startPosition = mDragPosition;
final int endPosition = tempPosition;
Log.e("log", "tempPosition===" + tempPosition
+ " dropPosition===" + dropPosition
+ " dragPosition===" + dragPosition);
int MoveNum = dropPosition - dragPosition;
int holdPosition;
if (dragPosition == dropPosition)
MoveNum = 0;
if (MoveNum != 0) {
int itemMoveNum = Math.abs(MoveNum);
float Xoffset, Yoffset;
Log.e("log", "itemMoveNum===" + itemMoveNum);
for (int i = 0; i < itemMoveNum; i++) {
Log.e("log", "i===" + i);
if (MoveNum > 0) {
holdPosition = dragPosition + 1;
Xoffset = (dragPosition / nColumns == holdPosition
/ nColumns) ? (-1) : (nColumns - 1);
Yoffset = (dragPosition / nColumns == holdPosition
/ nColumns) ? 0 : (-1);
} else {
holdPosition = dragPosition - 1;
Xoffset = (dragPosition / nColumns == holdPosition
/ nColumns) ? 1 : (-(nColumns - 1));
Yoffset = (dragPosition / nColumns == holdPosition
/ nColumns) ? 0 : 1;
}
ViewGroup moveView = (ViewGroup) getChildAt(holdPosition);
Log.e("log", "holdPosition===" + holdPosition);
Animation animation = getMoveAnimation(Xoffset, Yoffset);
moveView.startAnimation(animation);
dragPosition = holdPosition;
final DragAdapter adapter = (DragAdapter) this
.getAdapter();
isMoving = true;
if (i == itemMoveNum - 1)
animation
.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationStart(
Animation animation) {
}
@Override
public void onAnimationRepeat(
Animation animation) {
}
@Override
public void onAnimationEnd(
Animation animation) {
adapter.exchange(startPosition,
endPosition);
isMoving = false;
Log.e("log",
"isMoving=false====================================");
}
});
}
}
}
Log.e("log", "mDragPosition=" + mDragPosition
+ "=====tempPosition=" + tempPosition);
mDragPosition = tempPosition;
}
}
/**
* 动画交换交换item
*
* @param dropPosition
* @param dragPosition
*/
public void OnMove(int dropPosition, int dragPosition) {
}
/**
* 停止拖拽我们将之前隐藏的item显示出来，并将镜像移除
*/
private void onStopDrag() {
// View view = getChildAt(mDragPosition - getFirstVisiblePosition());
// if (view != null) {
// view.setVisibility(View.VISIBLE);
// }
DragAdapter adapter = (DragAdapter) this.getAdapter();
adapter.showDropItem(true);
adapter.notifyDataSetChanged();
removeDragImage();
}
/**
* 获取状态栏的高度
*
* @param context
* @return
*/
private static int getStatusHeight(Context context) {
int statusHeight = 0;
Rect localRect = new Rect();
((Activity) context).getWindow().getDecorView()
.getWindowVisibleDisplayFrame(localRect);
statusHeight = localRect.top;
if (0 == statusHeight) {
Class localClass;
try {
localClass = Class.forName("com.android.internal.R$dimen");
Object localObject = localClass.newInstance();
int i5 = Integer.parseInt(localClass
.getField("status_bar_height").get(localObject)
.toString());
statusHeight = context.getResources().getDimensionPixelSize(i5);
} catch (Exception e) {
e.printStackTrace();
}
}
return statusHeight;
}
/**
* 移动动画
*
* @author wangxuanao
*
*/
public Animation getMoveAnimation(float x, float y) {
TranslateAnimation go = new TranslateAnimation(
Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, x,
Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, y);
go.setFillAfter(true);
go.setDuration(300);
return go;
}
}
运行截图：
此demo支持长按滑动。支持动画效果，支持向下跨屏滑动。不过在跨屏滑动的时候存在bug。有兴趣的同学可以修改一下。源代码下载