一个可以拖动的自定义Gridview代码

public class DragGridView extends GridView { private long dragResponseMS = 700; // item长按响应的时间 private int mDragPosition;// 正在拖拽的position private boolean isDrag = false; // 是不是可以拖拽，用于控件内部逻辑实现 private boolean canDrag = true; // 是不是可用拖拽，主要用于外部开放设置 private boolean mAnimationEnd = true; private int mDownX; private int mDownY; private int moveX; private int moveY; private View mStartDragItemView = null; // 刚开始拖拽的item对应的View private ImageView mDragImageView; // 用于拖拽时显示的幻影镜像 private Bitmap mDragBitmap; // 幻影镜像对应的Bitmap private final Vibrator mVibrator; // 震动器 private final int mStatusHeight;// 状态栏的高度 private final WindowManager mWindowManager; private WindowManager.LayoutParams mWindowLayoutParams; // item镜像的布局参数 private int mPoint2ItemTop; // 按下的点到所在item的上边沿的距离 private int mPoint2ItemLeft; private int mOffset2Top; // DragGridView距离屏幕顶部的偏移量 private int mOffset2Left; private int mDownScrollBorder; // DragGridView自动向下转动的边界值 private int mUpScrollBorder; // DragGridView自动向上转动的边界值 private DragGridBaseAdapter mDragAdapter; private int mNumColumns; private int mColumnWidth; private boolean mNumColumnsSet; private int mHorizontalSpacing; private static final int speed = 20; // DragGridView自动转动的速度 private static final int MOVE_OFFSET = 25; private boolean moved = false; public static final int HANDLE_START = 0x3587; public static final int HANDLE_CANCLE = 0x3588; public static final int HANDLE_FINISH = 0x3589; private static OnMoveListener moveListener; // 拖拽开始与结束监听器 private OnDeleteListener deleteListener; // 移动到垃圾桶时的监听器 private float dragViewScale = 1.3f; private final TouchRect moveRect = new TouchRect(); private final TouchRect gridRect = new TouchRect(); private final TouchRect trashRect = new TouchRect(); 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); // 获得状态栏的高度 if (!mNumColumnsSet) { mNumColumns = AUTO_FIT; } } /** * 获得状态栏的高度 * * @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; } private static final Handler mHandler = new Handler() { @Override public void handleMessage(android.os.Message msg) { if (moveListener != null) { if (msg.what == HANDLE_START) { moveListener.startMove(); } else if (msg.what == HANDLE_FINISH) { moveListener.finishMove(); } else if (msg.what == HANDLE_CANCLE) { moveListener.cancleMove(); } } } ; }; // 用来处理是不是为长按的Runnable private final Runnable mLongClickRunnable = new Runnable() { @Override public void run() { if (!canDrag) { return; } isDrag = true; // 设置可以拖拽 moved = true; mHandler.sendEmptyMessage(HANDLE_START); mVibrator.vibrate(50); // 震动1下 mStartDragItemView.setVisibility(View.INVISIBLE);// 隐藏该item createDragImage(mDragBitmap, mDownX, mDownY); mDragBitmap = null; } }; /** * 若设置为AUTO_FIT，计算有多少列 */ @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (mNumColumns == AUTO_FIT) { int numFittedColumns = 1; // 可用列 if (mColumnWidth > 0) { int gridWidth = Math.max(MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight(), 0); numFittedColumns = gridWidth / mColumnWidth; if (numFittedColumns > 0) { while (numFittedColumns != 1) { if (numFittedColumns * mColumnWidth + (numFittedColumns - 1) * mHorizontalSpacing > gridWidth) { numFittedColumns--; } else { break; } } } } else { numFittedColumns = 2; } mNumColumns = numFittedColumns; } super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); initRecord(); } /** * 初始化坐标数据 */ private void initRecord() { gridRect.left = this.getLeft(); gridRect.right = this.getRight(); gridRect.top = this.getTop(); gridRect.bottom = this.getBottom(); } @Override public void setAdapter(ListAdapter adapter) { super.setAdapter(adapter); if (adapter instanceof DragGridBaseAdapter) { mDragAdapter = (DragGridBaseAdapter) adapter; } else { throw new IllegalStateException( "the adapter must be implements DragGridAdapter"); } } @Override public void setNumColumns(int numColumns) { super.setNumColumns(numColumns); mNumColumnsSet = true; this.mNumColumns = numColumns; } @Override public void setColumnWidth(int columnWidth) { super.setColumnWidth(columnWidth); mColumnWidth = columnWidth; } @Override public void setHorizontalSpacing(int horizontalSpacing) { super.setHorizontalSpacing(horizontalSpacing); this.mHorizontalSpacing = horizontalSpacing; } /** * 设置响应拖拽的毫秒数，默许是700毫秒 * @param dragResponseMS */ public void setDragResponseMS(long dragResponseMS) { this.dragResponseMS = dragResponseMS; } public void setOnDeleteListener(OnDeleteListener l) { this.deleteListener = l; } public void setDragEnable(boolean isDrag) { this.canDrag = isDrag; if (canDrag) { mHandler.removeCallbacks(mLongClickRunnable); } } @Override public boolean dispatchTouchEvent(MotionEvent ev) { if (canDrag) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: mDownX = (int) ev.getX(); mDownY = (int) ev.getY(); moveRect.left = mDownX - MOVE_OFFSET; moveRect.right = mDownX + MOVE_OFFSET; moveRect.top = mDownY - MOVE_OFFSET; moveRect.bottom = mDownY + MOVE_OFFSET; // 根据按下的X,Y坐标获得所点击item的position mDragPosition = pointToPosition(mDownX, mDownY); if (mDragPosition == AdapterView.INVALID_POSITION || mDragPosition == getDragAdapter().getRealCount()) { return super.dispatchTouchEvent(ev); } // 使用Handler延迟dragResponseMS履行mLongClickRunnable mHandler.postDelayed(mLongClickRunnable, dragResponseMS); // 根据position获得该item所对应的View mStartDragItemView = getChildAt(mDragPosition - getFirstVisiblePosition()); mPoint2ItemTop = mDownY - mStartDragItemView.getTop(); mPoint2ItemLeft = mDownX - mStartDragItemView.getLeft(); mOffset2Top = (int) (ev.getRawY() - mDownY); mOffset2Left = (int) (ev.getRawX() - mDownX); // 获得DragGridView自动向上转动的偏移量，小于这个值，DragGridView向下转动 mDownScrollBorder = getHeight() / 5; // 大于这个值，DragGridView向上转动 mUpScrollBorder = getHeight() * 4 / 5; // 开启mDragItemView绘图缓存 mStartDragItemView.setDrawingCacheEnabled(true); // 获得mDragItemView在缓存中的Bitmap对象 mDragBitmap = Bitmap.createBitmap(mStartDragItemView .getDrawingCache()); // 这1步很关键，释放绘图缓存，避免出现重复的镜像 mStartDragItemView.destroyDrawingCache(); break; case MotionEvent.ACTION_MOVE: // 如果我们在按下的item上面移动，只要不超过item的边界我们就不移除mRunnable if (!isTouchInItem(moveRect, ev.getX(), ev.getY())) { mHandler.removeCallbacks(mLongClickRunnable); } break; case MotionEvent.ACTION_UP: mHandler.removeCallbacks(mScrollRunnable); mHandler.removeCallbacks(mLongClickRunnable); if (moved && getAdapter().getCount() > 0) { mHandler.sendEmptyMessage(HANDLE_FINISH); } else { mHandler.sendEmptyMessage(HANDLE_CANCLE); } moved = false; break; } } return super.dispatchTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent ev) { if (isDrag && canDrag && mDragImageView != null) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: initRecord(); break; case MotionEvent.ACTION_MOVE: moveX = (int) ev.getX(); moveY = (int) ev.getY(); onDragItem(moveX, moveY);// 拖动item break; case MotionEvent.ACTION_UP: onStopDrag(); isDrag = false; break; } return true; } return super.onTouchEvent(ev); } /** * 是不是点击在GridView的item上面 * * @param moveRect * @param x * @param y * @return */ private boolean isTouchInItem(TouchRect moveRect, float x, float y) { // 避免手抖的处理，如果是横向在item上移动是没有影响的， // 但是纵向由于外层上下拉控件还是会有影响，具体解决请看NoteBookFragment类中的mSwipeRefreshLayout.setOnTouchListener方法 if (x < moveRect.right && x > moveRect.left && y < moveRect.bottom && y > moveRect.top) { return true; } else { return false; } } /** * 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) { mWindowLayoutParams = new WindowManager.LayoutParams(); mWindowLayoutParams.format = PixelFormat.TRANSLUCENT; // 图片以外的其他地方透明 mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT; initDragOffset(bitmap); mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left; mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top - mStatusHeight; mWindowLayoutParams.alpha = 0.618f; // 透明度 mWindowLayoutParams.width = (int) (bitmap.getWidth() * dragViewScale); mWindowLayoutParams.height = (int) (bitmap.getHeight() * dragViewScale); mWindowLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE; mDragImageView = new ImageView(getContext()); mDragImageView.setScaleType(ImageView.ScaleType.FIT_XY); mDragImageView.setImageBitmap(bitmap); mWindowManager.addView(mDragImageView, mWindowLayoutParams); } private void initDragOffset(Bitmap bitmap){ mOffset2Left = mOffset2Left - (int) (bitmap.getWidth() * (dragViewScale - 1) / 2); mOffset2Top = mOffset2Top - (int) (bitmap.getHeight() * (dragViewScale - 1) / 2); } /** * 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的相互交换和GridView的自行转动 * * @param moveX * @param moveY */ private void onDragItem(int moveX, int moveY) { mWindowLayoutParams.x = moveX - mPoint2ItemLeft + mOffset2Left; mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top - mStatusHeight; mWindowManager.updateViewLayout(mDragImageView, mWindowLayoutParams); // 更新镜像的位置 onSwapItem(moveX, moveY); // GridView自动转动 mHandler.post(mScrollRunnable); } /** * 当moveY的值大于向上转动的边界值，触发GridView自动向上转动 当moveY的值小于向下转动的边界值，触发GridView自动向下转动 * 否则不进行转动 */ private final Runnable mScrollRunnable = new Runnable() { @Override public void run() { int scrollY; if (getFirstVisiblePosition() == 0 || getLastVisiblePosition() == getCount() - 1) { mHandler.removeCallbacks(mScrollRunnable); } 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); } 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) { // 获得我们手指移动到的那个item的position final int tempPosition = pointToPosition(moveX, moveY); // 假设tempPosition 改变了并且tempPosition不等于⑴,则进行交换 if (tempPosition != mDragPosition && tempPosition != AdapterView.INVALID_POSITION && tempPosition != getDragAdapter().getRealCount() && mAnimationEnd) { mDragAdapter.reorderItems(mDragPosition, tempPosition); mDragAdapter.setHideItem(tempPosition); final ViewTreeObserver observer = getViewTreeObserver(); observer.addOnPreDrawListener(new OnPreDrawListener() { @Override public boolean onPreDraw() { observer.removeOnPreDrawListener(this); animateReorder(mDragPosition, tempPosition); mDragPosition = tempPosition; return true; } }); } } /** * 创建移动动画 * * @param view * @param startX * @param endX * @param startY * @param endY * @return */ private AnimatorSet createTranslationAnimations(View view, float startX, float endX, float startY, float endY) { ObjectAnimator animX = ObjectAnimator.ofFloat(view, "translationX", startX, endX); ObjectAnimator animY = ObjectAnimator.ofFloat(view, "translationY", startY, endY); AnimatorSet animSetXY = new AnimatorSet(); animSetXY.playTogether(animX, animY); return animSetXY; } /** * item的交换动画效果 * * @param oldPosition * @param newPosition */ private void animateReorder(final int oldPosition, final int newPosition) { boolean isForward = newPosition > oldPosition; List<Animator> resultList = new LinkedList<Animator>(); if (isForward) { for (int pos = oldPosition; pos < newPosition; pos++) { View view = getChildAt(pos - getFirstVisiblePosition()); if (view == null) { continue; } if ((pos + 1) % mNumColumns == 0) { resultList.add(createTranslationAnimations(view, -view.getWidth() * (mNumColumns - 1), 0, view.getHeight(), 0)); } else { resultList.add(createTranslationAnimations(view, view.getWidth(), 0, 0, 0)); } } } else { for (int pos = oldPosition; pos > newPosition; pos--) { View view = getChildAt(pos - getFirstVisiblePosition()); if ((pos + mNumColumns) % mNumColumns == 0) { resultList.add(createTranslationAnimations(view, view.getWidth() * (mNumColumns - 1), 0, -view.getHeight(), 0)); } else { resultList.add(createTranslationAnimations(view, -view.getWidth(), 0, 0, 0)); } } } AnimatorSet resultSet = new AnimatorSet(); resultSet.playTogether(resultList); resultSet.setDuration(300); resultSet.setInterpolator(new AccelerateDecelerateInterpolator()); resultSet.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationStart(Animator animation) { mAnimationEnd = false; } @Override public void onAnimationEnd(Animator animation) { mAnimationEnd = true; } }); resultSet.start(); } /** * 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); } mDragAdapter.setHideItem(⑴); removeDragImage(); } private DragGridBaseAdapter getDragAdapter() { return (DragGridBaseAdapter) getAdapter(); } public void setOnMoveListener(OnMoveListener listener) { moveListener = listener; } public interface OnMoveListener { void startMove(); void finishMove(); void cancleMove(); } public interface OnDeleteListener { void onDelete(int position); } public interface DragGridBaseAdapter { /** * 移动时回调 */ void reorderItems(int oldPosition, int newPosition); /** * 隐藏时回调 */ void setHideItem(int hidePosition); int getRealCount(); } private class TouchRect { int top; int bottom; int left; int right; } }