/*
* Copyright (c) 2015, 张涛.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.kymjs.blog.ui.widget;
import java.util.LinkedList;
import java.util.List;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.os.Handler;
import android.os.Vibrator;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnPreDrawListener;
import android.view.WindowManager;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ListAdapter;
/**
* 感谢这篇博客的作者，http://blog.csdn.net/xiaanming/article/details/17718579<br>
* 在这个基础上解决了原作者的问题:Adapter无法使用ViewHolder优化的问题，优化了手势识别率，并添加了trashView功能，
* 优化自定义控件对外扩展性，解决在上下拉环境下手势冲突问题<br>
*
* @author kymjs (https://kymjs.com/)
*/
public class KJDragGridView 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; // 是否可以拖拽，用于控件内部逻辑实现
private boolean canDrag = true; // 是否可用拖拽，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 View mTrashView; // 删除item的垃圾桶图标
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的上边缘的距离
private int mPoint2ItemLeft;
private int mOffset2Top; // DragGridView距离屏幕顶部的偏移量
private int mOffset2Left;
private int mDownScrollBorder; // DragGridView自动向下滚动的边界值
private int mUpScrollBorder; // DragGridView自动向上滚动的边界值
private DragGridBaseAdapter mDragAdapter;
private int mNumColumns;
private int mColumnWidth;
private boolean mNumColumnsSet;
private int mHorizontalSpacing;
private static final int speed = 20; // DragGridView自动滚动的速度
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 final TouchRect moveRect = new TouchRect();
private final TouchRect gridRect = new TouchRect();
private final TouchRect trashRect = new TouchRect();
public KJDragGridView(Context context) {
this(context, null);
}
public KJDragGridView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public KJDragGridView(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
if (!mNumColumnsSet) {
mNumColumns = AUTO_FIT;
}
}
/**
* 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;
}
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();
}
}
};
};
// 用来处理是否为长按的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); // 震动一下
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();
if (mTrashView != null) {
trashRect.left = mTrashView.getLeft();
trashRect.right = mTrashView.getRight();
trashRect.bottom = mTrashView.getBottom();
trashRect.top = mTrashView.getTop();
}
}
/******************** preference method ********************/
@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，默认是700毫秒
*
* @param dragResponseMS
*/
public void setDragResponseMS(long dragResponseMS) {
this.dragResponseMS = dragResponseMS;
}
public void setOnDeleteListener(OnDeleteListener l) {
this.deleteListener = l;
}
public void setTrashView(View trashView) {
this.mTrashView = trashView;
}
public void setDragEnable(boolean isDrag) {
this.canDrag = isDrag;
if (canDrag) {
mHandler.removeCallbacks(mLongClickRunnable);
}
}
/******************** touch method ********************/
@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坐标获取所点击item的position
mDragPosition = pointToPosition(mDownX, mDownY);
if (mDragPosition == AdapterView.INVALID_POSITION) {
return super.dispatchTouchEvent(ev);
}
// 使用Handler延迟dragResponseMS执行mLongClickRunnable
mHandler.postDelayed(mLongClickRunnable, dragResponseMS);
// 根据position获取该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);
// 获取DragGridView自动向上滚动的偏移量，小于这个值，DragGridView向下滚动
mDownScrollBorder = getHeight() / 5;
// 大于这个值，DragGridView向上滚动
mUpScrollBorder = getHeight() * 4 / 5;
// 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();
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
if (mTrashView != null) {
if (inTrash(moveX, moveY)) {
mTrashView.setScaleX(1.7f);
mTrashView.setScaleY(1.7f);
} else {
mTrashView.setScaleX(1f);
mTrashView.setScaleY(1f);
}
}
break;
case MotionEvent.ACTION_UP:
onStopDrag();
isDrag = false;
if (deleteListener != null && inTrash(ev.getX(), ev.getY())) {
deleteListener.onDelete(mDragPosition);
}
break;
}
return true;
}
return super.onTouchEvent(ev);
}
/**
* 是否点击在GridView的item上面
*
* @param itemView
* @param x
* @param y
* @return
*/
private boolean isTouchInItem(TouchRect moveRect, float x, float y) {
// 防止手抖的处理，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; // 图片之外的其他地方透明
mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT;
mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left;
mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top
- mStatusHeight;
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;
mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top
- mStatusHeight;
mWindowManager.updateViewLayout(mDragImageView, mWindowLayoutParams); // 更新镜像的位置
onSwapItem(moveX, moveY);
// GridView自动滚动
mHandler.post(mScrollRunnable);
}
/**
* 手指当前处于垃圾桶图标上
*
* @param x
* @param y
* @return
*/
private boolean inTrash(float x, float y) {
x += gridRect.left;
y += gridRect.top;
if (x > trashRect.left && x < trashRect.right && y > trashRect.top
&& y < trashRect.bottom) {
if (mHandler != null && mScrollRunnable != null) {
mHandler.removeCallbacks(mScrollRunnable);
}
if (mDragImageView != null) {
mDragImageView.setScaleX(0.6f);
mDragImageView.setScaleY(0.6f);
}
return true;
} else {
if (mDragImageView != null) {
mDragImageView.setScaleX(1f);
mDragImageView.setScaleY(1f);
}
return false;
}
}
/**
* 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，触发GridView自动向下滚动
* 否则不进行滚动
*/
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
&& 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(-1);
removeDragImage();
if (mTrashView != null) {
mTrashView.setScaleX(1f);
mTrashView.setScaleY(1f);
}
}
public void setOnMoveListener(OnMoveListener l) {
moveListener = l;
}
public interface OnMoveListener {
void startMove();
void finishMove();
void cancleMove();
}
public interface OnDeleteListener {
void onDelete(int position);
}
public interface DragGridBaseAdapter {
/**
* 移动时回调
*/
public void reorderItems(int oldPosition, int newPosition);
/**
* 隐藏时回调
*/
public void setHideItem(int hidePosition);
}
private class TouchRect {
int top;
int bottom;
int left;
int right;
}
}
