Android 圆形滚动菜单

public class CircleMenuLayout extends ViewGroup
{
private int mRadius;
/**
* 该容器内child item的默认尺寸
*/
private static final float RADIO_DEFAULT_CHILD_DIMENSION = 1 / 4f;
/**
* 菜单的中心child的默认尺寸
*/
private float RADIO_DEFAULT_CENTERITEM_DIMENSION = 1 / 3f;
/**
* 该容器的内边距,无视padding属性，如需边距请用该变量
*/
private static final float RADIO_PADDING_LAYOUT = 1 / 12f;

/**
* 当每秒移动角度达到该值时，认为是快速移动
*/
private static final int FLINGABLE_VALUE = 300;

/**
* 如果移动角度达到该值，则屏蔽点击
*/
private static final int NOCLICK_VALUE = 3;

/**
* 当每秒移动角度达到该值时，认为是快速移动
*/
private int mFlingableValue = FLINGABLE_VALUE;
/**
* 该容器的内边距,无视padding属性，如需边距请用该变量
*/
private float mPadding;
/**
* 布局时的开始角度
*/
private double mStartAngle = 0;
/**
* 菜单项的文本
*/
private String[] mItemTexts;
/**
* 菜单项的图标
*/
private int[] mItemImgs;

/**
* 菜单的个数
*/
private int mMenuItemCount;

/**
* 检测按下到抬起时旋转的角度
*/
private float mTmpAngle;
/**
* 检测按下到抬起时使用的时间
*/
private long mDownTime;

/**
* 判断是否正在自动滚动
*/
private boolean isFling;

private int mMenuItemLayoutId = R.layout.circle_menu_item;

public CircleMenuLayout(Context context, AttributeSet attrs)
{
super(context, attrs);
// 无视padding
setPadding(0, 0, 0, 0);
}

/**
* 设置布局的宽高，并策略menu item宽高
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int resWidth = 0;
int resHeight = 0;

/**
* 根据传入的参数，分别获取测量模式和测量值
*/
int width = MeasureSpec.getSize(widthMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);

int height = MeasureSpec.getSize(heightMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);

/**
* 如果宽或者高的测量模式非精确值
*/
if (widthMode != MeasureSpec.EXACTLY
|| heightMode != MeasureSpec.EXACTLY)
{
// 主要设置为背景图的高度
resWidth = getSuggestedMinimumWidth();
// 如果未设置背景图片，则设置为屏幕宽高的默认值
resWidth = resWidth == 0 ? getDefaultWidth() : resWidth;

resHeight = getSuggestedMinimumHeight();
// 如果未设置背景图片，则设置为屏幕宽高的默认值
resHeight = resHeight == 0 ? getDefaultWidth() : resHeight;
} else
{
// 如果都设置为精确值，则直接取小值；
resWidth = resHeight = Math.min(width, height);
}

setMeasuredDimension(resWidth, resHeight);

// 获得半径
mRadius = Math.max(getMeasuredWidth(), getMeasuredHeight());

// menu item数量
final int count = getChildCount();
// menu item尺寸
int childSize = (int) (mRadius * RADIO_DEFAULT_CHILD_DIMENSION);
// menu item测量模式
int childMode = MeasureSpec.EXACTLY;

// 迭代测量
for (int i = 0; i < count; i++)
{
final View child = getChildAt(i);

if (child.getVisibility() == GONE)
{
continue;
}

// 计算menu item的尺寸；以及和设置好的模式，去对item进行测量
int makeMeasureSpec = -1;

if (child.getId() == R.id.id_circle_menu_item_center)
{
makeMeasureSpec = MeasureSpec.makeMeasureSpec(
(int) (mRadius * RADIO_DEFAULT_CENTERITEM_DIMENSION),
childMode);
} else
{
makeMeasureSpec = MeasureSpec.makeMeasureSpec(childSize,
childMode);
}
child.measure(makeMeasureSpec, makeMeasureSpec);
}

mPadding = RADIO_PADDING_LAYOUT * mRadius;

}

/**
* MenuItem的点击事件接口
*
* @author zhy
*
*/
public interface OnMenuItemClickListener
{
void itemClick(View view, int pos);

void itemCenterClick(View view);
}

/**
* MenuItem的点击事件接口
*/
private OnMenuItemClickListener mOnMenuItemClickListener;

/**
* 设置MenuItem的点击事件接口
*
* @param mOnMenuItemClickListener
*/
public void setOnMenuItemClickListener(
OnMenuItemClickListener mOnMenuItemClickListener)
{
this.mOnMenuItemClickListener = mOnMenuItemClickListener;
}

/**
* 设置menu item的位置
*/
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b)
{
int layoutRadius = mRadius;

// Laying out the child views
final int childCount = getChildCount();

int left, top;
// menu item 的尺寸
int cWidth = (int) (layoutRadius * RADIO_DEFAULT_CHILD_DIMENSION);

// 根据menu item的个数，计算角度
float angleDelay = 360 / (getChildCount() - 1);

// 遍历去设置menuitem的位置
for (int i = 0; i < childCount; i++)
{
final View child = getChildAt(i);

if (child.getId() == R.id.id_circle_menu_item_center)
continue;

if (child.getVisibility() == GONE)
{
continue;
}

mStartAngle %= 360;

// 计算，中心点到menu item中心的距离
float tmp = layoutRadius / 2f - cWidth / 2 - mPadding;

// tmp cosa 即menu item中心点的横坐标
left = layoutRadius
/ 2
+ (int) Math.round(tmp
* Math.cos(Math.toRadians(mStartAngle)) - 1 / 2f
* cWidth);
// tmp sina 即menu item的纵坐标
top = layoutRadius
/ 2
+ (int) Math.round(tmp
* Math.sin(Math.toRadians(mStartAngle)) - 1 / 2f
* cWidth);

child.layout(left, top, left + cWidth, top + cWidth);
// 叠加尺寸
mStartAngle += angleDelay;
}

// 找到中心的view，如果存在设置onclick事件
View cView = findViewById(R.id.id_circle_menu_item_center);
if (cView != null)
{
cView.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{

if (mOnMenuItemClickListener != null)
{
mOnMenuItemClickListener.itemCenterClick(v);
}
}
});
// 设置center item位置
int cl = layoutRadius / 2 - cView.getMeasuredWidth() / 2;
int cr = cl + cView.getMeasuredWidth();
cView.layout(cl, cl, cr, cr);
}

}

/**
* 记录上一次的x，y坐标
*/
private float mLastX;
private float mLastY;

/**
* 自动滚动的Runnable
*/
private AutoFlingRunnable mFlingRunnable;

@Override
public boolean dispatchTouchEvent(MotionEvent event)
{
float x = event.getX();
float y = event.getY();

// Log.e("TAG", "x = " + x + " , y = " + y);

switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:

mLastX = x;
mLastY = y;
mDownTime = System.currentTimeMillis();
mTmpAngle = 0;

// 如果当前已经在快速滚动
if (isFling)
{
// 移除快速滚动的回调
removeCallbacks(mFlingRunnable);
isFling = false;
return true;
}

break;
case MotionEvent.ACTION_MOVE:

/**
* 获得开始的角度
*/
float start = getAngle(mLastX, mLastY);
/**
* 获得当前的角度
*/
float end = getAngle(x, y);

// Log.e("TAG", "start = " + start + " , end =" + end);
// 如果是一、四象限，则直接end-start，角度值都是正值
if (getQuadrant(x, y) == 1 || getQuadrant(x, y) == 4)
{
mStartAngle += end - start;
mTmpAngle += end - start;
} else
// 二、三象限，色角度值是付值
{
mStartAngle += start - end;
mTmpAngle += start - end;
}
// 重新布局
requestLayout();

mLastX = x;
mLastY = y;

break;
case MotionEvent.ACTION_UP:

// 计算，每秒移动的角度
float anglePerSecond = mTmpAngle * 1000
/ (System.currentTimeMillis() - mDownTime);

// Log.e("TAG", anglePrMillionSecond + " , mTmpAngel = " +
// mTmpAngle);

// 如果达到该值认为是快速移动
if (Math.abs(anglePerSecond) > mFlingableValue && !isFling)
{
// post一个任务，去自动滚动
post(mFlingRunnable = new AutoFlingRunnable(anglePerSecond));

return true;
}

// 如果当前旋转角度超过NOCLICK_VALUE屏蔽点击
if (Math.abs(mTmpAngle) > NOCLICK_VALUE)
{
return true;
}

break;
}
return super.dispatchTouchEvent(event);
}

/**
* 主要为了action_down时，返回true
*/
@Override
public boolean onTouchEvent(MotionEvent event)
{
return true;
}

/**
* 根据触摸的位置，计算角度
*
* @param xTouch
* @param yTouch
* @return
*/
private float getAngle(float xTouch, float yTouch)
{
double x = xTouch - (mRadius / 2d);
double y = yTouch - (mRadius / 2d);
return (float) (Math.asin(y / Math.hypot(x, y)) * 180 / Math.PI);
}

/**
* 根据当前位置计算象限
*
* @param x
* @param y
* @return
*/
private int getQuadrant(float x, float y)
{
int tmpX = (int) (x - mRadius / 2);
int tmpY = (int) (y - mRadius / 2);
if (tmpX >= 0)
{
return tmpY >= 0 ? 4 : 1;
} else
{
return tmpY >= 0 ? 3 : 2;
}

}

/**
* 设置菜单条目的图标和文本
*
* @param resIds
*/
public void setMenuItemIconsAndTexts(int[] resIds, String[] texts)
{
mItemImgs = resIds;
mItemTexts = texts;

// 参数检查
if (resIds == null && texts == null)
{
throw new IllegalArgumentException("菜单项文本和图片至少设置其一");
}

// 初始化mMenuCount
mMenuItemCount = resIds == null ? texts.length : resIds.length;

if (resIds != null && texts != null)
{
mMenuItemCount = Math.min(resIds.length, texts.length);
}

addMenuItems();

}

/**
* 设置MenuItem的布局文件，必须在setMenuItemIconsAndTexts之前调用
*
* @param mMenuItemLayoutId
*/
public void setMenuItemLayoutId(int mMenuItemLayoutId)
{
this.mMenuItemLayoutId = mMenuItemLayoutId;
}

/**
* 添加菜单项
*/
private void addMenuItems()
{
LayoutInflater mInflater = LayoutInflater.from(getContext());

/**
* 根据用户设置的参数，初始化view
*/
for (int i = 0; i < mMenuItemCount; i++)
{
final int j = i;
View view = mInflater.inflate(mMenuItemLayoutId, this, false);
ImageView iv = (ImageView) view
.findViewById(R.id.id_circle_menu_item_image);
TextView tv = (TextView) view
.findViewById(R.id.id_circle_menu_item_text);

if (iv != null)
{
iv.setVisibility(View.VISIBLE);
iv.setImageResource(mItemImgs[i]);
iv.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{

if (mOnMenuItemClickListener != null)
{
mOnMenuItemClickListener.itemClick(v, j);
}
}
});
}
if (tv != null)
{
tv.setVisibility(View.VISIBLE);
tv.setText(mItemTexts[i]);
}

// 添加view到容器中
addView(view);
}
}

/**
* 如果每秒旋转角度到达该值，则认为是自动滚动
*
* @param mFlingableValue
*/
public void setFlingableValue(int mFlingableValue)
{
this.mFlingableValue = mFlingableValue;
}

/**
* 设置内边距的比例
*
* @param mPadding
*/
public void setPadding(float mPadding)
{
this.mPadding = mPadding;
}

/**
* 获得默认该layout的尺寸
*
* @return
*/
private int getDefaultWidth()
{
WindowManager wm = (WindowManager) getContext().getSystemService(
Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
return Math.min(outMetrics.widthPixels, outMetrics.heightPixels);
}

/**
* 自动滚动的任务
*
* @author zhy
*
*/
private class AutoFlingRunnable implements Runnable
{

private float angelPerSecond;

public AutoFlingRunnable(float velocity)
{
this.angelPerSecond = velocity;
}

public void run()
{
// 如果小于20,则停止
if ((int) Math.abs(angelPerSecond) < 20)
{
isFling = false;
return;
}
isFling = true;
// 不断改变mStartAngle，让其滚动，/30为了避免滚动太快
mStartAngle += (angelPerSecond / 30);
// 逐渐减小这个值
angelPerSecond /= 1.0666F;
postDelayed(this, 30);
// 重新布局
requestLayout();
}
}

}