快速查询A 到Z

/**
 * 快速查询View
 * @author Jiang
 *
 */
public class MyQuickSearchView extends View {

	/**
	 * 构造函数
	 * @param context
	 */
	public MyQuickSearchView(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
	}

	public MyQuickSearchView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}

	public MyQuickSearchView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
	}
	
	//事件监听器
	private OnTouchingLetterChangedListener onTouchingLetterChangedListener = null;
	//显示的字母
	private String[] mAllChar = { "#", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K",
			"L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X",
			"Y", "Z" };
	
	private int mChoose = -1;
	private Paint mPaint = new Paint();
	private boolean isShowBackground = false;
	
	/*
	 * (non-Javadoc)
	 * @see android.view.View#onDraw(android.graphics.Canvas)
	 */
	@Override
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		if (null == mPaint) {
			return;
		}
		float height = getHeight();
		float width = getWidth();

		if (isShowBackground) {
			// 设置半透明,圆角背景
			RectF rect = new RectF(0, 0, width, height);
			mPaint.setColor(Color.parseColor("#40000000"));
			canvas.drawRoundRect(rect, width / 2, width / 2, mPaint);
		}

		float singleHeight = height / mAllChar.length;

		for (int i = 0; i < mAllChar.length; i++) {
			// 设置字体的颜色
			mPaint.setColor(getResources().getColor(R.color.color_small_text));
			// 设置字体
			mPaint.setTypeface(Typeface.DEFAULT);
			// 设置字体大小，自动适应屏幕大小
			mPaint.setTextSize(singleHeight);
			// 效果设置
			mPaint.setAntiAlias(true);
			if (i == mChoose) {
				mPaint.setColor(Color.RED);
				mPaint.setFakeBoldText(true);
			}
			// 计算宽度，把字母画在水平居中的位置
			float xPos = width / 2 - mPaint.measureText(mAllChar[i]) / 2;
			// 计算高度
			float yPos = singleHeight * i + singleHeight;
			// 把字母画出来
			canvas.drawText(mAllChar[i], xPos, yPos, mPaint);
			mPaint.reset();
		}

	}

	/*
	 * (non-Javadoc)
	 * @see android.view.View#dispatchTouchEvent(android.view.MotionEvent)
	 */
	@Override
	public boolean dispatchTouchEvent(MotionEvent event) {
		final int action = event.getAction();
		final float y = event.getY();
		final int oldChoose = mChoose;
		final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;
		// 计算出当前点击的位置
		final int position = (int) (y / getHeight() * mAllChar.length);

		switch (action) {
		case MotionEvent.ACTION_DOWN:
			isShowBackground = true;
			if (null != listener && oldChoose != position) {
				if (position > 0 && position < mAllChar.length) {
					listener.onTouchingLetterChanged(mAllChar[position]);
					mChoose = position;
					invalidate();
				}
			}

			break;
		case MotionEvent.ACTION_MOVE:
			if (oldChoose != position && listener != null) {
				if (position > 0 && position < mAllChar.length) {
					listener.onTouchingLetterChanged(mAllChar[position]);
					mChoose = position;
					invalidate();
				}
			}
			break;
		case MotionEvent.ACTION_UP:
			isShowBackground = false;
			mChoose = -1;
			invalidate();
			break;
		}
		return true;
	}
	
	/*
	 * (non-Javadoc)
	 * @see android.view.View#onTouchEvent(android.view.MotionEvent)
	 */
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		return super.onTouchEvent(event);
	}

	/**
	 * 
	 * @param onTouchingLetterChangedListener
	 */
	public void setOnTouchingLetterChangedListener(OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
		
		this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
	}
	
	/**
	 * listener interface
	 * @author Jiang
	 *
	 */
	public interface OnTouchingLetterChangedListener {
		public void onTouchingLetterChanged(String s);
	}

}