android TextView实现实现跑马灯效果，并监听滚动完成动作。

因项目需求，需要实现监听跑马灯效果滚动完成的动作，因此继承textview，添加监听滚动完成动作的监听器。

package com.example.textviewtest;import android.content.Context;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.Rect;import android.util.AttributeSet;import android.view.ViewDebug.ExportedProperty;import android.widget.TextView;public class MarqueeTextView extends TextView implements Runnable {private static final int MARQUEE_DELAY = 1200;private static final int MARQUEE_RESTART_DELAY = 10;private int currentScrollX;private boolean isStop = false;private int textWidth;private boolean isMeasure = false;private int mMarqueeRepeatLimit = 1;private int mMarqueeVelocity = 2;private OnMarqueeCompleteListener marqueeCompleteListener;public MarqueeTextView(Context context) {this(context, null);}public MarqueeTextView(Context context, AttributeSet attrs) {this(context, attrs,0);}public MarqueeTextView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);mMarqueeRepeatLimit = getMarqueeRepeatLimit();}interface OnMarqueeCompleteListener {void onMarqueeComplete();}public OnMarqueeCompleteListener getMarqueeCompleteListener() {return marqueeCompleteListener;}public void setOnMarqueeCompleteListener(OnMarqueeCompleteListener marqueeCompleteListener) {this.marqueeCompleteListener = marqueeCompleteListener;}/** * 获取文字滚动的速度，每秒移动的像素 * @return */public int getMarqueeVelocity() {return mMarqueeVelocity;}/** * 设置文字的滚动的速度 * @param mMarqueeVelocity 每秒移动的像素 */public void setMarqueeVelocity(int velocity) {this.mMarqueeVelocity = velocity ;}@Override@ExportedProperty(category = "focus")public boolean isFocused() {return false;}@Override@ExportedPropertypublic boolean isSelected() {return false;}@Overridepublic void setSelected(boolean selected) {super.setSelected(selected);startStopMarquee(selected);}@Overrideprotected void onFocusChanged(boolean focused, int direction,Rect previouslyFocusedRect) {super.onFocusChanged(focused, direction, previouslyFocusedRect);startStopMarquee(focused);}public void startStopMarquee(boolean bool){if(bool){startScroll();}else{stopScroll();}}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);if (!isMeasure) {textWidth = getTextWidth();isMeasure = true;}}/** * 获取文字宽度 */private int getTextWidth() {Paint paint = this.getPaint();String str = this.getText().toString();return (int) paint.measureText(str);}@Overridepublic void run() {if(textWidth <= getWidth()){ if(null != marqueeCompleteListener){marqueeCompleteListener.onMarqueeComplete();}return; }if (isStop) {currentScrollX = 0;scrollTo(currentScrollX, 0);return;}currentScrollX += mMarqueeVelocity;scrollTo(currentScrollX, 0);if (textWidth != 0  && getScrollX() >= textWidth) {mMarqueeRepeatLimit--;if(mMarqueeRepeatLimit <= 0){if(null != marqueeCompleteListener){marqueeCompleteListener.onMarqueeComplete();}return;}currentScrollX = -getWidth();}postDelayed(this, MARQUEE_RESTART_DELAY);}/** *  开始滚动 */private void startScroll() {isStop = false;this.removeCallbacks(this);this.invalidate();currentScrollX = 0;postDelayed(this, MARQUEE_DELAY);}/** *  停止滚动 */private void stopScroll() {isStop = true;}/** *  从头开始滚动 */public void startFor0() {currentScrollX = 0;startScroll();}}