【Android】不依赖焦点和选中的TextView跑马灯

前言

继承TextView，并仿照源码修改而来，主要是取消了焦点和选中了判断，也不依赖文本的宽度。

声明
欢迎转载，但请保留文章原始出处:)
博客园：http://www.cnblogs.com

农民伯伯： http://over140.cnblogs.com

正文

 
   importjava.lang.ref.WeakReference; 
   
 
   
 
   importandroid.content.Context; 
   
 
   importandroid.graphics.Canvas; 
   
 
   importandroid.os.Handler; 
   
 
   importandroid.os.Message; 
   
 
   importandroid.util.AttributeSet; 
   
 
   importandroid.widget.TextView; 
   
 
   
 
   public 
   classMarqueeTextView 
   extendsTextView{ 
   
 
   
  
   privateMarqueemMarquee; 
   
 
   
  
   publicMarqueeTextView(Contextcontext,AttributeSetattrs){ 
   
  
   super(context,attrs); 
   
 } 
   
 
   
  
   intdefStyle){ 
   
  
   publicMarqueeTextView(Contextcontext){ 
   
  
   super(context); 
   
 } 
   
 
   
  
   voidstartMarquee(){ 
   
 startMarquee(-1); 
   
 } 
   
 
   
  
   voidstartMarquee( 
   intrepeatLimit){ 
   
  
   if(mMarquee== 
   null) 
   
 mMarquee= 
   newMarquee( 
   this); 
   
 mMarquee.start(repeatLimit); 
   
 } 
   
 
   
  
   voidstopMarquee(){ 
   
  
   if(mMarquee!= 
   null&&!mMarquee.isStopped()){ 
   
 mMarquee.stop(); 
   
 } 
   
 } 
   
 
   
  
   voidtoggleMarquee(){ 
   
  
   null||mMarquee.isStopped()) 
   
 startMarquee(); 
   
  
   else 
   
 stopMarquee(); 
   
 } 
   
 
   
 @Override 
   
  
   protected 
   voidonDraw(Canvascanvas){ 
   
  
   null&&mMarquee.isRunning()){ 
   
  
   final 
   floatdx=-mMarquee.getScroll(); 
   
 canvas.translate(getLayoutDirection()==LAYOUT_DIRECTION_RTL?-dx 
   
 :+dx,0.0f); 
   
 } 
   
  
   super.onDraw(canvas); 
   
 } 
   
 
   
 @SuppressWarnings("unused") 
   
  
   private 
   static 
   classMarquee 
   extendsHandler{ 
   
  
   // 
   TODO:Addanoptiontoconfigurethis 
   
  
   floatMARQUEE_DELTA_MAX=0.07f; 
   
  
   intMARQUEE_DELAY=0; 
   1200; 
   intMARQUEE_RESTART_DELAY=1200; 
   
  
   intMARQUEE_RESOLUTION=1000/30; 
   
  
   intMARQUEE_PIXELS_PER_SECOND=30; 
   
 
   
  
   byteMARQUEE_STOPPED=0x0; 
   
  
   byteMARQUEE_STARTING=0x1; 
   
  
   byteMARQUEE_RUNNING=0x2; 
   
 
   
  
   intMESSAGE_START=0x1; 
   
  
   intMESSAGE_TICK=0x2; 
   
  
   intMESSAGE_RESTART=0x3; 
   
 
   
  
   finalWeakReference<TextView>mView; 
   
 
   
  
   bytemStatus=MARQUEE_STOPPED; 
   
  
   floatmScrollUnit; 
   
  
   floatmMaxScroll; 
   
  
   floatmMaxFadeScroll; 
   
  
   floatmGhostStart; 
   
  
   floatmGhostOffset; 
   
  
   floatmFadeStop; 
   
  
   intmRepeatLimit; 
   
 
   
  
   floatmScroll; 
   
 
   
 Marquee(TextViewv){ 
   
  
   floatdensity=v.getContext().getResources() 
   
 .getDisplayMetrics().density; 
   
 mScrollUnit=(MARQUEE_PIXELS_PER_SECOND*density) 
   
 /MARQUEE_RESOLUTION; 
   
 mView= 
   newWeakReference<TextView>(v); 
   
 } 
   
 
   
 @Override 
   
  
   voidhandleMessage(Messagemsg){ 
   
  
   switch(msg.what){ 
   
  
   caseMESSAGE_START: 
   
 mStatus=MARQUEE_RUNNING; 
   
 tick(); 
   
  
   break; 
   
  
   caseMESSAGE_TICK: 
   
 tick(); 
   
  
   caseMESSAGE_RESTART: 
   
  
   if(mStatus==MARQUEE_RUNNING){ 
   
  
   if(mRepeatLimit>=0){ 
   
 mRepeatLimit--; 
   
 } 
   
 start(mRepeatLimit); 
   
 } 
   
  
   break; 
   
 } 
   
 } 
   
 
   
  
   voidtick(){ 
   
  
   if(mStatus!=MARQUEE_RUNNING){ 
   
  
   return; 
   
 } 
   
 
   
 removeMessages(MESSAGE_TICK); 
   
 
   
  
   finalTextViewtextView=mView.get(); 
   
  
   &&(textView.isFocused()||textView.isSelected()) 
   if(textView!= 
   null){ 
   
 mScroll+=mScrollUnit; 
   
  
   if(mScroll>mMaxScroll){ 
   
 mScroll=mMaxScroll; 
   
 sendEmptyMessageDelayed(MESSAGE_RESTART,
 MARQUEE_RESTART_DELAY); 
   
 } 
   else{ 
   
 sendEmptyMessageDelayed(MESSAGE_TICK,MARQUEE_RESOLUTION); 
   
 } 
   
 textView.invalidate(); 
   
 } 
   
 } 
   
 
   
  
   voidstop(){ 
   
 mStatus=MARQUEE_STOPPED; 
   
 removeMessages(MESSAGE_START); 
   
 removeMessages(MESSAGE_RESTART); 
   
 removeMessages(MESSAGE_TICK); 
   
 resetScroll(); 
   
 } 
   
 
   
  
   voidresetScroll(){ 
   
 mScroll=0.0f; 
   
  
   null){ 
   
 textView.invalidate(); 
   
 } 
   
 } 
   
 
   
  
   voidstart( 
   if(repeatLimit==0){ 
   
 stop(); 
   
  
   return; 
   
 } 
   
 mRepeatLimit=repeatLimit; 
   
  
   null&&textView.getLayout()!= 
   null){ 
   
 mStatus=MARQUEE_STARTING; 
   
 mScroll=0.0f; 
   
  
   inttextWidth=textView.getWidth() 
   
 -textView.getCompoundPaddingLeft() 
   
 -textView.getCompoundPaddingRight(); 
   
  
   floatlineWidth=textView.getLayout().getLineWidth(0); 
   
  
   floatgap=textWidth/3.0f; 
   
 mGhostStart=lineWidth-textWidth+gap; 
   
 mMaxScroll=mGhostStart+textWidth; 
   
 mGhostOffset=lineWidth+gap; 
   
 mFadeStop=lineWidth+textWidth/6.0f; 
   
 mMaxFadeScroll=mGhostStart+lineWidth+lineWidth; 
   
 
   
 textView.invalidate(); 
   
 sendEmptyMessageDelayed(MESSAGE_START,MARQUEE_DELAY); 
   
 } 
   
 } 
   
 
   
  
   floatgetGhostOffset(){ 
   
  
   returnmGhostOffset; 
   
 } 
   
 
   
  
   floatgetScroll(){ 
   
  
   returnmScroll; 
   
 } 
   
 
   
  
   floatgetMaxFadeScroll(){ 
   
  
   returnmMaxFadeScroll; 
   
 } 
   
 
   
  
   booleanshouldDrawLeftFade(){ 
   
  
   returnmScroll<=mFadeStop; 
   
 } 
   
 
   
  
   booleanshouldDrawGhost(){ 
   
  
   returnmStatus==MARQUEE_RUNNING&&mScroll>mGhostStart; 
   
 } 
   
 
   
  
   booleanisRunning(){ 
   
  
   returnmStatus==MARQUEE_RUNNING; 
   
 } 
   
 
   
  
   booleanisStopped(){ 
   
  
   returnmStatus==MARQUEE_STOPPED; 
   
 } 
   
 } 
   
 } 
  

代码说明：

1、取消了焦点和选中的判断

2、将延迟1200改为0，立即执行跑马灯效果。

3、核心代码都是直接从TextView拷贝出来。

结束

这里主要是提供一种解决问题的思路，实际使用还需要进行相应的修改。