Android Animation Alpha

Question

I ve got animation    lt set xmlns android  http   schemas android com apk res android       android interpolator   android anim linear interpolator  gt        lt alpha          android fromAlpha  0 2           android toAlpha  1 0           android duration  500   gt     lt  set gt    and ImageView    lt ImageView     android id    id listViewIcon      android layout width  wrap content      android layout height  wrap content      android src   drawable settings       android alpha  0 2   gt      and code   final Animation anim   AnimationUtils loadAnimation this  R anim alpha   final ImageView iv    ImageView  findViewById R id listViewIcon   anim  setFillAfter true   iv startAnimation anim     So at the beginning I have ImageView with alpha 0 2 and at the end I want to have ImageView with alpha 1  But it doesn t work like that - when animation starts more alpha is added and animation finish with alpha 0 2  What do I have to change to animate my image from 0 2 up to 1   I ve checked with different settings - I set android alpha  1 0   fromAlpa  1 0   toAlpha  0 2  it works like I expected - from alpha 1 to 0 2  It looks like alpha from ImageView is multiplied by alpha from animation

User · Answer

This my extension  this is an example of change image with FadIn and FadOut   fun ImageView setImageDrawableWithAnimation  DrawableRes   resId  Int  duration  Long   300            if  drawable    null            animate                alpha 0f               setDuration duration                withEndAction                    setImageResource resId                   animate                         alpha 1f                        setDuration duration                        else if  drawable    null            setAlpha 0f          setImageResource resId          animate                alpha 1f               setDuration duration

User · Answer

The  setStartOffset  should be smaller  else animation starts at view alpha 0 xf and waits for start offset before animating to 1f  Hope the following code helps   AlphaAnimation animation1   new AlphaAnimation 0 1f  1f    animation1 setDuration 1000   animation1 setStartOffset 50    animation1 setFillAfter true    view setVisibility View VISIBLE    view startAnimation animation1

User · Answer

View setOnTouchListener   v  event - gt      when  event action            MotionEvent ACTION DOWN - gt                v alpha   0f             v invalidate                     MotionEvent ACTION UP - gt                v alpha   1f             v invalidate                         false

User · Answer

Setting alpha to 1 before starting the animation worked for me   AlphaAnimation animation1   new AlphaAnimation 0 2f  1 0f   animation1 setDuration 500   iv setAlpha 1f   iv startAnimation animation1     At least on my tests  there s no flickering because of setting alpha before starting the animation  It just works fine

User · Answer

Hm      The thing is wrong  and possibly in the proper operation of the animations in the Android API   The fact is that when you set in your code alpha value of 0 2f is based on the settings in the xml file for android it means that    0 2f   0 2f of 0 2f  20  from 100   ie from 0 2f   5   0 04f 1f   0 2f   So your animation in fact works from 0 04f to 0 2f  flag setFillAfter true  certainly works  but you need to understand that at the end of your animation ImageView will have the alpha value 0 2f instead of one  because you specify 0 2f as marginally acceptable value in the animation  a kind of maximum alpha channel    So if you want to have the desired result shall carry all your logic to your code and manipulate animations in code instead of determining in xml   You should understand that your animations directly depends of two things    LayoutParams of Animated View Animation parameters    Animation parameters manipulate your LayoutParams in setFillAfter setFillBefore methods

User · Answer

lt ImageView     android id    id listViewIcon      android layout width  wrap content      android layout height  wrap content      android src   drawable settings   gt      Remove android alpha 0 2 from XML-  ImageView

User · Answer

Try this  AlphaAnimation animation1   new AlphaAnimation 0 2f  1 0f   animation1 setDuration 1000   animation1 setStartOffset 5000   animation1 setFillAfter true   iv startAnimation animation1

User · Answer

Kotlin Version  Simply use ViewPropertyAnimator like this   iv alpha   0 2f iv animate   apply       interpolator   LinearInterpolator       duration   500     alpha 1f      startDelay   1000     start

User · Answer

Might be a little late  but found a lovely solution in the android docs     In transition   alpha from 0 to 0 5  view setAlpha 0f   view setVisibility View VISIBLE   view animate       alpha 0 5f      setDuration 400      setListener null      Out transition   alpha from 0 5 to 0  view setAlpha 0 5f  view animate       alpha 0f      setDuration 400      setListener new AnimatorListenerAdapter                 Override            public void onAnimationEnd Animator animation               view setVisibility View GONE

[java] Android Animation Alpha

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