null pointer exceptions when the view is not visiable on screen

[michaelsam94]

there is null point exception thrown when fragment which contain the viewpager and indicator not visible on screen. Here is stacktrace. java.lang.NullPointerException: Attempt to invoke virtual method 'int io.github.vejei.viewpagerindicator.animation.AnimationValue$SlideAnimationValue.getCoordinateX()' on a null object reference at io.github.vejei.viewpagerindicator.painter.RectPainter$SlideAnimationPainter.draw(RectPainter.java:101) at io.github.vejei.viewpagerindicator.indicator.RectIndicator.onDraw(RectIndicator.java:175) at android.view.View.draw(View.java:16270) at android.view.View.updateDisplayListIfDirty(View.java:15267) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1882) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1882) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at androidx.fragment.app.FragmentContainerView.drawChild(FragmentContainerView.java:235) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.fragment.app.FragmentContainerView.dispatchDraw(FragmentContainerView.java:223) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1882) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at androidx.drawerlayout.widget.DrawerLayout.drawChild(DrawerLayout.java:1478) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at androidx.fragment.app.FragmentContainerView.drawChild(FragmentContainerView.java:235) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.fragment.app.FragmentContainerView.dispatchDraw(FragmentContainerView.java:223) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at androidx.fragment.app.FragmentContainerView.drawChild(FragmentContainerView.java:235) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.fragment.app.FragmentContainerView.dispatchDraw(FragmentContainerView.java:223) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1882) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at android.view.View.updateDisplayListIfDirty(View.java:15262) at android.view.View.draw(View.java:16040) at android.view.ViewGroup.drawChild(ViewGroup.java:3610) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3400) at android.view.View.updateDisplayListIfDirty(View.

[michaelsam94]

also there is error in rendering layout on layout editor tell that is there is null pointer exception in draw method of SlideAnimationPainter class in line 101 which is drawing the rectangle on screen canvas.drawRoundRect(value.getCoordinateX(), coordinateY, value.getCoordinateX() + width, coordinateY + height, cornerRadius, cornerRadius, paint ); the value object which throw nullpointer exception when calling getCoordinateX() method

[michaelsam94]

this issue happens when I put the same layout which contain indicator and viewpager in two fragments and try to add and remove those two fragment the first fragment is behave normal and when I remove the first fragment and add the second fragment the issue appears