Increase viewpager smoothscroll duration

android, android-animation, android-viewpager

Solution

Can you modify this part of the code and insert a Log statement?

private void postInitViewPager() {
    try {
         Class<?> viewpager = ViewPager.class;
            Field scroller = viewpager.getDeclaredField("mScroller");
            scroller.setAccessible(true);
            Field interpolator = viewpager.getDeclaredField("sInterpolator");
            interpolator.setAccessible(true);

            mScroller = new ScrollerCustomDuration(getContext(),
                    (Interpolator) interpolator.get(null));
            Log.d("TAG", "mScroller is: " + mScroller + ", "
                + mScroller.getClass().getSuperclass().getCanonicalName() + "; this class is "
                + this + ", " + getClass().getSuperclass().getCanonicalName());
            scroller.set(this, mScroller);
    } catch (Exception e) {
        Log.e("MyPager", e.getMessage());
    }

And then post the output?

EDIT: The issue is the import statements are not correct. `mScroller` is a `android.widget.Scroller` and you cannot assign to it a `com.WazaBe.HoloEverywhere.widget.Scroller`.

Problem

I'm using a `ViewPager` subclass `MyPager` (which is almost the same), and I use its `setCurrentItem(int index, boolean smooth)` method, with the smooth parameter set to true. It's actually a little smoother than with parameter set to 'false', but I'd like to increase the animation duration to make the transition more visible. I have gathered some information from different posts and this solution looks perfect. I've ended up with this code" MyPager.java : ``` public class MyPager extends ViewPager { public MyPager(Context context, AttributeSet attrs) { super(context, attrs); this.enabled = true; postInitViewPager(); } private ScrollerCustomDuration mScroller = null; /** * Override the Scroller instance with our own class so we can change the * duration */ private void postInitViewPager() { try { Class<?> viewpager = ViewPager.class; Field scroller = viewpager.getDeclaredField("mScroller"); scroller.setAccessible(true); Field interpolator = viewpager.getDeclaredField("sInterpolator"); interpolator.setAccessible(true); mScroller = new ScrollerCustomDuration(getContext(), (Interpolator) interpolator.get(null)); scroller.set(this, mScroller); } catch (Exception e) { Log.e("MyPager", e.getMessage()); } } /** * Set the factor by which the duration will change */ public void setScrollDurationFactor(double scrollFactor) { mScroller.setScrollDurationFactor(scrollFactor); } } ``` ScrollerCustomDuration.java ``` public class ScrollerCustomDuration extends Scroller { private double mScrollFactor = 2; public ScrollerCustomDuration(Context context) { super(context); } public ScrollerCustomDuration(Context context, Interpolator interpolator) { super(context, interpolator); } public ScrollerCustomDuration(Context context, Interpolator interpolator, boolean flywheel) { super(context, interpolator, flywheel); } /** * Set the factor by which the duration will change */ public void setScrollDurationFactor(double scrollFactor) { mScrollFactor = scrollFactor; } @Override public void startScroll(int startX, int startY, int dx, int dy, int duration) { super.startScroll(startX, startY, dx, dy, (int) (duration * mScrollFactor)); } } ``` The thing is, I can't get rid of this exception, when running through the line `scroller.set(this, mScroller);` of MyPager : ``` java.lang.IllegalArgumentException: invalid value for field ``` Any idea?

Original source

Related problems