PagerSlidingTabStrip Changing colour of the indicator

Question

Hi I am using PagerSlidingTabStrip for showing tabs in viewpager. I have to change the colour of the indicator from red to green when the user slides from 1st to 2nd fragment. The transition of colors has to be a smooth one. But I am not able to decide how I can do it. Please Help !!! Thanks in advance!!!!

Answer 1

Try this!

int NTABS = 2;
int[] COLORS = { 0xFFFF0000, 0xFF00FF00 }; // COLORS.length == NTABS

mPagerSlidingTabStrip.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        mPagerSlidingTabStrip.setIndicatorColor(getNewColor(position, positionOffset));
    }

    @Override public void onPageSelected(int position) {

    }

    @Override public void onPageScrollStateChanged(int state) {

    }
});


private int getNewColor(int position, float offset) {
    int next;
    if (offset > 0) next = (position < NTABS) ? position+1 : position;
    else next = (position > 0) ? position-1 : 0;
    return blendColors(COLORS[next], COLORS[position], offset);
}

public int blendColors(int color1, int color2, float ratio) {
    final float inverseRation = 1f - ratio;
    float a = (Color.alpha(color1) * ratio) + (Color.alpha(color2) * inverseRation);
    float r = (Color.red  (color1) * ratio) + (Color.red  (color2) * inverseRation);
    float g = (Color.green(color1) * ratio) + (Color.green(color2) * inverseRation);
    float b = (Color.blue (color1) * ratio) + (Color.blue (color2) * inverseRation);
    return Color.argb((int) a, (int) r, (int) g, (int) b);
}