ViewPager with TabLayout issue with AnimatedVectorDrawable

user_112496 0
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I'm trying to implement simple ViewPager with some animations on VectorDrawable.
Following this very good example solution for nice tab scrolling with dot's switching.

The only difference is that I'm using vector animations. As an activity it works like a charm, with ViewPager added, animations are not started consistently.

compileSdkVersion 25
buildToolsVersion "26.0.2"
targetSdkVersion 25

I'm debugging on my device (SG7), I set break-point on animation.start()

  • on the middle screen, break-point is not always invoked
  • more often on screen 1 & 3, animations are not triggered
  • when jumping using dots, between 1&3 animations are always triggered! but not when doing 1-2 or 2-3 !!

All this is working on one big VectorDrawable with 3 groups which are animated.
2 captions sliding in on start, and then is infinitely rolling spin, spin always work.

Activity

   @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);

    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mHideHandler.post(mHidePart2Runnable);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabDots);
    tabLayout.setupWithViewPager(mViewPager, true);

    };

Fragment:

  public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        return PlaceholderFragment.newInstance(position + 1);
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

Static Fragment

      public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    public PlaceholderFragment() {
    }

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.activity_fullscreen, container, false);
        View imgView = rootView.findViewById(R.id.vec_anim);

        Drawable drawable = ((ImageView)imgView).getDrawable();
        if (drawable instanceof Animatable) {
            ((Animatable) drawable).start();
        };
        return rootView;
    }

I'm new to all of this, wanted to profile the impact of SVG size on performance (thinking of caching svgs and triggering animations on view creation maybe...) and I'm trying to optimize it all and make it smooth. But first of all, it doesn't work properly.

Why is breakpoint not always hit when swapping pages?
Is there any better way of doing this?

android-fragmentactivity android-viewpager android-vectordrawable android user-interface
2 Answers

try this,

  1. Add library compile com.mcxiaoke.viewpagerindicator:library:2.4.1@aar'.

  2. Your main layout file,

    <RelativeLayout
        android:id="@+id/pager_layout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="right">
        <android.support.v4.view.ViewPager
            android:id="@+id/pager_profile"
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">
        </android.support.v4.view.ViewPager>
    
        <yourpackagename.utils.CirclePageIndicator
           android:id="@+id/cover_photo_indicator"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:foregroundGravity="right"
           android:layout_alignParentBottom="true"
           android:layout_alignParentEnd="true"
           android:padding="10dip" />
</RelativeLayout>
  1. Create custom class CirclePageIndicator
/**
 * Draws circles (one for each view). The current view position is filled and
 * others are only stroked.
 */
public class CirclePageIndicator extends View implements PageIndicator {
    private static final int INVALID_POINTER = -1;

    private float mRadius;
    private final Paint mPaintPageFill = new Paint(ANTI_ALIAS_FLAG);
    private final Paint mPaintStroke = new Paint(ANTI_ALIAS_FLAG);
    private final Paint mPaintFill = new Paint(ANTI_ALIAS_FLAG);
    private ViewPager mViewPager;
    private ViewPager.OnPageChangeListener mListener;
    private int mCurrentPage;
    private int mSnapPage;
    private float mPageOffset;
    private int mScrollState;
    private int mOrientation;
    private boolean mCentered;
    private boolean mSnap;

    private int mTouchSlop;
    private float mLastMotionX = -1;
    private int mActivePointerId = INVALID_POINTER;
    private boolean mIsDragging;


    public CirclePageIndicator(Context context) {
        this(context, null);
    }

    public CirclePageIndicator(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.vpiCirclePageIndicatorStyle);
    }

    public CirclePageIndicator(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        if (isInEditMode()) return;

        //Load defaults from resources
        final Resources res = getResources();
        final int defaultPageColor = res.getColor(R.color.default_circle_indicator_page_color);
        //default_circle_indicator_fill_color
        final int defaultFillColor = res.getColor(R.color.holo_blue_dark);
        final int defaultOrientation = res.getInteger(R.integer.default_circle_indicator_orientation);
        final int defaultStrokeColor = res.getColor(R.color.default_circle_indicator_stroke_color);
        final float defaultStrokeWidth = res.getDimension(R.dimen.default_circle_indicator_stroke_width);
        final float defaultRadius = res.getDimension(R.dimen.default_circle_indicator_radius);
        final boolean defaultCentered = res.getBoolean(R.bool.default_circle_indicator_centered);
        final boolean defaultSnap = res.getBoolean(R.bool.default_circle_indicator_snap);

        //Retrieve styles attributes
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CirclePageIndicator, defStyle, 0);

        mCentered = a.getBoolean(R.styleable.CirclePageIndicator_centered, defaultCentered);
        mOrientation = a.getInt(R.styleable.CirclePageIndicator_android_orientation, defaultOrientation);
        mPaintPageFill.setStyle(Style.FILL);
        mPaintPageFill.setColor(a.getColor(R.styleable.CirclePageIndicator_pageColor, defaultPageColor));
        mPaintStroke.setStyle(Style.STROKE);
        mPaintStroke.setColor(a.getColor(R.styleable.CirclePageIndicator_strokeColor, defaultStrokeColor));
        mPaintStroke.setStrokeWidth(a.getDimension(R.styleable.CirclePageIndicator_strokeWidth, defaultStrokeWidth));
        mPaintFill.setStyle(Style.FILL);
        mPaintFill.setColor(a.getColor(R.styleable.CirclePageIndicator_fillColor, defaultFillColor));
        mRadius = a.getDimension(R.styleable.CirclePageIndicator_radius, defaultRadius);
        mSnap = a.getBoolean(R.styleable.CirclePageIndicator_snap, defaultSnap);

        Drawable background = a.getDrawable(R.styleable.CirclePageIndicator_android_background);
        if (background != null) {
            setBackgroundDrawable(background);
        }

        a.recycle();

        final ViewConfiguration configuration = ViewConfiguration.get(context);
        mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);
    }


    public void setCentered(boolean centered) {
        mCentered = centered;
        invalidate();
    }

    public boolean isCentered() {
        return mCentered;
    }

    public void setPageColor(int pageColor) {
        mPaintPageFill.setColor(pageColor);
        invalidate();
    }

    public int getPageColor() {
        return mPaintPageFill.getColor();
    }

    public void setFillColor(int fillColor) {
        mPaintFill.setColor(fillColor);
        invalidate();
    }

    public int getFillColor() {
        return mPaintFill.getColor();
    }

    public void setOrientation(int orientation) {
        switch (orientation) {
            case HORIZONTAL:
            case VERTICAL:
                mOrientation = orientation;
                requestLayout();
                break;

            default:
                throw new IllegalArgumentException("Orientation must be either HORIZONTAL or VERTICAL.");
        }
    }

    public int getOrientation() {
        return mOrientation;
    }

    public void setStrokeColor(int strokeColor) {
        mPaintStroke.setColor(strokeColor);
        invalidate();
    }

    public int getStrokeColor() {
        return mPaintStroke.getColor();
    }

    public void setStrokeWidth(float strokeWidth) {
        mPaintStroke.setStrokeWidth(strokeWidth);
        invalidate();
    }

    public float getStrokeWidth() {
        return mPaintStroke.getStrokeWidth();
    }

    public void setRadius(float radius) {
        mRadius = radius;
        invalidate();
    }

    public float getRadius() {
        return mRadius;
    }

    public void setSnap(boolean snap) {
        mSnap = snap;
        invalidate();
    }

    public boolean isSnap() {
        return mSnap;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if (mViewPager == null) {
            return;
        }
        final int count = mViewPager.getAdapter().getCount();
        if (count == 0) {
            return;
        }

        if (mCurrentPage >= count) {
            setCurrentItem(count - 1);
            return;
        }

        int longSize;
        int longPaddingBefore;
        int longPaddingAfter;
        int shortPaddingBefore;
        if (mOrientation == HORIZONTAL) {
            longSize = getWidth();
            longPaddingBefore = getPaddingLeft();
            longPaddingAfter = getPaddingRight();
            shortPaddingBefore = getPaddingTop();
        } else {
            longSize = getHeight();
            longPaddingBefore = getPaddingTop();
            longPaddingAfter = getPaddingBottom();
            shortPaddingBefore = getPaddingLeft();
        }

        final float threeRadius = mRadius * 3;
        final float shortOffset = shortPaddingBefore + mRadius;
        float longOffset = longPaddingBefore + mRadius;
        if (mCentered) {
            longOffset += ((longSize - longPaddingBefore - longPaddingAfter) / 2.0f) - ((count * threeRadius) / 2.0f);
        }

        float dX;
        float dY;

        float pageFillRadius = mRadius;
        if (mPaintStroke.getStrokeWidth() > 0) {
            pageFillRadius -= mPaintStroke.getStrokeWidth() / 2.0f;
        }

        //Draw stroked circles
        for (int iLoop = 0; iLoop < count; iLoop++) {
            float drawLong = longOffset + (iLoop * threeRadius);
            if (mOrientation == HORIZONTAL) {
                dX = drawLong;
                dY = shortOffset;
            } else {
                dX = shortOffset;
                dY = drawLong;
            }
            // Only paint fill if not completely transparent
            if (mPaintPageFill.getAlpha() > 0) {
                canvas.drawCircle(dX, dY, pageFillRadius, mPaintPageFill);
            }

            // Only paint stroke if a stroke width was non-zero
            if (pageFillRadius != mRadius) {
                canvas.drawCircle(dX, dY, mRadius, mPaintStroke);
            }
        }

        //Draw the filled circle according to the current scroll
        float cx = (mSnap ? mSnapPage : mCurrentPage) * threeRadius;
        if (!mSnap) {
            cx += mPageOffset * threeRadius;
        }
        if (mOrientation == HORIZONTAL) {
            dX = longOffset + cx;
            dY = shortOffset;
        } else {
            dX = shortOffset;
            dY = longOffset + cx;
        }
        canvas.drawCircle(dX, dY, mRadius, mPaintFill);
    }

    public boolean onTouchEvent(android.view.MotionEvent ev) {
        if (super.onTouchEvent(ev)) {
            return true;
        }
        if ((mViewPager == null) || (mViewPager.getAdapter().getCount() == 0)) {
            return false;
        }

        final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
                mLastMotionX = ev.getX();
                break;

            case MotionEvent.ACTION_MOVE: {
                final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
                final float x = MotionEventCompat.getX(ev, activePointerIndex);
                final float deltaX = x - mLastMotionX;

                if (!mIsDragging) {
                    if (Math.abs(deltaX) > mTouchSlop) {
                        mIsDragging = true;
                    }
                }

                if (mIsDragging) {
                    mLastMotionX = x;
                    if (mViewPager.isFakeDragging() || mViewPager.beginFakeDrag()) {
                        mViewPager.fakeDragBy(deltaX);
                    }
                }

                break;
            }

            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
                if (!mIsDragging) {
                    final int count = mViewPager.getAdapter().getCount();
                    final int width = getWidth();
                    final float halfWidth = width / 2f;
                    final float sixthWidth = width / 6f;

                    if ((mCurrentPage > 0) && (ev.getX() < halfWidth - sixthWidth)) {
                        if (action != MotionEvent.ACTION_CANCEL) {
                            mViewPager.setCurrentItem(mCurrentPage - 1);
                        }
                        return true;
                    } else if ((mCurrentPage < count - 1) && (ev.getX() > halfWidth + sixthWidth)) {
                        if (action != MotionEvent.ACTION_CANCEL) {
                            mViewPager.setCurrentItem(mCurrentPage + 1);
                        }
                        return true;
                    }
                }

                mIsDragging = false;
                mActivePointerId = INVALID_POINTER;
                if (mViewPager.isFakeDragging()) mViewPager.endFakeDrag();
                break;

            case MotionEventCompat.ACTION_POINTER_DOWN: {
                final int index = MotionEventCompat.getActionIndex(ev);
                mLastMotionX = MotionEventCompat.getX(ev, index);
                mActivePointerId = MotionEventCompat.getPointerId(ev, index);
                break;
            }

            case MotionEventCompat.ACTION_POINTER_UP:
                final int pointerIndex = MotionEventCompat.getActionIndex(ev);
                final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);
                if (pointerId == mActivePointerId) {
                    final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
                    mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);
                }
                mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
                break;
        }

        return true;
    }

    @Override
    public void setViewPager(ViewPager view) {
        if (mViewPager == view) {
            return;
        }
        if (mViewPager != null) {
            mViewPager.setOnPageChangeListener(null);
        }
        if (view.getAdapter() == null) {
            throw new IllegalStateException("ViewPager does not have adapter instance.");
        }
        mViewPager = view;
        mViewPager.setOnPageChangeListener(this);
        invalidate();
    }

    @Override
    public void setViewPager(ViewPager view, int initialPosition) {
        setViewPager(view);
        setCurrentItem(initialPosition);
    }

    @Override
    public void setCurrentItem(int item) {
        if (mViewPager == null) {
            throw new IllegalStateException("ViewPager has not been bound.");
        }
        mViewPager.setCurrentItem(item);
        mCurrentPage = item;
        invalidate();
    }

    @Override
    public void notifyDataSetChanged() {
        invalidate();
    }

    @Override
    public void onPageScrollStateChanged(int state) {
        mScrollState = state;

        if (mListener != null) {
            mListener.onPageScrollStateChanged(state);
        }
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        mCurrentPage = position;
        mPageOffset = positionOffset;
        invalidate();

        if (mListener != null) {
            mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
        }
    }

    @Override
    public void onPageSelected(int position) {
        if (mSnap || mScrollState == ViewPager.SCROLL_STATE_IDLE) {
            mCurrentPage = position;
            mSnapPage = position;
            invalidate();
        }

        if (mListener != null) {
            mListener.onPageSelected(position);
        }
    }

    @Override
    public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
        mListener = listener;
    }

    /*
     * (non-Javadoc)
     *
     * @see android.view.View#onMeasure(int, int)
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (mOrientation == HORIZONTAL) {
            setMeasuredDimension(measureLong(widthMeasureSpec), measureShort(heightMeasureSpec));
        } else {
            setMeasuredDimension(measureShort(widthMeasureSpec), measureLong(heightMeasureSpec));
        }
    }

    /**
     * Determines the width of this view
     *
     * @param measureSpec
     *            A measureSpec packed into an int
     * @return The width of the view, honoring constraints from measureSpec
     */
    private int measureLong(int measureSpec) {
        int result;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if ((specMode == MeasureSpec.EXACTLY) || (mViewPager == null)) {
            //We were told how big to be
            result = specSize;
        } else {
            //Calculate the width according the views count
            final int count = mViewPager.getAdapter().getCount();
            result = (int)(getPaddingLeft() + getPaddingRight()
                    + (count * 2 * mRadius) + (count - 1) * mRadius + 1);
            //Respect AT_MOST value if that was what is called for by measureSpec
            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        return result;
    }

    /**
     * Determines the height of this view
     *
     * @param measureSpec
     *            A measureSpec packed into an int
     * @return The height of the view, honoring constraints from measureSpec
     */
    private int measureShort(int measureSpec) {
        int result;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {
            //We were told how big to be
            result = specSize;
        } else {
            //Measure the height
            result = (int)(2 * mRadius + getPaddingTop() + getPaddingBottom() + 1);
            //Respect AT_MOST value if that was what is called for by measureSpec
            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        return result;
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        SavedState savedState = (SavedState)state;
        super.onRestoreInstanceState(savedState.getSuperState());
        mCurrentPage = savedState.currentPage;
        mSnapPage = savedState.currentPage;
        requestLayout();
    }

    @Override
    public Parcelable onSaveInstanceState() {
        Parcelable superState = super.onSaveInstanceState();
        SavedState savedState = new SavedState(superState);
        savedState.currentPage = mCurrentPage;
        return savedState;
    }

    static class SavedState extends BaseSavedState {
        int currentPage;

        public SavedState(Parcelable superState) {
            super(superState);
        }

        private SavedState(Parcel in) {
            super(in);
            currentPage = in.readInt();
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            super.writeToParcel(dest, flags);
            dest.writeInt(currentPage);
        }

        @SuppressWarnings("UnusedDeclaration")
        public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
            @Override
            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in);
            }

            @Override
            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
    }
}
  1. Create indicator_tags.xml inside res -> values
<resources>

    <bool name="default_circle_indicator_centered">true</bool>

    <color name="default_circle_indicator_fill_color">#FFFF0000</color>
    <color name="default_circle_indicator_page_color">#00000000</color>

    <integer name="default_circle_indicator_orientation">0</integer>

    <dimen name="default_circle_indicator_radius">4dp</dimen>

    <bool name="default_circle_indicator_snap">false</bool>

    <color name="default_circle_indicator_stroke_color">#FFDDDDDD</color>

    <dimen name="default_circle_indicator_stroke_width">1dp</dimen>

    <declare-styleable name="ViewPagerIndicator">

        <!-- Style of the circle indicator. -->
        <attr name="vpiCirclePageIndicatorStyle" format="reference" />
        <!-- Style of the icon indicator's views. -->
        <attr name="vpiIconPageIndicatorStyle" format="reference" />
        <!-- Style of the line indicator. -->
        <attr name="vpiLinePageIndicatorStyle" format="reference" />
        <!-- Style of the title indicator. -->
        <attr name="vpiTitlePageIndicatorStyle" format="reference" />
        <!-- Style of the tab indicator's tabs. -->
        <attr name="vpiTabPageIndicatorStyle" format="reference" />
        <!-- Style of the underline indicator. -->
        <attr name="vpiUnderlinePageIndicatorStyle" format="reference" />
    </declare-styleable>

    <attr name="centered" format="boolean" />
    <attr name="selectedColor" format="color" />
    <attr name="strokeWidth" format="dimension" />
    <attr name="unselectedColor" format="color" />

    <declare-styleable name="CirclePageIndicator">

        <!-- Whether or not the indicators should be centered. -->
        <attr name="centered" />
        <!-- Color of the filled circle that represents the current page. -->
        <attr name="fillColor" format="color" />
        <!-- Color of the filled circles that represents pages. -->
        <attr name="pageColor" format="color" />
        <!-- Orientation of the indicator. -->
        <attr name="android:orientation" />
        <!-- Radius of the circles. This is also the spacing between circles. -->
        <attr name="radius" format="dimension" />
        <!-- Whether or not the selected indicator snaps to the circles. -->
        <attr name="snap" format="boolean" />
        <!-- Color of the open circles. -->
        <attr name="strokeColor" format="color" />
        <!-- Width of the stroke used to draw the circles. -->
        <attr name="strokeWidth" />
        <!-- View background -->
        <attr name="android:background" />
    </declare-styleable>
    <declare-styleable name="LinePageIndicator">

        <!-- Whether or not the indicators should be centered. -->
        <attr name="centered" />
        <!-- Color of the unselected lines that represent the pages. -->
        <attr name="unselectedColor" />
        <!-- Color of the selected line that represents the current page. -->
        <attr name="selectedColor" />
        <!-- Width of each indicator line. -->
        <attr name="lineWidth" format="dimension" />
        <!-- Width of each indicator line's stroke. -->
        <attr name="strokeWidth" />
        <!-- Width of the gap between each indicator line. -->
        <attr name="gapWidth" format="dimension" />
        <!-- View background -->
        <attr name="android:background" />
    </declare-styleable>
    <declare-styleable name="TitlePageIndicator">

        <!-- Screen edge padding. -->
        <attr name="clipPadding" format="dimension" />
        <!-- Color of the footer line and indicator. -->
        <attr name="footerColor" format="color" />
        <!-- Height of the footer line. -->
        <attr name="footerLineHeight" format="dimension" />
        <!-- Style of the indicator. Default is triangle. -->
        <attr name="footerIndicatorStyle">
            <enum name="none" value="0" />
            <enum name="triangle" value="1" />
            <enum name="underline" value="2" />
        </attr>
        <!-- Height of the indicator above the footer line. -->
        <attr name="footerIndicatorHeight" format="dimension" />
        <!-- Left and right padding of the underline indicator. -->
        <attr name="footerIndicatorUnderlinePadding" format="dimension" />
        <!-- Padding between the bottom of the title and the footer. -->
        <attr name="footerPadding" format="dimension" />
        <!-- Position of the line. -->
        <attr name="linePosition">
            <enum name="bottom" value="0" />
            <enum name="top" value="1" />
        </attr>
        <!-- Color of the selected title. -->
        <attr name="selectedColor" />
        <!-- Whether or not the selected item is displayed as bold. -->
        <attr name="selectedBold" format="boolean" />
        <!-- Color of regular titles. -->
        <attr name="android:textColor" />
        <!-- Size of title text. -->
        <attr name="android:textSize" />
        <!-- Padding between titles when bumping into each other. -->
        <attr name="titlePadding" format="dimension" />
        <!-- Padding between titles and the top of the View. -->
        <attr name="topPadding" format="dimension" />
        <!-- View background -->
        <attr name="android:background" />
    </declare-styleable>
    <declare-styleable name="UnderlinePageIndicator">

        <!-- Whether or not the selected indicator fades. -->
        <attr name="fades" format="boolean" />
        <!-- Length of the delay to fade the indicator. -->
        <attr name="fadeDelay" format="integer" />
        <!-- Length of the indicator fade to transparent. -->
        <attr name="fadeLength" format="integer" />
        <!-- Color of the selected line that represents the current page. -->
        <attr name="selectedColor" />
        <!-- View background -->
        <attr name="android:background" />
    </declare-styleable>

</resources>
  1. Call this from MainActivity like
    // setup the view pager with its adapter
    vpagerProfile.setAdapter(objProfilePageTopListAdapter);
    
    // initialize circular indicator class
    mCirclePageIndicator = (CirclePageIndicator)findViewById(R.id.cover_photo_indicator);
    
    mCirclePageIndicator.setPageColor(android.R.color.transparent);
    
    // set viewpager to indicator so it can indicate when you change the page
    mCirclePageIndicator.setViewPager(vpagerProfile);
user_63498150

Breakpoint is not invoked in the second fragment because it gets created along with the first one or the third one. Android always creates at least 2 fragments at the same time - the one that is in focus and the next one that could come in focus (either forward or back). That is why you will find that in your case the middle fragment is always in cache and hence it's "onCreate" will never execute separately but in conjunction with 1 or 3.

Trying to synchronise animation with Viewpager is a nightmare. However, if you really must then my suggestion would be to implement ViewPager.OnPageChangeListener and write the code to detect to getCurrentItem() of the viewpager. Once you know which fragment you are on, you can initiate the animation as you would like to.

This should give you a lot more control of the behaviour without excessive lines of code.

Let me know if you need me to elaborate a certain point.

user_56959440
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