Circular scrolling with View Pager

Question

We have a requirement for sycing rotating wheel with sliding images. I have used ViewPager for it but after 360 degree rotation

I have to start scrolling ViewPager from X = 0. Is there any ViewPager which starts from first page after scrolled to last position?

I use setScrollX for scrolling ViewPager which also introduce glitches in rotating animation.

Answer 1

Forget about ViewPager it's expensive, views is everything. You need three inflated views let's say v1,v2,v3

I work with your provide git sample project, replace your HorizontalPaging with xml

<RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="300dp"
        android:id="@+id/scroller"
        app:layout_constraintEnd_toEndOf="parent"
        android:fillViewport="true"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">


        <ImageView
            android:id="@+id/v1"
            android:layout_width="match_parent"
            android:layout_height="300dp"
            android:contentDescription="@null"
            android:src="@drawable/slider_topup" />

        <ImageView
            android:id="@+id/v2"
            android:layout_width="match_parent"
            android:layout_height="300dp"
            android:contentDescription="@null"
            android:src="@drawable/slider_balance" />

        <ImageView
            android:id="@+id/v3"
            android:layout_width="match_parent"
            android:layout_height="300dp"
            android:contentDescription="@null"
            android:src="@drawable/slider_bundles" />

    </RelativeLayout>

and add code to your onCreate

final View v1 = findViewById(R.id.v1);
        final View v2 = findViewById(R.id.v2);
        final View v3 = findViewById(R.id.v3);

        //set initial state keep it sync with wheel at start
        v1.setX(0);
        v2.setX(screenSize);
        v3.setX(2*screenSize);

        circle.setOnAngleChangeListener(new NowCircle.OnAngleChangeListener() {
            @Override
            public void onAngleChange(float delta) {
                float v1x = v1.getX() + (oneDegree * delta);
                float v2x = v2.getX() + (oneDegree * delta);
                float v3x = v3.getX() + (oneDegree * delta);

                Log.d("dd","delta:"+delta+", v1x:"+v1x+", v2x:"+v2x +", v3x:"+v3x);

                v1.setX(v1x);
                v2.setX(v2x);
                v3.setX(v3x);

                if(delta > 0){

                    if (v1x >= 0 && v1x <= screenSize) {
                        v3.setX(-screenSize+v1x);
                        //update data here
                    }else if (v3x >= 0  && v3x <= screenSize){
                        v2.setX(-screenSize+v3x);
                        //update data here
                    }else {
                        v1.setX(-screenSize+v2x);
                        //update data here
                    }
                }else {
                    if (v3x <= 0 && v3x >= -screenSize) {
                        v1.setX(screenSize+v3x);
                        //update data here
                    }else if(v1x <= 0 && v1x >= -screenSize){
                        v2.setX(screenSize+v1x);
                        //update data here
                    }else {
                        v3.setX(screenSize+v2x);
                        //update data here
                    }
                }
            }
        });

animation is achieved, working fine.

You need to improve this and bind data with your custom views and create one separate manage class. I put my time into this. you know :)

Answer 2

If you want to acheive something like your design then i suggest you to use ArcLayoutManager Library, I have used this library alongwith recycler View to get Arc Like menu.

Answer 3

It'd be simpler just to write a custom View for this. The layout seems simple (just a bunch of images) and ViewPager has a big overhead for simple things like this. With a custom view you can also deal with scrolling yourself via touch listeners.