Develop Reference

How to get vertical ViewPager curl page animation in Android

I am implementing a ViewPager for vertical scrolling. I have used ViewPager.PageTransformer for animation.
Below is my code.
public class VerticalPageTransformer implements ViewPager.PageTransformer {
private float MIN_SCALE = 1f;
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
//view.setTranslationX(1);
view.setScaleX(1);
view.setScaleY(1);
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
view.setTranslationX(-1 * view.getWidth() * position);
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
view.setTranslationX(-1 * view.getWidth() * position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
I want to make animation like this

Vertical ViewPager with smooth scrolling and page transformation like inshorts app

I wanted to make a Vertical ViewPager looklike inshorts application.
I have tried several solutions found on Stack Overflow and in Github.
All of them have the same way of implementation of code, and all of them have the same lagging issue while scrolling up and down(vertical scroll), you can see in the video, but the design implementation is same as inshorts.
The link which I have tried are,
1) VerticalViewPager
2) DirectionViewPager
3) Github Repos
I have also tried for mFlingDistance,mMinimumVelocity etc from android's Viewpager class for increasing fling in Viewpager. But with no luck of making it working.
Below is my VerticalViewPager class
public class VerticalViewPager extends ViewPager {
public VerticalViewPager(Context context) {
super(context);
init();
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
// The majority of the magic happens here
setPageTransformer(true, new VerticalPageTransformer());
// The easiest way to get rid of the overscroll drawing that happens on the left and right
setOverScrollMode(OVER_SCROLL_NEVER);
}
/**
* Swaps the X and Y coordinates of your touch event.
*/
private MotionEvent swapXY(MotionEvent ev) {
float width = getWidth();
float height = getHeight();
float newX = (ev.getY() / height) * width;
float newY = (ev.getX() / width) * height;
ev.setLocation(newX, newY);
return ev;
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev){
boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
swapXY(ev); // return touch coordinates to original reference frame for any child views
return intercepted;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapXY(ev));
}
}
And using VerticaPageTransformer class for page transition.
class VerticalPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.75f;
#Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
//set Y position to swipe in from top
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // [0,1]
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
The one that worked for me was of castorflex solution for smooth scrolling, but when I apply a PageTransformer to castorflex solution, instead of scrolling vertically is scroll diagonally.You can see the reference video here.
I have also tried with ViewPager2 and with RecyclerView(with SnapHelper) but with viewpager2, I am getting the same diagonal issue. And with Snaphelper, I am unable to provide a page effect like inshorts(see the videos). May be, it will be possible by LinearLayoutManager of RecyclerView, as I have seen here. But failed to convert my page animation.
So anyone can give me any hint, or any idea about
1) How to make smooth scrolling with above approach? or
2) How to make vertical page transition from below approach, instead of diagonal? or
3) Or any other way if you people have.
Thanks in advance
You can see Castorflex's VerticalViewPager class, and using the same VerticlePageTransform class for page transformation

Check this Github Repo https://github.com/dipanshukr/Viewpager-Transformation
SampleActivity.java
private void initViewPager() {
VerticalViewPager viewPager = (VerticalViewPager) findViewById(R.id.vertical_viewpager);
//viewPager.setPageTransformer(false, new ZoomOutTransformer());
//viewPager.setPageTransformer(true, new StackTransformer());
String title = "ContentFragment";
viewPager.setAdapter(new ContentFragmentAdapter.Holder(getSupportFragmentManager())
.add(ContentFragment.newInstance(title, 1))
.add(ContentFragment.newInstance(title, 2))
.add(ContentFragment.newInstance(title, 3))
.add(ContentFragment.newInstance(title, 4))
.add(ContentFragment.newInstance(title, 5))
.set());
// If you setting other scroll mode,
// the scrolled fade is shown from either side of display.
viewPager.setOverScrollMode(View.OVER_SCROLL_NEVER);
}
VerticalViewPager.java
public class VerticalViewPager extends ViewPager {
public VerticalViewPager(Context context) {
this(context, null);
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
setPageTransformer(false, new DefaultTransformer());
}
private MotionEvent swapTouchEvent(MotionEvent event) {
float width = getWidth();
float height = getHeight();
float swappedX = (event.getY() / height) * width;
float swappedY = (event.getX() / width) * height;
event.setLocation(swappedX, swappedY);
return event;
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
boolean intercept = super.onInterceptTouchEvent(swapTouchEvent(event));
//If not intercept, touch event should not be swapped.
swapTouchEvent(event);
return intercept;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapTouchEvent(ev));
}
}
DefaultTransformer.java
public class DefaultTransformer implements ViewPager.PageTransformer {
#Override
public void transformPage(View view, float position) {
float alpha = 0;
if (0 <= position && position <= 1) {
alpha = 1 - position;
} else if (-1 < position && position < 0) {
alpha = position + 1;
}
view.setAlpha(alpha);
view.setTranslationX(view.getWidth() * -position);
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
}
}

Viewpager Transform Animation for vertical Swipe

I am using a vertical swipe in view pager. and am using a tranform animation for it. but when i swipe vertically animation happens horizontally. Can any one show me the error in this code
public class DepthPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.75f;
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
// Counteract the default slide transition
view.setTranslationX(pageWidth * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}

use this code
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(view.getWidth() * -position);
//set Y position to swipe in from top
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
// Counteract the default slide transition
view.setTranslationX(pageWidth * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
replace [-1,0] code

How to implement the vertical stack transformer in viewpager

In vertical viewpager, while swipe in vertically current screen are move to left side but i have to move my second view over the first view (i.e)first view should be fit to the screen.I had implement the vertical stack transformer but its not working fine to me. Can you anyone help me to fix this issue.
Thanks in advance.
This is viewpager I had used.
public class VerticalViewPager extends ViewPager {
public VerticalViewPager(Context context) {
super(context);
init();
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
setPageTransformer(true, new VerticalPageTransformer());
setOverScrollMode(OVER_SCROLL_NEVER);
}
private class VerticalPageTransformer implements ViewPager.PageTransformer {
#Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // (0,1]
// Counteract the default slide transition
view.setTranslationY(position < 0 ? 0f : -view.getHeight() * position);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
/**
* Swaps the X and Y coordinates of your touch event.
*/
private MotionEvent swapXY(MotionEvent ev) {
float width = getWidth();
float height = getHeight();
float newX = (ev.getY() / height) * width;
float newY = (ev.getX() / width) * height;
ev.setLocation(newX, newY);
return ev;
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
try {
boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
swapXY(ev); // return touch coordinates to original reference frame for any child views
return intercepted;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapXY(ev));
}
}
Here my code I had modified.
#Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // (0,1]
// Counteract the default slide transition
view.setTranslationY(position < 0 ? 0f : -view.getHeight() * position);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}

Android viewpager with DepthPageTransformer z-index issue

I implemented a viewpager with a DepthPageTransformer , in pages I have some inputs ( radio , check boxs , select options ... ). It works fine except one wired bug: Sometimes when I click on position(x,y) on a page P1 the input in that position of page P2 gets triggered.
P1:
P2( the one after P1):
Now when I click on this position on page P1 :
I get the select options displayed of page P2:
It's similar to z-index problem in web development.
The code of the DepthPage Transformer is the same as in the documentation : http://developer.android.com/training/animation/screen-slide.html#pagetransformer.
public class DepthPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.75f;
#Override
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
// Counteract the default slide transition
view.setTranslationX(pageWidth * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
Any idea on how to solve this overlapping problem ?

Try this:
public class DepthPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.75f;
#Override
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
// -------- THIS LINE ---
view.bringToFront();
// -------- THIS LINE ---
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
// Counteract the default slide transition
view.setTranslationX(pageWidth * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}

You just need to reverse draw order:
mPager.setPageTransformer(true, new DepthPageTransformer());
In any case you can play with code sample here

Other solution is use OnPageChangeListener:
pager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { }
#Override public void onPageSelected(final int position) {
pager.postDelayed(new Runnable() {
#Override
public void run() {
pagerAdapter.getItem(position).getView().bringToFront();
}
}, 300);
}
#Override public void onPageScrollStateChanged(int state) { }
});
is more efficient.