Develop Reference

Viewpager is not sliding properly in OnePlus 5T device

I'm in my android app I need a viewpager which slide vertically (up
down manner). For this I have made a custom viewpager & in which I'm
using the traditional viewpager & applied PageTransfirmer to make it
swipe vertically not horizontly. Everything is working fine in other
devices except One Plus 5t (andriod version 9)
My code is below:
public class VerticalViewPager extends ViewPager {
private float initialXValue;
private float initialYValue;
private float minXDifference = 200;
private float minYDifference = 100;
public static SwapListener swapListener;
public static String SwipeLeft = "left";
public static String SwipeRight = "right";
public static boolean swipeTriggered = false;
public static boolean verticalSwipeTriggered = false;
private FixedSpeedScroller mScroller = null;
private boolean enabled;
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);
try {
Class<?> viewpager = ViewPager.class;
Field scroller = viewpager.getDeclaredField("mScroller");
scroller.setAccessible(true);
mScroller = new FixedSpeedScroller(getContext(),
new DecelerateInterpolator());
scroller.set(this, mScroller);
} catch (Exception ignored) {
}
}
/*
* Set the factor by which the duration will change
*/
public void setScrollDuration(int duration) {
mScroller.setScrollDuration(duration);
}
private class FixedSpeedScroller extends Scroller {
private int mDuration = 1000;
public FixedSpeedScroller(Context context) {super(context);}
public FixedSpeedScroller(Context context, Interpolator interpolator) {
super(context, interpolator);
}
public FixedSpeedScroller(Context context, Interpolator interpolator,
boolean flywheel) {super(context, interpolator, flywheel);}
#Override
public void startScroll(int startX, int startY, int dx, int dy, int
duration) {
// Ignore received duration, use fixed one instead
super.startScroll(startX, startY, dx, dy, mDuration);
}
#Override
public void startScroll(int startX, int startY, int dx, int dy) {
// Ignore received duration, use fixed one instead
super.startScroll(startX, startY, dx, dy, mDuration);
}
public void setScrollDuration(int duration) {mDuration = duration;}
}
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 <= 1) {
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);
}
else {
// 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){
boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
swapXY(ev); // return touch coordinates to original reference frame
for any child views
//IsSwipeAllowed(ev);
return intercepted;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
IsSwipeAllowed(ev);
return super.onTouchEvent(swapXY(ev));
}
private void IsSwipeAllowed(MotionEvent event) {
if(event.getAction() == MotionEvent.ACTION_DOWN) {
initialXValue = event.getX();
initialYValue = event.getY();
}
if(event.getAction()==MotionEvent.ACTION_MOVE) {
try {
float diffX = Math.abs(event.getX() - initialXValue);
float diffy = Math.abs(event.getY() - initialYValue);
if (diffX > diffy && diffX > minXDifference) {
// swipe horizotal
if (!swipeTriggered && event.getX() > initialXValue) {
swapListener.listenSwapEvent(SwipeRight);
swipeTriggered = true;
}
else if (event.getX() < initialXValue) {
if (!HomeScreen.projectName.equals("ABMCPL") &&
CustomViewPager.IsSwipeAllowed(event) && !swipeTriggered) {
swapListener.listenSwapEvent(SwipeLeft); // to webview page
swipeTriggered = true;
}
}
}
else if (diffX < diffy && diffy > minYDifference) {
if (!verticalSwipeTriggered && event.getY() > initialYValue) {
viewPager.setCurrentItem(LandingPage.viewPager.getCurrentItem() - 1);
verticalSwipeTriggered = true;
}
else if (!verticalSwipeTriggered && event.getY() < initialYValue){
verticalSwipeTriggered = true;
}
}
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
public interface SwapListener {
void listenSwapEvent (String direction);
}
}

how to make vertical animation like feedly android app

i am using vertical viewpager but it is not smooth like feedly android app.I dont know what component is used by feedly.
Any help will be appreciated.
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);
}
private class VerticalPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = .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);
}
}
}
/*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 <= 1) { // [-1,1]
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);
} 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){
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));
final boolean toHandle = super.onTouchEvent(swapXY(ev));
// Return MotionEvent to normal
swapXY(ev);
return toHandle;
}
#Override
public boolean canScrollVertically(int direction) {
return true;
}
#Override
public boolean canScrollHorizontally(int direction) {
return false;
}
}

I think you have to go with this link , i think in your xml two scroll function is calling and that's why it gives issue .
https://stackoverflow.com/questions/14326317/view-pager-not-smooth-when-embedded-within-scrollview

How to scroll back to vertical Viewpager while having a Horizontal Viewpager as its child?

i have a vertical viewpager with Fragment A, and Fragment B. Fragment B has a horizontal viewpager with 3 pages, but there i have a problem: when i am at page 2 or 3 inside Fragment B, i can't scroll vertically to return to fragment A, i can do it only from page 1. i don't know where the problem is, as the 3 pages are almost the same.
Here's my VerticalPager code:
public class VerticalPager extends ViewPager {
public VerticalPager(Context context) {
super(context);
init();
}
public VerticalPager(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);
}
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 <= 1) { // [-1,1]
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);
} 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){
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));
}
}

Android: layout animation like Inshorts news app

swipe up and down effect like those news apps inshorts,hike news,murmur.
whole layout smoothly up/down.
check app on this link inshorts and murmur.
i tried this code...
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);
}
private class VerticalPageTransformer implements PageTransformer {
#SuppressLint("NewApi")
#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 <= 1) { // [-1,1]
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);
} 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){
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));
}
}
In MainActivity.java
VerticalViewPager Pager2;
PagerAdapter adapter;
String[] articleTitle;
String[] articleName;
String[] articleDiscription;
OnCreate()
Pager2=(VerticalViewPager)findViewById(R.id.pager);
// Pass results to ViewPagerAdapter Class
adapter = new ViewPagerAdapter(getActivity(), articleTitle, articleName, articleDiscription, btnBack,articleImage);
// Binds the Adapter to the ViewPager
Pager2.setAdapter(adapter);
activity_main.xml
<com.example.flipnews.VerticalViewPager
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/pager"
/>
In my code simple up-down swipe done,like this link.
but i want to create better animation effect like above mentioned apps.
or phone inbuilt photo gallery effect.
Thanks in advance.

I found solution after many research i hope its helpful for others.
Tip: set view pager background color black for better swipe effect.
private static class VerticalPageTransformer implements PageTransformer {
private static 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(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);
}
}
}
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));
}
}

Android - View is moving out of screen post rotation

Hi I'm trying to perform Translate, Scale and Rotate on View (FrameLayout) in android.
In brief, I've a Fresco's SimpleDraweeView inside FrameLayout, as Fresco is not supporting Matrix transformations, so as an alternative I put that in FrameLayout and doing Translation, Rotation and Scaling.
I've extended FrameLayout here..
public class InteractiveFrameLayout extends FrameLayout {
private ViewTransformer mViewTransformer;
public InteractiveFrameLayout(Context context) {
super(context);
init(context);
}
public InteractiveFrameLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public InteractiveFrameLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
private void init(Context context) {
// Determine dimensions of 'earth' image
int baseViewWidth = (int) getResources().getDimension(R.dimen.animation_image_size);
int baseViewHeight = (int) getResources().getDimension(R.dimen.animation_image_size);
// Setup Gesture Detectors
mViewTransformer = new ViewTransformer(this, baseViewWidth, baseViewHeight);
}
public boolean onTouchEvent(MotionEvent event) {
return mViewTransformer.onTouchEvent(event) || super.onTouchEvent(event);
}
}
Below class takes view and does everything related to ViewTransformations.
public class ViewTransformer {
private View mView;
private Vector2D position;
private float scale = 1;
private float angle = 0;
private TouchManager touchManager = new TouchManager(2);
public ViewTransformer(View view, int viewWidth, int viewHeight) {
mView = view;
position = new Vector2D();
position.set(viewWidth / 2, viewHeight / 2);
}
public boolean onTouchEvent(MotionEvent event) {
try {
touchManager.update(event);
if (touchManager.getPressCount() == 1) {
position.add(touchManager.moveDelta(0));
ViewAffineOperation.moveViewTo(mView, position.getX(), position.getY());
}
else {
if (touchManager.getPressCount() == 2) {
Vector2D current = touchManager.getVector(0, 1);
Vector2D previous = touchManager.getPreviousVector(0, 1);
float currentDistance = current.getLength();
float previousDistance = previous.getLength();
if (previousDistance != 0) {
scale *= currentDistance / previousDistance;
ViewAffineOperation.scaleViewBy(mView, scale);
}
angle -= Vector2D.getSignedAngleBetween(current, previous);
ViewAffineOperation.rotateViewBy(mView, getDegreesFromRadians(angle));
}
}
mView.invalidate();
}
catch(Throwable t) {
// So lazy...
}
return true;
}
private static float getDegreesFromRadians(float angle) {
return (float)(angle * 180.0 / Math.PI);
}
public float getScale() {
return scale;
}
public float getRotationDegrees() {
return angle;
}
}
and this one
public class ViewAffineOperation {
public static void moveViewTo(View view, float focusX, float focusY) {
ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
int midPointX = layoutParams.width >> 1;
int midPointY = layoutParams.height >> 1;
float dx = (focusX - midPointX);
float dy = (focusY - midPointY);
view.setTranslationX(view.getTranslationX() + dx);
view.setTranslationY(view.getTranslationY() + dy);
}
public static void scaleViewBy(View view, float scaleFactor) {
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
}
public static void rotateViewBy(View view, float degrees) {
view.setRotation(degrees);
}
}
The Key problem is in
view.setTranslationX(view.getTranslationX() + dx);
view.setTranslationY(view.getTranslationY() + dy);
This one is most promising thing what I've found in stack over flow.. Rotate and scale a view based on one handle in Android
Thanks a ton in Advance.
#Sasha Salauyou I'm trying to reach you to help me in finding solution.