Develop Reference

Andriod Development Zoom in, page swipe all in one animation

I am very new to Android Development and for a project of mine I want to be able to have multiple animations for a fragment. The ones I want is to be able to swipe left and right and zoom in and out for each fragment. An example would be to have an Image in each fragment, and I could zoom in and out and swipe to the next image. I have seen examples online where this is achieved using a grid view. Is there any example or resources online where I can do this?
In my example I have here is that I used Viewpager 2 for the swipe animation then I attempted to implement a zoom-in feature but when I ran it overwrites the viewpager and I am unable to swipe pages only zoom in and out of that image. Can I somehow add the zoom feature in the PageTransformer class? I know this is probably a very poor way of going about it.
I know probably that in the in the PageTransformer class I need to add the zoom in and out animation how would I do that?
package com.example.viewpager;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.github.chrisbanes.photoview.PhotoView;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setPageTransformer(true, new DepthPageTransformer());
viewPager.setAdapter(new MyPagerAdapter(this));
PhotoView photoView = (PhotoView) findViewById(R.id.photo_view);
photoView.setImageResource(R.drawable.a_child_of_the_king);
photoView.setImageResource(R.drawable.a_mighty_fortress);
photoView.setImageResource(R.drawable.a_quiet_place);
photoView.setImageResource(R.drawable.all_the_way);
}
//PageTranformer class
package com.example.viewpager;
import android.support.v4.view.ViewPager;
import android.view.View;
import com.github.chrisbanes.photoview.PhotoView;
//import androidx.viewpager.widget.ViewPager;
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(0f);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1f);
view.setTranslationX(0f);
view.setScaleX(1f);
view.setScaleY(1f);
} 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(0f);
}
}
}

Swiping with Viewpager makes sense in a way.
Do you load all the images into the same Layout?
Are you inflating a Fragment and inflate the single Layout onto it and then load the image into the displayed ImageView?
If so, for zooming in and out you might have to modify this approach to register touches correctly:
private ScaleGestureDetector scaleGestureDetector;
private float mScaleFactor = 1.0f;
private ImageView imageView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView=findViewById(R.id.imageView);
scaleGestureDetector = new ScaleGestureDetector(this, new ScaleListener());
}
#Override
public boolean onTouchEvent(MotionEvent motionEvent) {
scaleGestureDetector.onTouchEvent(motionEvent);
return true;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector scaleGestureDetector) {
mScaleFactor *= scaleGestureDetector.getScaleFactor();
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
imageView.setScaleX(mScaleFactor);
imageView.setScaleY(mScaleFactor);
return true;
}
}
Happy Coding :)

Thanks, I am loading the images into the same layout. This is done in a separate class. see code below. Now The code that you provided am I able to just implement that to the Main Activity class? Would I be able to call:
viewPager.setPageTransformer(true, new DepthPageTransformer());
viewPager.setAdapter(new MyPagerAdapter(this)); as well as scaleGestureDetector function?
public class MyPagerAdapter extends PagerAdapter {
private Context mContext;
private int[] images = {
R.drawable.a_child_of_the_king,
R.drawable.a_mighty_fortress,
R.drawable.a_quiet_place,
R.drawable.all_the_way,
R.drawable.because_he_lives,
R.drawable.before_jehovahs_awful_throne,
R.drawable.before_jehovahs_awful_throne2,
R.drawable.beneath_the_cross_of_jesus
};
public MyPagerAdapter(Context context) {
mContext = context;
}
#Override
public Object instantiateItem(ViewGroup collection, int position) {
LayoutInflater inflater = LayoutInflater.from(mContext);
ViewGroup viewGroup = (ViewGroup) inflater.inflate(R.layout.imagelayout,
collection, false);
ImageView imageView = (ImageView)viewGroup.findViewById(R.id.imageView);
imageView.setImageResource(images[position]);
collection.addView(viewGroup);
return viewGroup;
}
#Override
public void destroyItem(ViewGroup collection, int position, Object view) {
((ViewGroup) collection).removeView((View) view);
}
#Override
public int getCount() {
return images.length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
#Override
public CharSequence getPageTitle(int position) {
ModelObject customPagerEnum = ModelObject.values()[position];
return mContext.getString(customPagerEnum.getTitleResId());
}

Vertical ViewPager and Android Pie Inconsistent Behavior with Swipe Gesture

My problem is closely related to two other questions that haven't been answered yet.
ViewPager not responding to touch in layout area created dynamically in Fragment
https://stackoverflow.com/questions/53469581/problem-with-vertical-viewpager-like-inshorts
My Vertical ViewPager works wonderfully and consistently within any device I have tested and with any OS 5 - 8. I recently upgraded a pixel 2XL with Android Pie and now my Vertical ViewPager appears to be unresponsive, then works, then it acts like it loses focus, then works. Drag a page and it moves and snaps back to original position. Or just bounces back. Again, similar to the other two questions linked above.
Prior to Android 9, vertical scrolling and paging is perfect. I've tried using reflection with a little success. It will swipe better and doesn't seem to lose focus as much. But if I try swiping with my other hand it stops, or if I change my placement of where I am swiping it will stop. This is very perplexing. I have added all the code required to replicate this issue on a device running Android 9.
The Activity
public class FullscreenActivity extends AppCompatActivity {
VerticalViewPager verticalViewPager;
FragmentStatePagerExample fragmentStatePagerExample;
int pagerPadding;
/**
* Whether or not the system UI should be auto-hidden after
* {#link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
*/
private static final boolean AUTO_HIDE = true;
/**
* If {#link #AUTO_HIDE} is set, the number of milliseconds to wait after
* user interaction before hiding the system UI.
*/
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
/**
* Some older devices needs a small delay between UI widget updates
* and a change of the status and navigation bar.
*/
private static final int UI_ANIMATION_DELAY = 300;
private final Handler mHideHandler = new Handler();
private FrameLayout mContentView;
private final Runnable mHidePart2Runnable = new Runnable() {
#SuppressLint("InlinedApi")
#Override
public void run() {
// Delayed removal of status and navigation bar
// Note that some of these constants are new as of API 16 (Jelly Bean)
// and API 19 (KitKat). It is safe to use them, as they are inlined
// at compile-time and do nothing on earlier devices.
verticalViewPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
}
};
private View mControlsView;
private final Runnable mShowPart2Runnable = new Runnable() {
#Override
public void run() {
// Delayed display of UI elements
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.show();
}
mControlsView.setVisibility(View.VISIBLE);
}
};
private boolean mVisible;
private final Runnable mHideRunnable = new Runnable() {
#Override
public void run() {
hide();
}
};
/**
* Touch listener to use for in-layout UI controls to delay hiding the
* system UI. This is to prevent the jarring behavior of controls going away
* while interacting with activity UI.
*/
private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (AUTO_HIDE) {
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
return false;
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fullscreen);
pagerPadding = getScreenDimension(this);
mVisible = true;
mControlsView = findViewById(R.id.fullscreen_content_controls);
verticalViewPager = findViewById(R.id.main_viewpager);
verticalViewPager.setPadding(0,0,0,pagerPadding);
verticalViewPager.setClipToPadding(false);
fragmentStatePagerExample = new FragmentStatePagerExample(getSupportFragmentManager());
verticalViewPager.setAdapter(fragmentStatePagerExample);
verticalViewPager.setCurrentItem(0);
// Set up the user interaction to manually show or hide the system UI.
verticalViewPager.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
toggle();
}
});
// Upon interacting with UI controls, delay any scheduled hide()
// operations to prevent the jarring behavior of controls going away
// while interacting with the UI.
findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Trigger the initial hide() shortly after the activity has been
// created, to briefly hint to the user that UI controls
// are available.
delayedHide(100);
}
private void toggle() {
if (mVisible) {
hide();
} else {
show();
}
}
private void hide() {
// Hide UI first
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.hide();
}
mControlsView.setVisibility(View.GONE);
mVisible = false;
// Schedule a runnable to remove the status and navigation bar after a delay
mHideHandler.removeCallbacks(mShowPart2Runnable);
mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
}
#SuppressLint("InlinedApi")
private void show() {
// Show the system bar
mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
mVisible = true;
// Schedule a runnable to display UI elements after a delay
mHideHandler.removeCallbacks(mHidePart2Runnable);
mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
}
/**
* Schedules a call to hide() in delay milliseconds, canceling any
* previously scheduled calls.
*/
private void delayedHide(int delayMillis) {
mHideHandler.removeCallbacks(mHideRunnable);
mHideHandler.postDelayed(mHideRunnable, delayMillis);
}
private static int getScreenDimension(Context context)
{
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
int width = metrics.widthPixels;
int height = metrics.heightPixels;
return (int)Math.round(height * .2);
}
}
The Fragment
public class ImageFragment extends Fragment{
ImageView imageView;
String imageUrl = "";
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
Bundle bundle = getArguments();
imageUrl = bundle.getString("url");
return inflater.inflate(R.layout.fragment_image, container,false);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
imageView = (ImageView)view.findViewById(R.id.iv_imagefragment);
Glide.with(getActivity()).load(imageUrl).into(imageView);
}
public static Fragment getInstance(int position, String url){
Bundle bundle = new Bundle();
bundle.putString("url",url);
ImageFragment fragment = new ImageFragment();
fragment.setArguments(bundle);
return fragment;
}
}
The ViewPager
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());
setOffscreenPageLimit(2);
// 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));
}
}
The ViewPager Adapter
public class FragmentStatePagerExample extends FragmentStatePagerAdapter {
String url = "";
public FragmentStatePagerExample(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position){
case 0:
url = "https://images.unsplash.com/photo-1532977692289-827d858a170b?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=29b1d5377ad9db8de64b1b73d21812c7&auto=format&fit=crop&w=1474&q=80";
return ImageFragment.getInstance(position,url);
case 1:
url = "https://images.unsplash.com/photo-1533029516911-0458c644baea?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=0f618e036e338f48ef919b8fb86c5ba1&auto=format&fit=crop&w=701&q=80";
return ImageFragment.getInstance(position,url);
case 2:
url = "https://images.unsplash.com/photo-1532989622000-d4f013a215e1?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=1a69643c04176376315714b9b2897de5&auto=format&fit=crop&w=677&q=80";
return ImageFragment.getInstance(position,url);
default:
url = "https://images.unsplash.com/photo-1532983819500-85d633c73b7a?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=1f0b228b67f03064241534a6c65d9497&auto=format&fit=crop&w=1050&q=80";
return ImageFragment.getInstance(position,url);
}
}
#Override
public int getCount() {
return 4;
}
}
Activity XML
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#0099cc"
tools:context=".FullscreenActivity">
<!-- This FrameLayout insets its children based on system windows using
android:fitsSystemWindows. -->
<com.david.verticalviewpagerexample.VerticalViewPager
android:id="#+id/main_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<LinearLayout
android:id="#+id/fullscreen_content_controls"
style="?metaButtonBarStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:background="#color/black_overlay"
android:orientation="horizontal"
tools:ignore="UselessParent">
<Button
android:id="#+id/dummy_button"
style="?metaButtonBarButtonStyle"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="#string/dummy_button" />
</LinearLayout>
</FrameLayout>
Fragment XML
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/iv_imagefragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"/>
</LinearLayout>
Update : 1
https://github.com/youngkaaa/YViewPagerDemo
There is another library and that works really smooth on Android Pie, but it has few soft crashes. Also, it crashes on API 19.
Update : 2
Google has recently released ViewPager2 with androidx support library https://developer.android.com/jetpack/androidx/releases/viewpager2, that supports vertical viewpager. However, it is still in alpha version and it has many known issues.

After spending hell amount of time on SO, trying many GitHub
libraries and waiting for someone to respond on the bounty,
then I came up with below solutions and hope that it helps whoever needs it.
At first, this question got my attention and I think most of the answers over there are helpful, hence I upvoted them.
The main answer which helped me are link-1 and link-2.
Even though I have to make a few minor changes to ignore horizontal swipe
fling events.
Please do try this code and provide your feedback for any further improvements, thanks in advance. Happy Coding :)
import android.content.Context;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
public class VerticalViewPager extends ViewPager {
float x = 0;
float mStartDragX = 0;
private static final float SWIPE_X_MIN_THRESHOLD = 50; // Decide this magical nuber as per your requirement
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);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (getAdapter() != null) {
if (getCurrentItem() >= 0 || getCurrentItem() < getAdapter().getCount()) {
swapXY(event);
final int action = event.getAction();
switch (action & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_MOVE:
break;
case MotionEvent.ACTION_UP:
mStartDragX = event.getX();
if (x < mStartDragX
&& (mStartDragX - x > SWIPE_X_MIN_THRESHOLD)
&& getCurrentItem() > 0) {
Log.i("VerticalViewPager", "down " + x + " : " + mStartDragX + " : " + (mStartDragX - x));
setCurrentItem(getCurrentItem() - 1, true);
return true;
} else if (x > mStartDragX
&& (x - mStartDragX > SWIPE_X_MIN_THRESHOLD)
&& getCurrentItem() < getAdapter().getCount() - 1) {
Log.i("VerticalViewPager", "up " + x + " : " + mStartDragX + " : " + (x - mStartDragX));
mStartDragX = 0;
setCurrentItem(getCurrentItem() + 1, true);
return true;
}
break;
}
} else {
mStartDragX = 0;
}
swapXY(event);
return super.onTouchEvent(swapXY(event));
}
return false;
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
boolean intercepted = super.onInterceptTouchEvent(swapXY(event));
switch (event.getAction() & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
x = event.getX();
break;
}
swapXY(event); // return touch coordinates to original reference frame for any child views
return intercepted;
}
/**
* 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;
}
private class VerticalPageTransformer implements 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);
}
}
}
}

You can try this lib:
VerticalViewPager, this works fine on my project.
But this lib is copied from v19, so some methods will not exist, you can implement yourself.

The problem seems to be in the way #swapXY exchanges the x and y values. I believe that the VelocityTracker used in ViewPager uses #getAxisValue and not #getX/#getY, and the result is not swapped. But there doesn't seem to be a way to set the axis values nor to subclass MotionEvent so I didn't find a way to stick with the simple #swapXY solution. I forked ViewPager and use VelocityTracker.getYVelocity when I detect the unswapped condition.
diff --git project/src/main/java/org/gc/project/util/ShopVerticalViewPager.java project/src/main/java/org/gc/project/util/ShopVerticalViewPager.java
index e5560a0..f23f9f7 100644
--- project/src/main/java/org/gc/project/util/MyVerticalViewPager.java
+++ project/src/main/java/org/gc/project/util/MyVerticalViewPager.java
## -179,4 +179,8 ## public class ShopVerticalViewPager extends ViewPager {
return super.onTouchEvent( swapXY( ev ) );
}
+ public boolean isVerticalMode() {
+ return true;
+ }
+
}
\ No newline at end of file
diff --git project/src/main/java/gcandroid/support/v4/view/ViewPager.java project/src/main/java/gcandroid/support/v4/view/ViewPager.java
index 20e1448..4ae2d3c 100644
--- project/src/main/java/gcandroid/support/v4/view/ViewPager.java
+++ project/src/main/java/gcandroid/support/v4/view/ViewPager.java
## -205,6 +205,7 ## public class ViewPager extends ViewGroup {
private int mMaximumVelocity;
private int mFlingDistance;
private int mCloseEnough;
+ private boolean mInvertedVelocityTrackerInVerticalMode = false;
// If the pager is at least this close to its final position, complete the scroll
// on touch down and let the user interact with the content inside instead of
## -391,6 +392,21 ## public class ViewPager extends ViewGroup {
ViewCompat.setImportantForAccessibility(this,
ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES);
}
+
+ // tell if the velocity tracker is inverted in vertical mode (most probably uses MotionEvent.getAxisValue instead of MotionEvent.getX but
+ // I can't change these values nor inherit from MotionEvent)
+ VelocityTracker vt = VelocityTracker.obtain();
+ long time = SystemClock.uptimeMillis();
+ MotionEvent ev = MotionEvent.obtain(time, time, MotionEvent.ACTION_DOWN, 0, 0, 0);
+ vt.addMovement(ev);
+ ev.recycle();
+ ev = MotionEvent.obtain(time, time + 10, MotionEvent.ACTION_MOVE, 10, 0, 0);
+ ev.setLocation( 0, 10 );
+ vt.addMovement(ev);
+ ev.recycle();
+ vt.computeCurrentVelocity(1000, mMaximumVelocity);
+ mInvertedVelocityTrackerInVerticalMode = vt.getYVelocity() == 0;
+ vt.recycle();
}
#Override
## -2027,6 +2043,10 ## public class ViewPager extends ViewGroup {
return mIsBeingDragged;
}
+ public boolean isVerticalMode() {
+ return false;
+ }
+
#Override
public boolean onTouchEvent(MotionEvent ev) {
if (mFakeDragging) {
## -2111,8 +2131,9 ## public class ViewPager extends ViewGroup {
if (mIsBeingDragged) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
- int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(
- velocityTracker, mActivePointerId);
+ int initialVelocity = (int) ( isVerticalMode() && mInvertedVelocityTrackerInVerticalMode ? VelocityTrackerCompat.getYVelocity( velocityTracker, mActivePointerId )
+ : VelocityTrackerCompat.getXVelocity( velocityTracker, mActivePointerId ) );
+
mPopulatePending = true;
final int width = getClientWidth();
final int scrollX = getScrollX();

Viewpager inside Viewpager Scroll Issue

in my main activity i have a horizontal viewpager. Inside one of the fragment of the viewpager i have another vertical viewpager. Both works fine. But for the horizontal viewpager, i need to scroll from the edge of the screens. But i want it to be scrolled from anywhere in the screen.
my horizontal viewpager setup:
viewPager = (ViewPager) findViewById(R.id.viewpager);
adapterViewPager = new HorizontalViewPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(adapterViewPager);
viewPager.setCurrentItem(1);
horizontal viewpager adapter:
public class HorizontalViewPagerAdapter extends FragmentPagerAdapter {
private static int NUM_ITEMS = 3;
public HorizontalViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return MoreFragment.newInstance("Fragment MoreFragment", "HA HA HA");
case 1:
return NewsFragment.newInstance("Fragment 1", "HA HA HA");
case 2:
return WebViewFragment.newInstance("Fragment Webview", "HA HA HA");
default:
return null;
}
}
#Override
public int getCount() {
return NUM_ITEMS;
}
#Override
public CharSequence getPageTitle(int position) {
return "Tab " + position;
}
}
in my news fragment i have another viewpager.
viewPager = view.findViewById(R.id.shortpager);
adapterViewPager = new VerticalPagerAdapter(getActivity().getSupportFragmentManager(), newsList);
viewPager.setAdapter(adapterViewPager);
My vertical viewpager 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));
}
private 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/top page
view.setAlpha(1);
ViewCompat.setElevation(view, 1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
view.setTranslationY(0);
//set Y position to swipe in from top
float scaleFactor = MIN_SCALE + (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else if (position <= 1) { // [0,1]
view.setAlpha(1);
ViewCompat.setElevation(view, 2);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
view.setTranslationY(position * view.getHeight());
// Scale the page down (between MIN_SCALE and 1)
view.setScaleX(1);
view.setScaleY(1);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
}
vertical viewpager adapter:
public class VerticalPagerAdapter extends FragmentPagerAdapter {
private static int NUM_ITEMS = 3;
private final ArrayList<News> newsList;
public VerticalPagerAdapter(FragmentManager fm, ArrayList<News> newsList) {
super(fm);
this.newsList = newsList;
}
#Override
public Fragment getItem(int position) {
return ShortFragment.newInstance("Fragment 1", "HA HA HA", newsList.get(position));
}
#Override
public int getCount() {
return this.newsList.size();
}
#Override
public CharSequence getPageTitle(int position) {
return "Tab " + position;
}
}
Vertical viewpager scrolls smoothly. Currently for horizontal viewpager, i have to scroll from the edge of the screens. But i need to make it scrolled like the vertical one from anywhere in the screen.

Issue with your code is your VerticalViewPager
If you notice the code,
#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;
}
Step-1, Call super with swapped gesture.
Step-2, Perform actions on vertical view pager with current gesture.
And if you specifically see the comment, // return touch coordinates to original reference frame for any child views this clearly tells that gesture is first consumed by child.
So in your vertical view pager since you are swapping the gestures, it is consuming the Horizontal Gesture even before passing it to the parent. Thats why your horizontal view pager do not get the gesture.
If you are using Vertical View Pager with any conflicting gesture implementation like ScrollView, Lists, RecyclerView, ViewPager, etc. use the one as in the link below. It is deprecated but works with all Gesture Conflicting Views.
https://github.com/kaelaela/VerticalViewPager

I had this issue and I resolved it by wrapping the viewpager in a Scrollview
<ScrollView
android:id="#+id/nested_scroll"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/view_pager"
android:nestedScrollingEnabled="false"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</ScrollView>

View Pager Issue in Android

I m using a viewpager which is rendering fragments one after the other. The problem which I m facing is that once I touch the current fragment visible,it takes the touch event of the next fragment which is yet to be loaded. How should I make sure the current/visible fragment is touched & the touch event is handled accordingly.
This is my adapter which renders the fragments.
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
public ScreenSlidePagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
Log.d("zambob",position+":"+slideShowItems.get(position).name);
Fragment fragment = new ScreenSlidePageFragment();
Bundle bundle = new Bundle();
bundle.putString("IMAGE_URL",slideShowItems.get(position).image);
bundle.putString("CAPTION", slideShowItems.get(position).name);
fragment.setArguments(bundle);
return fragment;
}
#Override
public int getCount() {
return slideShowItems.size();
}
}
This is the Fragment Class which handles the touch event as well.
public class ScreenSlidePageFragment extends Fragment {
String imageUrl,text;
UWSharedPreference preference;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ViewGroup rootView = (ViewGroup) inflater.inflate(
R.layout.fragment_slide_show, container, false);
rootView.getBackground().setAlpha(200);
preference = new UWSharedPreference(getActivity());
imageUrl = getArguments().getString("IMAGE_URL");
text = getArguments().getString("CAPTION");
TouchImageView iv_image = (TouchImageView) rootView.findViewById(R.id.jj_image);
TextView tv_caption = (TextView) rootView.findViewById(R.id.caption_text);
iv_image.setImageUrl(imageUrl, AppController.getInstance().getImageLoader());
if (text != null && text.equals("custom")){
tv_caption.setText("");
}
else {
tv_caption.setText(text);
}
iv_image.setOnTouchListener(new OnTouchListener());
return rootView;
}
class OnTouchListener implements View.OnTouchListener {
public boolean onTouch(View v, MotionEvent event) {
Log.d("zambob","On Touch Called for text" + text +" diner txn id" + preference.getDinerTxnID());
if (text.equals("custom") && preference.getDinerTxnID()!=0 ){
startActivity(new Intent(getActivity(), FBCheckInActivity.class));
getActivity().finish();
}
else {
getActivity().onBackPressed();
}
return true;
}
}
}
Now the problem is that in view pager, 3 fragments are loaded initially. The one visible, one behind it & the one which will come next. When i touch the fragment which is required to start the intent process doesn't work. But when i touch the fragment before the above one, then the required process is going on .
How should i make sure that when i touch the visible fragment, then the required process starts?

Finally I found the solution myself & a little help from Google as well :P.
Actually i was using Depth Page Transformer to show the swipe movements between the fragments. So i just tweaked the page transformer by using this-:
mPager.setPageTransformer(true, new ViewPager.PageTransformer() {
#Override
public void transformPage(View page, float position) {
float translationX;
float scale;
float alpha;
if (position >= 1 || position <= -1) {
// Fix for https://code.google.com/p/android/issues/detail?id=58918
translationX = 0;
scale = 1;
alpha = 1;
} else if (position >= 0) {
translationX = -page.getWidth() * position;
scale = -0.2f * position + 1;
alpha = Math.max(1 - position, 0);
} else {
translationX = 0.5f * page.getWidth() * position;
scale = 1.0f;
alpha = Math.max(0.1f * position + 1, 0);
}
mPager.setTranslationX(translationX);
mPager.setScaleX(scale);
mPager.setScaleY(scale);
mPager.setAlpha(alpha);
}
});
This simply makes sure the visible fragment is getting touched and not the one behind the visible fragment by setting the scale, alpha & translation of the View Pager. Also make the root layout of View Pager as clickable.
XML for the activity rendering the View Pager.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:urbanwand="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
tools:context="com.urbanwand.diner.SlideShowActivity">
<com.urbanwand.MyViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
urbanwand:scrollduration="500"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
Hope this answer helps !

Android - How would I go about implementing an activity that I can drag horizontally? [duplicate]

Does anybody has an idea how Pinterest or Tumblr has implemented there "swipe back" method.
i.e. on Pinterest you can click on a post on the news feed. Than the DetailActivity is started and displays the details for the selected post. Than you can press the back button to return to the news feed activity, or you can swipe (the details activity) to the left to come back to the news feed activity.
Video: http://youtu.be/eVcSCWetnTA
Normally I would use overridePendingTransition(), but overridePendingTransition() takes animations (Resource ids like R.anim.foo). Pinterest and Tumblr start the animation only if the user do a swipe gesture. They also support some kind of "frame by frame animation" according the fingers move. So they track the distance of the finger move and animate the transition to the corresponding percentage value.
I know how to use a "real java" Animation / AnimatorSet Object with FragmentTransaction to animate a fragment replacement. With fragments I have to override onCreateAnimator(), but I have no clue how to implement something like that with Activities. Is there a onCreateAnimator() (or something similar) for Activities? Also not sure how to swipe behaviour, since its not starting the animation right now, but more a step by step property changement of the Window / Activity/ Fragment or whatever ...
Any suggestions?
EDIT:
I have found a video of the pinterest app at youtube: http://youtu.be/eVcSCWetnTA
Thats what I want to implement.
I guess Pinterest is working with Fragments and onCreateAnimator() to achieve the "swipe back".
Since my App has already Fragment and ChildFragments in a activity it would be so much easier for me if I could implement that for Activities.
Once more: I know how to detect swipe gestures and thats not what I'm asking for. Watch the youtube video: http://youtu.be/eVcSCWetnTA
UPDATE:
I have created a little library, which has not exactly the same behavior like Pinterest or Tumblrs implementation, however for my apps this seems to me a good solution:
https://github.com/sockeqwe/SwipeBack?source=c

It seems that the effect you're looking for is one of the samples for ViewPager in the android developer's website.
Check out http://developer.android.com/training/animation/screen-slide.html#depth-page , in the Depth page transformer section. It has a video and source code.
Using a ViewPager.PageTransformer you can decide how the pages behave when switching from one to the next.
The only difference between the sample and the video you linked to is that left-right seems to be inverted, but should be a good starting point for what I saw on the YouTube video linked in the question. The actions on the two views would have to be swaped. As shown in this piece of code (the 1st parameter to mPager.setPageTransformer should be reverseDrawingOrder = false). Note the middle 2 if sections are swaped and the position variable is handled slightly different to switch sides. The bouncy effect is left as an exercise. Please share when you get that!
package com.example.android.animationsdemo;
import android.support.v4.view.ViewPager;
import android.view.View;
public class SinkPageTransformer implements ViewPager.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]
// 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 if (position <= 1) { // (0,1]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
And just in case the page with the sample goes poof, here's that section's original code:
public class DepthPageTransformer implements ViewPager.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(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);
}
}
}

Update:
fixed memory usage problem for this project and changed the slide back style to iOS like.
I wrote a demo exactly like Pinterest and tumblr like,you just extend the BaseActivity and you get a swipe back effect,works smoothly!
check this:https://github.com/chenjishi/SlideActivity
and the screenshot:

I found a GitHub project that is based on SwipeBack like Pinterest.
It is really a great open source project that should solve your problem. It does as you needed like go to previous screen by pressing back or simple swipe. As this project having option
1. Swipe left to Right
2. Swipe Right to Left
3. Swipe Bottom to top
https://github.com/Issacw0ng/SwipeBackLayout
and also you install this demo application from Google Play.
https://play.google.com/store/apps/details?id=me.imid.swipebacklayout.demo
Attached Screenshots:-
Hope this will help you.

I was able to do this in 15 minutes, it is not bad for a start. If you spend some time, you might be able to optimize it.
package mobi.sherif.activitydrag;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.AnimationSet;
import android.view.animation.AnimationUtils;
import android.view.animation.LinearInterpolator;
import android.view.animation.TranslateAnimation;
import android.widget.FrameLayout.LayoutParams;
public class MainActivity extends Activity {
private static final double PERCENT_OF_SCROLL_OF_ACTIVITY_TO_FINISH = 0.3;
View mView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mView = LayoutInflater.from(this).inflate(R.layout.activity_main, null);
setContentView(mView);
}
private boolean isDragging = false;
int startX;
int currentX;
#Override
public boolean onTouchEvent(MotionEvent event) {
Log.v("sherif", isDragging?"YES":"NO" + ": " + event.getX());
if(!isDragging) {
if(event.getAction() == MotionEvent.ACTION_DOWN && event.getX()<24) {
isDragging = true;
startX = (int) event.getX();
currentX = 0;
return true;
}
return super.onTouchEvent(event);
}
switch(event.getAction()) {
case MotionEvent.ACTION_MOVE:
currentX = (int) event.getX() - startX;
LayoutParams params = (LayoutParams) mView.getLayoutParams();
params.leftMargin = currentX;
params.rightMargin = -1 * currentX;
mView.requestLayout();
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
isDragging = false;
double currentPercent1 = (double) currentX / mView.getWidth();
float currentPercent = (float) currentPercent1;
if(currentX > PERCENT_OF_SCROLL_OF_ACTIVITY_TO_FINISH * mView.getWidth()) {
AnimationSet animation = new AnimationSet(false);
Animation anim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 1.0f - currentPercent, Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 0.0f);
anim.setDuration(getResources().getInteger(android.R.integer.config_mediumAnimTime));
anim.setInterpolator(new LinearInterpolator());
anim.setStartTime(AnimationUtils.currentAnimationTimeMillis());
animation.addAnimation(anim);
anim = new AlphaAnimation(1.0f, 0.5f);
anim.setDuration(getResources().getInteger(android.R.integer.config_shortAnimTime));
anim.setInterpolator(new LinearInterpolator());
anim.setStartTime(AnimationUtils.currentAnimationTimeMillis());
animation.addAnimation(anim);
animation.setFillAfter(true);
animation.setAnimationListener(new AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {}
#Override
public void onAnimationRepeat(Animation animation) {}
#Override
public void onAnimationEnd(Animation animation) {
finish();
}
});
mView.startAnimation(animation);
}
else {
AnimationSet animation = new AnimationSet(false);
Animation anim = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 0.0f -1 * currentPercent, Animation.RELATIVE_TO_SELF, 0.0f, Animation.RELATIVE_TO_SELF, 0.0f);
anim.setDuration(getResources().getInteger(android.R.integer.config_shortAnimTime));
anim.setInterpolator(new LinearInterpolator());
anim.setStartTime(AnimationUtils.currentAnimationTimeMillis());
animation.addAnimation(anim);
animation.setFillAfter(true);
animation.setAnimationListener(new AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {}
#Override
public void onAnimationRepeat(Animation animation) {}
#Override
public void onAnimationEnd(Animation animation) {
LayoutParams params = (LayoutParams) mView.getLayoutParams();
params.leftMargin = 0;
params.rightMargin = 0;
mView.requestLayout();
mView.clearAnimation();
}
});
mView.startAnimation(animation);
}
break;
}
return true;
}
}

I just checked with hierarchy viewer. It seems like they are using ViewPager with a screenshot of the previous activity.

I would suggest doing the following:
Firstly detect the gesture that the user is doing in the device. You can refer to this link
I am not going to copy the relevant code from the above link, as I believe it is the accepted answer
Secondly you can in this method
public void onSwipeLeft() {
Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();
}
Do the following as suggested by this question
They there talk about finishing an activity with an animation
Look into doing it through a theme. You can define enter exit animations for activities or the entire application
Hope this helps you

So I guess I found the solution by my self:
First of all:
Pinterest indeed uses a ViewPager with a custom Page Transformer like #frozenkoi has mentioned in his answer. You can see the oversroll edge effect of the view pager in the pinterest app.
#Amit Gupta has pointed to library that let the activity slide. Its pretty the same concept like various Navigation drawers does and sets also the theme to translucent. They slide the layout. But thats not exactly what I was looking for, because it slides the top activity to the right and than simply calls finish(). But the underneath activity will not be animated in.
The solution is (and I guess this is was Tumblr does) to write your very own Animation with Animation Objects and animate it step by step.
This can be done with ActivityOptions. In my opinion this will be the solution.

I wrote a project. It allows you to develop an app navigated by Fragments easily, performs just like Pinterest.
https://github.com/fengdai/FragmentMaster
Maybe it's not the answer what you want. But I hope it's useful to someone else.

I was dealing with this one in project I am currently working on and came up with following code. Maybe it's not relevant for you now, but it could help someone new in this post. :)
Basically it's ViewPager implementation as you mention in your answer, but I think it's the simplest and quickest solution to your question. The cons are that it's only for Fragments (could be easily changed for Objects) and if you want to add ActionBar into swipe, you probably end up creating a custom one.
public class DoubleViewPager extends FrameLayout implements ViewPager.OnPageChangeListener {
/**
* Represents number of objects in DelegateViewPager. In others words it stands for one main content
* window and one content detail window
*/
private static final int SCREEN_COUNT = 2;
private static final int CONTENT_SCREEN = 0;
private static final int DETAIL_SCREEN = 1;
private DelegateViewPager delegateViewPager;
private SparseArray<Fragment> activeScreens = new SparseArray<Fragment>(SCREEN_COUNT) ;
private DelegateAdapter adapter;
public DoubleViewPager(Context context) {
this(context, null);
}
public DoubleViewPager(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public DoubleViewPager(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
delegateViewPager = new DelegateViewPager(context);
delegateViewPager.setId(R.id.main_page_id);
delegateViewPager.setOverScrollMode(ViewPager.OVER_SCROLL_NEVER);
final FrameLayout.LayoutParams params = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT, Gravity.CENTER);
addView(delegateViewPager, params);
}
/**
* Create a new PagerAdapter and set content fragment as a first object in ViewPager;
* #param fragment Fragment you want to use as a main content
* #param fm FragmentManager required for ViewPager transactions
*/
public void initialize(final Fragment fragment, final FragmentManager fm) {
adapter = new DelegateAdapter(fm);
delegateViewPager.setAdapter(adapter);
activeScreens.put(CONTENT_SCREEN, fragment);
adapter.notifyDataSetChanged();
}
/**
* Adds fragment to stack and set it as current selected item. Basically it the same thing as calling
* startActivity() with some transitions effects
* #param fragment Fragment you want go into
*/
public void openDetailScreen(Fragment fragment) {
activeScreens.put(DETAIL_SCREEN, fragment);
adapter.notifyDataSetChanged();
delegateViewPager.setCurrentItem(1, true);
}
public void hideDetailScreen() {
delegateViewPager.setCurrentItem(CONTENT_SCREEN);
if (activeScreens.get(DETAIL_SCREEN) != null) {
activeScreens.remove(DETAIL_SCREEN);
adapter.notifyDataSetChanged();
}
}
#Override
public void onPageScrolled(int i, float v, int i2) {
// unused
}
#Override
public void onPageSelected(int i) {
if (i == CONTENT_SCREEN) hideDetailScreen();
}
#Override
public void onPageScrollStateChanged(int i) {
// unused
}
private class DelegateViewPager extends ViewPager {
public DelegateViewPager(Context context) {
super(context);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
return getCurrentItem() != CONTENT_SCREEN && super.onInterceptTouchEvent(event);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
return getCurrentItem() != CONTENT_SCREEN && super.onTouchEvent(event);
}
}
private final class DelegateAdapter extends FragmentPagerAdapter {
public DelegateAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
return activeScreens.get(i);
}
#Override
public int getCount() {
return activeScreens.size();
}
}
}
Here is activity which implements it with another ViewPager as a SlidingMenu. (as extra)
public class DoubleViewPagerActivity extends FragmentActivity {
DoubleViewPager doubleViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_double_view_pager);
doubleViewPager = (DoubleViewPager) findViewById(R.id.doublePager);
doubleViewPager.initialize(new MainContentFragment(), getSupportFragmentManager());
}
public static final class MainContentFragment extends Fragment {
public MainContentFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_doublepager_content_window, parent, false);
final ViewPager pager = (ViewPager) view.findViewById(R.id.contentPager);
pager.setAdapter(new SimpleMenuAdapter(getChildFragmentManager()));
pager.setOffscreenPageLimit(2);
pager.setCurrentItem(1);
return view;
}
}
public static final class SimpleMenuAdapter extends FragmentPagerAdapter {
public SimpleMenuAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
return DoubleViewPagerActivity.PagerFragment.instance(i);
}
#Override
public int getCount() {
return 3;
}
#Override
public float getPageWidth(int position) {
switch (position) {
case 0:
case 2:
return 0.7f;
}
return super.getPageWidth(position);
}
}
public static final class PagerFragment extends Fragment {
public static PagerFragment instance(int position) {
final PagerFragment fr = new PagerFragment();
Bundle args = new Bundle();
args.putInt("position", position);
fr.setArguments(args);
return fr;
}
public PagerFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {
final FrameLayout fl = new FrameLayout(getActivity());
fl.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
int position = getArguments().getInt("position");
switch (position) {
case 0:
fl.setBackgroundColor(Color.RED);
break;
case 1:
fl.setBackgroundColor(Color.GREEN);
initListView(fl);
break;
case 2:
fl.setBackgroundColor(Color.BLUE);
break;
}
return fl;
}
private void initListView(FrameLayout fl) {
int max = 50;
final ArrayList<String> items = new ArrayList<String>(max);
for (int i = 1; i <= max; i++) {
items.add("Items " + i);
}
ListView listView = new ListView(getActivity());
fl.addView(listView, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT, Gravity.CENTER));
listView.setAdapter(new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, items));
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
((DoubleViewPagerActivity) getActivity()).doubleViewPager.openDetailScreen(new DetailFragment());
}
});
}
}
public final static class DetailFragment extends Fragment {
public DetailFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {
FrameLayout l = new FrameLayout(getActivity());
l.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
l.setBackgroundColor(getResources().getColor(android.R.color.holo_purple));
return l;
}
}
}

This library allows you to open fragments as in iOS and close them using swipes
https://github.com/shikleev/fragula

Navigation library
Here is a library fully integrated with NavComponent.
I'm still working on it, but it's already stable so you can use it in production.
https://github.com/massivemadness/Fragula
Note: it works only with fragments