I am trying to use the AHBottomNavigation (https://github.com/aurelhubert/ahbottomnavigation) and I am following its demo app for make my own.
In the demo app it uses ViewPager and FragmentPagerAdapter to change between fragments, and everything is working perfectly.
My problem is, I want to add a fade-in fade-out transition between the fragments, I had tried to change this:
viewPager.setCurrentItem(position, false);
for
viewPager.setCurrentItem(position);
And I had added this in my MainActivity:
viewPager.setPageTransformer(false, new FadePageTransformer());
...
public class FadePageTransformer implements ViewPager.PageTransformer {
public void transformPage(View view, float position) {
view.setTranslationX(view.getWidth() * -position);
if(position <= -1.0F || position >= 1.0F) {
view.setAlpha(0.0F);
} else if( position == 0.0F ) {
view.setAlpha(1.0F);
} else {
// position is between -1.0F & 0.0F OR 0.0F & 1.0F
view.setAlpha(1.0F - Math.abs(position));
}
}
}
It actually works, but if I want to go from the first fragment to the last one, it shows all the fragments between them, like a scroll view.
It has a method in the Fragment class (DemoFragment) that I think I can use for a fade-in fade-out transition, but I have no idea of how to implement it, this is the method:
/**
* Called when a fragment will be displayed
*/
public void willBeDisplayed() {
// Do what you want here, for example animate the content
}
Sorry, I am new in android, I still learning, and I hope you can help me, thanks!
UPDATE:
I want to add a cross-fade animation between the fragments, like the example in Material Design (https://www.google.com/design/spec/components/bottom-navigation.html#bottom-navigation-behavior)
Transition between active and inactive views using a cross-fade
animation.
Since viewpagers transition through the pages inbetween, its animated page change should not be used according to the material design guidelines. Instead, you should use setCurrentItem(int, boolean) with the boolean parameter as false (this removes the transition through the inbetween elements) and perform the animation inside onTabSelected:
private Animation fadeOut;
private Animation fadeIn;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
fadeOut = AnimationUtils.loadAnimation(this, android.R.anim.fade_out);
fadeOut.setDuration(150);
fadeIn = AnimationUtils.loadAnimation(this, android.R.anim.fade_in);
fadeIn.setDuration(150);
...
bottomNavigation.setOnTabSelectedListener(new AHBottomNavigation.OnTabSelectedListener() {
#Override
public boolean onTabSelected(int position, boolean wasSelected) {
if(!wasSelected) {
Fragment oldFrag = getCurrentFragment();
if(oldFrag.getView() != null) {
oldFrag.getView().startAnimation(fadeOut);
}
mViewPager.setCurrentItem(position, false);
// The following line might not be necessary
getSupportFragmentManager().executePendingTransactions();
Fragment newFrag = getCurrentFragment();
if(newFrag.getView() != null) {
newFrag.getView().startAnimation(fadeIn);
}
} else {
getCurrentFragment().onReopen();
}
return true;
}
});
}
Related
I am developing an Android app in which I have one ViewPager on top and one horizontal RecyclerView below the ViewPager.
When I scroll the RecyclerView, I am updating the ViewPager item with viewPager.setCurrentItem(position). So that the ViewPager will swipe to that position.
It is working fine. But the ViewPager does not swipe with animation. It only moves to the current position.
I want apply some animation while swiping the ViewPager on RecyclerView scroll. How can I implement that animated behaviour?
Try with
viewPager.setCurrentItem(position, true)
As per the documentation of the ViewPager, it allows moving to that position smoothly.
I think you want to use fade In effect for animation.
you should import this class in your file...
public class FadePageTransformer implements ViewPager.PageTransformer {
#Override
public void transformPage(#NonNull View page, float position) {
page.setTranslationX(page.getWidth() * -position);
if (position <= -1.0F || position >= 1.0F) {
page.setAlpha(0.0F);
} else if (position == 0.0F) {
page.setAlpha(1.0F);
} else {
// position is between -1.0F & 0.0F OR 0.0F & 1.0F
page.setAlpha(1.0F - Math.abs(position));
}
}
}
And after include that class you need to set your view pager like this...
viewPager.setPageTransformer(false,new FadePageTransformer());
it Will help you to implement animation effect in view pager
I have a ViewPager with the PageTransformer implementation that does some funky stuff to the next page of the ViewPager. My implementation looks like this:
class ZoomOutPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.85f;
private static final float MIN_ALPHA = 0.5f;
#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
} else if (position < 1) { // (0,1]
do some funky stuff to the page currently being scrolled into the main view on scrolling left
} else if (position==1) {
do some funky stuff to the next page
}
else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(1);
}
}
}
The problem is that these transform animations are available as soon as the pager is loaded, but they're not available to the first fragment of my viewpager. I.e. the first time a fragment is loaded, the transformPage method is not being called. Is there a way to call the transformPage method manually? I.e. when I'm setting up my ViewPager inside onCreateView? Or somewhere else?
I had a similar situation and I ended up using a fake drag to cause the initial transform:
public void onResume() {
...
Handler handler = new Handler();
final Runnable r = new Runnable() {
public void run() {
// force transform with a 1 pixel nudge
mViewPager.beginFakeDrag();
mViewPager.fakeDragBy(1.0f);
mViewPager.endFakeDrag();
}
};
handler.postDelayed(r, 10); // some small delay in ms
}
As per the Android Developer's site:
A PageTransformer is invoked whenever a visible/attached page is scrolled. This offers an opportunity for the application to apply a custom transformation to the page views using animation properties
So, you wouldn't see any transition animation when the pager is loaded for the first time.
That's a good hack that you have been using, but I don't know if you had tried it already but can you animate the viewpager as a whole itself when it loads for the first time.
Is it possible to setup different PageTransformers for different fragments in ViewPager?
I would like to use ZoomOutPageTransformer when the user swipes between (0, 1) and (n-1, n) fragments of ViewPager with n fragments and use the default transitions for all other cases.
What I tried:
Detect the current page with mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { ... }) and apply different transitions here. But, for example, if the user is on the first page - how to set ZoomOutPageTransformer only for the case when he will swipe to the left (0 page) and do it before animation is started?
I had a less similar requirement wherein I had applied Depth page transformer to all my pages by default and on tap of a button I changed it to Vertical page transformer and then back to Depth page. (A lil wierd but thats how it was)
I did the below:
Applied viewPager.setPageTransformer(true, new DepthPageTransformer()); for all the pages.
onClick I changed it to viewPager.setPageTransformer(true, new VerticalPageTransformer());. Now here's the catch in-order for this to function smoothly I had to use a handler in order to change the page a little later to ensure VerticalPager takes effect. I achieved this by calling viewPager.setCurrentPosition(viewPager.getCurrentItem() + 1)
After this inside onPageChangeListener's onPageSelected method I changed it back to viewPager.setPageTransformer(true, new DepthPageTransformer()); again inside a handler to ensure it's done after my vertical animation is completed.
Note - I had also accessed ViewPager's scroller to achieve the above to define my own speed for the page change.
Let me know if this makes sense, since you need it to be done based on page numbers. If it does I will share my code. :)
This is quite old, but wish it's not too late for somebody
Step 1:
Create custom ViewPager which extends from ViewPager.
Step 2:
Determine which Fragment positions (ViewPager page integers) you need to have a unique PageTransformer for them. Then add these indices into a list within the custom ViewPager.
Step 3:
Override onPageScrolled(int position, float offset, int offsetPixels):
Check if the position is in your list of indices, if so, then you have to create a Custom PageTransformer object; and then utilize the ViewPager setPageTransformer() to change the page transformation.
For positions other than that, then you've to set the default PageTransformer (or you can also you another custom PageTransformer object if you wish.
Code
public class CustomViewPager extends ViewPager {
public CustomViewPager(Context context) {
super(context);
}
public CustomViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
PageTransformer mDepthPageTransformer = new PageTransformer() {
private static final float MIN_SCALE = 0.75f;
public void transformPage(#NonNull 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);
}
}
};
PageTransformer mDefaultPageTransformer = new PageTransformer() {
#Override
public void transformPage(#NonNull View page, float position) {
}
};
#Override
protected void onPageScrolled(int position, float offset, int offsetPixels) {
List<Integer> pos = new ArrayList<>();
pos.add(0);
pos.add(n - 1); // n is the no. of pages as in the question
if (pos.contains(position)) {
this.setPageTransformer(true, mDepthPageTransformer);
} else {
this.setPageTransformer(true, mDefaultPageTransformer);
}
super.onPageScrolled(position, offset, offsetPixels);
}
}
Documentation
Slide between fragments using ViewPager
setPageTransformer() method
Note: mDepthPageTransformer used in my example is taken from the above mentioned documentation.
Inspite Of using mViewPager.setOnPageChangeListener , a single PageTransformer with different animations can help.
Have a look at first paragraph here ,
http://developer.android.com/training/animation/screen-slide.html#pagetransformer
I have a ViewPager in which the pages contain ListViews.
Everything works fine and my viewPAger as well as ListViews work as expected : it is possible to swipe from page to page, and the listviews scroll vertically as they should.
Now I wanted to add a PageTransformer to smooth out paging anbd I used the ZoomOutPageTransformer offered in the google docs.
Now I have a nice animation when swiping between views but the Lists are not scrollable anymore.
Here's the code :
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
LayoutInflater inflater = LayoutInflater.from(getActivity());
viewPager = (ViewPager) view.findViewById(R.id.bookMenuPager);
viewPager.setPageTransformer(false, new ZoomOutPageTransformer());
pagerAdapter = new MenuPagerAdapter();
viewPager.setAdapter(pagerAdapter);
}
class MenuPagerAdapter extends PagerAdapter{
#Override
public int getCount() {
return 3; //change this as needed
}
#Override
public boolean isViewFromObject(View view, Object o) {
return view.equals( o );
}
#Override
public Object instantiateItem(ViewGroup collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if(position == 0){
if(!rootMenuAdded){
viewPager.addView(rootMenucont, 0);
rootMenuAdded = true;
}
return rootMenucont;
}else if(position == 1){
if(!level1MenuAdded){
viewPager.addView(level1MenuCont, 0);
level1MenuAdded = true;
}
return level1MenuCont;
}else if(position == 2){
if(!level2MenuAdded){
viewPager.addView(level2MenuCont, 0);
level2MenuAdded = true;
}
return level2MenuCont;
}
//we got a problem houston
return null;
}
}
and the layout for a page :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/level1MenuCont"
android:layout_height="match_parent"
android:layout_width="match_parent"
>
<ListView
android:id="#+id/level1Menu"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#f02bb6"
>
</ListView>
</RelativeLayout>
What can I do to have my lists scrolling as expected ? What does the PageTransformer break in my ListView so that it wont scroll anymore?
Is this a known bug?
Thanks for any help :)
I think I have found a workaround for this issue.
After some investigation, I think this only happens if you apply a PageTransformer that changes the coordinates of the Views so they are all on top of each other (the two example transformers do exactly this).
When you swipe in the direction such as the NEW VIEW has a Z-index LOWER than the OLD VIEW (normally a swipe backwards), what happens with those transformers is that the OLD VIEW is on top of the NEW VIEW, with Alpha==0, and is the one that later on gets the "ghost" touches.
Unfortunately, the solution by #ngatyrauks bringToFront() didn't work for me (although it definitely should).
However, I have tweaked the transformer so invisible views are changed its visibility to "GONE". And this does the trick.
I have yet to investigate if this Visibility change has any side effects (A GONE view will return null and zeros in layout etc, so maybe this breaks other things inside ViewPager), but so far it's working perfect.
I post here a tweaked DepthPageTransformer (the same in the docs) with these changes. Hope it helps anybody!
package com.regaliz.gui.fx;
import android.util.Log;
import android.view.View;
import android.support.v4.view.ViewPager;
public class DepthPageTransformer implements ViewPager.PageTransformer {
private static final String TAG="DepthTransformer";
private static float MIN_SCALE = 0.75f;
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
Log.d(TAG, "VIew "+view+" Position: "+position);
if (position <= -1) { // [-Infinity,-1) ] ***
// RLP> I Changed to include "-1" as well: When position is -1, the view is not visible
// This page is way off-screen to the left.
view.setAlpha(0);
Log.d(TAG, "VIew "+view+" Position: "+position+", way left");
view.setVisibility(View.GONE);
} 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);
if (position==0) {
Log.d(TAG, "View "+view+" focused now?");
}
if (view.getVisibility()!=View.VISIBLE)
view.setVisibility(View.VISIBLE);
} else if (position <= 1) { // (0,1]
// Fade the page out.
view.setAlpha(1 - position);
// Counteract the default slide transition
// I THINK THIS IS WHAT BREAKS EVERYTHING
// ViewPager normally has the views one after another, but this makes all views on top
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);
if (position==1) {
Log.d(TAG, "View "+view+" invisible now?");
view.setVisibility(View.GONE);
// we totally hide the view. This seems to solve focus issue
} else {
if (view.getVisibility()!=View.VISIBLE)
view.setVisibility(View.VISIBLE);
}
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
// we totally hide the view. This seems to solve focus issue
// I have to check for strange side-effects, but so far I found none :)
view.setVisibility(View.GONE);
Log.d(TAG, "VIew "+view+" Position: "+position+", way right");
}
}
}
Here is the detail of the reason
after 4.1 that the framework respects a custom child drawing order as implied Z-ordering for dispatching touch events. If your views overlap after this page transformation they may not receive touch events in the expected order on older platform versions. Check which view is receiving the touch events to be certain.
If this is what you are seeing you have a few options:
Enforce the desired ordering as you add/remove child views in your PagerAdapter
Remove the X translation applied by the PageTransformer when a page is no longer fully visible - i.e. the "position" parameter reports a full -1 or 1.
And here is my solution
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
if (position <= -1 || position >= 1) { // [-Infinity,-1) ] ***
// [-Infinity,-1] or [1,+Infinity]
// This page is way off-screen to the left or way off-screen to the right.
view.setAlpha(0);
view.setTranslationX(0);
view.setScaleX(1);
view.setScaleY(1);
} 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);
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);
}
}
ref link: https://code.google.com/p/android/issues/detail?id=58918
I don't know if you got this working, but I have the same issue, with a PageDepthTransformer. I'm using a gridview though, the scrolling works, however my subsequent fragments seem to have focus and my top level Fragment doesn't register the correct onClick() events.
My work around for this was to add global layout listener to viewPager and bring the current view to the front
viewPager.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
View view = viewPager.getChildAt(currentFragmentPosition);
if (view != null) {
view.bringToFront();
}
}
)};
This seems like hackery to me, and I haven't quite got this working on rotation. But hopefully it might help you.
Hi: When the user clicks on another tab an animation should appear to the next view? What is the best to do this?
By default, no animation is applied, at least on honeycomb. The view will just pop on.
You could do something like this if you wanted to animate it:
Find the child of the tab and play an animation on it.
Example:
First set a listener:
exampleTabhost.setOnTabChangedListener(new OnTabChangeListener()
{
#Override
public void onTabChanged(String tabId)
{
refreshTabHostUI(exampleTabhost);
}
});
In your listener play the animation on your tab:
View tab1 = th.findViewById(R.id.tab1);
if( tab1 != null )
playAnim(tab1, getBaseContext(), android.R.anim.fade_in, 500);
Play anim function:
public Animation playAnim( View v, Context con, int animationid, int startOffset )
{
if( v != null )
{
Animation animation = AnimationUtils.loadAnimation(con, animationid );
animation.setStartOffset(startOffset);
v.startAnimation(animation);
return animation;
}
return null;
}