Develop Reference

Scroll List View one item at time

Hello guys i would like to make my Listview like this, One item scroll at a time and smooth .
here what i've tried so far but no luck :(
Please help and thanks in advance
Custom ListView Class
public class SingleScrollListView extends ListView {
private boolean mSingleScroll = false;
private VelocityTracker mVelocity = null;
final private float mEscapeVelocity = 2000.0f;
final private int mMinDistanceMoved = 20;
private float mStartY = 0;
public SingleScrollListView(Context context) {
super(context);
}
public SingleScrollListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SingleScrollListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public void setSingleScroll(boolean aSingleScroll) {
mSingleScroll = aSingleScroll;
}
public int getVerticalScrollOffset() {
return getFirstVisiblePosition();
}
#Override
public boolean dispatchTouchEvent(MotionEvent aMotionEvent) {
if (aMotionEvent.getAction() == MotionEvent.ACTION_DOWN) {
if (mSingleScroll && mVelocity == null)
mVelocity = VelocityTracker.obtain();
mStartY = aMotionEvent.getY();
return super.dispatchTouchEvent(aMotionEvent);
}
if (aMotionEvent.getAction() == MotionEvent.ACTION_UP) {
if (mVelocity != null) {
if (Math.abs(aMotionEvent.getY() - mStartY) > mMinDistanceMoved) {
mVelocity.computeCurrentVelocity(1000);
float velocity = mVelocity.getYVelocity();
if (aMotionEvent.getY() > mStartY) {
// always lock
if (velocity > mEscapeVelocity) {
smoothScrollToPosition(getFirstVisiblePosition());
} else {
// lock if over half way there
View view = getChildAt(0);
if (view != null) {
if (view.getBottom() >= getHeight() / 2)
smoothScrollToPosition(getFirstVisiblePosition());
else
smoothScrollToPosition(getFirstVisiblePosition() + 1);
}
}
} else {
if (velocity < -mEscapeVelocity)
smoothScrollToPosition(getFirstVisiblePosition() + 1);
else {
// lock if over half way there
View view = getChildAt(1);
if (view != null) {
if (view.getTop() <= getHeight() / 2)
smoothScrollToPosition(getFirstVisiblePosition() + 1);
else
smoothScrollToPosition(getFirstVisiblePosition());
}
}
}
}
mVelocity.recycle();
}
mVelocity = null;
if (mSingleScroll) {
if (Math.abs(aMotionEvent.getY() - mStartY) > mMinDistanceMoved)
return super.dispatchTouchEvent(aMotionEvent);
} else
return super.dispatchTouchEvent(aMotionEvent);
}
if (mSingleScroll) {
if (mVelocity == null) {
mVelocity = VelocityTracker.obtain();
mStartY = aMotionEvent.getY();
}
mVelocity.addMovement(aMotionEvent);
}
return super.dispatchTouchEvent(aMotionEvent);
}
}
Custom Adapter
private class CarListAdapter extends ArrayAdapter<CarList> {
public CarListAdapter() {
super(MainActivity.this, R.layout.list_view_layout, listArray);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View itemView = convertView;
if (itemView == null) {
itemView = getLayoutInflater().inflate(R.layout.list_view_layout, parent, false);
}
CarList data = listArray.get(position);
ImageView Image = (ImageView) itemView.findViewById(R.id.image_holder);
Image.setImageResource(data.getImageID());
return itemView;
}
}
List View Layout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/image_holder"
android:layout_width="match_parent"
android:layout_height="400dp"
android:scaleType="centerCrop"
android:src="#drawable/car_1" />

I liked the UI of your app. For the Answer part I suggest you to use viewpager instead of ListView .
Which come to first real question how to make viewPager scroll vertical ?
Answer is :- override touch events and use use viewpager transformer to give illusion of vertical pager as described in this Answer.
I am just copying snippet here
/**
* Uses a combination of a PageTransformer and swapping X & Y coordinates
* of touch events to create the illusion of a vertically scrolling ViewPager.
*
* Requires API 11+
*
*/
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 {
#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));
}
}
and it look like this
Now for second part of how to make textView used for cost is go up along with page swipe
You can use vertical view pager with textSwitcher
costNameSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
#Override
public android.view.View makeView() {
LayoutInflater inflater = LayoutInflater.from(getActivity());
TextView textView = (TextView) inflater.inflate(R.layout.offer_heading, null);
return textView;
}
});
costNameSwitcher.setInAnimation(getActivity(), R.anim.slide_in_up);
costNameSwitcher.setOutAnimation(getActivity(), R.anim.slide_out_up);
And on page switch change text in textswitcher like this
verticalViewPager
.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position,
float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
costNameSwitcher.setText("Some Cost");
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
Animations
slide_in_up
<?xml version="1.0" encoding="UTF-8"?>
<translate android:toYDelta="0%p" android:fromYDelta="100%p" android:duration="500" xmlns:android="http://schemas.android.com/apk/res/android"/>
slide_out_up
<?xml version="1.0" encoding="UTF-8"?>
<translate android:toYDelta="-100%p" android:fromYDelta="0%p" android:duration="500" xmlns:android="http://schemas.android.com/apk/res/android"/>
ViewPager with views
/**
* The Class slidingPagerAdapter.
*/
public class slidingPagerAdapter extends PagerAdapter {
private final List<HotOffer> listOfOffers;
private Context mContext;
private LayoutInflater mLayoutInflater;
/**
* Instantiates a new home slides pager adapter.
*
* #param context the context
* #param carousalImage
*/
public slidingPagerAdapter(Context context, List<HotOffer> carousalImage) {
mContext = context;
mLayoutInflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.listOfOffers = carousalImage;
}
#Override
public int getCount() {
return listOfOffers.size();
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((FrameLayout) object);
}
#Override
public Object instantiateItem(ViewGroup container, final int position) {
final View itemView = mLayoutInflater.inflate(R.layout.carousal_page, container,
false);
Picasso.with(mContext)
.load(listOfOffers.get(position).getImageUrl())
.networkPolicy(NetworkPolicy.OFFLINE)
.fit()
.centerCrop()
.into((ImageView) itemView
.findViewById(R.id.image), new Callback() {
#Override
public void onSuccess() {
}
#Override
public void onError() {
// Try again online if cache failed
Picasso.with(mContext)
.load(listOfOffers.get(position).getImageUrl())
.fit()
.centerCrop()
.into((ImageView) itemView
.findViewById(R.id.image));
}
});
container.addView(itemView);
return itemView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((FrameLayout) object);
}
}
Showing little bit of next/previous view
// Disable clip to padding
viewPager.setClipToPadding(false);
// set padding manually, the more you set the padding the more you see of prev & next page
viewPager.setPadding(40, 0, 40, 0);
Result :-
You dont need to set left padding ie use
viewPager.setPadding(40, 0, 0, 0);

Why dont you use vertical scrollable viewpager with fragments for this purpose.
I am copying this answer here for your reference.
You can use a ViewPager.PageTransformer to give the illusion of a vertical ViewPager. To achieve scrolling with a vertical instead of a horizontal drag you will have to override ViewPager's default touch events and swap the coordinates of MotionEvents prior to handling them, e.g.:
/**
* Uses a combination of a PageTransformer and swapping X & Y coordinates
* of touch events to create the illusion of a vertically scrolling ViewPager.
*
* Requires API 11+
*
*/
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 {
#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));
}
}
Of course you can tweak these settings as you see fit.

Swipe effect like inshorts news app

link check this news app, i want to develop like this.
i want swipe up/down side effect..
i tried this code,but not correctly swiping as i want.
in this code when i swipe up/down,only the text is changing not a layout.
public class ArticlesActivity extends Activity implements GestureDetector.OnGestureListener{
ImageView image,imageArticle;
TextView tv1,tv2,tv3;
private GestureDetector gd;
LinearLayout layout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_articles);
//Creating GestureDetector Object
gd = new GestureDetector(this, this);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
//Registering TouchEvent with GestureDetector
return gd.onTouchEvent(event);
}
#Override
public void onBackPressed() {
// TODO Auto-generated method stub
//Destroying Activity
finish();
}
#Override
public boolean onDown(MotionEvent arg0) {
// TODO Auto-generated method stub
return false;
}
#Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
// TODO Auto-generated method stub
//Defining Sensitivity
float sensitivity = 50;
//Swipe Up Check
if(e1.getY() - e2.getY() > sensitivity){
//Setting Image Resource to Up_Arrow on Swipe Up
tv1.setText("Some Text");
tv2.setText("Some Text");
tv3.setText("Some Text");
image.setImageResource(R.drawable.logo);
imageArticle.setImageResource(R.drawable.ic_launcher);
return true;
}
//Swipe Down Check
else if(e2.getY() - e1.getY() > sensitivity){
//Setting Image Resource to Down_Arrow on Swipe Down
tv1.setText("Some Text");
tv2.setText("Some Text");
tv3.setText("Some Text");
image.setImageResource(R.drawable.ic_launcher);
imageArticle.setImageResource(R.drawable.logo);
return true;
}
else{
//If some error occurrs, setting again to Default_Image (Actually it will never happen in this case)
image.setImageResource(R.drawable.logo);
return true;
}
}
#Override
public void onLongPress(MotionEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
return false;
}
#Override
public void onShowPress(MotionEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public boolean onSingleTapUp(MotionEvent arg0) {
// TODO Auto-generated method stub
return false;
}
}

This will work like inshorts app
main.xml
<com.cardviewanimation.VerticalViewPager
android:id="#+id/verticleViewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
android:id="#+id/card_view"
android:layout_gravity="center"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
card_view:cardCornerRadius="2dp"
card_view:contentPadding="10dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="300dp"
android:src="#drawable/background"
android:scaleType="fitXY"/>
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"/>
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
VerticleViewPagerActivity.java
public class VerticleViewPagerActivity extends AppCompatActivity {
VerticalViewPager verticalViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
verticalViewPager = (VerticalViewPager) findViewById(R.id.verticleViewPager);
verticalViewPager.setAdapter(new VerticlePagerAdapter(this));
}
}
VerticlePagerAdapter.java
public class VerticlePagerAdapter extends PagerAdapter {
String mResources[] = {"To start off lets understand what exactly Android CardView is? Its a new widget for Android, which can be used to display a card sort of a layout in android. As you may know Android material design is inspired from paper and ink concept. Mostly it displays views on top of each other, with shadows. In simple terms, Android CardView is such a view which has all material design properties, most importantly showing shadows according the elevation. The best part about this view is that it extends FrameLayout and it can be displayed on all the platforms of android since it’s available through the Support v7 library. Lets have a look at some of its properties:","To start off lets understand what exactly Android CardView is? Its a new widget for Android, which can be used to display a card sort of a layout in android. As you may know Android material design is inspired from paper and ink concept. Mostly it displays views on top of each other, with shadows. In simple terms, Android CardView is such a view which has all material design properties, most importantly showing shadows according the elevation. The best part about this view is that it extends FrameLayout and it can be displayed on all the platforms of android since it’s available through the Support v7 library. Lets have a look at some of its properties:"};
Context mContext;
LayoutInflater mLayoutInflater;
public VerticlePagerAdapter(Context context) {
mContext = context;
mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return mResources.length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((LinearLayout) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
View itemView = mLayoutInflater.inflate(R.layout.content_main, container, false);
TextView label = (TextView) itemView.findViewById(R.id.textView);
label.setText(mResources[position]);
container.addView(itemView);
return itemView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((LinearLayout) object);
}
}
VerticalViewPager.java
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 = 0.75f;
#Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 0) { // [-1,0]
// Use the default slide transition when moving to the left page
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
//set Y position to swipe in from top
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
view.setScaleX(1);
view.setScaleY(1);
} else if (position <= 1) { // [0,1]
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
// Scale the page down (between MIN_SCALE and 1)
float scaleFactor = MIN_SCALE
+ (1 - MIN_SCALE) * (1 - Math.abs(position));
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
/**
* 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));
}
}

I got the solution for your problem as inshorts app using vertical view pager. I am sharing some code that can serve your purpose.
public class VerticalViewPager extends ViewPager {
public VerticalViewPager(Context context) {
this(context, null);
}
public VerticalViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
setPageTransformer(false, new DefaultTransformer());
}
private MotionEvent swapTouchEvent(MotionEvent event) {
float width = getWidth();
float height = getHeight();
float swappedX = (event.getY() / height) * width;
float swappedY = (event.getX() / width) * height;
event.setLocation(swappedX, swappedY);
return event;
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
boolean intercept = super.onInterceptTouchEvent(swapTouchEvent(event));
//If not intercept, touch event should not be swapped.
swapTouchEvent(event);
return intercept;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapTouchEvent(ev));
}
}
As you can see the class above uses the DefaultTransformer class for transformation which implement ViewPager.PageTransformer for custom animation this class code is given below
public class DefaultTransformer implements ViewPager.PageTransformer {
#Override
public void transformPage(View view, float position) {
float alpha = 0;
if (0 <= position && position <= 1) {
alpha = 1 - position;
} else if (-1 < position && position < 0) {
alpha = position + 1;
}
System.out.println("alpha--" + alpha);
view.setAlpha(alpha);
System.out.println("position--" + position);
System.out.println("view.getWidth()--" + view.getWidth());
view.setTranslationX(view.getWidth() * -position);
float yPosition = position * view.getHeight();
System.out.println("yPosition---"+yPosition);
view.setTranslationY(yPosition);
}
}
and my activity code is like this
public class SwipeUpActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipe_layout);
setTitle("");
initViewPager();
}
private void initViewPager() {
VerticalViewPager viewPager = (VerticalViewPager) findViewById(R.id.vertical_viewpager);
//viewPager.setPageTransformer(false, new ZoomOutTransformer());
//viewPager.setPageTransformer(true, new StackTransformer());
String title = "ContentFragment";
viewPager.setAdapter(new ContentFragmentAdapter.Holder(getSupportFragmentManager())
.add(ContentFragment.newInstance(title, 1))
.add(ContentFragment.newInstance(title, 2))
.add(ContentFragment.newInstance(title, 3))
.add(ContentFragment.newInstance(title, 4))
.add(ContentFragment.newInstance(title, 5))
.set());
//If you setting other scroll mode, the scrolled fade is shown from either side of display.
viewPager.setOverScrollMode(View.OVER_SCROLL_NEVER);
}
The layout named activity_swipe_layout is like this
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:background="#A6000000"
android:layout_height="match_parent">
<gmaillogindemo.com.irk.transforms.VerticalViewPager
android:id="#+id/vertical_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
and the result is looking like this:
after swipe up

Android Gallery zoom in/out

Hi I am using the Gallery widget to show images downloaded from the internet.
to show several images and I would like to have a gradual zoom while people slide up and down on the screen. I know how to implement the touch event the only thing I don't know how to make the whole gallery view grow gradually. I don't want to zoom in on one image I want the whole gallery to zoom in/out gradually.
EDIT3: I manage to zoom the visible part of the gallery but the problem is I need to find a way for the gallery to find out about it and update it's other children too.
What happens is if 3 images are visible then you start zooming and the gallery does get smaller, so do the images but what I would like in this case is more images to be visible but I don't know how to reach this desired effect. Here's the entire code:
public class Gallery1 extends Activity implements OnTouchListener {
private static final String TAG = "GalleryTest";
private float zoom=0.0f;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
Gallery g;
LinearLayout layout2;
private ImageAdapter ad;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gallery_1);
layout2=(LinearLayout) findViewById(R.id.layout2);
// Reference the Gallery view
g = (Gallery) findViewById(R.id.gallery);
// Set the adapter to our custom adapter (below)
ad=new ImageAdapter(this);
g.setAdapter(ad);
layout2.setOnTouchListener(this);
}
public void zoomList(boolean increase) {
Log.i(TAG, "startig animation");
AnimatorSet set = new AnimatorSet();
set.playTogether(
ObjectAnimator.ofFloat(g, "scaleX", zoom),
ObjectAnimator.ofFloat(g, "scaleY", zoom)
);
set.addListener(new AnimatorListener() {
#Override
public void onAnimationStart(Animator animation) {
}
#Override
public void onAnimationRepeat(Animator animation) {
// TODO Auto-generated method stub
}
#Override
public void onAnimationEnd(Animator animation) {
}
#Override
public void onAnimationCancel(Animator animation) {
// TODO Auto-generated method stub
}
});
set.setDuration(100).start();
}
public class ImageAdapter extends BaseAdapter {
private static final int ITEM_WIDTH = 136;
private static final int ITEM_HEIGHT = 88;
private final int mGalleryItemBackground;
private final Context mContext;
private final Integer[] mImageIds = {
R.drawable.gallery_photo_1,
R.drawable.gallery_photo_2,
R.drawable.gallery_photo_3,
R.drawable.gallery_photo_4,
R.drawable.gallery_photo_5,
R.drawable.gallery_photo_6,
R.drawable.gallery_photo_7,
R.drawable.gallery_photo_8
};
private final float mDensity;
public ImageAdapter(Context c) {
mContext = c;
// See res/values/attrs.xml for the <declare-styleable> that defines
// Gallery1.
TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
mGalleryItemBackground = a.getResourceId(
R.styleable.Gallery1_android_galleryItemBackground, 1);
a.recycle();
mDensity = c.getResources().getDisplayMetrics().density;
}
public int getCount() {
return mImageIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
convertView = new ImageView(mContext);
imageView = (ImageView) convertView;
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setLayoutParams(new Gallery.LayoutParams(
(int) (ITEM_WIDTH * mDensity + 0.5f),
(int) (ITEM_HEIGHT * mDensity + 0.5f)));
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mImageIds[position]);
return imageView;
}
}
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_MOVE
&& event.getPointerCount() > 1) {
midPoint(mid, event);
if(mid.y > start.y){
Log.i(TAG, "Going down (Math.abs(mid.y - start.y)= "+(Math.abs(mid.y - start.y))+" and zoom="+zoom); // going down so increase
if ((Math.abs(mid.y - start.y) > 10) && (zoom<2.5f)){
zoom=zoom+0.1f;
midPoint(start, event);
zoomList(true);
}
return true;
}else if(mid.y < start.y){
Log.i(TAG, "Going up (Math.abs(mid.y - start.y)= "+(Math.abs(mid.y - start.y))+" and zoom="+zoom); //smaller
if ((Math.abs(mid.y - start.y) > 10) &&(zoom>0.1)){
midPoint(start, event);
zoom=zoom-0.1f;
zoomList(false);
}
return true;
}
}
else if (event.getAction() == MotionEvent.ACTION_POINTER_DOWN) {
Log.e(TAG, "Pointer went down: " + event.getPointerCount());
return true;
}
else if (event.getAction() == MotionEvent.ACTION_UP) {
Log.i(TAG, "Pointer going up");
return true;
}
else if (event.getAction() == MotionEvent.ACTION_DOWN) {
Log.i(TAG, "Pointer going down");
start.set(event.getX(), event.getY());
return true;
}
return false;
// indicate event was handled or not
}
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
I realise I will probably have to extend the Gallery or even another View group or create my own class but I don't know where to start: which method use the one responsible for scaling...
EDIT4: I don't know if he question is clear enough. Here is an example of states:
State one: initial state, we have 3 images in view
State 2: we detect vertical touches going up with 2 fingers = we have to zoom out
state 3: we start zooming = animation on the gallery or on the children???
state 4: gallery detects that it's 3 children are smaller
state 5: gallery adds 1 /more children according to the new available space
LAST UPDATE:
Thanks to all that have posted but I have finally reached a conclusion and that is to not use Gallery at all:
1. It's deprecated
2. It's not customizable enough for my case
If you want to animate several images at once you may want to consider using OpenGl, I am using libgdx library:
https://github.com/libgdx/libgdx

The following ScalingGallery implementation might be of help.
This gallery subclass overrides the getChildStaticTransformation(View child, Transformation t) method in which the scaling is performed. You can further customize the scaling parameters to fit your own needs.
Please note the ScalingGalleryItemLayout.java class. This is necessary because after you have performed the scaling operationg on the child views, their hit boxes are no longer valid so they must be updated from with the getChildStaticTransformation(View child, Transformation t) method.
This is done by wrapping each gallery item in a ScalingGalleryItemLayout which extends a LinearLayout. Again, you can customize this to fit your own needs if a LinearLayout does not meet your needs for layout out your gallery items.
File : /src/com/example/ScalingGallery.java
/**
* A Customized Gallery component which alters the size and position of its items based on their position in the Gallery.
*/
public class ScalingGallery extends Gallery {
public static final int ITEM_SPACING = -20;
private static final float SIZE_SCALE_MULTIPLIER = 0.25f;
private static final float ALPHA_SCALE_MULTIPLIER = 0.5f;
private static final float X_OFFSET = 20.0f;
/**
* Implemented by child view to adjust the boundaries after it has been matrix transformed.
*/
public interface SetHitRectInterface {
public void setHitRect(RectF newRect);
}
/**
* #param context
* Context that this Gallery will be used in.
* #param attrs
* Attributes for this Gallery (via either xml or in-code)
*/
public ScalingGallery(Context context, AttributeSet attrs) {
super(context, attrs);
setStaticTransformationsEnabled(true);
setChildrenDrawingOrderEnabled(true);
}
/**
* {#inheritDoc}
*
* #see #setStaticTransformationsEnabled(boolean)
*
* This is where the scaling happens.
*/
protected boolean getChildStaticTransformation(View child, Transformation t) {
child.invalidate();
t.clear();
t.setTransformationType(Transformation.TYPE_BOTH);
// Position of the child in the Gallery (... +2 +1 0 -1 -2 ... 0 being the middle)
final int childPosition = getSelectedItemPosition() - getPositionForView(child);
final int childPositionAbs = (int) Math.abs(childPosition);
final float left = child.getLeft();
final float top = child.getTop();
final float right = child.getRight();
final float bottom = child.getBottom();
Matrix matrix = t.getMatrix();
RectF modifiedHitBox = new RectF();
// Change alpha, scale and translate non-middle child views.
if (childPosition != 0) {
final int height = child.getMeasuredHeight();
final int width = child.getMeasuredWidth();
// Scale the size.
float scaledSize = 1.0f - (childPositionAbs * SIZE_SCALE_MULTIPLIER);
if (scaledSize < 0) {
scaledSize = 0;
}
matrix.setScale(scaledSize, scaledSize);
float moveX = 0;
float moveY = 0;
// Moving from right to left -- linear move since the scaling is done with respect to top-left corner of the view.
if (childPosition < 0) {
moveX = ((childPositionAbs - 1) * SIZE_SCALE_MULTIPLIER * width) + X_OFFSET;
moveX *= -1;
} else { // Moving from left to right -- sum of the previous positions' x displacements.
// X(n) = X(0) + X(1) + X(2) + ... + X(n-1)
for (int i = childPositionAbs; i > 0; i--) {
moveX += (i * SIZE_SCALE_MULTIPLIER * width);
}
moveX += X_OFFSET;
}
// Moving down y-axis is linear.
moveY = ((childPositionAbs * SIZE_SCALE_MULTIPLIER * height) / 2);
matrix.postTranslate(moveX, moveY);
// Scale alpha value.
final float alpha = (1.0f / childPositionAbs) * ALPHA_SCALE_MULTIPLIER;
t.setAlpha(alpha);
// Calculate new hit box. Since we moved the child, the hitbox is no longer lined up with the new child position.
final float newLeft = left + moveX;
final float newTop = top + moveY;
final float newRight = newLeft + (width * scaledSize);
final float newBottom = newTop + (height * scaledSize);
modifiedHitBox = new RectF(newLeft, newTop, newRight, newBottom);
} else {
modifiedHitBox = new RectF(left, top, right, bottom);
}
// update child hit box so you can tap within the child's boundary
((SetHitRectInterface) child).setHitRect(modifiedHitBox);
return true;
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// Helps to smooth out jittering during scrolling.
// read more - http://www.unwesen.de/2011/04/17/android-jittery-scrolling-gallery/
final int viewsOnScreen = getLastVisiblePosition() - getFirstVisiblePosition();
if (viewsOnScreen <= 0) {
super.onLayout(changed, l, t, r, b);
}
}
private int mLastDrawnPosition;
#Override
protected int getChildDrawingOrder(int childCount, int i) {
//Reset the last position variable every time we are starting a new drawing loop
if (i == 0) {
mLastDrawnPosition = 0;
}
final int centerPosition = getSelectedItemPosition() - getFirstVisiblePosition();
if (i == childCount - 1) {
return centerPosition;
} else if (i >= centerPosition) {
mLastDrawnPosition++;
return childCount - mLastDrawnPosition;
} else {
return i;
}
}
}
File : /src/com/example/ScalingGalleryItemLayout.java
public class ScalingGalleryItemLayout extends LinearLayout implements SetHitRectInterface {
public ScalingGalleryItemLayout(Context context) {
super(context);
}
public ScalingGalleryItemLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ScalingGalleryItemLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
private Rect mTransformedRect;
#Override
public void setHitRect(RectF newRect) {
if (newRect == null) {
return;
}
if (mTransformedRect == null) {
mTransformedRect = new Rect();
}
newRect.round(mTransformedRect);
}
#Override
public void getHitRect(Rect outRect) {
if (mTransformedRect == null) {
super.getHitRect(outRect);
} else {
outRect.set(mTransformedRect);
}
}
}
File : /res/layout/ScaledGalleryItemLayout.xml
<?xml version="1.0" encoding="utf-8"?>
<com.example.ScalingGalleryItemLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/gallery_item_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center"
android:orientation="vertical"
android:padding="5dp" >
<ImageView
android:id="#+id/gallery_item_image"
android:layout_width="360px"
android:layout_height="210px"
android:layout_gravity="center"
android:antialias="true"
android:background="#drawable/gallery_item_button_selector"
android:cropToPadding="true"
android:padding="35dp"
android:scaleType="centerInside" />
<TextView
android:id="#+id/gallery_item_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:textColor="#drawable/white"
android:textSize="30sp" />
</com.example.ScalingGalleryItemLayout>

To keep the state of the animation after it is done, just do this on your animation:
youranim.setFillAfter(true);
Edit :
In my project, I use this method and i think, it's help you :
http://developer.sonymobile.com/wp/2011/04/12/how-to-take-advantage-of-the-pinch-to-zoom-feature-in-your-xperia%E2%84%A2-10-apps-part-1/

U can do Image Zoom pinch option for gallery also.
by using below code lines:
you can download the example.
https://github.com/alvinsj/android-image-gallery/downloads
I hope this example will help to u..if u have any queries ask me.....

This is solution
integrate gallery component in android with gesture-image library
gesture-imageView
And here is full sample code
SampleCode

Android - ListView slide left/right like Samsung contact ListView

I am developing an application, and I need a ListView like conctact ListView of my Samsung Galaxy S:
When I slide my finger to the right I can send message to this contact.
When I slide my finger to the right I can call to my contact.
I have my ListView and only need the function for do it...
Thanks in advance.
PD:
I searched a lot and have not found anything. The most similar:
Resource for Android Slight Left/Right Slide action on listview

From another post, there was a link to this Google Code : https://gist.github.com/2980593
Which come from this Google+ post : https://plus.google.com/u/0/113735310430199015092/posts/Fgo1p5uWZLu .
This is a Swipe-To-Dismiss functionality.
From this you can provide your own Swipe-To-Action code. So here is my version, were I can personalize the left and right action and you can triggered the Dismiss animation (this is just a modification of Roman Nuric's code).
You have to include this class in your project :
public class SwipeListViewTouchListener implements View.OnTouchListener {
// Cached ViewConfiguration and system-wide constant values
private int mSlop;
private int mMinFlingVelocity;
private int mMaxFlingVelocity;
private long mAnimationTime;
// Fixed properties
private ListView mListView;
private OnSwipeCallback mCallback;
private int mViewWidth = 1; // 1 and not 0 to prevent dividing by zero
private boolean dismissLeft = true;
private boolean dismissRight = true;
// Transient properties
private List < PendingSwipeData > mPendingSwipes = new ArrayList < PendingSwipeData > ();
private int mDismissAnimationRefCount = 0;
private float mDownX;
private boolean mSwiping;
private VelocityTracker mVelocityTracker;
private int mDownPosition;
private View mDownView;
private boolean mPaused;
/**
* The callback interface used by {#link SwipeListViewTouchListener} to inform its client
* about a successful swipe of one or more list item positions.
*/
public interface OnSwipeCallback {
/**
* Called when the user has swiped the list item to the left.
*
* #param listView The originating {#link ListView}.
* #param reverseSortedPositions An array of positions to dismiss, sorted in descending
* order for convenience.
*/
void onSwipeLeft(ListView listView, int[] reverseSortedPositions);
void onSwipeRight(ListView listView, int[] reverseSortedPositions);
}
/**
* Constructs a new swipe-to-action touch listener for the given list view.
*
* #param listView The list view whose items should be dismissable.
* #param callback The callback to trigger when the user has indicated that she would like to
* dismiss one or more list items.
*/
public SwipeListViewTouchListener(ListView listView, OnSwipeCallback callback) {
ViewConfiguration vc = ViewConfiguration.get(listView.getContext());
mSlop = vc.getScaledTouchSlop();
mMinFlingVelocity = vc.getScaledMinimumFlingVelocity();
mMaxFlingVelocity = vc.getScaledMaximumFlingVelocity();
mAnimationTime = listView.getContext().getResources().getInteger(
android.R.integer.config_shortAnimTime);
mListView = listView;
mCallback = callback;
}
/**
* Constructs a new swipe-to-action touch listener for the given list view.
*
* #param listView The list view whose items should be dismissable.
* #param callback The callback to trigger when the user has indicated that she would like to
* dismiss one or more list items.
* #param dismissLeft set if the dismiss animation is up when the user swipe to the left
* #param dismissRight set if the dismiss animation is up when the user swipe to the right
* #see #SwipeListViewTouchListener(ListView, OnSwipeCallback, boolean, boolean)
*/
public SwipeListViewTouchListener(ListView listView, OnSwipeCallback callback, boolean dismissLeft, boolean dismissRight) {
this(listView, callback);
this.dismissLeft = dismissLeft;
this.dismissRight = dismissRight;
}
/**
* Enables or disables (pauses or resumes) watching for swipe-to-dismiss gestures.
*
* #param enabled Whether or not to watch for gestures.
*/
public void setEnabled(boolean enabled) {
mPaused = !enabled;
}
/**
* Returns an {#link android.widget.AbsListView.OnScrollListener} to be added to the
* {#link ListView} using
* {#link ListView#setOnScrollListener(android.widget.AbsListView.OnScrollListener)}.
* If a scroll listener is already assigned, the caller should still pass scroll changes
* through to this listener. This will ensure that this
* {#link SwipeListViewTouchListener} is paused during list view scrolling.</p>
*
* #see {#link SwipeListViewTouchListener}
*/
public AbsListView.OnScrollListener makeScrollListener() {
return new AbsListView.OnScrollListener() {#
Override
public void onScrollStateChanged(AbsListView absListView, int scrollState) {
setEnabled(scrollState != AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL);
}
#
Override
public void onScroll(AbsListView absListView, int i, int i1, int i2) {}
};
}
#
Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (mViewWidth < 2) {
mViewWidth = mListView.getWidth();
}
switch (motionEvent.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
{
if (mPaused) {
return false;
}
// TODO: ensure this is a finger, and set a flag
// Find the child view that was touched (perform a hit test)
Rect rect = new Rect();
int childCount = mListView.getChildCount();
int[] listViewCoords = new int[2];
mListView.getLocationOnScreen(listViewCoords);
int x = (int) motionEvent.getRawX() - listViewCoords[0];
int y = (int) motionEvent.getRawY() - listViewCoords[1];
View child;
for (int i = 0; i < childCount; i++) {
child = mListView.getChildAt(i);
child.getHitRect(rect);
if (rect.contains(x, y)) {
mDownView = child;
break;
}
}
if (mDownView != null) {
mDownX = motionEvent.getRawX();
mDownPosition = mListView.getPositionForView(mDownView);
mVelocityTracker = VelocityTracker.obtain();
mVelocityTracker.addMovement(motionEvent);
}
view.onTouchEvent(motionEvent);
return true;
}
case MotionEvent.ACTION_UP:
{
if (mVelocityTracker == null) {
break;
}
float deltaX = motionEvent.getRawX() - mDownX;
mVelocityTracker.addMovement(motionEvent);
mVelocityTracker.computeCurrentVelocity(500); // 1000 by defaut but it was too much
float velocityX = Math.abs(mVelocityTracker.getXVelocity());
float velocityY = Math.abs(mVelocityTracker.getYVelocity());
boolean swipe = false;
boolean swipeRight = false;
if (Math.abs(deltaX) > mViewWidth / 2) {
swipe = true;
swipeRight = deltaX > 0;
} else if (mMinFlingVelocity <= velocityX && velocityX <= mMaxFlingVelocity && velocityY < velocityX) {
swipe = true;
swipeRight = mVelocityTracker.getXVelocity() > 0;
}
if (swipe) {
// sufficent swipe value
final View downView = mDownView; // mDownView gets null'd before animation ends
final int downPosition = mDownPosition;
final boolean toTheRight = swipeRight;
++mDismissAnimationRefCount;
mDownView.animate()
.translationX(swipeRight ? mViewWidth : -mViewWidth)
.alpha(0)
.setDuration(mAnimationTime)
.setListener(new AnimatorListenerAdapter() {#
Override
public void onAnimationEnd(Animator animation) {
performSwipeAction(downView, downPosition, toTheRight, toTheRight ? dismissRight : dismissLeft);
}
});
} else {
// cancel
mDownView.animate()
.translationX(0)
.alpha(1)
.setDuration(mAnimationTime)
.setListener(null);
}
mVelocityTracker = null;
mDownX = 0;
mDownView = null;
mDownPosition = ListView.INVALID_POSITION;
mSwiping = false;
break;
}
case MotionEvent.ACTION_MOVE:
{
if (mVelocityTracker == null || mPaused) {
break;
}
mVelocityTracker.addMovement(motionEvent);
float deltaX = motionEvent.getRawX() - mDownX;
if (Math.abs(deltaX) > mSlop) {
mSwiping = true;
mListView.requestDisallowInterceptTouchEvent(true);
// Cancel ListView's touch (un-highlighting the item)
MotionEvent cancelEvent = MotionEvent.obtain(motionEvent);
cancelEvent.setAction(MotionEvent.ACTION_CANCEL |
(motionEvent.getActionIndex() << MotionEvent.ACTION_POINTER_INDEX_SHIFT));
mListView.onTouchEvent(cancelEvent);
}
if (mSwiping) {
mDownView.setTranslationX(deltaX);
mDownView.setAlpha(Math.max(0f, Math.min(1f,
1f - 2f * Math.abs(deltaX) / mViewWidth)));
return true;
}
break;
}
}
return false;
}
class PendingSwipeData implements Comparable < PendingSwipeData > {
public int position;
public View view;
public PendingSwipeData(int position, View view) {
this.position = position;
this.view = view;
}
#
Override
public int compareTo(PendingSwipeData other) {
// Sort by descending position
return other.position - position;
}
}
private void performSwipeAction(final View swipeView, final int swipePosition, boolean toTheRight, boolean dismiss) {
// Animate the dismissed list item to zero-height and fire the dismiss callback when
// all dismissed list item animations have completed. This triggers layout on each animation
// frame; in the future we may want to do something smarter and more performant.
final ViewGroup.LayoutParams lp = swipeView.getLayoutParams();
final int originalHeight = swipeView.getHeight();
final boolean swipeRight = toTheRight;
ValueAnimator animator;
if (dismiss)
animator = ValueAnimator.ofInt(originalHeight, 1).setDuration(mAnimationTime);
else
animator = ValueAnimator.ofInt(originalHeight, originalHeight - 1).setDuration(mAnimationTime);
animator.addListener(new AnimatorListenerAdapter() {#
Override
public void onAnimationEnd(Animator animation) {
--mDismissAnimationRefCount;
if (mDismissAnimationRefCount == 0) {
// No active animations, process all pending dismisses.
// Sort by descending position
Collections.sort(mPendingSwipes);
int[] swipePositions = new int[mPendingSwipes.size()];
for (int i = mPendingSwipes.size() - 1; i >= 0; i--) {
swipePositions[i] = mPendingSwipes.get(i).position;
}
if (swipeRight)
mCallback.onSwipeRight(mListView, swipePositions);
else
mCallback.onSwipeLeft(mListView, swipePositions);
ViewGroup.LayoutParams lp;
for (PendingSwipeData pendingDismiss: mPendingSwipes) {
// Reset view presentation
pendingDismiss.view.setAlpha(1f);
pendingDismiss.view.setTranslationX(0);
lp = pendingDismiss.view.getLayoutParams();
lp.height = originalHeight;
pendingDismiss.view.setLayoutParams(lp);
}
mPendingSwipes.clear();
}
}
});
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {#
Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
lp.height = (Integer) valueAnimator.getAnimatedValue();
swipeView.setLayoutParams(lp);
}
});
mPendingSwipes.add(new PendingSwipeData(swipePosition, swipeView));
animator.start();
}
}
From there, you can add the following code to your onCreate in the Activity with the ListView :
// Create a ListView-specific touch listener. ListViews are given special treatment because
// by default they handle touches for their list items... i.e. they're in charge of drawing
// the pressed state (the list selector), handling list item clicks, etc.
SwipeListViewTouchListener touchListener =
new SwipeListViewTouchListener(
listView,
new SwipeListViewTouchListener.OnSwipeCallback() {
#Override
public void onSwipeLeft(ListView listView, int [] reverseSortedPositions) {
// Log.i(this.getClass().getName(), "swipe left : pos="+reverseSortedPositions[0]);
// TODO : YOUR CODE HERE FOR LEFT ACTION
}
#Override
public void onSwipeRight(ListView listView, int [] reverseSortedPositions) {
// Log.i(ProfileMenuActivity.class.getClass().getName(), "swipe right : pos="+reverseSortedPositions[0]);
// TODO : YOUR CODE HERE FOR RIGHT ACTION
}
},
true, // example : left action = dismiss
false); // example : right action without dismiss animation
listView.setOnTouchListener(touchListener);
// Setting this scroll listener is required to ensure that during ListView scrolling,
// we don't look for swipes.
listView.setOnScrollListener(touchListener.makeScrollListener());
Edit:
To add a color modification while swiping, your code must be in the case MotionEvent.ACTION_MOVE close to the mDownView.setAlpha.

What you might what to do here is create a new view especially for the list view (call it ListViewFlinger or something). Then in this view, override its onTouchEvent method and place some code in there to determine a slide gesture. Once you have the slide gesture, fire a onSlideComplete event (you'll have to make that listener) an voialla, you a ListView with slide activated content.
float historicX = Float.NaN, historicY = Float.NaN;
static final TRIGGER_DELTA = 50; // Number of pixels to travel till trigger
#Override public boolean onTouchEvent(MotionEvent e) {
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
historicX = e.getX();
historicY = e.getY();
break;
case MotionEvent.ACTION_UP:
if (e.getX() - historicX > -TRIGGER_DELTA) {
onSlideComplete(Direction.LEFT);
return true;
}
else if (e.getX() - historicX > TRIGGER_DELTA) {
onSlideComplete(Direction.RIGHT);
return true;
} break;
default:
return super.onTouchEvent(e);
}
}
enum Direction {
LEFT, RIGHT;
}
interface OnSlideCompleteListener {
void onSlideComplete(Direction dir);
}

If you want to Perform an action On Swiping:
Check out SwipeActionAdapter
It's an awesome library that allows Swipe in both directions with an underlying Layout or Color, and performs a desired action when the swipe/slide gesture is done. You can configure it to reveal/change the layout.
~ I haven't used the Samsung Contacts app, but sounds like this is what you want
If you want to swipe to Reveal actionable buttons:
Check out SwipeMenuListView
In a sense, it is more like the Swipe-able TableViews in iOS.

Make a scrollView autoscroll with drag and drop in Android

I searched all over, but could not find a solution.
I have a view (lets call it myView) inside a scrollview. myView is bigger than the screen. Since I'm able to get the relative x,y position of my finger inside myView, I would like to make the scrollView autoscroll to the top/bottom when my finger enters a certain top/bottom threshold.
I have some ideas, namely translating the drag location to the screen position but this did not solve this problem.
thanks in advance
cheers

All right I figured it out by myself.
First I had to extend the ScrollView class and added an interface OnScrollViewListener.
public class MyScrollView extends ScrollView {
private OnScrollViewListener mListener;
public MyScrollView(Context c, AttributeSet attrs) {
super(c, attrs);
}
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (mListener != null) {
mListener.onScrollChanged((OnScrollViewListener) this);
}
}
public void setOnScrollViewListener(OnScrollViewListener listener) {
mListener = listener;
}
public static interface OnScrollViewListener {
public void onScrollChanged(OnScrollViewListener listener);
}
}
Next in my Activity I inserted a member mScrollDistance that indicates the amount of
pixels the user scrolls.
public class ScrollActivity extends Activity {
private int mScrollDistance;
#Override
protected void OnCreate(...) {
...
final MyScrollView myScrollView = (MyScrollView) findViewById(R.id.scroll_view);
myScrollView.setOnScrollViewListener(new MyScrollView.OnScrollViewListener() {
public void onScrollChanged(OnScrollViewListener listener) {
mScrollDistance = listener.getScrollY();
}
}
// making an drag and drop in an view that is inside the MyScrollView
final LinearLayout myLayout = (LinearLayout)findViewById(R.id.linear_layout);
myLayout.setOnDragListener(new View.OnDragListener() {
public boolean onDrag (View v, DragEvent event) {
int action = event.getAction();
switch(action) {
case DragEvent.ACTION_DRAG_STARTED: {
}
case DragEvent.ACTION_DRAG_LOCATION: {
int y = Math.round(event.getY());
int translatedY = y - mScrollDistance;
int threshold = 50;
// make a scrolling up due the y has passed the threshold
if (translatedY < threshold) {
// make a scroll up by 30 px
myScrollView.scrollBy(0, -30);
}
// make a autoscrolling down due y has passed the 500 px border
if (translatedY + threshold > 500) {
// make a scroll down by 30 px
myScrollView.scrollBy(0, 30);
}
// listen for more actions here
// ...
}
}
}
}
Now, mScrollDistance gets always a new value and the drag location will be translated to the view location.
I tested this and it works on layouts/views that are bigger than the screen size.
Hope that helps.

I came up with a different solution and I am happy with it.
I want to be able to drag and drop views inside a ScrollView. The ScrollView then needs to scroll up and down automatically when the shadow reaches the edges of the scroll view.
I ended up with a solution that detects wether the drop zone is completely visible inside the scrollview (with a 100px margin) and adjust the scroll view otherwise.
#Override
public boolean onDrag(View view, DragEvent event) {
MainWidget dropZoneView = (MainWidget) view;
int action = event.getAction();
switch (action) {
case DragEvent.ACTION_DRAG_STARTED:
//(... other stuff happens here)
case DragEvent.ACTION_DRAG_LOCATION:
ScrollView mainScrollView = (ScrollView) findViewById(R.id.main_scroll);
int topOfDropZone = dropZoneView.getTop();
int bottomOfDropZone = dropZoneView.getBottom();
int scrollY = mainScrollView.getScrollY();
int scrollViewHeight = mainScrollView.getMeasuredHeight();
Log.d(LOG_TAG,"location: Scroll Y: "+ scrollY + " Scroll Y+Height: "+(scrollY + scrollViewHeight));
Log.d(LOG_TAG," top: "+ topOfDropZone +" bottom: "+bottomOfDropZone);
if (bottomOfDropZone > (scrollY + scrollViewHeight - 100))
mainScrollView.smoothScrollBy(0, 30);
if (topOfDropZone < (scrollY + 100))
mainScrollView.smoothScrollBy(0, -30);
break;
default:
break;
}
return true;
}
Hope this helps!

I used a timer in In C#
ScrollCalendar ScrollCalendar = new ScrollCalendar (yourScrollView);
Inside the drag event
public bool OnDrag (View v, DragEvent e)
{
var dragshadow = new EventDateDragShadow (v);
switch (e.Action) {
case DragAction.Started:
return true;
case DragAction.Entered:
break;
case Android.Views.DragAction.Location:
if (e.GetY () < 90) {
ScrollCalendar.StartScroll (-15);
} else if (e.GetY () > yourScrollView.Height - 90) {
ScrollCalendar.StartScroll (15);
} else
ScrollCalendar.StopScroll ();
return (true);
case DragAction.Exited:
return true;
case DragAction.Drop:
return true;
case DragAction.Ended:
ScrollCalendar.StopScroll ();
v.SetOnDragListener (null);
return true;
}
return true;
}
The ScrollCalendar class
public class ScrollCalendar
{
private ScrollView Calendar;
private System.Timers.Timer Timer;
private int ScrollDistance;
public ScrollCalendar(ScrollView calendar)
{
Calendar = calendar;
Timer = new System.Timers.Timer();
Timer.Elapsed+=new ElapsedEventHandler(Scroll);
Timer.Interval = 50;
}
public void StartScroll(int scrollDistance)
{
if (Timer.Enabled) {
return;
}
ScrollDistance = scrollDistance;
Timer.Enabled = true;
}
public void StopScroll()
{
Timer.Enabled = false;
}
private void Scroll(object source, ElapsedEventArgs e)
{
Calendar.SmoothScrollBy (0, ScrollDistance);
}
}
Change the StartScroll value and the Timer.Interval to adjust the speed of the scroll.

I have modified answer of Tiago A.
I faced the same problem and the solution from Tiago A was small and easy but have some limitation so if others require this may help.
Thanks to Tiago A.
case DragEvent.ACTION_DRAG_LOCATION:
ScrollView myScrollView =findViewById(R.id.myScrollView);
int topOfDropZone = myScrollView.getChildAt(0).getTop();
int bottomOfDropZone = myScrollView.getChildAt(0).getBottom();
int scrollY = myScrollView.getScrollY();
int scrollViewHeight = myScrollView.getMeasuredHeight();
if (Math.round(event.getY()) > scrollViewHeight - (scrollViewHeight / 45))
if (bottomOfDropZone > (scrollY + scrollViewHeight - 100))
myScrollView.smoothScrollBy(0, 30);
if (Math.round(event.getY()) < (scrollViewHeight / 45))
if (topOfDropZone < (scrollY + 100))
myScrollView.smoothScrollBy(0, -30);
return true;