Hello I have a RecyclerView, and I use HorizontalScrollView in children of theRecyclerView`. I need to scroll all of them when I scrolling one. Anyone can tell me How to make that,thanks!
I'm going to assume you're doing something similar to what I did where you have some sort of tabular view and the HorizontalScrollViews are all the same width.
This is how I did it:
First I made a customization to the HorizontalScrollView so I could get event notifications when the view was swiped:
public class HorizontalScrollView extends android.widget.HorizontalScrollView {
private OnScrollListener mListener;
public HorizontalScrollView(Context context) {
super(context);
}
public HorizontalScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public HorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public void setOnScrollListener(OnScrollListener listener) {
mListener = listener;
}
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (mListener != null) {
mListener.onScrollChanged(this, l);
}
}
public interface OnScrollListener {
public void onScrollChanged(View view, int scrollX);
}
}
Then when I create the ViewHolders I add a listener that will set all the views to the same scrollX:
view.setOnScrollListener(new OnScrollListener() {
#Override
public void onScrollChanged(View scrollView, int scrollX) {
for (int i = 0; i < recyclerView.getChildCount(); i++) {
View child = recyclerView.getChildAt(i);
if (child instanceof HorizontalScrollView && child != scrollView) {
HorizontalScrollView scrollView2 = (HorizontalScrollView) child;
if (scrollView2.getScrollX() != scrollX) {
scrollView2.setScrollX(scrollX);
}
}
}
}
});
This code is just for illustration purposes; don't expect to copy/paste this and have it work.
I'm assuming that your ViewHolder can get a reference to your RecyclerView to access all the current list items.
This code had some problems, when you swiped one view then swiped another view while everything was still moving from the first swipe, things could get out of sync. But this is a basic idea to get you started in a positive direction.
I am using ViewPager with FragmentStatePageAdapter to show a number of views where user can go through. With current implementation only one page is changed at any single swipe. Instead I want to flip through multiple views based on user swipe. If swipe is long/fast i need to flip through multiple views and vice versa.
here is my current code
public class MyAdapter extends FragmentStatePagerAdapter
{
public MyAdapter(FragmentManager fragmentManager) {
super(fragmentManager);
}
#Override
public int getCount() {
return 10;
}
#Override
public Fragment getItem(int position) {
return ItemFragment.init(position);
}
}
PageContainer class
public class PagerContainer extends FrameLayout implements ViewPager.OnPageChangeListener {
private ViewPager mPager;
boolean mNeedsRedraw = false;
public PagerContainer(Context context) {
super(context);
init();
}
public PagerContainer(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public PagerContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
//Disable clipping of children so non-selected pages are visible
setClipChildren(false);
//Child clipping doesn't work with hardware acceleration in Android 3.x/4.x
//You need to set this value here if using hardware acceleration in an
// application targeted at these releases.
setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
#Override
protected void onFinishInflate() {
try {
mPager = (ViewPager) getChildAt(0);
mPager.setOnPageChangeListener(this);
} catch (Exception e) {
throw new IllegalStateException("The root child of PagerContainer must be a ViewPager");
}
}
public ViewPager getViewPager() {
return mPager;
}
private Point mCenter = new Point();
private Point mInitialTouch = new Point();
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mCenter.x = w / 2;
mCenter.y = h / 2;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
//We capture any touches not already handled by the ViewPager
// to implement scrolling from a touch outside the pager bounds.
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mInitialTouch.x = (int)ev.getX();
mInitialTouch.y = (int)ev.getY();
default:
ev.offsetLocation(mCenter.x - mInitialTouch.x, mCenter.y - mInitialTouch.y);
break;
}
return mPager.dispatchTouchEvent(ev);
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
//Force the container to redraw on scrolling.
//Without this the outer pages render initially and then stay static
if (mNeedsRedraw) invalidate();
}
#Override
public void onPageSelected(int position) { }
#Override
public void onPageScrollStateChanged(int state) {
mNeedsRedraw = (state != ViewPager.SCROLL_STATE_IDLE);
}
}
How can I do this in android?
Thanks
You can change the view by calling:
ViewPager.setCurrentItem(int index)
ViewPager.setCurrentItem(int index, bool animation)
You must handle the sliding commands yourself, but on a certain slide you cloud call setCurrentItem of the ViewPager. The setCurrentItem method also allows you to enable or disable animations.
i had a pageView, i use a code from dave to have some views on the same screen, like gallery widget, but the problem its seems its kind slow, not sure how to modify the ontouch event, what can i do to make fast scrollig i had this PageScroll code
public class PagerContainer extends FrameLayout implements ViewPager.OnPageChangeListener {
private ViewPager mPager;
boolean mNeedsRedraw = false;
public PagerContainer(Context context) {
super(context);
init();
}
public PagerContainer(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public PagerContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
//Disable clipping of children so non-selected pages are visible
setClipChildren(false);
//Child clipping doesn't work with hardware acceleration in Android 3.x/4.x
//You need to set this value here if using hardware acceleration in an
// application targeted at these releases.
setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
#Override
protected void onFinishInflate() {
try {
mPager = (ViewPager) getChildAt(0);
mPager.setOnPageChangeListener(this);
} catch (Exception e) {
throw new IllegalStateException("The root child of PagerContainer must be a ViewPager");
}
}
public ViewPager getViewPager() {
return mPager;
}
private Point mCenter = new Point();
private Point mInitialTouch = new Point();
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mCenter.x = w / 2;
mCenter.y = h / 2;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
//We capture any touches not already handled by the ViewPager
// to implement scrolling from a touch outside the pager bounds.
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mInitialTouch.x = (int)ev.getX();
mInitialTouch.y = (int)ev.getY();
default:
ev.offsetLocation(mCenter.x - mInitialTouch.x, mCenter.y - mInitialTouch.y);
break;
}
return mPager.dispatchTouchEvent(ev);
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
//Force the container to redraw on scrolling.
//Without this the outer pages render initially and then stay static
if (mNeedsRedraw) invalidate();
}
#Override
public void onPageSelected(int position) { }
#Override
public void onPageScrollStateChanged(int state) {
mNeedsRedraw = (state != ViewPager.SCROLL_STATE_IDLE);
}
}
and this its the web where i take the code:
PageView code and this is the image of what i get since Gallery its depreacted this should be used, and gallery throws me outofmemory exception because im using images (i tried asyntask and a lot of things) Thanks
I have custom gallery.
Gallery represents items that are frame layout.
There are one imageView and textView above it.
If text in textView is too long, i need it to be scrolled automatically.
It's one line of text, and it's needed to be scrolled horizontally.
I've found this snippet of code:
TextView
android:text="Single-line text view that scrolls automatically"
android:singleLine="true"
android:ellipsize="marquee"
android:marqueeRepeatLimit ="marquee_forever"
android:focusable="true"
android:focusableInTouchMode="true"
android:scrollHorizontally="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
It works in my test app with only one text view in it.
But it doesn't work in my gallery. Noting happens, text just stay still.
Any help?
Try this custom TextView class:
public class AutoScrollingTextView extends TextView {
public AutoScrollingTextView(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
}
public AutoScrollingTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public AutoScrollingTextView(Context context) {
super(context);
}
#Override
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
if (focused) {
super.onFocusChanged(focused, direction, previouslyFocusedRect);
}
}
#Override
public void onWindowFocusChanged(boolean focused) {
if (focused) {
super.onWindowFocusChanged(focused);
}
}
#Override
public boolean isFocused() {
return true;
}
}
and set the following XML attributes:
android:scrollHorizontally="true"
android:ellipsize="marquee"
android:marqueeRepeatLimit="marquee_forever"
This works beautifully in my dictionary apps where multiple entries may need to auto-scroll simultaneously to display complete content.
The marquee effect on a TextView is only designed to work when the view is focused or selected. The XML code you have tries to make the TextView focused all the time. Unfortunately, since only one view can be focused at any time, and since you have multiple views in the gallery, this approach will not work for you.
The easiest way to accomplish this otherwise is to make the TextViews always be selected. Multiple TextViews can hold the selected state at one time. Selection is meant to be used for an active element of an AdapterView, but still works outside of one. Firstly, remove the attributes modifying the focus from the XML and then just call TextView.setSelected(true) sometime after the view is initialised, e.g. in Activity.onCreate(Bundle) (there is no XML attribute for this). If you are supplying the views from an adapter, then you can call TextView.setSelected(true) during the getView() method after you inflate the view.
Here is an example project showing marquee working for multiple TextViews, and the behaviour inside a Gallery.
Try using ViewPager instead of gallery. This is available in android support packages. http://android-developers.blogspot.in/2011/08/horizontal-view-swiping-with-viewpager.html
I've tried everything, and finally came up with this. This works for me...hope that this will help you someday. Cheers.
package com.gui.custom_views;
import android.content.Context;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.LinearInterpolator;
import android.view.animation.TranslateAnimation;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TextView;
import com.media_player.AndroidMediaPlayerActivity;
/**
* Custom Automatic Scrollable Text View
*
* #author Veljko Ilkic
*
*/
public class AutomaticScrollTextView extends LinearLayout {
// Context of application
Context context;
// TextView
private TextView mTextField1;
// Horizontal scroll
private ScrollView mScrollView1;
// Animation on start
private Animation mMoveTextOnStart = null;
// Out animation
private Animation mMoveText1TextOut = null;
// Duration of animation on start
private int durationStart;
// Duration of animation
private int duration;
// Pain for drawing text
private Paint mPaint;
// Text current width
private float mText1TextWidth;
/**
* Control the speed. The lower this value, the faster it will scroll.
*/
public static final int MS_PER_PX = 80;
/**
* Control the pause between the animations. Also, after starting this
* activity.
*/
public static final int PAUSE_BETWEEN_ANIMATIONS = 0;
private boolean mCancelled = false;
// Layout width
private int mWidth;
// Animation thread
private Runnable mAnimation1StartRunnable;
public AutomaticScrollTextView(Context context) {
super(context);
init(context);
this.context = context;
}
public AutomaticScrollTextView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
this.context = context;
}
private void init(Context context) {
initView(context);
// init helper
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setStrokeWidth(1);
mPaint.setStrokeCap(Paint.Cap.ROUND);
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
mWidth = getMeasuredWidth();
// Calculate
prepare();
// Setup
setupText1Marquee();
}
#Override
public void setOnClickListener(OnClickListener l) {
super.setOnClickListener(l);
mTextField1.setOnClickListener(l);
}
// Method to finally start the marquee.
public void startMarquee() {
prepare();
prepareTextFields();
startTextField1Animation();
mCancelled = false;
}
private void startTextField1Animation() {
mAnimation1StartRunnable = new Runnable() {
public void run() {
mTextField1.setVisibility(View.VISIBLE);
mTextField1.startAnimation(mMoveTextOnStart);
}
};
postDelayed(mAnimation1StartRunnable, PAUSE_BETWEEN_ANIMATIONS);
}
public void reset() {
mCancelled = true;
if (mAnimation1StartRunnable != null) {
removeCallbacks(mAnimation1StartRunnable);
}
mTextField1.clearAnimation();
prepareTextFields();
mMoveTextOnStart.reset();
mMoveText1TextOut.reset();
mScrollView1.removeView(mTextField1);
mScrollView1.addView(mTextField1);
mTextField1.setEllipsize(TextUtils.TruncateAt.END);
invalidate();
}
public void prepareTextFields() {
mTextField1.setEllipsize(TextUtils.TruncateAt.END);
mTextField1.setVisibility(View.INVISIBLE);
expandTextView(mTextField1);
}
private void setupText1Marquee() {
// Calculate duration of animations
durationStart = (int) ((mWidth + mText1TextWidth) * MS_PER_PX);
duration = (int) (2 * mWidth * MS_PER_PX);
// On start animation
mMoveTextOnStart = new TranslateAnimation(0, -mWidth - mText1TextWidth,
0, 0);
mMoveTextOnStart.setDuration(durationStart);
mMoveTextOnStart.setInterpolator(new LinearInterpolator());
mMoveTextOnStart.setFillAfter(true);
// Main scrolling animation
mMoveText1TextOut = new TranslateAnimation(mWidth, -mWidth
- mText1TextWidth, 0, 0);
mMoveText1TextOut.setDuration(duration);
mMoveText1TextOut.setInterpolator(new LinearInterpolator());
mMoveText1TextOut.setFillAfter(true);
mMoveText1TextOut.setRepeatCount(Animation.INFINITE);
// Animation listeners
mMoveTextOnStart
.setAnimationListener(new Animation.AnimationListener() {
public void onAnimationStart(Animation animation) {
invalidate();
mTextField1.invalidate();
}
public void onAnimationEnd(Animation animation) {
if (mCancelled) {
return;
}
mTextField1.startAnimation(mMoveText1TextOut);
}
public void onAnimationRepeat(Animation animation) {
invalidate();
mTextField1.invalidate();
}
});
mMoveText1TextOut
.setAnimationListener(new Animation.AnimationListener() {
public void onAnimationStart(Animation animation) {
invalidate();
mTextField1.invalidate();
}
public void onAnimationEnd(Animation animation) {
if (mCancelled) {
return;
}
}
public void onAnimationRepeat(Animation animation) {
invalidate();
mTextField1.invalidate();
}
});
}
private void prepare() {
// Measure
mPaint.setTextSize(mTextField1.getTextSize());
mPaint.setTypeface(mTextField1.getTypeface());
mText1TextWidth = mPaint.measureText(mTextField1.getText().toString());
setupText1Marquee();
}
private void initView(Context context) {
setOrientation(LinearLayout.VERTICAL);
setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT, Gravity.LEFT));
setPadding(0, 0, 0, 0);
// Scroll View 1
LayoutParams sv1lp = new LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT);
sv1lp.gravity = Gravity.CENTER_HORIZONTAL;
mScrollView1 = new ScrollView(context);
// Scroll View 1 - Text Field
mTextField1 = new TextView(context);
mTextField1.setSingleLine(true);
mTextField1.setEllipsize(TextUtils.TruncateAt.END);
mTextField1.setTypeface(null, Typeface.BOLD);
mScrollView1.addView(mTextField1, new ScrollView.LayoutParams(
mTextField1.getWidth(), LayoutParams.WRAP_CONTENT));
addView(mScrollView1, sv1lp);
}
public void setText1(String text) {
String temp = "";
if (text.length() < 10) {
temp = " " + text + " ";
} else {
temp = text;
}
mTextField1.setText(temp);
}
public void setTextSize1(int textSize) {
mTextField1.setTextSize(textSize);
}
public void setTextColor1(int textColor) {
mTextField1.setTextColor(textColor);
}
private void expandTextView(TextView textView) {
ViewGroup.LayoutParams lp = textView.getLayoutParams();
lp.width = AndroidMediaPlayerActivity.getScreenWidth();
textView.setLayoutParams(lp);
}
}
I came across this problem once and finally fixed the problem by calling .setFocus() on the textView.
Hi You have Tag in the xml file itself. And also use the Scrollview Property of FOCUS_DOWN in the java file ... Hope It helps to u ...
This code is working properly for me.
scrollview=(ScrollView)findViewById(R.id.scrollview1);
tb2.setTextSize(30);
tb2.setMovementMethod(new ScrollingMovementMethod());
scrollview.post(new Runnable() {
public void run() {
scrollview.fullScroll(View.FOCUS_DOWN);
}
});
public class ScrollingTextView extends TextView {
public ScrollingTextView(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
}
public ScrollingTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ScrollingTextView(Context context) {
super(context);
}
#Override
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
if (focused) {
super.onFocusChanged(focused, direction, previouslyFocusedRect);
}
}
#Override
public void onWindowFocusChanged(boolean focused) {
if (focused) {
super.onWindowFocusChanged(focused);
}
}
#Override
public boolean isFocused() {
return true;
}
}
<com.test.autoscroll.ScrollingTextView
android:id="#+id/actionbar_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="10dip"
android:paddingRight="10dip"
android:textSize="16dip"
android:textStyle="bold"
android:lines="1"
android:scrollHorizontally="true"
android:ellipsize="marquee"
android:text="autoscrollable textview without focus to textview...working...."
android:marqueeRepeatLimit="marquee_forever"
/>
Add this code to your own
findViewById(R.id.yourtextviewid).setSelected(true);
maybe your problem is fixed.
I'm using a ScrollView in Android and where the visible portion of the ScrollView is the same size as one of the cells inside the Scrollview. Every "cell" is the same height. So what I am trying to do is snap into position after the ScrollView has been scrolled.
Currently I am detecting when the user has touched the ScrollView and when they've started scrolling and working it out from there, but it is quite buggy. It also needs to work when the user just flicks it and it scrolls and then decelerates.
On iPhone there is a function that is something like didDecelerate and there I can do any code I want when the ScrollView has finished scrolling. Is there such a thing with Android? Or is there some code I could look at to figure out a better way of doing it?
I've looked over the Android docs and could not find anything like that.
I recently had to implement the function you described. What i did was to have a Runnable checking out if the ScrollView had stopped scrolling by comparing the value returned by getScrollY() when the onTouchEvent is first triggered with the value returned after a time defined by the variable newCheck.
See code below (working solution):
public class MyScrollView extends ScrollView{
private Runnable scrollerTask;
private int initialPosition;
private int newCheck = 100;
private static final String TAG = "MyScrollView";
public interface OnScrollStoppedListener{
void onScrollStopped();
}
private OnScrollStoppedListener onScrollStoppedListener;
public MyScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
scrollerTask = new Runnable() {
public void run() {
int newPosition = getScrollY();
if(initialPosition - newPosition == 0){//has stopped
if(onScrollStoppedListener!=null){
onScrollStoppedListener.onScrollStopped();
}
}else{
initialPosition = getScrollY();
MyScrollView.this.postDelayed(scrollerTask, newCheck);
}
}
};
}
public void setOnScrollStoppedListener(MyScrollView.OnScrollStoppedListener listener){
onScrollStoppedListener = listener;
}
public void startScrollerTask(){
initialPosition = getScrollY();
MyScrollView.this.postDelayed(scrollerTask, newCheck);
}
}
Then i have:
scroll.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_UP) {
scroll.startScrollerTask();
}
return false;
}
});
scroll.setOnScrollStoppedListener(new OnScrollStoppedListener() {
public void onScrollStopped() {
Log.i(TAG, "stopped");
}
});
Here is yet another fix to the, IMHO, missing OnEndScroll event bug in the ScrollView.
Its inspired by hambonious answer.
Simply drop this class into your project (change package to match your own) and use the below xml
package com.thecrag.components.ui;
import android.content.Context;
import android.util.AttributeSet;
import android.widget.ScrollView;
public class ResponsiveScrollView extends ScrollView {
public interface OnEndScrollListener {
public void onEndScroll();
}
private boolean mIsFling;
private OnEndScrollListener mOnEndScrollListener;
public ResponsiveScrollView(Context context) {
this(context, null, 0);
}
public ResponsiveScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ResponsiveScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
#Override
public void fling(int velocityY) {
super.fling(velocityY);
mIsFling = true;
}
#Override
protected void onScrollChanged(int x, int y, int oldX, int oldY) {
super.onScrollChanged(x, y, oldX, oldY);
if (mIsFling) {
if (Math.abs(y - oldY) < 2 || y >= getMeasuredHeight() || y == 0) {
if (mOnEndScrollListener != null) {
mOnEndScrollListener.onEndScroll();
}
mIsFling = false;
}
}
}
public OnEndScrollListener getOnEndScrollListener() {
return mOnEndScrollListener;
}
public void setOnEndScrollListener(OnEndScrollListener mOnEndScrollListener) {
this.mOnEndScrollListener = mOnEndScrollListener;
}
}
again changing the package name to match your project
<com.thecrag.components.ui.ResponsiveScrollView
android:id="#+id/welcome_scroller"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/welcome_scroll_command_help_container"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_below="#+id/welcome_header_text_thecrag"
android:layout_margin="6dp">
....
</com.thecrag.components.ui.ResponsiveScrollView>
I subclassed (Horizontal)ScrollView and did something like this:
#Override
protected void onScrollChanged(int x, int y, int oldX, int oldY) {
if (Math.abs(x - oldX) > SlowDownThreshold) {
currentlyScrolling = true;
} else {
currentlyScrolling = false;
if (!currentlyTouching) {
//scrolling stopped...handle here
}
}
super.onScrollChanged(x, y, oldX, oldY);
}
I used a value of 1 for the SlowDownThreshold since it always seems to be the difference of the last onScrollChanged event.
In order to make this behave correctly when dragging slowly, I had to do this:
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
currentlyTouching = true;
}
return super.onInterceptTouchEvent(event);
}
#Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
currentlyTouching = false;
if (!currentlyScrolling) {
//I handle the release from a drag here
return true;
}
}
return false;
}
My approach is determine scrolling state by a timestamp changed each time the onScrollChanged() is called.
It's very easy to determine when is start and end of scrolling.
You can also change threshold ( I use 100ms ) to fix sensitivity.
public class CustomScrollView extends ScrollView {
private long lastScrollUpdate = -1;
private class ScrollStateHandler implements Runnable {
#Override
public void run() {
long currentTime = System.currentTimeMillis();
if ((currentTime - lastScrollUpdate) > 100) {
lastScrollUpdate = -1;
onScrollEnd();
} else {
postDelayed(this, 100);
}
}
}
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (lastScrollUpdate == -1) {
onScrollStart();
postDelayed(new ScrollStateHandler(), 100);
}
lastScrollUpdate = System.currentTimeMillis();
}
private void onScrollStart() {
// do something
}
private void onScrollEnd() {
// do something
}
}
Here is yet another solution, quite simple and clean in my opinion, naturally inspired by answers above. Basically once user ended gesture check if getScrollY() is still changing, after a brief delay (here 50ms).
public class ScrollViewWithOnStopListener extends ScrollView {
OnScrollStopListener listener;
public interface OnScrollStopListener {
void onScrollStopped(int y);
}
public ScrollViewWithOnStopListener(Context context) {
super(context);
}
public ScrollViewWithOnStopListener(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_UP:
checkIfScrollStopped();
}
return super.onTouchEvent(ev);
}
int initialY = 0;
private void checkIfScrollStopped() {
initialY = getScrollY();
this.postDelayed(new Runnable() {
#Override
public void run() {
int updatedY = getScrollY();
if (updatedY == initialY) {
//we've stopped
if (listener != null) {
listener.onScrollStopped(getScrollY());
}
} else {
initialY = updatedY;
checkIfScrollStopped();
}
}
}, 50);
}
public void setOnScrollStoppedListener(OnScrollStopListener yListener) {
listener = yListener;
}
}
My approach for this question is to use a timer to check for the following 2 "events".
1) onScrollChanged() stopped being called
2) User's finger is lift from the scrollview
public class CustomScrollView extends HorizontalScrollView {
public CustomScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
Timer ntimer = new Timer();
MotionEvent event;
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt)
{
checkAgain();
super.onScrollChanged(l, t, oldl, oldt);
}
public void checkAgain(){
try{
ntimer.cancel();
ntimer.purge();
}
catch(Exception e){}
ntimer = new Timer();
ntimer.schedule(new TimerTask() {
#Override
public void run() {
if(event.getAction() == MotionEvent.ACTION_UP){
// ScrollView Stopped Scrolling and Finger is not on the ScrollView
}
else{
// ScrollView Stopped Scrolling But Finger is still on the ScrollView
checkAgain();
}
}
},100);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
this.event = event;
return super.onTouchEvent(event);
}
}
For a simple case like you described, you can probably get away with overriding fling method in your custom scroll view. Fling method gets called to perform "deceleration" every time user raises his finger from the screen.
So what you should do is something like this:
Subclass ScrollView.
public class MyScrollView extends ScrollView {
private Scroller scroller;
private Runnable scrollerTask;
//...
public MyScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
scroller = new Scroller(getContext()); //or OverScroller for 3.0+
scrollerTask = new Runnable() {
#Override
public void run() {
scroller.computeScrollOffset();
scrollTo(0, scroller.getCurrY());
if (!scroller.isFinished()) {
MyScrollView.this.post(this);
} else {
//deceleration ends here, do your code
}
}
};
//...
}
}
Subclass fling method and DO NOT call superclass implementation.
#Override
public void fling(int velocityY) {
scroller.fling(getScrollX(), getScrollY(), 0, velocityY, 0, 0, 0, container.getHeight());
post(scrollerTask);
//add any extra functions you need from android source code:
//show scroll bars
//change focus
//etc.
}
Fling will not trigger if the user stops scrolling before raising up his finger (velocityY == 0). In case you want to intercept this sort of events aswell, override onTouchEvent.
#Override
public boolean onTouchEvent(MotionEvent ev) {
boolean eventConsumed = super.onTouchEvent(ev);
if (eventConsumed && ev.getAction() == MotionEvent.ACTION_UP) {
if (scroller.isFinished()) {
//do your code
}
}
return eventConsumed;
}
NOTE Although this works, overriding fling method might be a bad idea. It is public, but its barely designed for subclassing. Right now it does 3 things - it initiates fling for private mScroller, handles possible focus changes and shows scroll bars. This might change in future android release. For instance, private mScroller instance changed its class from Scroller to OvershootScroller between 2.3 and 3.0. You have to keep in mind all this small differences. In any case, be ready for unforeseen consequences in the future.
My solution is a variation of Lin Yu Cheng's great solution and also detects when scrolling has started and stopped.
Step 1. Define a HorizontalScrollView and OnScrollChangedListener:
CustomHorizontalScrollView scrollView = (CustomHorizontalScrollView) findViewById(R.id.horizontalScrollView);
horizontalScrollListener = new CustomHorizontalScrollView.OnScrollChangedListener() {
#Override
public void onScrollStart() {
// Scrolling has started. Insert your code here...
}
#Override
public void onScrollEnd() {
// Scrolling has stopped. Insert your code here...
}
};
scrollView.setOnScrollChangedListener(horizontalScrollListener);
Step 2. Add the CustomHorizontalScrollView class:
public class CustomHorizontalScrollView extends HorizontalScrollView {
public interface OnScrollChangedListener {
// Developer must implement these methods.
void onScrollStart();
void onScrollEnd();
}
private long lastScrollUpdate = -1;
private int scrollTaskInterval = 100;
private Runnable mScrollingRunnable;
public OnScrollChangedListener mOnScrollListener;
public CustomHorizontalScrollView(Context context) {
this(context, null, 0);
init(context);
}
public CustomHorizontalScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
init(context);
}
public CustomHorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
private void init(Context context) {
// Check for scrolling every scrollTaskInterval milliseconds
mScrollingRunnable = new Runnable() {
public void run() {
if ((System.currentTimeMillis() - lastScrollUpdate) > scrollTaskInterval) {
// Scrolling has stopped.
lastScrollUpdate = -1;
//CustomHorizontalScrollView.this.onScrollEnd();
mOnScrollListener.onScrollEnd();
} else {
// Still scrolling - Check again in scrollTaskInterval milliseconds...
postDelayed(this, scrollTaskInterval);
}
}
};
}
public void setOnScrollChangedListener(OnScrollChangedListener onScrollChangedListener) {
this.mOnScrollListener = onScrollChangedListener;
}
public void setScrollTaskInterval(int scrollTaskInterval) {
this.scrollTaskInterval = scrollTaskInterval;
}
//void onScrollStart() {
// System.out.println("Scroll started...");
//}
//void onScrollEnd() {
// System.out.println("Scroll ended...");
//}
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (mOnScrollListener != null) {
if (lastScrollUpdate == -1) {
//CustomHorizontalScrollView.this.onScrollStart();
mOnScrollListener.onScrollStart();
postDelayed(mScrollingRunnable, scrollTaskInterval);
}
lastScrollUpdate = System.currentTimeMillis();
}
}
}
Try taking a look at this question here on StackOverflow - it's not exactly the same as your question, but it gives an idea on how you can manage the scroll event of a ScrollView.
Basicly you need to create your own CustomScrollView by extending ScrollView and override onScrollChanged(int x, int y, int oldx, int oldy). Then you need to reference this in your layout file instead of the standard ScrollView like com.mypackage.CustomScrollView.
There are some great answers here, but my code can detect when scrolling stops without having to extend ScrollView class.
every view instance can call getViewTreeObserver(). when Holding this instance of ViewTreeObserver you can add a OnScrollChangedListener using the function addOnScrollChangedListener().
declare the following:
private ScrollView scrollListener;
private volatile long milesec;
private Handler scrollStopDetector;
private Thread scrollcalled = new Thread() {
#Override
public void run() {
if (System.currentTimeMillis() - milesec > 200) {
//scroll stopped - put your code here
}
}
};
and in your onCreate (or another place) add:
scrollListener = (ScrollView) findViewById(R.id.scroll);
scrollListener.getViewTreeObserver().addOnScrollChangedListener(new OnScrollChangedListener() {
#Override
public void onScrollChanged() {
milesec = System.currentTimeMillis();
scrollStopDetector.postDelayed(scrollcalled, 200);
}
});
you might want to take longer or slower time between this checks, but when scrolling this listner gets called really fast so it will work very fast.
Here's my solution which includes scroll tracking and scroll ending:
public class ObservableHorizontalScrollView extends HorizontalScrollView {
public interface OnScrollListener {
public void onScrollChanged(ObservableHorizontalScrollView scrollView, int x, int y, int oldX, int oldY);
public void onEndScroll(ObservableHorizontalScrollView scrollView);
}
private boolean mIsScrolling;
private boolean mIsTouching;
private Runnable mScrollingRunnable;
private OnScrollListener mOnScrollListener;
public ObservableHorizontalScrollView(Context context) {
this(context, null, 0);
}
public ObservableHorizontalScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ObservableHorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
int action = ev.getAction();
if (action == MotionEvent.ACTION_MOVE) {
mIsTouching = true;
mIsScrolling = true;
} else if (action == MotionEvent.ACTION_UP) {
if (mIsTouching && !mIsScrolling) {
if (mOnScrollListener != null) {
mOnScrollListener.onEndScroll(this);
}
}
mIsTouching = false;
}
return super.onTouchEvent(ev);
}
#Override
protected void onScrollChanged(int x, int y, int oldX, int oldY) {
super.onScrollChanged(x, y, oldX, oldY);
if (Math.abs(oldX - x) > 0) {
if (mScrollingRunnable != null) {
removeCallbacks(mScrollingRunnable);
}
mScrollingRunnable = new Runnable() {
public void run() {
if (mIsScrolling && !mIsTouching) {
if (mOnScrollListener != null) {
mOnScrollListener.onEndScroll(ObservableHorizontalScrollView.this);
}
}
mIsScrolling = false;
mScrollingRunnable = null;
}
};
postDelayed(mScrollingRunnable, 200);
}
if (mOnScrollListener != null) {
mOnScrollListener.onScrollChanged(this, x, y, oldX, oldY);
}
}
public OnScrollListener getOnScrollListener() {
return mOnScrollListener;
}
public void setOnScrollListener(OnScrollListener mOnEndScrollListener) {
this.mOnScrollListener = mOnEndScrollListener;
}
}
I think this has come up in the past. AFAIK, you can't easily detect that. My suggestion is that you take a look at ScrollView.java (that's how we do things in Android land :)) and figure out how you can extend the class to provide the functionality you are looking for. This is what I would try first:
#Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
if (mScroller.isFinished()) {
// do something, for example call a listener
}
}
this is an old thread but I'd like to add a shorter solution I came up with:
buttonsScrollView.setOnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY ->
handler.removeCallbacksAndMessages(null)
handler.postDelayed({
//YOUR CODE TO BE EXECUTED HERE
},1000)
}
Naturally there's a 1000 milliseconds delay. Adjust that if you need to.
I've made some improvements to ZeroG's answer. Mainly cancellation of excess task calls and implementing the whole thing as a private OnTouchListener, so all the scroll detection code would be in one place.
Paste the following code into your own ScrollView implementation:
private class ScrollFinishHandler implements OnTouchListener
{
private static final int SCROLL_TASK_INTERVAL = 100;
private Runnable mScrollerTask;
private int mInitialPosition = 0;
public ScrollFinishHandler()
{
mScrollerTask = new Runnable() {
public void run() {
int newPosition = getScrollY();
if(mInitialPosition - newPosition == 0)
{//has stopped
onScrollStopped(); // Implement this on your main ScrollView class
}else{
mInitialPosition = getScrollY();
ExpandingLinearLayout.this.postDelayed(mScrollerTask, SCROLL_TASK_INTERVAL);
}
}
};
}
#Override
public boolean onTouch(View v, MotionEvent event)
{
if (event.getAction() == MotionEvent.ACTION_UP)
{
startScrollerTask();
}
else
{
stopScrollerTask();
}
return false;
}
}
And then in your ScrollView implementation:
setOnTouchListener( new ScrollFinishHandler() );
this.getListView().setOnScrollListener(new OnScrollListener(){
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {}
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
if( firstVisibleItem + visibleItemCount >= totalItemCount )
// Last item is shown...
}
Hope the snippet help :)