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Scroll to particular Text view inside the Scroll view

There is a program generated scroll view like this:
The scroll view XML is just simple empty LinearLayout
<ScrollView>
<LinearLayout>
</LinearLayout>
</ScrollView>
Then , in the run time , I have an ArrayList<TextView>, and add the items to the ScrollView like this
for (TextView t : test_views) {
scroll_view.addView(t);
}
And now , I have one of the listView and I would like to scroll to that TextView programmatic , the case is quite special so that can not change the scrollview to listview, how to achieve that?
Thanks a lot for helping.

Try using scrollTo() function. More details available in this link http://developer.android.com/reference/android/widget/ScrollView.html#scrollTo(int, int)

Please check the below code.
sv.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
tv.getParent().requestDisallowInterceptTouchEvent(false);
return false;
}
});
tv.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
tv.getParent().requestDisallowInterceptTouchEvent(true);
return false;
}
});
Hope it will help you.
Let me know if you need any further help.

Prevent Click-through of Android ImageVIew?

I have an ImageView overlay inside of a RelativeLayout and want to prevent any clicks from going through the ImageView to the Buttons etc that are behind it (thus in effect disabling the entire RelativeLayout).
Is the a simpler way of doing this then iterating the RelativeLayout views and setting them to disabled as I currently am doing using this code:
RelativeLayout rlTest = (RelativeLayout ) findViewById(R.id.rlTest);
for (int i = 0; i < rlTest.getChildCount(); i++) {
View view = rlTest.getChildAt(i);
view.setEnabled(true);
}

you can set the image to be
android:clickable="true"

Simply call rlTest.setClickable(false). This will prevent the click to be propagate to the children

There is a much cleaner way
You can use:
android:onClick="preventClicks"
in XML and in your Activity
public void preventClicks(View view) {}
This works with fragments.
Example inside this Activity has multiple fragments overlapping one another, just by adding the XML attribute in the background of your fragment it will still call the Activity.preventClicks and will prevent touches on fragments behind it

The following solution works in the general case:
_container.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// NOTE: This prevents the touches from propagating through the view and incorrectly invoking the button behind it
return true;
}
});
It basically blocks any touches from propagating through the view by marking the touch event as handled.
This works on both UI controls and layout containers (ie: LinearLayout, FrameLayout etc.).
The solution to set "clickable" as false did not work for me for layout containers either in code or in the view XML.

I assume that you are using onClickListeners.
How about using onTouchListener instead of onClickListeners. By doing this you will have a control over how deep down in your hierarchy the touch even can be visible. For example, if you have toch listeners on a relative-layout(RL) and a image-view(IV)(contained in RL), and you assign touchListeners to both. Now if you return true from IV's touch event, the lower down member RL will not receive the touch event. However if you return false from from IV's touch event, the lower down member RL will receive the touch event.
Hope this helps!

Just add these two listeners:
// Set an OnTouchListener to always return true for onTouch events so that a touch
// sequence cannot pass through the item to the item below.
view.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
v.onTouchEvent(event);
return true;
}
});
// Set an OnHoverListener to always return true for onHover events so that focus cannot
// pass through the item to the item below.
view.setOnHoverListener(new OnHoverListener() {
#Override
public boolean onHover(View v, MotionEvent event) {
v.onHoverEvent(event);
return true;
}
});

You could use databindings and consume the clicks like this:
android:onClick="#{() -> true}"

In C#, I use an empty delegate:
objectName.Click += delegate {};
I haven't encountered any problems with it but it does prevent clicks from filtering through to underlying controls.

you can also se the root click listener to null:
// Do not process clicks on other areas of this fragment
binding.root.setOnClickListener(null)
This works 100%.
It doesnt affect other listeners that are already set on the fragment's views.

Adding a Button on a View

I am going nuts over this.
I did not find any working solution (tried a few from stackoverflow)
Scenario (this is an actual screenshot what is already done):
I have a Activity that has a View as his Attribute.
This view adds another view via View.addView(myView).
I now want to add a Button to myView (to be specific: after MotionEvent.ACTION_UP the button should appear in the right lower corner (this will start the robot to drive the track))
Here is a shortcut of my code:
public class ModeRouting extends View {
public ModeRouting(Context context) {
super(context);
Button asuroStartButton = new Button(context) //does not work
}
#Override
public boolean onTouchEvent(MotionEvent event) {
int actionevent = event.getAction();
if (actionevent == MotionEvent.ACTION_UP
|| actionevent == MotionEvent.ACTION_CANCEL) {
asuroStartButton.visible=true;
view.add(asuroStartButton);
}
return true;
}
}
and my Activity:
//in constructor
contentView = (FrameLayout) findViewById(R.id.content);
onClickListenerFacade(routingMode, route);
//this removes all views from stack and places the new one on the view
private void onClickListenerFacade(View v, final View target) {
v.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
contentView.removeAllViews();
contentView.setBackgroundColor(0xff000000);
contentView.addView(target);
modeSelectorAnimation();
}
});
}
I tried to create a button in my mainactivity.xml and instantiate in my mainactivity.
I am missing some point in here but i am not sure which.
Since my view is purely dynamic (no layout.xml) i dont think i should use a layout.xml (maybe thats my mind-blockage) but instead set the button attributes dynamically too.
Any hint is appreciated!

You want to extend ViewGroup rather than just a View (LinearLayout, RelativeLayout, FrameLayout, etc) - they handle child views for you.

I think maybe you need to refresh the whole view/activity. Try to do this in the onResume methode, maybe this helps. But as you don't use a layout.xml, I'm not sure if this helps you much..
#Override
protected void onResume(){
super.onResume();
setContentView(R.layout.activity_main);
}

2 Simultaneous Android Touches / not triggered

So hi there.
I have a simple Layout with 2 Views in it. Both have an onTouchListener attached.
view.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent event) {
System.out.println("Touching");
return false;
}
});
But when I open the application on my phone and touch the first view and do NOT relase my finger and touch the second view with another finger, the second view wont trigger the touch event. why is this so?

I think in this case both touches are passed to the first view as a multi-touch event. So this is one event but contains (I forgot the details) both touch positions.

Android: HorizontalScrollView inside ScrollView

I have multiple HorizontalScrollViews inside a ScrollView. Horizontal scroll isn't smooth at all. I have to scroll almost perfectly horizontally for scrolling to work. Is there a simple fix to tweak this ??? Thanks!

You can use Recycler view with Staggered layout manager
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(4, StaggeredGridLayoutManager.HORIZONTAL);
RecyclerViewAdapter recyclerViewAdapter = newRecyclerViewAdapter(this);
recyclerView.setAdapter(recyclerViewAdapter); //Don't miss to initialize your adapter

This class creates a ScrollView containing a HorizontalScrollView combined into one class. You can put stuff inside it using the AddChild() method. The dispatchTouchEvent overide keeps the scrolling smooth so you can pan around with a single slide of the finger.
(I recently used this to wrap a programmatically created TextView)
class MultiScrollView extends ScrollView
{
public HorizontalScrollView hscroll;
public MultiScrollView ( Context context )
{
super( context );
}
public void AddChild( View child )
{
hscroll.addView( child );
}
#Override
public boolean dispatchTouchEvent( MotionEvent event )
{
hscroll.dispatchTouchEvent(event);
onTouchEvent(event);
return true;
}
}

If you are using the horizontal scroll view solution from (http://www.dev-smart.com/archives/34) the solution for the cross focus problem between the scroll view and the list view is blocking the focus to the scroll view once you have focus on the list view.
From a technical point of view you should add the following line to the onScroll function inside the HorizontalListView class.
getParent().requestDisallowInterceptTouchEvent(true);
Hope this helps.

I've found the solution and still can't believe that this is what you have to do to make this work normal! Just added blank onClickListener to the each item in the HorizontalScrollView:
item.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
After this slide is really smooth, both upwards and downwards.

In general, you shouldn't be using nested ScrollViews in Android at all, the behaviour of scrolling in this way is unnatural too.
You may want to rethink your layout design, is it anything that couldn't be achieved with an expandable list?

While David's answer works, it has a downside. It passes ScrollView's MotionEvent object directly to HorizontalScrollView.onTouchEvent(), so if HorizontalScrollView or its children try to get the event coordinates, they will get the wrong coordinates which based on ScrollView.
My solution:
public class CustomScrollView extends ScrollView{
/*************skip initialization*************/
#Override
public boolean onInterceptTouchEvent(MotionEvent e){
//returning false means ScrollView is not interested at any events,
//so ScrollView's onTouchEvent() won't be called,
//and all of the events will be passed to ScrollView's child
return false;
}
#Override
public boolean dispatchTouchEvent(MotionEvent ev) {
//manually call ScrollView's onTouchEvent(),
//the vertical scrolling happens there.
onTouchEvent(ev);
//dispatch the event,
//ScrollView's child will have every event.
return super.dispatchTouchEvent(ev);
}
}
Just wrap this CustomScrollView around the HorizontalScrollView in your layout file.