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onGlobalLayout differentiate between various invocations

I have a logo view, which is a full screen fragment containing single ImageView.
I have to perform some operations after the logo image is completely visible.
Following code is used to invoke the special task
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ImageView logoImageMaster = new ImageView(getContext());
//logoImageMaster.setImageResource(resID); //even after removing this, i am getting the callback twice
try {
// get input stream
InputStream ims = getActivity().getAssets().open("product_logo.png");
// load image as Drawable
Drawable d = Drawable.createFromStream(ims, null);
// set image to ImageView
logoImageMaster.setImageDrawable(d);
}
catch(IOException ex) {
}
logoImageMaster.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() { //FIXME get called twice. Check this out, no info to distinguish first from second
// Log.e("PANEL", "onGlobalLayout of Logo IV ---------------------------------");
activityInterface.doSpecialLogic();
}
});
return logoImageMaster;
}
My exact problem is, onGlobalLayout is called twice for this view hierarchy.
I know that onGlobalLayout is invoked in performTraversal of View.java hence this is expected.
For my use case of Single parent with Single child view, I want to distinguish the view attributes such that doSpecialLogic is called once[onGlobalLayout is called twice] , after the logo image is completely made visible.
Please suggest some ideas.

OnGlobalLayoutListener gets called every time the view layout or visibility changes. Maybe you reset the views in your doSpecialLogic call??
edit
as #Guille89 pointed out, the two set calls cause onGlobalLayout to be called two times
Anyhow, if you want to call OnGlobalLayoutListener just once and don't need it for anything else, how about removing it after doSpecialLogic() call??
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
//noinspection deprecation
logoImageMaster.getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
logoImageMaster.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
activityInterface.doSpecialLogic();

It seems to be called one time for each set done over the imageView
logoImageMaster.setImageResource(resID);
logoImageMaster.setImageDrawable(d);

You should Try using kotlin plugin in android
This layout listener is usually used to do something after a view is measured, so you typically would need to wait until width and height are greater than 0. And we probably want to do something with the view that called it,in your case
Imageview
So generified the function so that it can be used by any object that extends View and also be able to access to all its specific functions and properties from the function
[kotlin]
inline fun <T: View> T.afterMeasured(crossinline f: T.() -> Unit) {
viewTreeObserver.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
override fun onGlobalLayout() {
if (measuredWidth > 0 && measuredHeight > 0) {
viewTreeObserver.removeOnGlobalLayoutListener(this)
f()
}
}
})
}
[/kotlin]
Note:
make sure that ImageView is described properly in the layout. That is its layout_width and layout_height must not be wrap_content. Moreover, other views must not result in this ImageView has 0 size.

Android - Event after createView

I want to get width and height of my layout after it had been drawn.
My code is actually called in the createView() method. But I want to wait until the layout is drawn before execute this code :
Log.i(TAG, "Height: "+myButton.getHeight()+" - width : "+myButton.getWidth());
// result is Height: 0 - width : 0
Is there any event launched after onCreateView() call ?

Using a global layout listener has always worked well for me. It has the advantage of being able to remeasure things if the layout is changed, e.g. if something is set to View.GONE or child views are added/removed.
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// inflate your main layout here (use RelativeLayout or whatever your root ViewGroup type is
LinearLayout mainLayout = (LinearLayout ) this.getLayoutInflater().inflate(R.layout.main, null);
// set a global layout listener which will be called when the layout pass is completed and the view is drawn
mainLayout.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener() {
public void onGlobalLayout() {
//Remove the listener before proceeding
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mainLayout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
} else {
mainLayout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
// measure your views here
}
}
);
setContentView(mainLayout);
Depending on your usage, you might want to remove the listener when you're done with it as shown.

createView does not exits. I suppose you mean Fragment.onCreateView
inside onCreateView,
onCreateView(...) {
View view = infalter.inflate...
final View button = view.findViewById
view.post(new Runnable() {
#Override
public void run() {
Log.i(TAG, "Height: "+button.getHeight()+" - width : "+button.getWidth());
}
});
return view;
}

I think onWindowFocusChanged(boolean hasFocus) is what you are looking for.
Keep in mind that it is called whenever the window focus changes.
#Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
Log.i(TAG, "Height: "+myButton.getHeight()+" - width : "+myButton.getWidth());
}

getWidth() and getHeight() always returning 0. Custom view

In a Fragment, I am inflating a Layout with multiple child View. I need to get the dimensions (width and height) of one of them which is a custom view.
Inside the custom view class I can do it easily. But if I try to do it from the fragment I always get 0 as dimensions.
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
View culoide = view.findViewWithTag(DRAW_AREA_TAG);
Log.d("event", "culoide is: "+culoide.getWidth()); // always 0
}
I figure that onViewCreated should be the right place to get it, but well this happens. I tried before super.onViewCreated, in debug it looks like 'findViewWithTag' finds the right view, tried with api 7 v4 support only.
Any help?

You must wait until after the first measure and layout in order to get nonzero values for getWidth() and getHeight(). You can do this with a ViewTreeObserver.OnGlobalLayouListener
public void onViewCreated(final View view, Bundle saved) {
super.onViewCreated(view, saved);
view.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
} else {
view.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
// get width and height of the view
}
});
}

My preferred method is to add an OnLayoutChangeListener to the view that you want to track itself
CustomView customView = ...
customView.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
#Override
public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
// Make changes
}
});
You can remove the listener in the callback if you only want the initial layout.

Using ViewTreeObserver.OnGlobalLayoutListener, View.post(Runnable action) or onWindowFocusChanged() isn't the best solution. This article (note: I am the author of this article) explains why and provides a working solution using doOnLayout kotlin extension, which is based on View.OnLayoutChangeListener. If you want it in Java, in the article there's a link to doOnLayout source code, it's very simple and you can do something similar in Java too.

You have to wait until the onSizeChanged() method is called before you can reliably determine the View size.
This is called during layout when the size of this view has changed.
If you were just added to the view hierarchy, you're called with the
old values of 0.

Try calling
culoide.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
first, then try getWidth() and getHeight()

Try checking in onWindowFocusChanged and it should have valid values:
public void onWindowFocusChanged (boolean hasFocus) { }
I had a similar issue where I needed to get width and height of a widget and this was the function in which I could guarantee the widget reported it's correct size.

this is a real pain especially because you expected with a name like onViewCreated in fragments lifecycle that the view is ready. for me get the fragment view itself like this:
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
getView()?.let{
it.doOnLayout{// do your UI work here }
}
}
this ensures the fragments getView has actually had one layout pass already.

Why view width and height 0 in post() runnable?

I'm getting height and width of a view, inflated in the getView() method. It's a grid item.
Usually I use post() on the view to get the size, after it was attached to the layout. But it returns 0.
final View convertViewFinal = convertView;
convertView.post(new Runnable() {
#Override
public void run() {
doSomethingWithConvertView(convertViewFinal);
}
});
...
doSomethingWithConvertView(View v) {v.getWidth(); /*returns 0*/};
How do I get the size?

While using a viewTreeObserver definitely works, I have found that calling measurements requirements on inflated views can be done reliably using a runnable from the activity's view. i.e.
someActivityInstance.getWindow().getDecorView().post(new Runnable() {
#override
public void run() {
// someMeasurements
}
});

The thing is that convertview most likely is not drawn on the phone screen yet, so you have to wait until it is ready.
You need to use a ViewTreeObserver, to know exactly when the view has been drawn.
Check this answer for more info:
When Can I First Measure a View?

You probably is calling this at onCreate or onStart or onResume, methods which runs before layout measure.
But there is a lot of work arounds, this is one good option:
ViewTreeObserver vto = rootView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
public void onGlobalLayout() {
v.getWidth();//already measured...
}
});
Where rootView may be any viewGroup in a higher level than the one you want the width.
But be aware that this listner may run more than once.

Android ScrollView, scroll before visible

how can I set scroll of scrollview to x pixels, before it's even shown?
In ScrollView I have some Views and i know that it will fill screen. Can I scroll to let say second View, so that first View is not visible when activity is started?
Now I have sth like this, but I think it's not perfect, sometimes, I see first View, and then it's scrolled to the second one
#Override
public void onGlobalLayout() {
if (mHorizontalScrollView.getChildCount() > 0 && mHorizontalScrollView.getChildAt(0).getWidth() > mScreenWidth) {
hsv.scrollTo(100, 0);
}
}
EDIT!!
Second attempt was to use http://developer.android.com/reference/android/view/ViewTreeObserver.OnPreDrawListener.html instead of http://developer.android.com/reference/android/view/ViewTreeObserver.OnGlobalLayoutListener.html
In OnPreDrawListener we can read that At this point, all views in the tree have been measured and given a frame. Clients can use this to adjust their scroll bounds or even to request a new layout before drawing occurs. so basically at this point we should adjust scrolling. So I created:
#Override
public boolean onPreDraw() {
if (hsv.getChildCount() > 0 && hsv.getChildAt(0).getWidth() > mScreenWidth) {
hsv.scrollTo(100, 0);
return false;
}
return true;
}
but now it's never working for me.

I combined onGlobalLayout with code below. It's not so great to use that hack but it still quite efficient. When I get onGlobalLayout event I check if layouts are done and then if it's ok I use method below.
// hsv - horizontal scroll view
private void forceShowColumn(final int column) {
int scrollTo = childViewWidth * column;
if (scrollTo == hsv.getScrollX()) {
return;
}
hsv.scrollTo(scrollTo, 0);
hsv.postDelayed(new Runnable() {
#Override
public void run() {
forceShowColumn(column);
}
}, 10);
}

try View.post(Runnable) in onCreate-method.

I solved this issue by implementing View.OnLayoutChangeListener in the fragment that controls my ScrollView.
public class YourFragment extends Fragment implements View.OnLayoutChangeListener{
...
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.your_fragment_layout, container, false);
//set scrollview layout change listener to be handled in this fragment
sv = (ScrollView) view.findViewById(R.id.your_scroll_view);
sv.addOnLayoutChangeListener(this);
return view;
}
...
public void onLayoutChange (View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom){
switch (v.getId())
{
case R.id.your_scroll_view:
{
sv.scrollTo(0, sv.getTop());
}
}
}

The correct way to do this, is to call scrollTo() on the ScrollView after the view has been through its measurement and layout passes, otherwise the width of the content in the scrollView will be 0, and thus scrollTo() will not scroll to the right position. Usually after the constructor has been called and after the view has been added to its parent.
See http://developer.android.com/guide/topics/ui/how-android-draws.html for more insight on how android draws views.

MrJre gives the most elegant solution: "override onLayout() in the scrollview and do it there after super.onLayout()"
Example code here:
https://stackoverflow.com/a/10209457/1310343

Use :
scrollTo (int x, int y)
It sets the scrolled position of your view. This will cause a call to onScrollChanged
For more details : see this
ScrollView ScrollTo