How to retrieve the dimensions of a view

Question

I have a view made up of TableLayout  TableRow and TextView  I want it to look like a grid   I need to get the height and width of this grid   The methods getHeight   and getWidth   always return 0   This happens when I format the grid dynamically and also when I use an XML version     How to retrieve the dimensions for a view       Here is my test program I used in Debug to check the results    import android app Activity  import android os Bundle  import android widget TableLayout  import android widget TextView   public class appwig extends Activity          Override     public void onCreate Bundle savedInstanceState          super onCreate savedInstanceState         setContentView R layout maindemo       lt - includes the grid called  board        int vh   0           int vw   0           Test-1 used the xml layout  which is displayed on the screen         TableLayout tl    TableLayout  findViewById R id board           tl    TableLayout  findViewById R id board         vh   tl getHeight           lt - getHeight returned 0  Why          vw   tl getWidth           lt - getWidth returned 0  Why              Test-2 used a simple dynamically generated view                TextView tv   new TextView this         tv setHeight 20         tv setWidth 20         vh   tv getHeight          lt - getHeight returned 0  Why               vw   tv getWidth          lt - getWidth returned 0  Why           eof method     eof class

User · Answer

CORRECTION  I found out that the above solution is terrible  Especially when your phone is slow  And here  I found another solution  calculate out the px value of the element  including the margins and paddings  dp to px      https   stackoverflow com a 6327095 1982712  or dimens xml to px      https   stackoverflow com a 16276351 1982712  sp to px      https   stackoverflow com a 9219417 1982712  reverse the solution   or dimens to px      https   stackoverflow com a 16276351 1982712  and that s it

User · Answer

Are you trying to get sizes in a constructor  or any other method that is run BEFORE you get the actual picture   You won t be getting any dimensions before all components are actually measured  since your xml doesn t know about your display size  parents positions and whatever   Try getting values after onSizeChanged    though it can be called with zero   or just simply waiting when you ll get an actual image

User · Answer

Use getMeasuredWidth   and getMeasuredHeight   for your view   Developer guide  View

User · Answer

I guess this is what you need to look at  use onSizeChanged   of your view  Here is an EXTENDED code snippet on how to use onSizeChanged   to get your layout s or view s height and width dynamically http   syedrakibalhasan blogspot com 2011 02 how-to-get-width-and-height-dimensions html

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I tried to use onGlobalLayout   to do some custom formatting of a TextView  but as  George Bailey noticed  onGlobalLayout   is indeed called twice  once on the initial layout path  and second time after modifying the text   View onSizeChanged   works better for me because if I modify the text there  the method is called only once  during the layout pass   This required sub-classing of TextView  but on API Level 11  View  addOnLayoutChangeListener   can be used to avoid sub-classing   One more thing  in order to get correct width of the view in View onSizeChanged    the layout width should be set to match parent  not wrap content

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Height and width are zero because view has not been created by the time you are requesting it s height and width   One simplest solution is  view post new Runnable          Override     public void run             view getHeight      height is ready         view getWidth      width is ready             This method is good as compared to other methods as it is short and crisp

User · Answer

You should rather look at View lifecycle  http   developer android com reference android view View html Generally you should not know width and height for sure until your activity comes to onResume state

User · Answer

You are trying to get width and height of an elements  that weren t drawn yet   If you use debug and stop at some point  you ll see  that your device screen is still empty  that s because your elements weren t drawn yet  so you can t get width and height of something  that doesn t yet exist   And  I might be wrong  but setWidth   is not always respected  Layout lays out it s children and decides how to measure them  calling child measure     so If you set setWidth    you are not guaranteed to get this width after element will be drawn   What you need  is to use getMeasuredWidth    the most recent measure of your View  somewhere after the view was actually drawn   Look into Activity lifecycle for finding the best moment   http   developer android com reference android app Activity html ActivityLifecycle  I believe a good practice is to use OnGlobalLayoutListener like this   yourView getViewTreeObserver   addOnGlobalLayoutListener new OnGlobalLayoutListener              Override         public void onGlobalLayout                 if   mMeasured                       Here your view is already layed out and measured for the first time                 mMeasured   true     Some optional flag to mark  that we already got the sizes                                   You can place this code directly in onCreate    and it will be invoked when views will be laid out

User · Answer

As F X  mentioned  you can use an OnLayoutChangeListener to the view that you want to track itself  view 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

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You can use a broadcast that is called in OnResume     For example   int vh   0     int vw   0   public void onCreate Bundle savedInstanceState          super onCreate savedInstanceState         setContentView R layout maindemo       lt - includes the grid called  board         registerReceiver new BroadcastReceiver                  Override             public void onReceive Context context  Intent intent                    TableLayout tl    TableLayout  findViewById R id board                     tl    TableLayout  findViewById R id board                   vh   tl getHeight                           vw   tl getWidth                                          new IntentFilter  Test        protected void onResume             super onResume             Intent it   new Intent  Test            sendBroadcast it        You can not get the height of a view in OnCreate     onStart     or even in onResume    for the reason that kcoppock responded

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I ll just add an alternative solution  override your activity s onWindowFocusChanged method and you will be able to get the values of getHeight    getWidth   from there     Override public void onWindowFocusChanged  boolean hasFocus               the height will be set at this point         int height   myEverySoTallView getMeasuredHeight

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I believe the OP is long gone  but in case this answer is able to help future searchers  I thought I d post a solution that I have found  I have added this code into my onCreate   method   EDITED  07 05 11 to include code from comments   final TextView tv    TextView findViewById R id image test   ViewTreeObserver vto   tv getViewTreeObserver    vto addOnGlobalLayoutListener new OnGlobalLayoutListener           Override     public void onGlobalLayout             LayerDrawable ld    LayerDrawable tv getBackground            ld setLayerInset 1  0  tv getHeight     2  0  0           ViewTreeObserver obs   tv getViewTreeObserver             if  Build VERSION SDK INT  gt   Build VERSION CODES JELLY BEAN                obs removeOnGlobalLayoutListener this             else               obs removeGlobalOnLayoutListener this                          First I get a final reference to my TextView  to access in the onGlobalLayout   method   Next  I get the ViewTreeObserver from my TextView  and add an OnGlobalLayoutListener  overriding onGLobalLayout  there does not seem to be a superclass method to invoke here     and adding my code which requires knowing the measurements of the view into this listener  All works as expected for me  so I hope that this is able to help

User · Answer

Use the View s post method like this  post new Runnable             Override     public void run             Log d TAG   width     MyView this getMeasuredWidth

User · Answer

ViewTreeObserver and onWindowFocusChanged   are not so necessary at all   If you inflate the TextView as layout and or put some content in it and set LayoutParams then you can use getMeasuredHeight   and getMeasuredWidth     BUT you have to be careful with LinearLayouts  maybe also other ViewGroups   The issue there is  that you can get the width and height after onWindowFocusChanged   but if you try to add some views in it  then you can t get that information until everything have been drawn  I was trying to add multiple TextViews to LinearLayouts to mimic a FlowLayout  wrapping style  and so couldn t use Listeners  Once the process is started  it should continue synchronously  So in such case  you might want to keep the width in a variable to use it later  as during adding views to layout  you might need it

User · Answer

Simple Response   This worked for me with no Problem   It seems the key is to ensure that the View has focus before you getHeight etc  Do this by using the hasFocus   method  then using getHeight   method in that order  Just 3 lines of code required   ImageButton myImageButton1   ImageButton findViewById R id imageButton1   myImageButton1 hasFocus     int myButtonHeight   myImageButton1 getHeight     Log d  Button Height        myButtonHeight     Not required  Hope it helps

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Even though the proposed solution works  it might not be the best solution for every case because based on the documentation for ViewTreeObserver OnGlobalLayoutListener     Interface definition for a callback to be invoked when the global layout state or the visibility of views within the view tree changes     which means it gets called many times and not always the view is measured  it has its height and width determined   An alternative is to use ViewTreeObserver OnPreDrawListener which gets called only when the view is ready to be drawn and has all of its measurements   final TextView tv    TextView findViewById R id image test   ViewTreeObserver vto   tv getViewTreeObserver    vto addOnPreDrawListener new OnPreDrawListener           Override     public void onPreDraw             tv getViewTreeObserver   removeOnPreDrawListener this              Your view will have valid height and width at this point         tv getHeight            tv getWidth

[android] How to retrieve the dimensions of a view?

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