I have a layout with some Views that I need to change size depending on some parameters, that depend on width of the View. The width is set to "match_parent". So when I try to get the width it returns 0. Here is what I have tried so far:
mask.getWidth();
mask.getLayoutParams().width
ViewTreeObserver vto = mask.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
mask.getViewTreeObserver().removeGlobalOnLayoutListener(this);
int width = mask.getMeasuredWidth();
}
});
So my question is how do I get the width in this situation?
Thank you.
After digging around I found a solution that answers my question but has a major problem that I am yet to resolve. We can use method post() that every View has and adds a Runnable to the message queue. So as I understand what happens is after View is fully measured in method post() we can get dimensions that we need like this:
holder.button.post(new Runnable() {
#Override
public void run() {
width = holder.button.getWidth();
}
});
However the problem here is that RecyclerView won't wait until this view is measured as and will go to next row and rows won't be updated according to measures that you expect.
If anyway has a way to go about this problem please leave a comment. Thank you.
I'm making my own custom view and having trouble accessing the layout object immediately after initializing it.
I understand the documentation says layout can be null. But is there a certain event which I can override which will tell me when it's available? I've seen answers on SO which recommend adding a ViewTreeObserver (here)
It seems weird to me that I would need a separate class to know when the layout is available. Is there another way?
From what I understood, there exist no such method which you can override to know when the layout is available. If you find ViewTreeObserver difficult, you can try posting a runnable in the UI Thread i.e.,
view.post(new Runnable() {
#Override
public void run() {
int height = view.getHeight();
int width = view.getWidth();
}
});
Basically, the initialization of the layouts occurs in onCreate() so it would be better if you try the below code in onResume() whether the custom layout is available or not.
if the custom layout is custom_layout.xml then try the below code
LayoutInflater inflater=getLayoutInflater();
View view=inflater.inflate(R.layout.custom_layout,null);
if(view!=null)
{
//Place your code over here
}
im trying to measure a ImageView, after my fragment is displayed, or if possible before.
I heared, that its not yet possible in the onActivityCreated. But somehow it works with the global Layout listener. -But how? -I have a method, wich measures and does some code, i just don't know when to call the method.
Can somebody gice an example?
the beginning of the measure method:
public void skalierung() {
InputStream dots=getResources().openRawResource(R.drawable.amountofdots);
Bitmap dotsBmp = BitmapFactory.decodeStream(dots);
View mainframe=(View)getActivity().findViewById(R.id.mainframe);
int breite=mainframe.getWidth();
Thanks!
To set a GlobalLayoutListener you have to get ViewTreeObserverof your View using the view.getViewTreeObserver() method which :
Returns the ViewTreeObserver for this view's hierarchy. The view tree observer can be used to get notifications when global events, like layout, happen.
After doing that well , you can addOnGlobalLayoutListener on your ViewTreeObserever
OnGlobalLayoutListener : Interface definition for a callback to be invoked when the global layout state or the visibility of views within the view tree changes.
and inside the onGlobalLayoutmethod you can call the getWidth on the your desired view, here's an example :
View mainframe=(View)getActivity().findViewById(R.id.mainframe);
ViewTreeObserver vto = mainframe.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
skalierung(); // here you can call the getWidth and getHeight methods
ViewTreeObserver obs = mainframe.getViewTreeObserver();
// you have to reset the ViewTreeObserver each time to ensure the reuse of the OnGlobalLayoutListener
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
obs.removeOnGlobalLayoutListener(this);
} else {
obs.removeGlobalOnLayoutListener(this);
}
}
});
Hope it helps.
I am trying to convert my Android app to Fragments to support multiple screen sizes and to use the new ICS tabs correctly. Previously I used the onWindowFocusChanged() method and ran the following code inside of it - basically this did some dynamic formatting of my layout after it was created.
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
LinearLayout theLayout = (LinearLayout)inflater.inflate(R.layout.tab_frag2_layout, container, false);
getWidthEditButton = (ImageButton) theLayout.findViewById(R.id.buttonEditPoints);
buttonAddPointsManual = (ImageView) theLayout.findViewById(R.id.buttonAddPointsManual);
linearPointsUsed = (LinearLayout) theLayout.findViewById(R.id.linearLayoutPointsUsed);
int paddingLeftForTracker = linearPointsUsed.getPaddingLeft();
int paddingRightForTracker = getWidthEditButton.getWidth();
linearPointsUsed.setPadding(paddingLeftForTracker, 0, paddingRightForTracker, 0);
}
Now that I have moved to Fragments and for some reason my paddingRightForTracker returns 0. I ran into an issue previously where I was trying to get width too early, hence my move to onWindowFocusChanged previously, but that is not available to Fragments. The strange thing is that paddingLeftForTracker actually returns a non-zero value.
If I set paddingRightForTracker manually, the change takes place so I know the code is running. Just can't figure out why my getWidth is returning 0.
Any help would be greatly appreciated.
You could try doing it in onActivityCreated(). So, you would save a reference to those views in onCreateView, and then access them in onActivityCreated(). I think the view isn't completed created when you're trying to access it, which is why it returns no width.
http://developer.android.com/reference/android/app/Fragment.html#onActivityCreated(android.os.Bundle)
Ok, so I found out about another way to get the width. I, too, cannot get a button width on neither onViewCreated, onCreateView, nor onResume. I found this, tried it, and it's returning a value, so maybe it'll work for you!
How to get height and width of Button
ViewTreeObserver vto = button.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
width = button.getWidth();
height = button.getHeight();
}
});
FYI, I ran this code in onResume, so I'm not exactly sure where else it could work.
This works for me and it looks cleaner (I am also using lambda but it's not required):
v.post(() -> {
int width = v.getWidth();
doSomething(width>300);
});
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); //<- 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(); //<- getHeight returned 0, Why?
vw = tl.getWidth(); //<- 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(); //<- getHeight returned 0, Why?
vw = tv.getWidth(); //<- getWidth returned 0, Why?
} //eof method
} //eof class
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 >= 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.
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();
}
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.
Use the View's post method like this
post(new Runnable() {
#Override
public void run() {
Log.d(TAG, "width " + MyView.this.getMeasuredWidth());
}
});
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.
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.
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.
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
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.
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();
}
});
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.
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.
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); //<- 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
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.
Use getMeasuredWidth() and getMeasuredHeight() for your view.
Developer guide: View
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.