Husky Husky - 6 days ago 5
Android Question

Relative Layout get Width/Height return 0

I need to get width and height of Relative layout, however I do not know when the Relative Layout is ready to provide me these two attributes. My activity has several tabs and I call the

getWidth()
and
getHeight()
in
onCreateView()
after
inflater.inflate(R.layout.fragment_pizza, container, false);
, however it returns 0 for both of them, so they are not apparently ready. Is there some kind of event like afterCreateView() or something similar where I can call these two methods and get the actual width and height?

Code:

public class PizzaFragment extends Fragment {

private static final String TAG = "PizzaFragment";

private Controller controller;

private static final int BUTTON_WIDTH = 70;
private static final int BUTTON_HEIGHT = 20;

private static final int MARGIN_LEFT = 80;
private static final int MARGIN_BOTTOM = 30;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

controller = Controller.getInstance();
controller.loadProducts("pizza", getActivity().getApplicationContext());
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_pizza, container, false);

RelativeLayout layout = (RelativeLayout) view.findViewById(R.id.rl_order_pizza);
Log.d(TAG, "Width: " + layout.getWidth());
Log.d(TAG, "Height: " + layout.getHeight());

int currentX = 10;
int currentY = 10;

RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(BUTTON_WIDTH, BUTTON_HEIGHT);


for (Product product: controller.getProducts("pizza")){

Button tempButton = new Button(getActivity());
tempButton.setId(product.getId());
tempButton.setText(product.getName());

if (layout.getWidth() < currentX + MARGIN_LEFT){
currentX = 10;
currentY = MARGIN_BOTTOM;

}
else{
currentX += MARGIN_LEFT;
}

Log.d(TAG, "CurrentY: " + currentY);
Log.d(TAG, "CurrentX: " + currentX);

layoutParams.leftMargin = currentX;
layoutParams.bottomMargin = currentY;

tempButton.setLayoutParams(layoutParams);

layout.addView(tempButton);
}

return view;

}
}

Answer

My suggestion is to use a global layout listener like this in onCreateView:

YOUR_LAYOUT_INSTANCE = view.findViewById(R.id.YOUR_LAYOUT_ID);

...

YOUR_LAYOUT_INSTANCE.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener()
{
    @Override
    public void onGlobalLayout()
    {
        // gets called after layout has been done but before display.
        YOUR_LAYOUT_INSTANCE.getViewTreeObserver().removeGlobalOnLayoutListener(this);

    // get width and height
    }
});