Question

In my android app I have a background image which is longer than the screen width for all the three types of screens.This implies that I have got 3 drawables each for different screen type(mdpi,ldpi,hdpi) and hence I have included a horizontal scroll bar in my app.

Now I want to know that how much does the actual background image extends beyond the visible screen.How do I calculate this?

Is the actual width and height of background image visible on the screen is same as the dimension of the image in the drawable folder or do i need to calculate this.If yes please tell me how to calculate the dimensions of a background image in such scenarios.

Answer 1

Well, you can get the dimensions of your image from this:

Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.image_resource);
int width = bitmap.getWidth();
int height = bitmap.getHeight();

And you can get the dimensions of the screen from this:

DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int screenWidth = displaymetrics.widthPixels; 
int screenHeight = displaymetrics.heightPixels;

Now you can do your calculation.