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So I overlayed a view of another view. And try to position my arrow so that it points to the image underneath it:

enter image description here

The arrow is an ImageView and I set its top and left margins to position it in the right place. I did it by adding the width of the TextView underneath it that says "No photo taken today" to the TextView's left border position. But funnily, the arrow is pointing to the middle and not the end of that TextView.

    int topMargin=(int)pxToDp(getRelativeTop(dailyPhotos)+(int)dailyPhotos.getHeight(),this);
    int leftMargin=(int)pxToDp(getRelativeLeft(dailyPhotos)+dailyPhotos.getWidth(),this);

getRelativeLeft() I copied from this answer.

I show the width of that TextView and the screen's width in a Toast. They are both correct since that TextView's width is set to match_parent. I don't what is wrong.

    DisplayMetrics displayMetrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
    int height = displayMetrics.heightPixels;
    int width = displayMetrics.widthPixels;
    Toast.makeText(this,"width="+dailyPhotos.getWidth()+", screen's width="+width,Toast.LENGTH_SHORT).show();
    showNote.putExtra("photoCountTopMargin", topMargin);
    showNote.putExtra("photoCountLeftMargin", leftMargin);
most venerable sir
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1 Answers1

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Reading/Changing the margin of a view needs to be done in the layoutparams of the view

LayoutParams layoutParams = (LayoutParams) view.getLayoutParams();
layoutParams.topMargin = ddd (in pixels)
Karim
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