Why does TextView have end padding when multi line?

I found the selected answer to be helpful, although it didn't quite account for padding. I combined the selected answer with this post's answer to come up with a view that works with padding. FYI, the other post's answer had a flaw where the view would sometimes get cut-off at the end by a few pixels.

public class TightTextView extends TextView {
  public TightTextView(Context context) {
    super(context);
  }

  public TightTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  public TightTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    int specModeW = MeasureSpec.getMode(widthMeasureSpec);
    if (specModeW != MeasureSpec.EXACTLY) {
      Layout layout = getLayout();
      if (layout != null) {
        int w = (int) Math.ceil(getMaxLineWidth(layout)) + getCompoundPaddingLeft() + getCompoundPaddingRight();
        if (w < getMeasuredWidth()) {
          super.onMeasure(MeasureSpec.makeMeasureSpec(w, MeasureSpec.AT_MOST),
          heightMeasureSpec);
        }
      }
    }
  }

  private float getMaxLineWidth(Layout layout) {
    float max_width = 0.0f;
    int lines = layout.getLineCount();
    for (int i = 0; i < lines; i++) {
      if (layout.getLineWidth(i) > max_width) {
        max_width = layout.getLineWidth(i);
      }
    }
    return max_width;
  }
}

At first, when seeing your post, i thought that the problem was because standard Android TextView have some default padding defined in their base style. If one wants to remove it, ones can try it something like :

android:paddingEnd="0dp"

or

android:paddingRight="0dp"

As your post has been updated, I understand that your problem does not comes from padding, but from word wrapping. Indeed, when there are several lines to display, Android TextView use the whole available space in width.

As stated in this post, there is no standard solution for this and you will need to customize your text view to fix its width after filling it.

Overriding onMeasure method of your textView like below shoud work (inspired from "sky" answer) :

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    int specModeW = MeasureSpec.getMode(widthMeasureSpec);
    if (specModeW != MeasureSpec.EXACTLY) {
        Layout layout = getLayout();
        int linesCount = layout.getLineCount();
        if (linesCount > 1) {
            float textRealMaxWidth = 0;
            for (int n = 0; n < linesCount; ++n) {
                textRealMaxWidth = Math.max(textRealMaxWidth, layout.getLineWidth(n));
            }
            int w = (int) Math.ceil(textRealMaxWidth);
            if (w < getMeasuredWidth()) {
                super.onMeasure(MeasureSpec.makeMeasureSpec(w, MeasureSpec.AT_MOST),
                        heightMeasureSpec);
            }
        }
    }
}