Question

I want to draw some text inside my layout that is full screen the problem is i can get an accurate point. Here is what i coded:

 DisplayMetrics display = getResources().getDisplayMetrics();
                    int width = display.widthPixels;
                    String data_azi = DateFormat.getDateTimeInstance().format(new Date()); 
                    cnv.drawText(data_azi, width - p.measureText(data_azi), 40,p);

Answer 1

you need to measure upfront and use that measurement during drawing time. For example you could call measureText() at init time. This method measures the width of the current date and adds 20% to the measured width.

private final Rect mBounds = new Rect();
private final Date mDate = new Date();


private void measureText(final Paint p){
    final String dummy =  DateFormat.getDateTimeInstance().format(mDate);
    p.getTextBounds(dummy, 0, dummy.length(), mBounds);
    final int inset = (int) (mBounds.width()*0.1f); //add safety margin
    mBounds.inset(-inset, 0);
}

Then you draw like this:

mDate.setTime(System.currentTimeMillis());
String data_azi = DateFormat.getDateTimeInstance().format(mDate); 
cnv.drawText(data_azi, width - mBounds.width(), mBounds.height(),p);

Also make sure that your paint object is left aligned p.setTextAlign(Align.LEFT);