Swing/AWT/SWT :: Using Doubles For Positioning Objects And Testing Equality

I've been noticing some of my programs have been a little buggy recently, and think it's down to confusion over doubles and positioning. Lets say I have a label called banner that I want to scroll across the screen. Now I need to know the label's width in order to position it, but the width depends on the amount of text, so i use this code:

double bannerWidth = banner.getWidth();

Which forces me into using a double if I want to be accurate.

But the problem is that I'm trying to use a condition that compares the label's horizontal position (currentX) to the left edge of the screen (LEFT_EDGE), minus the width of the label (bannerWidth). In other words when the label is off the screen, it should go back to its starting position.

I assume that means that any variables I use to track the label's position (in this case currentX), or constants that I use to check equality (LEFT_EDGE), have to be doubles as well?

My difficulty is that I iterate currentX. But currentX--; won't work because doubles don't iterate as I'd expect.

So casting becomes an option..... but if I cast to an integer I effectively lose width on the label. And that is magnified each loop, resulting in the label's starting position moving further and further to the left.