gistfile1.java

int[] location = new int[2];
		this.anchor.getLocationOnScreen(location);

		Rect anchorRect =
				new Rect(location[0], location[1], location[0] + this.anchor.getWidth(), location[1]
					+ this.anchor.getHeight());
		this.anchorRectangle = anchorRect;
		
		
		this.root.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
		this.root.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);

		int rootWidth = this.root.getMeasuredWidth();
		int rootHeight = this.root.getMeasuredHeight();

		 int screenWidth = this.windowManager.getDefaultDisplay().getWidth();

		int xPos, yPos;
		// Align popup with right side if the root is wider than anchor
		// Align with left otherwise
		if (rootWidth > anchorRect.right - anchorRect.left) {
			xPos = anchorRect.right - rootWidth;
		} else {
			xPos = anchorRect.left + 15;
		}
		
		// Correct for spilling off the edge
		if (xPos + rootWidth > screenWidth)
			xPos = screenWidth - rootWidth - 20;
		
		// xPos = ((screenWidth - rootWidth) / 2) + xOffset;
		yPos = anchorRect.top - rootHeight + yOffset;

		this.rootRectangle = new Rect(xPos, yPos, xPos + rootWidth, yPos + rootHeight);

		boolean onTop = true;
		// display on bottom
		if(rootHeight > anchorRect.top) {
			onTop = false;
			yPos = anchorRect.bottom + yOffset;
			this.window.setAnimationStyle(R.anim.grow_from_top);
		}

		this.window.showAtLocation(this.anchor, Gravity.NO_GRAVITY, xPos, yPos);