protected void setOffsetPixels(float offsetPixels) {
        final int oldOffset = (int) mOffsetPixels;
        final int newOffset = (int) offsetPixels;

        mOffsetPixels = offsetPixels;

        if (mSlideDrawable != null) {
            final float offset = Math.abs(mOffsetPixels) / mMenuSize;
            mSlideDrawable.setOffset(offset);
            updateUpContentDescription();
        }

        if (newOffset != oldOffset) {
            onOffsetPixelsChanged(newOffset);
            mMenuVisible = newOffset != 0;

            // Notify any attached listeners of the current open ratio
            final float openRatio = ((float) Math.abs(newOffset)) / mMenuSize;
            dispatchOnDrawerSlide(openRatio, newOffset);
        }
    }
Sets the number of pixels the content should be offset.

@param offsetPixels The number of pixels to offset the content by.
menudrawer/src/net/simonvt/menudrawer/MenuDrawer.java