Hello all,

What is the recommended way to make dragging scale the graph (vertically) around zero? I have graphs which contain positive and negative values, and the normal drag-scale extends the graph while keeping the minimum value at the bottom of the rectangle; I would like to change this so that it will keep the zero values (i.e., the horizontal axis) at the same vertical position and change the scale factor around that.

Should I calculate and re-apply the range in rangeChanged()?