Question

I use CorePlot 1.0 to display a scatter plot. I configured it correctly to display the whole graph, and I have locked the axes with a CPTConstraints, so they are fixed on the screen. What I would like to do now is “lock” the pan gesture on the graph so the user can’t pan vertically further than my axis’ maximum value.

For example, my axis goes from 0 to 100. When the graph loads, you can’t pan vertically, because you already see the whole graph. If you zoom in, for example until you see the vertical axis between 20 and 70. I want now the user to be able to pan upward until he sees the 100 tick, and then he can’t go further (same for downwards, until he sees the 0 tick).

Is anything similar possible ? Thanks a lot !

Answer 1

The easiest way is to use the “global” ranges on the plot space. If you need more control, you can use a plot space delegate.

CPTPlotRange *globalYRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f)
                                                          length:CPTDecimalFromFloat(100.0f)];
plotSpace.globalYRange = globalYRange;