2 Qs: Zoom starting outside axes and Margin at axis limits

[Aaron Peronto]

Two more questions from me and my users.

1. Is it possible to allow the start of the box drawn while zooming to begin outside the actual bounds of the visible axes? This is useful when the user is trying to zoom in on something really close to the top value of one of the Y axes. Without the ability to start the zoom box outside (in this case higher than) the max value of that axis, the user has to be very accurate with where they place their cursor to try to start the zoom box.

Currently we actually do a sort of manual buffering of the graph and the users interact with the bitmap of the graph. When they try to zoom, I use the location coordinates of the mouse to specify the zoom box to pass to the Teechart control itself. There is nothing that prevents me from passing coordinates that specify a box which starts and/or ends outside the axis boundaries. When that happens, the chart still zooms properly to the range that the user selected, even if that means the axis now displays a range that previously was outside the ends of the axes.

I just wanted to see if there was a way to tell the Teechart control to allow the user to start that zoom box outside the bounds of the axes.

2. This one is somewhat related to #1 above. I thought I had asked this one before but could not find the answer. Is there a way to specify how much of a margin the graph leaves between the maximum value for a point and the max that is set for its axis (when the Automatic setting is True on the axis)? The graph does a good job of maximizing the space used for the graph but sometimes, when the user needs to zoom in on a point very near the max extent of the axis, it is hard to zoom properly because of the small gap between the point representing that maximum data value and the maximum used by the axis.

If there were a way to specify that gap as a percentage of the range of the axis or something like that, it would be very useful in being able to control that gap.

Thanks again for your help.

[Narcís]

Hello Aaron,

Please find below the answers to your quesitons:

1. No, I can't think of a way to do that now. I've added your request to the wish-list to be considered for inclusion in future releases.

2. Yes, you could use axes offset, which is expressed in pixels. For example:

Code: Select all

			tChart1.Axes.Left.MaximumOffset = 10;
			tChart1.Axes.Left.MinimumOffset = 10;