Re: [Pharo-users] Zoom x-axis in RTGrapher?

March 29, 2018

      Hi Alexandre,

Thanks! (more below)

On 28 March 2018 at 14:56, Alexandre Bergel <alexandre.bergel@me.com> wrote:
...
Hi Alistair!
Yes, this is something we thought about some times ago.
After updating Roassal, try this:
-=-=-=-=-=-=-=-=-=-=-=-=
v := RTView new.
b := [ :someClasses |
        g := RTGrapher new.
        g view: v.
        ds := RTData new.
        ds points: someClasses.
        ds y: [ :cls | cls numberOfMethods ].
        ds x: [ :cls | cls numberOfLinesOfCode ].
        g add: ds.
g addDecorator: (RTRangeSelector new callback: [:es |
                | classesToZoomIn |
                classesToZoomIn := es collect: #model.
                v cleanAll.
                b value: classesToZoomIn
        ]).
        g build.
].
b value: RTShape withAllSubclasses.
v
-=-=-=-=-=-=-=-=-=-=-=-=
Let me know how it goes.
Great, it's working fine!

If you select an empty portion of the graph an error is raised -
"Error: No dataset has been added?".

I solved this with the following change, which simply ignores empty
areas and notifies the user:

RTRangeSelector>>callbackWithSelectedElements
    | selectedElements |
    selectedElements := self elementsWithinTheSelection.
    selectedElements ifEmpty: [
        UIManager default inform: 'Empty region selected, ignoring'.
        ^self ].
    self evaluateCallBackWithElements: selectedElements

That was a quick hack, so there could well be a better solution.
...
From what I can see, there isn't a way to zoom back out or scroll left
and right.
I might modify RTRangeSelector so that a right click zooms out.  I'll
have to think about scrolling a bit more.

Thanks again!
Alistair
...
Cheers,
Alexandre
--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel  http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
...
On Mar 28, 2018, at 4:02 AM, Alistair Grant <akgrant0710@gmail.com> wrote:
Hi Everyone,
I'm using RTGrapher to display a simple line graph where the x-axis
has values from roughly 0 to 500,000 and the y-axis from 0 to 20.
What I'd like to be able to do is to zoom in just the x-axis, i.e.
instead of displaying the entire 0 to 500,000 range, be able to narrow
it down in stages, to, e.g. 430,000 to 431,000.  The y-axis would be
unchanged, i.e. still 0 to 20.  Ideally I could then scroll left and
right along the x-axis.
I can create a Spec widget with buttons to redraw the graph, but was
wondering if there was a better way.
Thanks,
Alistair