Wt

Hey Thomas,

You are certainly right: WAxis was implemented with only WCartesianChart in mind, and there is some suspicious mixing of concerns, e.g. the axis is determining the extreme values of the chart, rather than simply asking them (and let the chart provide the extremes).

If I understand correctly: WAxis should be split in a WAbstractScale and WCartesianAxis (aka current WAxis) which still has about the same API, but which would allow other axis implementations that tie with other chart implementations ?

What other implementation do you have in mind, btw, and what algorithmic aspects (such as determining ticks & labels) of WAxis would you like to reuse, if any ?

Regards,

koen

I am playing with the idea of:

WAbstractScale <- WNumericScale

WAbstractScale <- WDateTimeScale

WAbstractScaleEngine <- WLinearScaleEngine

WAbstractScaleEngine <- WLog10ScaleEngine

The WAbstractScale would handle drawing of the scale.

The WAbstractScaleEngine would handle transformations for the axis & determine ticks.

The AbstractScale would expose how much space a label takes up and allow determining the maximum number of major ticks.

I'm sifting through WAxis trying to understand exactly how it decides ticks.

Mostly the idea with this is separate the drawing from the scaling. I in no way believe this is the best way, any input is encouraged.

The other concept is that there should be no need to have the switch statements for the types.

Also the ScalingEngine (or whatever provides the transformation) needs to have an inverse transformation because in the case of the spectrogram plot you iterate over pixels instead of points.

Code showing what I was thinking is in #511