[Spec][Draft] Stepped series (DateSerie, TimeSerie, FloatSerie)

[Seuleuzeuh]

The feature
Be able to declare series for Chart with an auto generation of the labels part, accordingly to a range and step size.

API
[ class abstract BaseChartSerie ]

Property	Type	Description
Entries	IEnumerable	Get (only) the Entries
Name	string	Gets or sets the name of the serie
Color	SkColor?	Gets or sets the color of the fill

[class ChartSerie]
Inherit from BaseChartSerie

Property	Type	Description
Entries	IEnumerable	Overided for Get and set the Entries

[class abstract BaseChartEntry]
Generic BaseChartEntry with Typed Label value

Property	Type	Description
Value	float	Get the value
Label	TLabel	Gets or sets the caption label
ValueLabel	string	Gets or sets the label associated to the value.
Color	SkColor	Gets or sets the color of the fill.
TextColor	SkColor	Gets or sets the color of the text (for the caption label).
ValueLabelColor	SkColor	Gets or sets the color of the value label

[class ChartEntry]
Inherit from BaseChartEntry.
Equivalient of the actual ChartEntry

[class DateTimeChartEntry]
Inherit from BaseChartEntry.

[enum StepDateType]

Name	Description
Day	.
Week	.
Month	.
Year	.

[class DateSerie]
Inherit from BaseChartSerie

Property	Type	Description
Entries	IEnumerable	Overided - generate Entries on get
StartDate	DateTime	Gets or sets the start date of the range of labels
EndDate	DateTime	Gets or sets the end date of the range of labels
StepType	DateStepType	Gets or sets the DateStepType for generating the labels
StepValueInterval	int	Gets or sets the number of StepType between each value
StepLabelInterval	int	Gets or sets the number of StepType between the drawing of label
LabelFormat	string	Gets or sets the datetime label formats
Values	IEnumerable	Gets or sets the values entries with DateTime labels

Scenario
All the 'magic' will be made during the first Get of DateSerie.Entries, and the entries will be generated accordingly to the others option of the class.
The same type of class can be applied for TimeSeries, FloatSeries, and others.
With this API Model, no change will be made of the core charts.

Additional context
Feedback required.

[Seuleuzeuh]

I've split the value generation (StepValueInterval) and the label generation (StepLabelInterval). For example : That allow user to draw a chart with daily value, but with label draw every 7 days.

I think an other update is required to manage monthly label generation (the first of every month for example). I don't know if it's a needed feature. I need some feedback.

[eman1986]

this looks pretty good, I like the direction you're going with this.

[gsgou]

Looks good, i could reserve some time to support on Tuesday 30. March.
Do you want to share your working branch in case you ll be on it on parallel so i can follow-up?

[Seuleuzeuh]

In my side, i've not started the implementation yet. You can start your own branch. If you want quick review during the implementation, launch the PullRequest quickly (without the complete implementation) and i'll review the commits as fast as i can.

And if you need help in the implementation, you can allow me to your repo, i'll help in my spare time.

[brett-estabrook]

I have a specific use case that would be nice, that I thought I'd mention. We have IoT sensors that are all displayed on a chart.
For each sensor, there are datapoints for each second in a day. We also like to show multiple sensors on the chart at a time.

It would also be nice to be able to pinch and zoom on the chart.