WIP: added horizontal bar chart

[j4nk3e]

Added horizontal bar charts.

To be able to reuse the bar_chart_data, I changed the naming of y and x to in the bars and groups to value, because in the horizontal bar they would be flipped.
Also, horizontal bars have the ability to put text onto the bar, which is saved in BarChartRodData.title.
We could also draw this text 90° rotated on the vertical bar chart to be consistent, but this is not implemented yet.

I added a temporary example

What do you think?

PS: it would be really cool if we could format the code according to effective dart, I just noticed there is a lot of whitespace change in the diff which is unrelated :(

[imaNNeo]

Wow, there are a lot of changes.
I'm so happy to see that, it fixes #113
I will review it ASAP, give me some time dude :)
And about the code format, I'm totally with you but do not reformat in a feature PR ever, it makes the review process hard,
make a new PR, and do all reformat in that, I will merge it ASAP.
Thanks!

[scostagabriel]

@imaNNeoFighT , thank you for this amazing library, it's really awesome! Thank you also @juumixx for this PR.

Do you have any expectations about when to merge this PR? I've tried to implement these classes but I think it isn't working anymore due to updates of the library.

[berengere13]

Hello,

Have you any news about this feature ? Our team is very interested !

Thanks you very much.

[imaNNeo]

Hello, I think it's not gonna implement soon,
because we are so busy, can make your hands dirty and try to implement it.
Thanks, regards!

[Nazacheres]

@imaNNeoFighT Actually similar results can be achieved, just by wrapping BarChart with RotatedBox. What would be good is just enable rotation for titles and tooltips :) That's a small change.

[imaNNeo]

Okay, make separate issues for them to follow up.
Thanks for suggesting!

[liasica]

@imaNNeoFighT Actually similar results can be achieved, just by wrapping BarChart with RotatedBox. What would be good is just enable rotation for titles and tooltips :) That's a small change.

tooltips rotation how?