All Charts Icons Support [Dub #629, #624]

[abjurato]

Finally, implemented Icons (Nodal Image) feature for all charts.

I've chosen to store image in data parameter of ChartDataEntry to allow icons to be specified per-value (example of use: to sign personal records in running application). Dataset can specify if it will draw icons and customise offset from default placement. IconOffset is CGSize, but for radial Radar and Pie only height value matters — as distance from centre.

ChartBaseDataSet, IChartDataSet:

1. drawIconsEnabled:Bool flag and isDrawIconsEnabled() accessor for it
2. iconsOffset:CGSize which allows to influence at placement of icon on chart in relation to value's text (wether it is visible or not)

ChartUtils:

1. drawImage(context:CGContext, image:NSUIImage, point:CGPoint, expectedSize:CGSize, offset:CGSize) - draws image in context

All xxxChartRenderers:

1. code to draw icon (if data set's isDrawIconsEnabled and image is included to entry's data) in drawValues() method

BarChartDataEntry:

1. initialiser for stacked bar with data parameter — one data for whole stack

Demos: included star image to project, for stacked bar, pie, scatter, radar, line, candle stick, bubble, bar and horizontal bar added Toggle Icon button and star to be drawn.

[liuxuan30]

Great work! Could you please squash the commits to compact :) if you can't, just leave it be, and Daniel will review it.

One thing to say that is, due to Daniel is working on 3.0 version, this could take longer time, as 3.0 has major changes.. Not sure the impact to this one

[liuxuan30]

also, does this mean we can close #624, #629?

[ghost]

@liuxuan30 thanks! squashed. Yes, all effects of #624 and #629 can be achieved using this branch. Will wait and hope there will not be too many conflicts with 3.0 release.

Btw, will version 3.0 be written on Swift3?

[liuxuan30]

@AnatolyRosencrantz thanks for the effort.
I think it depends on when @danielgindi will finish the work. If Charts 3.0 comes after swift 3 release, it will be converted into swift 3.0 I suppose.
The current swift-3.0 branch is just a temp branch I guess in order to test iOS 10 for apps. It's much easier to convert all in once than continuous converting... every Xcode beta has swift changes is annoying

[liuxuan30]

BTW, do you consider include some unit tests, it's nice to have the coverage. If you don't have time that's fine -

[ghost]

@liuxuan30 nope. Should I update BarChartTests and LineChartTests or something more complex?

[liuxuan30]

@AnatolyRosencrantz it's great that you could add the tests for icons, just have one sample for each chart type to test is enough? Take your time, it's nice to have but not forcing

[ghost]

@liuxuan30 updated existing BarChartTests and LineChartTests

[liuxuan30]

@AnatolyRosencrantz great work! Thanks so much. Travis good:)
I am not sure when @danielgindi would finish v3.0 and review this, but we will look into this when free. Please be patient:)

[ghost]

Is there a way to add different icons for each bar?

[ghost]

@michaeljules yes, icon is being set per-DataEntry (bar in BarChart or point in LineChart), in it's data property. This property is optional, so if no UIImage will be included or some other object will be found there — icon for that exact DataEntry will just not be drawn.

[liuxuan30]

@AnatolyRosencrantz just FYI, Daniel wants to release v3 first and review and merge this after v3

[anfriis]

Can this be merged now with the release of 3.0?

[abjurato]

Pull Request for Swift3 — #1793

[kiroskirin]

@abjurato Is it possible to show icons only for highlight values? Also automatic change base on user change highlight values.

[timotiuserick]

Can it support gif ? Really love this feature