Removed @objc from internal properties

[jjatie]

Since the framework is entirely Swift, internal properties do not need to be marked as @objc

[codecov-io]

Codecov Report

Merging #3038 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3038   +/-   ##
=======================================
  Coverage   19.77%   19.77%           
=======================================
  Files         113      113           
  Lines       13663    13663           
=======================================
  Hits         2702     2702           
  Misses      10961    10961

Impacted Files	Coverage Δ
Source/Charts/Charts/PieRadarChartViewBase.swift	0% <ø> (ø)	⬆️
Source/Charts/Charts/RadarChartView.swift	0% <ø> (ø)	⬆️
Source/Charts/Highlight/ChartHighlighter.swift	1.78% <ø> (ø)	⬆️
...ource/Charts/Renderers/CombinedChartRenderer.swift	0% <ø> (ø)	⬆️
Source/Charts/Jobs/AnimatedViewPortJob.swift	0% <ø> (ø)	⬆️
Source/Charts/Jobs/ViewPortJob.swift	0% <ø> (ø)	⬆️
Source/Charts/Utils/Transformer.swift	47.5% <ø> (ø)	⬆️
Source/Charts/Renderers/RadarChartRenderer.swift	0% <ø> (ø)	⬆️
...arts/Data/Implementations/Standard/ChartData.swift	30.5% <ø> (ø)	⬆️
Source/Charts/Highlight/RadarHighlighter.swift	0% <ø> (ø)	⬆️
... and 13 more

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[jjatie]

@liuxuan30 This is a quick and easy one.

[liuxuan30]

if it contains more than 3 files it's not a quick one lol

[liuxuan30]

I remember we just added those tags since swift 4.

Internal access enables entities to be used within any source file from their defining module, but not in any source file outside of that module. You typically use internal access when defining an app’s or a framework’s internal structure.

Does this mean no one need access to these internals outside Charts framework anymore? If true, we can remove then.

For _xxx variables it's safe to remove @objc as they have their public getters. however for methods, it seems weird ObjC can actually call internal methods, so removing the tag or just mark it public seems better choice. In history we had a commit moving many interval methods and classes into open. and we can do it if necessary.

[jjatie]

the internal access method means that the properties/methods can only be used within the Charts framework. Any consumer of the framework cannot see them.

Since any consumer of the framework cannot see them, and the framework is written in Swift internally, all internal and private functions and properties do not need to be marked as @objc because they will never be used by objective-c

[liuxuan30]

yes, but the trick is adding @objc will let Objc see it and break the rules

[liuxuan30]

for math refining I have to delay one day. get back to work