Easy to setup and highly customizable collection view based chart legends.

Swift 4.0, iOS 8+

• Define the layout with only a flag, in interface builder or code.
• Predefined shapes and possibility to use custom paths.
• Per-cell configuration or overrides, e.g. to set a different font or shape than other cells.
• Custom views via UICollectionView subclasses.
• Full autolayout support
• Interactive
• Scrollable
• Compatible with any chart type or library.

Add to your Podfile:

use_frameworks!
pod 'ChartLegends'

Add to your Cartfile:

github "i-schuetz/ChartLegends"

Simply:

@IBOutlet weak var legendsView: ChartLegendsView!

legendsView.setLegends(
	(text: "Chemicals", color: UIColor.orange),
    (text: "Forestry", color: UIColor.green)
)

ChartLegends currently supports these types out of the box:

Displays text in the given color. The example in the quick start section produces this kind of legends.

Displays text with a shape on the left side, with given color. Here, also, there are some predefined options, for example circle, with a specified radius, or rect, with specified width and height.

For example, to use legends with a small colored circle on the left:

legendsView.setLegends(.circle(radius: 7), [
	(text: "Chemicals", color: UIColor.orange),
    (text: "Forestry", color: UIColor.green)
])

If you want to show a shape that's not in the predefined types, you also can provide a path. Example:

let pathGenerator = {(size: CGSize) in
    return UIBezierPath()
}
legendsView.setLegends(pathGenerator, [
	(text: "Chemicals", color: UIColor.orange),
    (text: "Forestry", color: UIColor.green)
])

Of course the idea is to expand the predefined types to support all possible regularly used paths. Don't hesitate to make a pull request with your path if you think it's of common interest!

If you need more customization, you can also use custom cells. Example:

legendsView.configure(cellType: MyCustomCell.self) {cell, legend, indexPath in
	cell.label.text = legend.text
	// other custom configuration
}

This is type safe and concise - we don't need casting or delegates to configure the cell.

To implement a custom cell, you only have to extend UICollectionViewCell and conform to ChartLegendCell to add some additional functionality that ChartLegendsView needs to interact with the cell.

Here, again, feel free to submit a pull request with your cells, if you think they can be of common use.

You can configure the layout of ChartLegendsView, together with some other settings, directly in interface builder:

• flowLeft: Left aligned flow layout. This should be the most commonly used horizontal legends layout.

• columns: Column layout - you can specify the number of columns in the "Columns field".

• flow: The default flow collection view layout, which will "justify" cells in order to occupy available space.

Note that when layout type is not set to columns, the Columns field is ignored.

Download this repo and run the demo target!

Besides of adding new shapes and cells, there are surely several settings and refinements that can be done. Also, add animations!

1. Fork
2. Commit changes to a branch in your fork
3. Push your code and make a pull request

Ivan Schütz

SwiftCharts is Copyright (c) 2017 Ivan Schütz and released as open source under the attached Apache 2.0 license.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.