Merge branch 'master' of https://github.com/JuliaPlots/AbstractPlotti…

…ng.jl into master

docs/src/makielayout/axis.md

@@ -8,7 +8,7 @@ CairoMakie.activate!(type = "png")
 ## Creating an Axis
 
 The `Axis` is a 2D axis that works well with automatic layouts.
-Here's how you create one 
+Here's how you create one
 
 ```@example laxis
 using CairoMakie
@@ -571,7 +571,7 @@ You can check which interactions are currently active by calling `interactions(a
 Often, you don't want to remove an interaction entirely but only disable it for a moment, then reenable it again.
 You can use the functions `activate_interaction!(ax, name::Symbol)` and `deactivate_interaction!(ax, name::Symbol)` for that.
 
-#### `Function` Interaction 
+#### `Function` Interaction
 If `interaction` is a `Function`, it should accept two arguments, which correspond to an event and the axis.
 This function will then be called whenever the axis generates an event.
 
@@ -595,7 +595,7 @@ The function option is most suitable for interactions that don't involve much st
 A more verbose but flexible option is available.
 For this, you define a new type which typically holds all the state variables you're interested in.
 
-Whenever the axis generates an event, it calls `process_interaction(interaction, event, axis)` on all 
+Whenever the axis generates an event, it calls `process_interaction(interaction, event, axis)` on all
 stored interactions.
 By defining `process_interaction` for specific types of interaction and event, you can create more complex interaction patterns.
 
@@ -659,9 +659,27 @@ hlines!(ax2, [1, 2, 3, 4], xmax = [0.25, 0.5, 0.75, 1], color = :blue)
 scene
 ```
 
+### abline!
+
+abline works similar to v/hlines!:
+
+```@docs
+abline!
+```
+
+```@setup 1
+using CairoMakie
+CairoMakie.activate!(type = "png")
+```
+
+```@example 1
+fig, ax, pl = scatter(1:4)
+abline!(ax, 0, 1)
+abline!(ax, 0, 1.5, color = :red, linestyle=:dash, linewidth=2)
+fig
+```
 
 ```@eval
 using GLMakie
 GLMakie.activate!()
 ```
-

src/makielayout/MakieLayout.jl

@@ -94,7 +94,7 @@ export labelslider!, labelslidergrid!
 export addmouseevents!
 export interactions, register_interaction!, deregister_interaction!, activate_interaction!, deactivate_interaction!
 export MouseEventTypes, MouseEvent, ScrollEvent, KeysEvent
-export hlines!, vlines!
+export hlines!, vlines!, abline!
 
 
 # from GridLayoutBase

src/makielayout/helpers.jl

@@ -393,9 +393,9 @@ function labelslidergrid!(scene, labels, ranges; formats = [string],
     sliders = map(x -> x.slider, elements)
     labels = map(x -> x.label, elements)
     valuelabels = map(x -> x.valuelabel, elements)
-    
+
     layout = grid!(hcat(labels, sliders, valuelabels); layoutkw...)
-    
+
     (sliders = sliders, labels = labels, valuelabels = valuelabels, layout = layout)
 end
 
@@ -448,5 +448,19 @@ Create vertical lines across `ax` at `xs` in data coordinates and `ymin` to `yma
 in axis coordinates (0 to 1). All three of these can have single or multiple values because
 they are broadcast to calculate the final line segments.
 """
-vlines!(ax::Axis, xs; ymin = 0.0, ymax = 1.0, attrs...) = 
-    hvlines!(ax, 2, xs, ymin, ymax; attrs...)
+vlines!(ax::Axis, xs; ymin = 0.0, ymax = 1.0, attrs...) =
+    hvlines!(ax, 2, xs, ymin, ymax; attrs...)
+
+"""
+    abline!(axis::Axis, a::Number, b::Number; line_kw_args...)
+Adds a line defined by `f(x) = x * b + a` to the axis.
+kwargs are the same as for a `line` plot and are passed directly to the line attributess.
+"""
+function abline!(axis::Axis, a::Number, b::Number; kwargs...)
+    f(x) = x * b + a
+    line = map(axis.finallimits) do limits
+        xmin, xmax = first.(extrema(limits))
+        return [Point2f0(xmin, f(xmin)), Point2f0(xmax, f(xmax))]
+    end
+    return linesegments!(axis, line; xautolimits=false, yautolimits=false, kwargs...)
+end