Merge pull request #68 from JuliaGizmos/teh/unit_conversion

Perform unit conversions manually from cairomatrix

src/graphics_interaction.jl

@@ -12,6 +12,8 @@ Base.:>{U<:CairoUnit}(x::U, y::U) = Bool(x.val > y.val)
 Base.abs{U<:CairoUnit}(x::U) = U(abs(x.val))
 Base.min{U<:CairoUnit}(x::U, y::U) = U(min(x.val, y.val))
 Base.max{U<:CairoUnit}(x::U, y::U) = U(max(x.val, y.val))
+Base.isapprox(x::U, y::U; kwargs...) where U<:CairoUnit =
+    isapprox(x.val, y.val; kwargs...)
 # Most of these are for ambiguity resolution
 Base.convert{T<:CairoUnit}(::Type{T}, x::T) = x
 Base.convert(::Type{Bool}, x::CairoUnit) = convert(Bool, x.val)
@@ -57,7 +59,15 @@ Base.promote_rule{U<:UserUnit,D<:DeviceUnit}(::Type{U}, ::Type{D}) =
     error("UserUnit and DeviceUnit are incompatible, promotion not defined")
 
 function convertunits(::Type{UserUnit}, c, x::DeviceUnit, y::DeviceUnit)
-    xu, yu = device_to_user(getgc(c), x.val, y.val)
+    # For some unknown reason, the following doesn't seem to work
+    # over a remote X connection:
+    # xu, yu = device_to_user(getgc(c), x.val, y.val)
+    # So just do the inversion directly (see https://www.cairographics.org/manual/cairo-cairo-matrix-t.html#cairo-matrix-t)
+    m = Cairo.get_matrix(getgc(c))
+    Δx, Δy = x.val - m.x0, y.val - m.y0
+    det = m.xx * m.yy - m.yx * m.xy  # manually do inverse of 2x2 matrix
+    xu, yu = (m.yy * Δx - m.xy * Δy)/det, (-m.yx * Δx + m.xx * Δy)/det
+
     UserUnit(xu), UserUnit(yu)
 end
 function convertunits(::Type{UserUnit}, c, x::UserUnit, y::UserUnit)
@@ -67,7 +77,12 @@ function convertunits(::Type{DeviceUnit}, c, x::DeviceUnit, y::DeviceUnit)
     x, y
 end
 function convertunits(::Type{DeviceUnit}, c, x::UserUnit, y::UserUnit)
-    xd, yd = user_to_device(getgc(c), x.val, y.val)
+    # See above
+    # xd, yd = user_to_device(getgc(c), x.val, y.val)
+    m = Cairo.get_matrix(getgc(c))
+    xd = m.xx * x.val + m.xy * y.val + m.x0
+    yd = m.yx * x.val + m.yy * y.val + m.y0
+
     DeviceUnit(xd), DeviceUnit(yd)
 end
 

test/runtests.jl

@@ -2,9 +2,13 @@ using GtkReactive, Gtk.ShortNames, IntervalSets, Graphics, Colors,
       TestImages, FileIO, FixedPointNumbers, RoundingIntegers
 using Base.Test
 
-if !istaskdone(Reactive.runner_task)
+rtask = Reactive.runner_task # starting with Reactive 0.7.0, this became a Ref
+if isa(rtask, Base.RefValue)
+    rtask = rtask[]
+end
+if !istaskdone(rtask)
     Reactive.stop()
-    wait(Reactive.runner_task)
+    wait(rtask)
 end
 
 include("tools.jl")
@@ -242,7 +246,7 @@ include("tools.jl")
     @test value(pb) == 5
     pb = progressbar(2:8)
     @test value(pb) == 2
-    
+
 end
 
 ## button
@@ -348,7 +352,7 @@ end
                                  (ZoomRegion((5:10, 3:5)), (UserUnit(5), UserUnit(10))),
                                  ((-1:1, 101:110), (UserUnit(110), UserUnit(1))))
         set_coordinates(c, coords)
-        @test GtkReactive.convertunits(UserUnit, c, corner_dev...) == corner_usr
+        @test all(GtkReactive.convertunits(UserUnit, c, corner_dev...) .≈ corner_usr)
         @test GtkReactive.convertunits(DeviceUnit, c, corner_dev...) == corner_dev
         @test GtkReactive.convertunits(UserUnit, c, corner_usr...) == corner_usr
         @test GtkReactive.convertunits(DeviceUnit, c, corner_usr...) == corner_dev