Fix importing of GPX traces with a leading byte order marker

[rails.git] / lib / gpx.rb

diff --git a/lib/gpx.rb b/lib/gpx.rb
index 7c72c726fd93c89e92f82353e3eb53f73a620b42..1212db6423deadeaa62fca89cfd674b8b5a39646 100644 (file)
--- a/lib/gpx.rb
+++ b/lib/gpx.rb
@@ -12,17 +12,7 @@ module GPX
       @file = file
     end
 
-    def points
-      return enum_for(:points) unless block_given?
-
-      @possible_points = 0
-      @actual_points = 0
-      @tracksegs = 0
-
-      @file.rewind
-
-      reader = XML::Reader.io(@file)
-
+    def parse_file(reader)
       point = nil
 
       while reader.read
@@ -47,19 +37,42 @@ module GPX
       end
     end
 
-    def picture(min_lat, min_lon, max_lat, max_lon, _num_points)
+    def points(&block)
+      return enum_for(:points) unless block_given?
+
+      @possible_points = 0
+      @actual_points = 0
+      @tracksegs = 0
+
+      begin
+        Archive::Reader.open_filename(@file).each_entry_with_data do |_entry, data|
+          parse_file(XML::Reader.string(data), &block)
+        end
+      rescue Archive::Error
+        io = ::File.open(@file)
+
+        case MimeMagic.by_magic(io)&.type
+        when "application/gzip" then io = Zlib::GzipReader.open(@file)
+        when "application/x-bzip" then io = Bzip2::FFI::Reader.open(@file)
+        end
+
+        parse_file(XML::Reader.io(io), &block)
+      end
+    end
+
+    def picture(min_lat, min_lon, max_lat, max_lon, num_points)
       nframes = 10
       width = 250
       height = 250
       delay = 50
 
-      ptsper = _num_points / nframes;
+      points_per_frame = (num_points.to_f / nframes).ceil
 
       proj = OSM::Mercator.new(min_lat, min_lon, max_lat, max_lon, width, height)
 
-      frames = Array.new(nframes,  GD2::Image::IndexedColor.new(width, height))
+      frames = []
 
-      (0..nframes - 1).each do |n|
+      (0...nframes).each do |n|
         frames[n] = GD2::Image::IndexedColor.new(width, height)
         black = frames[n].palette.allocate(GD2::Color[0, 0, 0])
         white = frames[n].palette.allocate(GD2::Color[255, 255, 255])
@@ -84,30 +97,32 @@ module GPX
             px = proj.x(p.longitude)
             py = proj.y(p.latitude)
 
-            if ((pt >= (ptsper * n)) && (pt <= (ptsper * (n+1))))
-              pen.thickness=(3)
+            if (pt >= (points_per_frame * n)) && (pt <= (points_per_frame * (n + 1)))
+              pen.thickness = 3
               pen.color = black
             else
-              pen.thickness=(1)
+              pen.thickness = 1
               pen.color = grey
             end
 
             pen.line(px, py, oldpx, oldpy) unless first
-              first = false
-              oldpy = py
-              oldpx = px
+            first = false
+            oldpy = py
+            oldpx = px
           end
         end
       end
 
-      res = GD2::AnimatedGif::gif_anim_begin(frames[0])
-      res << GD2::AnimatedGif::gif_anim_add(frames[0], nil, delay)
-      (1..nframes - 1).each do |n|
-        res << GD2::AnimatedGif::gif_anim_add(frames[n], frames[n-1], delay)
+      image = GD2::AnimatedGif.new
+      image.add(frames.first)
+      frames.each do |frame|
+        image.add(frame, :delay => delay)
       end
-      res << GD2::AnimatedGif::gif_anim_end()
+      image.end
 
-      res
+      output = StringIO.new
+      image.export(output)
+      output.read
     end
 
     def icon(min_lat, min_lon, max_lat, max_lon)