Redmine 3.4.4

lib/redmine/thumbnail.rb

@@ -0,0 +1,61 @@
+# Redmine - project management software
+# Copyright (C) 2006-2017  Jean-Philippe Lang
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+require 'fileutils'
+require 'mimemagic'
+
+module Redmine
+  module Thumbnail
+    extend Redmine::Utils::Shell
+
+    CONVERT_BIN = (Redmine::Configuration['imagemagick_convert_command'] || 'convert').freeze
+    ALLOWED_TYPES = %w(image/bmp image/gif image/jpeg image/png)
+
+    # Generates a thumbnail for the source image to target
+    def self.generate(source, target, size)
+      return nil unless convert_available?
+      unless File.exists?(target)
+        # Make sure we only invoke Imagemagick if the file type is allowed
+        unless File.open(source) {|f| ALLOWED_TYPES.include? MimeMagic.by_magic(f).try(:type) }
+          return nil
+        end
+        directory = File.dirname(target)
+        unless File.exists?(directory)
+          FileUtils.mkdir_p directory
+        end
+        size_option = "#{size}x#{size}>"
+        cmd = "#{shell_quote CONVERT_BIN} #{shell_quote source} -thumbnail #{shell_quote size_option} #{shell_quote target}"
+        unless system(cmd)
+          logger.error("Creating thumbnail failed (#{$?}):\nCommand: #{cmd}")
+          return nil
+        end
+      end
+      target
+    end
+
+    def self.convert_available?
+      return @convert_available if defined?(@convert_available)
+      @convert_available = system("#{shell_quote CONVERT_BIN} -version") rescue false
+      logger.warn("Imagemagick's convert binary (#{CONVERT_BIN}) not available") unless @convert_available
+      @convert_available
+    end
+
+    def self.logger
+      Rails.logger
+    end
+  end
+end