3 * \file GraphicsConverter.h
4 * Copyright 2002 the LyX Team
5 * Read the file COPYING
7 * \author Angus Leeming <a.leeming@ic.ac.uk>
9 * class grfx::GConverter enables graphics files to be converted asynchronously
10 * to a loadable format. It does this by building a shell script of all
11 * the conversion commands needed for the transformation. This script is then
12 * sent to the forked calls controller for non-blocking execution. When it
13 * is finished a signal is emitted, thus informing us to proceed with the
14 * loading of the image.
16 * Ultimately, this class should be wrapped back into Dekel's converter class.
19 #ifndef GRAPHICSCONVERTER_H
20 #define GRAPHICSCONVERTER_H
24 #include <boost/smart_ptr.hpp>
25 #include <boost/utility.hpp>
26 #include <sigc++/signal_system.h>
35 class GConverter : boost::noncopyable {
38 /// This is a singleton class. Get the instance.
39 static GConverter & get();
41 /// Can the conversion be performed?
42 bool isReachable(string const & from_format_name,
43 string const & to_format_name) const;
45 /** Convert the file and at the end return it by emitting this signal
46 * If successful, the returned string will be the name of the
47 * converted file (to_file_base + extension(to_format_name)).
48 * If unsuccessful, the string will be empty.
50 typedef SigC::Signal1<void, string const &> SignalType;
52 typedef boost::shared_ptr<SignalType> SignalTypePtr;
54 void convert(string const & from_file, string const & to_file_base,
55 string const & from_format, string const & to_format,
56 SignalTypePtr on_finish);
59 /** Make the c-tor private so we can control how many objects
64 /** Build the conversion script, returning true if able to build it.
65 * The script is output to the ostringstream 'script'.
67 bool build_script(string const & from_file, string const & to_file_base,
68 string const & from_format, string const & to_format,
69 ostringstream & script) const;
71 /** Remove the ConvProcess from the list of all processes.
72 * Called by ConvProcess::converted.
74 friend class ConvProcess;
76 void erase(ConvProcess *);
78 /// The list of all conversion processs
79 typedef boost::shared_ptr<ConvProcess> ConvProcessPtr;
81 std::list<ConvProcessPtr> all_processes_;
85 /// Each ConvProcess represents a single conversion process.
86 struct ConvProcess : public SigC::Object
89 typedef GConverter::SignalTypePtr SignalTypePtr;
91 /** Each ConvProcess represents a single conversion process.
93 * 1. The name of the script_file, which it deletes once the
94 * conversion is comlpeted;
95 * 2. The script command itself, which it passes on to the forked
97 * 3. The name of the output file, which it returns to the calling
98 * process on successfull completion, by emitting
99 * 4. The signal on_finish.
101 ConvProcess(string const & script_file, string const & script_command,
102 string const & to_file, SignalTypePtr on_finish);
104 /** This method is connected to a signal passed to the forked call
105 * class, passing control back here when the conversion is completed.
106 * Cleans-up the temporary files, emits the on_finish signal and
107 * removes the ConvProcess from the list of all processes.
109 void converted(string cmd, pid_t pid, int retval);
116 SignalTypePtr on_finish_;
121 #endif // GRAPHICSCONVERTER_H