gtkmm-documentation r40 - in trunk: . examples/book/giomm examples/book/giomm/write_file

[murrayc svn gnome org]

Author: murrayc
Date: Fri Mar 28 16:29:28 2008
New Revision: 40
URL: http://svn.gnome.org/viewvc/gtkmm-documentation?rev=40&view=rev

Log:
2008-03-28  Murray Cumming  <murrayc murrayc com>

* configure.in:
* examples/book/giomm/Makefile.am:
* examples/book/giomm/write_file/: Added this example, showing how to 
create files and how to replace their contents using a stream.

Added:
   trunk/examples/book/giomm/write_file/
      - copied from r39, /trunk/examples/book/giomm/read_file/
Modified:
   trunk/ChangeLog
   trunk/configure.in
   trunk/examples/book/giomm/Makefile.am
   trunk/examples/book/giomm/write_file/main.cc

Modified: trunk/configure.in
==============================================================================
--- trunk/configure.in	(original)
+++ trunk/configure.in	Fri Mar 28 16:29:28 2008
@@ -314,6 +314,7 @@
           examples/book/giomm/getline/Makefile
           examples/book/giomm/monitor_directory/Makefile
           examples/book/giomm/usage/Makefile
+          examples/book/giomm/write_file/Makefile
         examples/book/frame/Makefile
         examples/book/helloworld/Makefile
         examples/book/helloworld2/Makefile

Modified: trunk/examples/book/giomm/Makefile.am
==============================================================================
--- trunk/examples/book/giomm/Makefile.am	(original)
+++ trunk/examples/book/giomm/Makefile.am	Fri Mar 28 16:29:28 2008
@@ -1 +1 @@
-SUBDIRS = directory_list read_file read_file_async volumes getline monitor_directory usage
+SUBDIRS = directory_list read_file read_file_async volumes getline monitor_directory usage write_file

Modified: trunk/examples/book/giomm/write_file/main.cc
==============================================================================
--- /trunk/examples/book/giomm/read_file/main.cc	(original)
+++ trunk/examples/book/giomm/write_file/main.cc	Fri Mar 28 16:29:28 2008
@@ -26,30 +26,43 @@
 
   try
   {
-    Glib::RefPtr<Gio::File> file = Gio::File::create_for_path("/etc/fstab");
+    Glib::RefPtr<Gio::File> file = Gio::File::create_for_path("test_output.txt");
     if(!file)
       std::cerr << "Gio::File::create_for_path() returned an empty RefPtr." << std::endl;
 
-    Glib::RefPtr<Gio::FileInputStream> stream = file->read();
+    Glib::RefPtr<Gio::FileOutputStream> stream;
+
+    //If the file exists already then replace it.
+    //Otherwise, create it:
+    if(file->query_exists())
+      stream = file->replace();
+    else
+      stream = file->create_file();
+
     if(!stream)
-      std::cerr << "Gio::File::read() returned an empty RefPtr." << std::endl;
+      std::cerr << "Gio::File::create_file() returned an empty RefPtr." << std::endl;
 
-    gchar buffer[1000]; //TODO: This is unpleasant.
-    memset(buffer, 0, 1000);
-    const gsize bytes_read = stream->read(buffer, 1000);
+    Glib::ustring contents = "This is some test output";
+    const gsize bytes_read = stream->write(contents);
     
     if(bytes_read)
-      std::cout << "File contents read: " << buffer << std::endl;
+      std::cout << "File contents written: " << contents << std::endl;
     else
-      std::cerr << "Gio::InputStream::read() read 0 bytes." << std::endl;
+      std::cerr << "Gio::InputStream::write() wrote 0 bytes." << std::endl;
 
+    //Close the stream to make sure that changes are written now, 
+    //instead of just when the stream goes out of scope,
+    //though that's the same time in this simple example.
+    //For instance, when using Gio::File::replace(), the file is only 
+    //actually replaced during close() or when the stream is destroyed.
+    stream->close();
+    stream.reset(); //Stream can't be used after we have closed it.
   }
   catch(const Glib::Exception& ex)
   {
     std::cerr << "Exception caught: " << ex.what() << std::endl; 
   }
 
-
   return 0;
 }