Improved Preferences database. Branches can now be accessed by index. Added UUID generation (better versions needed for Unix and MSWin!). Added access to group name and path

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6983 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

2 files changed, 156 insertions, 8 deletions

diff --git a/FL/Fl_Preferences.H b/FL/Fl_Preferences.H
index eba771aee..7ad5de756 100644
--- a/FL/Fl_Preferences.H
+++ b/FL/Fl_Preferences.H
@@ -79,13 +79,25 @@ public:
     SYSTEM=0,   ///< Preferences are used system-wide
     USER        ///< Preferences apply only to the current user
   };
+  
+  static const char *newUUID();
 
   Fl_Preferences( Root root, const char *vendor, const char *application );
   Fl_Preferences( const char *path, const char *vendor, const char *application );
   Fl_Preferences( Fl_Preferences &parent, const char *group );
-  Fl_Preferences( Fl_Preferences*, const char *group );
+  Fl_Preferences( Fl_Preferences *parent, const char *group );
+  Fl_Preferences( Fl_Preferences &parent, int groupIndex );
+  Fl_Preferences( Fl_Preferences *parent, int groupIndex );
   ~Fl_Preferences();
 
+  /** Return the name of this entry.
+   */
+  const char *name() { return node->name(); }
+  
+  /** Return the the full path to this entry.
+   */
+  const char *path() { return node->path(); }
+  
   int groups();
   const char *group( int num_group );
   char groupExists( const char *key );
@@ -163,6 +175,7 @@ private:
   Fl_Preferences &operator=(const Fl_Preferences&);
 
   static char nameBuffer[128];
+  static char uuidBuffer[40];
 
   class FL_EXPORT Node // a node contains a list to all its entries 
   {          // and all means to manage the tree structure
@@ -174,6 +187,8 @@ private:
     ~Node();
     // node methods
     int write( FILE *f );
+    const char *name();
+    const char *path() { return path_; }
     Node *find( const char *path );
     Node *search( const char *path, int offset=0 );
     Node *addChild( const char *path );
@@ -184,6 +199,7 @@ private:
     // entry methods
     int nChildren();
     const char *child( int ix );
+    Node *childNode( int ix );
     void set( const char *name, const char *value );
     void set( const char *line );
     void add( const char *line );
diff --git a/src/Fl_Preferences.cxx b/src/Fl_Preferences.cxx
index a24cf85d5..866c90cae 100644
--- a/src/Fl_Preferences.cxx
+++ b/src/Fl_Preferences.cxx
@@ -36,6 +36,7 @@
 #include <FL/fl_utf8.h>
 #include "flstring.h"
 #include <sys/stat.h>
+#include <time.h>
 
 #if defined(WIN32) && !defined(__CYGWIN__)
 #  include <direct.h>
@@ -52,10 +53,88 @@
 #endif
 
 #ifdef WIN32
-#include <windows.h>
+#  include <windows.h>
+#else
+#  include <sys/time.h>
 #endif // WIN32
 
 char Fl_Preferences::nameBuffer[128];
+char Fl_Preferences::uuidBuffer[40];
+
+/**
+ * Returns a UUID as generated by the system.
+ *
+ * A UUID is a "universally unique identifier" which is commonly used in 
+ * configuration files to create identities. A UUID in ASCII looks like this:
+ * <tt>937C4900-51AA-4C11-8DD3-7AB59944F03E</tt>. It has always 36 bytes plus
+ * a trailing zero.
+ *
+ * \return a pointer to a static buffer containing the new UUID in ASCII format.
+ *         The buffer is overwritten during every call to this function!
+ */
+const char *Fl_Preferences::newUUID() 
+{
+#ifdef __APPLE__
+  CFUUIDRef theUUID = CFUUIDCreate(NULL);
+  CFUUIDBytes b = CFUUIDGetUUIDBytes(theUUID);
+  sprintf(uuidBuffer, "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+          b.byte0, b.byte1, b.byte2, b.byte3, b.byte4, b.byte5, b.byte6, b.byte7,
+          b.byte8, b.byte9, b.byte10, b.byte11, b.byte12, b.byte13, b.byte14, b.byte15);
+  CFRelease(theUUID);
+#elif defined (WIN32)
+#warning MSWindows implementation missing!
+  // UUID b;
+  // UuidCreate(&b);
+  unsigned char b[16];
+  time_t t = time(0); // first 4 byte
+  b[0] = (unsigned char)t;
+  b[1] = (unsigned char)(t>>8);
+  b[2] = (unsigned char)(t>>16);
+  b[3] = (unsigned char)(t>>24);
+  int r = rand(); // four more bytes
+  b[4] = (unsigned char)r;
+  b[5] = (unsigned char)(r>>8);
+  b[6] = (unsigned char)(r>>16);
+  b[7] = (unsigned char)(r>>24);
+  unsigned int a = (unsigned int)&t; // four more bytes
+  b[8] = (unsigned char)a;
+  b[9] = (unsigned char)(a>>8);
+  b[10] = (unsigned char)(a>>16);
+  b[11] = (unsigned char)(a>>24);
+  char name[80]; // last four bytes
+  gethostname(name, 79);
+  memcpy(b+12, name, 4);
+  sprintf(uuidBuffer, "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+          b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7], 
+          b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15]);
+#else
+#warning Unix implementation missing!
+  // #include <uuid/uuid.h>
+  // void uuid_generate(uuid_t out);
+  unsigned char b[16];
+  time_t t = time(0); // first 4 byte
+  b[0] = (unsigned char)t;
+  b[1] = (unsigned char)(t>>8);
+  b[2] = (unsigned char)(t>>16);
+  b[3] = (unsigned char)(t>>24);
+  int r = rand(); // four more bytes
+  b[4] = (unsigned char)r;
+  b[5] = (unsigned char)(r>>8);
+  b[6] = (unsigned char)(r>>16);
+  b[7] = (unsigned char)(r>>24);
+  unsigned int a = (unsigned int)&t; // four more bytes
+  b[8] = (unsigned char)a;
+  b[9] = (unsigned char)(a>>8);
+  b[10] = (unsigned char)(a>>16);
+  b[11] = (unsigned char)(a>>24);
+  char name[80]; // last four bytes
+  gethostname(name, 79);
+  memcpy(b+12, name, 4);
+  sprintf(uuidBuffer, "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+          b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7], 
+          b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15]);
+#endif
+}
 
 
 /**
@@ -133,6 +212,41 @@ Fl_Preferences::Fl_Preferences( Fl_Preferences *parent, const char *group )
 
 
 /**
+ \brief Open a child group using a given index. 
+ 
+ Use the \p groupIndex argument to find the group that you would like to access.
+ If the given index is invalid (negative or too high), a new group is created
+ with a UUID as a name.
+ 
+ \param[in] parent reference object for the new group
+ \param[in] groupIndex zero based index into child groups
+ */
+Fl_Preferences::Fl_Preferences( Fl_Preferences &parent, int groupIndex )
+{
+  rootNode = parent.rootNode;
+  if (groupIndex<0 || groupIndex>=parent.groups()) {
+    node = parent.node->addChild( newUUID() );
+  } else {
+    node = parent.node->childNode( groupIndex );
+  }
+}
+
+
+/**
+ \see Fl_Preferences( Fl_Preferences&, int groupIndex )
+ */
+Fl_Preferences::Fl_Preferences( Fl_Preferences *parent, int groupIndex )
+{
+  rootNode = parent->rootNode;
+  if (groupIndex<0 || groupIndex>=parent->groups()) {
+    node = parent->node->addChild( newUUID() );
+  } else {
+    node = parent->node->childNode( groupIndex );
+  }
+}
+
+
+/**
    The destructor removes allocated resources. When used on the
    \em base preferences group, the destructor flushes all
    changes to the preferences file and deletes all internal
@@ -1348,20 +1462,38 @@ int Fl_Preferences::Node::nChildren()
   return cnt;
 }
 
+// return the node name
+const char *Fl_Preferences::Node::name()
+{
+  if ( path_ )
+  {
+    char *r = strrchr( path_, '/' );
+    return r ? r+1 : path_ ;
+  } else {
+    return 0L ;
+  }
+}
+
 // return the n'th child node
 const char *Fl_Preferences::Node::child( int ix )
 {
+  Node *nd = childNode( ix );
+  if ( nd )
+    return nd->name();
+  else
+    return 0L ;
+}
+
+// return the n'th child node
+Fl_Preferences::Node *Fl_Preferences::Node::childNode( int ix )
+{
   Node *nd;
   for ( nd = child_; nd; nd = nd->next_ )
   {
     if ( !ix-- ) break;
+    if ( !nd ) break;
   }
-  if ( nd && nd->path_ )
-  {
-    char *r = strrchr( nd->path_, '/' );
-    return r ? r+1 : nd->path_ ;
-  }
-  return 0L ;
+  return nd;
 }
 
 // remove myself from the list and delete me (and all children)