2 files changed, 45 insertions, 3 deletions

diff --git a/FL/Fl_Preferences.H b/FL/Fl_Preferences.H
index a5f56c1e6..44d007f90 100644
--- a/FL/Fl_Preferences.H
+++ b/FL/Fl_Preferences.H
@@ -57,7 +57,7 @@
    yet exist.
    
    Entries can be of any length. However, the size of each
-   preferences file should be kept under 100k for performance
+   preferences file should be kept small for performance
    reasons. One application can have multiple preferences files.
    Extensive binary data however should be stored in separate
    files: see getUserdataPath().
@@ -116,11 +116,15 @@ public:
   const char *group( int num_group );
   char groupExists( const char *key );
   char deleteGroup( const char *group );
+  char deleteAllGroups();
 
   int entries();
   const char *entry( int index );
   char entryExists( const char *key );
   char deleteEntry( const char *entry );
+  char deleteAllEntries();
+  
+  char clear();
 
   char set( const char *entry, int value );
   char set( const char *entry, float value );
@@ -223,6 +227,7 @@ private:
     RootNode *findRoot();
     char remove();
     char dirty();
+    void deleteAllChildren();
     // entry methods
     int nChildren();
     const char *child( int ix );
@@ -232,6 +237,7 @@ private:
     const char *get( const char *name );
     int getEntry( const char *name );
     char deleteEntry( const char *name );
+    void deleteAllEntries();
     // public values
     Entry *entry;
     int nEntry, NEntry;
diff --git a/src/Fl_Preferences.cxx b/src/Fl_Preferences.cxx
index 147711d3b..35752cfff 100644
--- a/src/Fl_Preferences.cxx
+++ b/src/Fl_Preferences.cxx
@@ -401,6 +401,14 @@ char Fl_Preferences::deleteGroup( const char *group )
   return 0;
 }
 
+/**
+ Delete all groups.
+ */
+char Fl_Preferences::deleteAllGroups()
+{
+  node->deleteAllChildren();
+  return 1;
+}
 
 /**
    Returns the number of entries (name/value pairs) in a group.
@@ -452,6 +460,24 @@ char Fl_Preferences::deleteEntry( const char *key )
   return node->deleteEntry( key );
 }
 
+/**
+ Delete all entries.
+ */
+char Fl_Preferences::deleteAllEntries()
+{
+  node->deleteAllEntries();
+  return 1;
+}
+
+/**
+ Delete all groups and all entries.
+ */
+char Fl_Preferences::clear() 
+{
+  char ret1 = deleteAllGroups();
+  char ret2 = deleteAllEntries();
+  return ret1 & ret2;
+}
 
 /**
  Reads an entry from the group. A default value must be
@@ -1248,8 +1274,7 @@ Fl_Preferences::Node::Node( const char *path )
   top_ = 0;
 }
 
-// delete this and all depending nodes
-Fl_Preferences::Node::~Node()
+void Fl_Preferences::Node::deleteAllChildren() 
 {
   Node *nx;
   for ( Node *nd = child_; nd; nd = nx )
@@ -1258,6 +1283,10 @@ Fl_Preferences::Node::~Node()
     delete nd;
   }
   child_ = 0L;
+}
+
+void Fl_Preferences::Node::deleteAllEntries() 
+{
   if ( entry )
   {
     for ( int i = 0; i < nEntry; i++ )
@@ -1275,6 +1304,13 @@ Fl_Preferences::Node::~Node()
     entry = 0L;
     nEntry = 0;
   }
+}
+
+// delete this and all depending nodes
+Fl_Preferences::Node::~Node()
+{
+  deleteAllChildren();
+  deleteAllEntries();
   if ( path_ ) {
     free( path_ );
     path_ = 0L;