Refactored preferences handling into a new version of

the Inkscape::Preferences class. Removed all use of 
prefs_get_string_attribute(), pref_path_get_nth_child() and 
create_pref() in favor of the new API. Replaced some "0 or 1" integer 
preferences with booleans.

(bzr r6823)

1 files changed, 106 insertions, 20 deletions

diff --git a/src/preferences.h b/src/preferences.h
index 4a7659586..90b2f518e 100644
--- a/src/preferences.h
+++ b/src/preferences.h
@@ -1,44 +1,130 @@
-/** \file
- * \brief  Static class where all preferences handling happens.
+/** @file
+ * @brief  Singleton class to access the preferences file in a convenient way.
  *
  * Authors:
- *   Ralf Stephan <ralf@ark.in-berlin.de>
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
  *
- * Copyright (C) 2005 Authors
+ * Copyright (C) 2008 Authors
  *
  * Released under GNU GPL.  Read the file 'COPYING' for more information.
  */
 
-#ifndef INKSCAPE_PREFERENCES_H
-#define INKSCAPE_PREFERENCES_H
+#ifndef INKSCAPE_PREFSTORE_H
+#define INKSCAPE_PREFSTORE_H
+
+#include <glibmm/ustring.h>
+#include <string>
+#include <climits>
+#include <cfloat>
 
 namespace Inkscape {
-    namespace XML {
-        class Document;
-    }
+namespace XML {
+    class Node;
+    class Document;
+    class NodeObserver;
+} // namespace XML
 
-class Preferences
-{
+/**
+ * @brief Preference storage class
+ *
+ * This is a singleton that allows one to access the user preferences stored in
+ * the preferences.xml file. The preferences are stored in a tree hierarchy.
+ * Each preference is identified by its key, and sections of the key
+ * corresponding to the levels of the hierarchy are delimited with dots.
+ * Preferences are generally typeless - it's up to the programmer to ensure
+ * that a given preference is always accessed as the correct type.
+ *
+ * All preferences are loaded when the first singleton pointer is requested,
+ * or when the static load() method is called. Before loading, the static
+ * variable @c use_gui should be set accordingly. To save the preferences,
+ * the method save() or the static function unload() can be used.
+ *
+ * In future, this could be a virtual base from which specific backends
+ * derive (e.g. GConf, Windows registry, flat XML file...)
+ */
+class Preferences {
 public:
-    static XML::Document *get();
-    static void load();
-    static void save();
-    static void loadSkeleton();
-   
+    // utility methods
+    void save();
+    bool isWritable() { return _writable; }
+    
+    // some helpers
+    bool exists(Glib::ustring const &pref_key);
+    unsigned int childCount(Glib::ustring const &pref_key);
+    Glib::ustring getNthChild(Glib::ustring const &father_path, unsigned int n);
+    bool create(Glib::ustring const &pref_key);
+    
+    // getter methods
+    // Note that default values supplied as arguments are last-chance,
+    // and are overridden by those in preferences-defaults.h
+    bool getBool(Glib::ustring const &pref_path, Glib::ustring const &attr, bool def=false);
+    int getInt(Glib::ustring const &pref_path, Glib::ustring const &attr, int def=0);
+    int getIntLimited(Glib::ustring const &pref_path, Glib::ustring const &attr, int def=0, int min=INT_MIN, int max=INT_MAX);
+    double getDouble(Glib::ustring const &pref_path, Glib::ustring const &attr, double def=0.0);
+    double getDoubleLimited(Glib::ustring const &pref_path, Glib::ustring const &attr, double def=0.0, double min=DBL_MIN, double max=DBL_MAX);
+    Glib::ustring getString(Glib::ustring const &pref_path, Glib::ustring const &attr);
+    
+    // setter methods
+    void setBool(Glib::ustring const &pref_path, Glib::ustring const &attr, bool value);
+    void setInt(Glib::ustring const &pref_path, Glib::ustring const &attr, int value);
+    void setDouble(Glib::ustring const &pref_path, Glib::ustring const &attr, double value);
+    void setString(Glib::ustring const &pref_path, Glib::ustring const &attr, Glib::ustring const &value);
+    
+    // do not use this - it is only temporarily public to ease porting old code to this class
+    XML::Node *_getNode(Glib::ustring const &pref_path, bool create=false);
+    
+    // used for some obscure purpose in sp_desktop_widget_init
+    void addPrefsObserver(XML::NodeObserver *observer);
+
+    // singleton accessor
+    static Preferences *get() {
+        if (!_instance) _instance = new Preferences();
+        return _instance;
+    }
+    static void load() {
+        if (!_instance) _instance = new Preferences();
+    }
+    static void unload() {
+        if(_instance)
+        {
+            delete _instance;
+            _instance = NULL;
+        }
+    }
+    // this is a static member to reduce dependency bloat for this class
+    static bool use_gui; ///< Whether to use GUI error notifications
+    
 private:
+    Preferences();
+    ~Preferences();
+    void _load();
+    void _loadDefaults();
+    void _errorDialog(Glib::ustring const &, Glib::ustring const &);
+    
+    // disable copying
+    Preferences(Preferences const &);
+    Preferences operator=(Preferences const &);
+    
+    std::string _prefs_basename; ///< Basename of the prefs file
+    std::string _prefs_dir; ///< Directory in which to look for the prefs file
+    std::string _prefs_filename; ///< Full filename (with directory) of the prefs file
+    bool _writable; ///< Will the preferences be saved at exit?
+    XML::Document *_prefs_doc; ///< XML document storing all the preferences
+    
+    static Preferences *_instance;
 };
 
 } // namespace Inkscape
 
-#endif // INKSCAPE_PREFERENCES_H
+#endif // INKSCAPE_PREFSTORE_H
 
 /*
   Local Variables:
   mode:c++
   c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  c-file-offsets:((innamespace . 0)(inline-open . 0))
   indent-tabs-mode:nil
-  fill-column:99
+  fill-column:75
   End:
 */
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :