--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mde/gui/WidgetDataSet.d	Thu Aug 07 11:25:27 2008 +0100
@@ -0,0 +1,110 @@
+/* LICENSE BLOCK
+Part of mde: a Modular D game-oriented Engine
+Copyright © 2007-2008 Diggory Hardy
+
+This program is free software: you can redistribute it and/or modify it under the terms
+of the GNU General Public License as published by the Free Software Foundation, either
+version 2 of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+/*************************************************************************************************
+ * Code to manage the data used to create widgets and save changes to it.
+ * 
+ * When loading, a WidgetDataSet instance is loaded from file and its data used to create the
+ * widgets. An empty WidgetDataChanges instance is also created.
+ * 
+ * If any data requires changing, it is added to the WidgetDataChanges instance, which also
+ * updates the the WidgetDataSet instance used to load the widgets (in case of a re-load from this
+ * data). When the data should be saved, if the WidgetDataChanges instance is not empty, data from
+ * the highest priority (i.e. the user) file is merged into it, preserving both the current
+ * changes and previous changes saved to the use file, before saving to the user file.
+ *************************************************************************************************/
+module mde.gui.WidgetDataSet;
+
+public import mde.gui.types;
+
+// For loading from file:
+import mt = mde.mergetag.DataSet;
+import mt = mde.mergetag.DefaultData;
+import mt = mde.mergetag.exception;
+import mde.mergetag.serialize;
+import tango.util.log.Log : Log, Logger;
+
+private Logger logger;
+static this () {
+    logger = Log.getLogger ("mde.gui.WidgetDataSet");
+}
+
+/*************************************************************************************************
+ * Contains data for all widgets in a GUI.
+ *************************************************************************************************/
+class WidgetDataSet : mt.IDataSection
+{
+    //BEGIN Mergetag code
+    void addTag (char[] tp, mt.ID id, char[] dt) {
+        // Priority is HIGH_LOW. Only load tag if it doesn't already exist.
+        if (tp == "WidgetData" && (id in widgetData) is null) {
+            widgetData[id] = deserialize!(WidgetData) (dt);
+        }
+    }
+    // Only WidgetDataChanges is used for writing.
+    void writeAll (ItemDelg dlg) {}
+    //END Mergetag code
+    
+    /** Get the widget data for widget i. */
+    WidgetData opIndex (widgetID id) {
+        auto p = id in widgetData;
+        if (p is null) {
+            logger.error ("No data for widget "~id~"; creating a debug widget instead.");
+            return WidgetData.dbg;
+        }
+        return *p;
+    }
+    
+    // Per-widget data:
+    protected WidgetData[widgetID] widgetData;
+}
+
+/*************************************************************************************************
+ * Contains changes to widget data.
+ * 
+ * Can be read as normal and written.
+ *************************************************************************************************/
+class WidgetDataChanges : WidgetDataSet
+{
+    /**
+     * Params:
+     *  wds = The base WidgetDataSet these changes are applied against. */
+    this (WidgetDataSet wds) {
+        base = wds;
+    }
+    
+    //BEGIN Mergetag code
+    // HIGH_LOW priority of addTag allows existing entries (i.e. the changes) to be preserved while
+    // other entries are read from files.
+    void writeAll (ItemDelg dlg) {
+        foreach (id,data; widgetData)
+            dlg ("WidgetData", id, serialize!(WidgetData) (data));
+    }
+    //END Mergetag code
+    
+    /** Set the widget data for widget i.
+     */
+    void opIndexAssign (WidgetData d, widgetID i) {
+        widgetData[i] = d;
+        base.widgetData[i] = d;
+    }
+    
+    /** Do any changes exist? True if no changes have been stored. */
+    bool none () {
+        return widgetData.length == 0;
+    }
+    
+    protected WidgetDataSet base;
+}