[gxml] GomProperty: New interface for GObject attributes

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 4b9a5d1d99473a36ffce68abe510b4418bc00438
Author: Daniel Espinosa <esodan gmail com>
Date:   Sun Nov 6 19:39:50 2016 -0600

    GomProperty: New interface for GObject attributes
    
    GomProperty binds Objects to DomElement's attributes.
    Basic types implementations have been added.

 gxml/GomProperty.vala          |  132 ++++++++++++++++++++++++++++++++++++++++
 gxml/Makefile.am               |    1 +
 test/GomSerializationTest.vala |   51 +++++++++++++++
 3 files changed, 184 insertions(+), 0 deletions(-)
---
diff --git a/gxml/GomProperty.vala b/gxml/GomProperty.vala
new file mode 100644
index 0000000..724a898
--- /dev/null
+++ b/gxml/GomProperty.vala
@@ -0,0 +1,132 @@
+/* -*- Mode: vala; indent-tabs-mode: nil; c-basic-offset: 2; tab-width: 2 -*- */
+/*
+ *
+ * Copyright (C) 2016  Daniel Espinosa <esodan gmail com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library 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
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *      Daniel Espinosa <esodan gmail com>
+ */
+
+
+/**
+ * An interface for {@link GomObject}'s properties translated to
+ * {@link DomElement} attributes.
+ */
+public interface GXml.GomProperty : Object
+{
+  /**
+   * Attribute's name in the parent {@link DomElement}.
+   */
+  public abstract string attribute_name { get; construct set; }
+  /**
+   * Attribute's value in the parent {@link DomElement}.
+   */
+  public abstract string value { owned get; set; }
+}
+
+public class GXml.GomDouble : Object, GomProperty {
+  protected double _value = 0.0;
+  protected string _attribute_name;
+  public string attribute_name {
+    get { return _attribute_name; }
+    construct set { _attribute_name = value;}
+  }
+  public string value {
+    owned get {
+      string s = "%."+decimals.to_string ()+"f";
+      return s.printf (_value);
+    }
+    set {
+      _value = double.parse (value);
+    }
+  }
+  public uint decimals { get; set; default = 4; }
+  public double get_double () { return _value; }
+}
+
+public class GXml.GomFloat : GomDouble {
+  public float get_double () { return (float) _value; }
+}
+
+
+public class GXml.GomInt : Object, GomProperty {
+  protected int _value = 0;
+  protected string _attribute_name;
+  public string attribute_name {
+    get { return _attribute_name; }
+    construct set { _attribute_name = value;}
+  }
+  public string value {
+    owned get {
+      return _value.to_string ();
+    }
+    set {
+      _value = (int) double.parse (value);
+    }
+  }
+  public int get_integer () { return _value; }
+}
+
+public class GXml.GomBoolean : Object, GomProperty {
+  protected bool _value = false;
+  protected string _attribute_name;
+  public string attribute_name {
+    get { return _attribute_name; }
+    construct set { _attribute_name = value;}
+  }
+  public string value {
+    owned get {
+      return _value.to_string ();
+    }
+    set {
+      _value = bool.parse (value);
+    }
+  }
+  public bool get_boolean () { return _value; }
+}
+
+public class GXml.GomEnum : Object, GomProperty {
+  protected int _value = 0;
+  protected string _attribute_name;
+  protected Type _enum_type;
+  public string attribute_name {
+    get { return _attribute_name; }
+    construct set { _attribute_name = value;}
+  }
+  public string value {
+    owned get {
+      string s = "";
+      try {
+        s = Enumeration.get_string (enum_type, _value, true, true);
+      } catch {
+        GLib.warning (_("Error when transform enum to attribute's value"));
+      }
+      return s;
+    }
+    set {
+      try {
+        _value = (int) Enumeration.parse (enum_type, value).value;
+      } catch {
+        GLib.warning (_("Error when transform from attribute string value to enum"));
+      }
+    }
+  }
+  public Type enum_type {
+    get { return _enum_type; }
+    construct set { _enum_type = value; }
+  }
+  public int get_enum () { return (int) _value; }
+}
diff --git a/gxml/Makefile.am b/gxml/Makefile.am
index 2cc4a37..fb901ff 100644
--- a/gxml/Makefile.am
+++ b/gxml/Makefile.am
@@ -89,6 +89,7 @@ sources = \
        GomText.vala \
        GomObject.vala \
        GomCollections.vala \
+       GomProperty.vala \
        Parser.vala \
        XParser.vala \
        $(NULL)
diff --git a/test/GomSerializationTest.vala b/test/GomSerializationTest.vala
index 085fb44..a1398ea 100644
--- a/test/GomSerializationTest.vala
+++ b/test/GomSerializationTest.vala
@@ -105,6 +105,50 @@ class GomSerializationTest : GXmlTest  {
       return parser.write_string ();
     }
   }
+  public class Motor : GomElement {
+    public On is_on { get; set; }
+    public Torque torque { get; set; }
+    public Speed speed { get; set; }
+    public Type tension_type { get; set; }
+    public Tension tension { get; set; }
+    construct {
+      _local_name = "Motor";
+    }
+    public string to_string () {
+      var parser = new XParser (this);
+      return parser.write_string ();
+    }
+    public enum Enum {
+      AC,
+      DC
+    }
+    public class On : GomBoolean {
+      construct {
+        _attribute_name = "On";
+      }
+    }
+    public class Torque : GomDouble {
+      construct {
+        _attribute_name = "Torque";
+      }
+    }
+    public class Speed : GomFloat {
+      construct {
+        _attribute_name = "Speed";
+      }
+    }
+    public class Type : GomEnum {
+      construct {
+        _enum_type = typeof (Enum);
+        _attribute_name = "Type";
+      }
+    }
+    public class Tension : GomInt {
+      construct {
+        _attribute_name = "Tension";
+      }
+    }
+  }
   public static void add_tests () {
     Test.add_func ("/gxml/gom-serialization/write/properties", () => {
       var b = new Book ();
@@ -241,6 +285,13 @@ class GomSerializationTest : GXmlTest  {
       assert ((bs.books.get("Title2") as Book).name == "Title2");
       assert ((bs.books.get("Title3") as Book).name == "Title3");
     });
+    Test.add_func ("/gxml/gom-serialization/write/gom-property", () => {
+      var c = new Motor ();
+      string s = c.to_string ();
+      assert (s != null);
+      GLib.message ("DOC:"+s);
+      assert ("<Motor/>" in s);
+    });
     Test.add_func ("/gxml/gom-serialization/read/properties", () => {
       var b = new Book ();
       var parser = new XParser (b);