[ease] Updated Element documentation and subclass constructors.

[Nate Stedman <natesm src gnome org>]

commit 1e9e21d5c9cb36e1bb267435ac9123b7d0e4ebb9
Author: Nate Stedman <natesm gmail com>
Date:   Thu Jun 10 06:01:08 2010 -0400

    Updated Element documentation and subclass constructors.

 src/Element.vala      |   47 +++++++++++++++++++++++++++++++++--------------
 src/ImageElement.vala |   19 ++++++++++++++++++-
 src/TextElement.vala  |   18 +++++++++++++++++-
 src/VideoElement.vala |   19 ++++++++++++++++++-
 4 files changed, 86 insertions(+), 17 deletions(-)
---
diff --git a/src/Element.vala b/src/Element.vala
index 0dba3d6..595b3ce 100644
--- a/src/Element.vala
+++ b/src/Element.vala
@@ -18,11 +18,20 @@
 /**
  * An object on a { link Slide}.
  *
+ * Elements form the content of { link Document}s. The Element class is
+ * abstract, so each type of element is represented by a subclass. The Element
+ * base class contains properties common to all types of element.
+ *
+ * To store data, Element uses a key/value store, { link ElementMap}. All
+ * properties of Element and its subclasses are simply wrappers around
+ * strings stored in ElementMap. This makes writing to and reading from JSON
+ * files very simple.
+ *
  * Element is also used in { link Theme}s, which handle sizing differently.
  *
  * Ease uses a "base resolution" of 1024 by 768, a common projector resolution.
  * Unlike { link Element}, which expresses positions in x, y, width, and height,
- * MasterElement expressed them in left, right, top, and bottom. As the total
+ * a master element expresses them in left, right, top, and bottom. As the total
  * size of the presentation is known, the actual sizes can be easily calculated.
  * Then, the Element's size can be increased or decreased by using the
  * four directional bind_ properties and the expand_.
@@ -47,7 +56,14 @@
  */
 public abstract class Ease.Element : GLib.Object
 {
+	/**
+	 * The default width of { link Theme} master slides.
+	 */
 	private const float THEME_WIDTH = 800;
+	
+	/**
+	 * The default height of { link Theme} master slides.
+	 */
 	private const float THEME_HEIGHT = 600;
 
 	/**
@@ -63,19 +79,6 @@ public abstract class Ease.Element : GLib.Object
 	protected ElementMap data;
 	
 	/**
-	 * Create a new element, with an empty { link ElementMap}.
-	 */
-	public Element()
-	{
-		data = new ElementMap();
-	}
-	
-	/**
-	 * Creates a completely empty Element, without an { link ElementMap}.
-	 */
-	public Element.empty() {}	
-	
-	/**
 	 * Creates and returns a copy of this Element.
 	 */
 	public abstract Element copy();
@@ -145,10 +148,26 @@ public abstract class Ease.Element : GLib.Object
 		exporter.add_progress(amount);
 	}
 	
+	/**
+	 * Creates the actual HTML markup for this Element.
+	 *
+	 * @param html The HTML string in its current state.
+	 * @param exporter The { link HTMLExporter}, for its path.
+	 */
 	protected abstract void write_html(ref string html, HTMLExporter exporter);
 	
+	/**
+	 * Renders this Element to a CairoContext.
+	 *
+	 * @param context The context to render to.
+	 */
 	public abstract void cairo_render(Cairo.Context context) throws Error;
 	
+	/**
+	 * Returns a ClutterActor for use in presentations and the editor.
+	 *
+	 * @param c The context of the actor.
+	 */
 	public abstract Actor actor(ActorContext c);
 	
 	/**
diff --git a/src/ImageElement.vala b/src/ImageElement.vala
index abd5b86..51b83db 100644
--- a/src/ImageElement.vala
+++ b/src/ImageElement.vala
@@ -15,8 +15,25 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+/**
+ * A {MediaElement} subclass for displaying an image. Linked with
+ * {link ImageActor}.
+ */
 public class Ease.ImageElement : MediaElement
-{	
+{
+	/**
+	 * Create a new element, with an empty { link ElementMap}.
+	 */
+	public ImageElement()
+	{
+		data = new ElementMap();
+	}
+	
+	/**
+	 * Creates a completely empty ImageElement, without an { link ElementMap}.
+	 */
+	public ImageElement.empty() {}	
+	
 	public override Element copy()
 	{
 		var element = new ImageElement.empty();
diff --git a/src/TextElement.vala b/src/TextElement.vala
index 851d451..95d8ca3 100644
--- a/src/TextElement.vala
+++ b/src/TextElement.vala
@@ -15,8 +15,24 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+/**
+ * An {Element} subclass for displaying text. Linked with { link TextActor}.
+ */
 public class Ease.TextElement : Element
-{		
+{
+	/**
+	 * Create a new element, with an empty { link ElementMap}.
+	 */
+	public TextElement()
+	{
+		data = new ElementMap();
+	}
+	
+	/**
+	 * Creates a completely empty TextElement, without an { link ElementMap}.
+	 */
+	public TextElement.empty() {}	
+
 	public override Element copy()
 	{
 		var element = new TextElement.empty();
diff --git a/src/VideoElement.vala b/src/VideoElement.vala
index 8862eef..656dc65 100644
--- a/src/VideoElement.vala
+++ b/src/VideoElement.vala
@@ -15,8 +15,25 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+/**
+ * A {MediaElement} subclass for playing a vide. Linked with
+ * {link VideoActor}.
+ */
 public class Ease.VideoElement : MediaElement
-{	
+{
+	/**
+	 * Create a new element, with an empty { link ElementMap}.
+	 */
+	public VideoElement()
+	{
+		data = new ElementMap();
+	}
+	
+	/**
+	 * Creates a completely empty VideoElement, without an { link ElementMap}.
+	 */
+	public VideoElement.empty() {}	
+
 	public override Element copy()
 	{
 		var element = new VideoElement.empty();