/// <summary>
/// Loads the content of an editing event.
/// </summary>
/// <param name="editDeserializer">The mechanism for reading back content.</param>
/// <returns>The created editing event object</returns>
static internal Change Deserialize(EditDeserializer editDeserializer)
{
Change result = editDeserializer.ReadPersistent <Change>(DataField.Edit);
// Note that calculated geometry is NOT defined at this stage. That happens
// when the model is asked to index the data.
// Associate referenced features with the edit
result.AddReferences();
// If we're dealing with an update, exchange update items. Do this NOW (rather than at it's natural
// spot in the editing sequence) so as to avoid repeated calculation loops during loading. When an
// update is applied during regular editing work, we have to rework the calculation sequence and
// rollforward all the subsequent edits. So we'd have to do that for every update. By applying changes
// now, we'll end up doing a single calculation loop.
UpdateOperation upo = (result as UpdateOperation);
if (upo != null)
{
upo.ApplyChanges();
}
return(result);
}
/// <summary>
/// Loads an observation back from a storage medium (so long as it comes next in the supplied
/// deserialization stream).
/// </summary>
/// <typeparam name="T">The type of object expected by the caller.</typeparam>
/// <param name="editDeserializer">The mechanism for reading back content.</param>
/// <param name="field">The tag that identifies the item.</param>
/// <returns>True if an observation was loaded, false if the next item in the deserialization
/// stream does not have the specified name.</returns>
internal bool ReadObservation <T>(EditDeserializer editDeserializer, DataField field) where T : Observation
{
if (editDeserializer.IsNextField(field))
{
T result = editDeserializer.ReadPersistent <T>(field);
Add(new UpdateItem(field, result));
return(true);
}
return(false);
}
/// <summary>
/// Reads data that was previously written using <see cref="WriteData"/>
/// </summary>
/// <param name="editDeserializer">The mechanism for reading back content.</param>
/// <param name="isTopological">Are we dealing with a polygon label</param>
/// <param name="polPos">The label reference point (usually applies onlt to polygon labels). Null if it's
/// identical to the position recorded via the geometry object.</param>
/// <param name="geom">The geometry for the text.</param>
static void ReadData(EditDeserializer editDeserializer, out bool isTopological, out PointGeometry polPos, out TextGeometry geom)
{
isTopological = editDeserializer.ReadBool(DataField.Topological);
if (editDeserializer.IsNextField(DataField.PolygonX))
{
polPos = editDeserializer.ReadPointGeometry(DataField.PolygonX, DataField.PolygonY);
}
else
{
polPos = null;
}
geom = editDeserializer.ReadPersistent <TextGeometry>(DataField.Type);
}
