Skins are now converted to use a "source"/"covert"/"render"-mechanism.

A "source" is a data-source. For example, the infobar has a source called
"CurrentService", which is the currently displayed service, i.e. the channel
the user is watching at the moment.

Now, a "current service" has a lot of properties, like
 - Service Name
 - service number
 - flags like "are subservices available?"
 - playback position, length, ...

Say you want to display the "service name" on screen. Only "renderers" can
paint on the screen. The most basic renderer is the "Label"-Renderer, which
can display a text. The "service name" is a text, so we use the
"Label"-renderer. We also know that "CurrentService" is our source.

But the renderer can only display texts, not "services". It needs something
to turn a "service" into a "text", i.e. something which extracts the service
name out of a service.

That's where "converters" come into action. If we want to extract the
servicename from a service, we need the "ServiceName"-converter. The
"ServiceName"-converter can not only extract the service *name*, but also
the provider name (another property of a service), so we have to specify
what we want.

So our skin data could look like:

<widget source="CurrentService" render="Label" position="69,25"
		size="427,26" font="Regular;22" backgroundColor="#101258" >
	<convert type="ServiceName">Name</convert>
</widget>

The "call chain" consists of

"CurrentService" -> "ServiceName(NAME)" -> "Label"


The are the following source types:

Clock - the current time
EventInfo - the current now&next events
MenuList - a menu
CurrentService - the currently playing service
FrontendStatus - frontend status, like BER, Signal Strength etc.
Boolean - a usually fixed boolean value, for example "is record possible?"

Actually used sources are defined in a "Screen". That is, a Screen offers
sources, which you can use inside your skin.

The "Infobar", for example, offers the following sources:

Event_Now
Event_Next
CurrentService
RecordingPossible
TimeshiftPossible
ExtensionsAvailable
Clock

Then there are the following "Converters":

ClockToText - turns a 'Clock' source into a text
  Parameters: 
    "WithSeconds": "hh:mm:ss"
    "InMinutes"  : "mm min"
    "Date"       : "Wednesday, 07 June, 2006"
    "Default"    : "hh:mm"
EventName - extracts the event name
  Parameters:
    "Description": Extracts the description of the event
    "ExtendedDescription": Extracts the extended description of the event
    "Name": extracts the name of the event
EventTime - extracts the event time
  Parameters: 
    "EndTime": extracts the end time of the event
    "Remaining": extracts the remaining time of the event
    "StartTime": extracts the start time of the event
    "Duration": extracts the duration of the event
    "Progress": extracts the progress of the event
RemainingToText - turns a "remaining"-time into text ("xxx m", or "+xx m")
  It automatically uses the event length when the remaining time is invalid
StringList - turns a menulist into a list usable for a "Listbox"-renderer
FrontendInfo - extracts specific information out of a frontend
  Parameters:
    BER
    SNR
    AGC
    LOCK

  You can either use a "Progress" or "Label" renderer, or, with Lock or
  BER, you can use a ConditionalShowHide to show a "warning symbol" when
  BER is >0.

ServiceInfo - extracts info out of a service
  Parameters:
    HasTeletext
    IsMultichannel
    IsCrypted
    IsWidescreen
    SubservicesAvailable
ConditionalShowHide - conditionally show/hide a widgets based on the
                      source's boolean output
  Optional parameter: "Invert" - inverts the sense, i.e. show when boolean
                      value is false
ServicePosition - extracts the current service play position out of a
                  service
  Parameters:
    "Length"
    "Position"
    "Remaining"
    "Gauge"
ServiceName
  Parameters:
    "Name"
    "Provider"

Then there are the following renderers:
Label
Progress
Listbox
Pixmap
PositionGauge
FixedLabel

You can also put multiple converters in a row. Each one will pick up the
output of the last coverter.

Of course you can only connect items which are compatible. Right now you
have to look at the examples :)

Some more examples:

"SUBSERVICES AVAILABLE DISPLAY"
===============================

			<widget source="CurrentService" render="Pixmap" pixmap="button_green.png" position="320,132" size="27,12" >
				<convert type="ServiceInfo">SubservicesAvailable</convert>
				<convert type="ConditionalShowHide" />
			</widget>

will display a pixmap whenever the "CurrentService" has
"SubservicesAvailable".

"CURRENT SERVICE POSITION IN A POSITION GAUGE"
==============================================

			<widget source="CurrentService" render="PositionGauge" position="247,60" size="225,20" zPosition="2" pointer="position_pointer.png:3,5" >
				<convert type="ServicePosition">Gauge</convert>
			</widget>

The "ServicePosition" is extracted from the CurrentService, and the
PositionGauge picks that information up and displays it on screen.

"START TIME OF CURRENT EVENT"
=============================

			<widget source="Event_Now" render="Label" position="210,68" size="60,22" font="Regular;20" backgroundColor="dark">
				<convert type="EventTime">StartTime</convert>
				<convert type="ClockToText">Default</convert>
			</widget>
The StartTime is extracted from the Event_Now (current event), and converted
into text with the standard (hh:mm) style, then displayed with the
"Label"-renderer.