/// <summary>
/// Gets a specified lyrics frame from the specified tag,
/// trying to to match the description and language but
/// accepting an incomplete match.
/// </summary>
/// <param name="tag">
/// A <see cref="Tag" /> object to search in.
/// </param>
/// <param name="description">
/// A <see cref="string" /> object specifying the description
/// to match.
/// </param>
/// <param name="language">
/// A <see cref="string" /> object specifying the ISO-639-2
/// language code to match.
/// </param>
/// <param name="type">
/// A <see cref="SynchedTextType" /> value specifying the
/// text type to match.
/// </param>
/// <returns>
/// A <see cref="SynchronisedLyricsFrame" /> object
/// containing the matching frame, or <see langword="null" />
/// if a match wasn't found.
/// </returns>
/// <remarks>
/// <para>The method tries matching with the following order
/// of precidence:</para>
/// <list type="number">
/// <item><term>The first frame with a matching
/// description, language, and type.</term></item>
/// <item><term>The first frame with a matching
/// description and language.</term></item>
/// <item><term>The first frame with a matching
/// language.</term></item>
/// <item><term>The first frame with a matching
/// description.</term></item>
/// <item><term>The first frame with a matching
/// type.</term></item>
/// <item><term>The first frame.</term></item>
/// </list>
/// </remarks>
public static SynchronisedLyricsFrame GetPreferred(Tag tag,
string description,
string language,
SynchedTextType type)
{
// This is weird, so bear with me. The best thing we can
// have is something straightforward and in our own
// language. If it has a description, then it is
// probably used for something other than an actual
// comment. If that doesn't work, we'd still rather have
// something in our language than something in another.
// After that all we have left are things in other
// languages, so we'd rather have one with actual
// content, so we try to get one with no description
// first.
int best_value = -1;
SynchronisedLyricsFrame best_frame = null;
foreach (Frame f in tag)
{
SynchronisedLyricsFrame cf =
f as SynchronisedLyricsFrame;
if (cf == null)
{
continue;
}
int value = 0;
if (cf.Language == language)
{
value += 4;
}
if (cf.Description == description)
{
value += 2;
}
if (cf.Type == type)
{
value += 1;
}
if (value == 7)
{
return(cf);
}
if (value <= best_value)
{
continue;
}
best_value = value;
best_frame = cf;
}
return(best_frame);
}
/// <summary>
/// Creates a deep copy of the current instance.
/// </summary>
/// <returns>
/// A new <see cref="Frame" /> object identical to the
/// current instance.
/// </returns>
public override Frame Clone()
{
SynchronisedLyricsFrame frame =
new SynchronisedLyricsFrame(description,
language, lyrics_type, encoding);
frame.timestamp_format = timestamp_format;
frame.text = (SynchedText[])text.Clone();
return(frame);
}
/// <summary>
/// Gets a specified lyrics frame from the specified tag,
/// optionally creating it if it does not exist.
/// </summary>
/// <param name="tag">
/// A <see cref="Tag" /> object to search in.
/// </param>
/// <param name="description">
/// A <see cref="string" /> object specifying the description
/// to match.
/// </param>
/// <param name="language">
/// A <see cref="string" /> object specifying the ISO-639-2
/// language code to match.
/// </param>
/// <param name="type">
/// A <see cref="SynchedTextType" /> value specifying the
/// text type to match.
/// </param>
/// <param name="create">
/// A <see cref="bool" /> specifying whether or not to create
/// and add a new frame to the tag if a match is not found.
/// </param>
/// <returns>
/// A <see cref="SynchronisedLyricsFrame" /> object
/// containing the matching frame, or <see langword="null" />
/// if a match wasn't found and <paramref name="create" /> is
/// <see langword="false" />.
/// </returns>
public static SynchronisedLyricsFrame Get(Tag tag,
string description,
string language,
SynchedTextType type,
bool create)
{
foreach (Frame f in tag)
{
SynchronisedLyricsFrame lyr =
f as SynchronisedLyricsFrame;
if (lyr == null)
{
continue;
}
if (lyr.Description == description &&
(language == null ||
language == lyr.Language) &&
type == lyr.Type)
{
return(lyr);
}
}
if (!create)
{
return(null);
}
SynchronisedLyricsFrame frame =
new SynchronisedLyricsFrame(description,
language, type);
tag.AddFrame(frame);
return(frame);
}