Ilst: Create Ilst::is_* methods for flag atoms

Author: Serial-ATA

lofty/src/mp4/ilst/constants.rs

@@ -1,92 +1,23 @@
-// https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW35
-
-/// Reserved for use where no type needs to be indicated
-pub const RESERVED: u32 = 0;
-/// UTF-8 string without any count or NULL terminator
-pub const UTF8: u32 = 1;
-/// A big-endian UTF-16 string
-pub const UTF16: u32 = 2;
-/// Deprecated unless it is needed for special Japanese characters
-pub const S_JIS: u32 = 3;
-/// The UTF-8 variant storage of a string for sorting only
-pub const UTF8_SORT: u32 = 4;
-/// The UTF-16 variant storage of a string for sorting only
-pub const UTF16_SORT: u32 = 5;
-/// A JPEG in a JFIF wrapper
-pub const JPEG: u32 = 13;
-/// A PNG in a PNG wrapper
-pub const PNG: u32 = 14;
-/// A big-endian signed integer in 1,2,3 or 4 bytes
-pub const BE_SIGNED_INTEGER: u32 = 21;
-/// A big-endian unsigned integer in 1,2,3 or 4 bytes; size of value determines integer size
-pub const BE_UNSIGNED_INTEGER: u32 = 22;
-/// A big-endian 32-bit floating point value (IEEE754)
-pub const BE_FLOAT32: u32 = 23;
-/// A big-endian 64-bit floating point value (IEEE754)
-pub const BE_FLOAT64: u32 = 24;
-/// Windows bitmap format graphics
-pub const BMP: u32 = 27;
-/// A QuickTime metadata atom
-pub const QUICKTIME_METADATA: u32 = 28;
-/// An 8-bit signed integer
-pub const SIGNED_8BIT_INTEGER: u32 = 65;
-/// A big-endian 16-bit signed integer
-pub const BE_16BIT_SIGNED_INTEGER: u32 = 66;
-/// A big-endian 32-bit signed integer
-pub const BE_32BIT_SIGNED_INTEGER: u32 = 67;
-/// A block of data representing a two dimensional (2D) point with 32-bit big-endian floating point x and y coordinates. It has the structure:
-///
-/// ```c
-/// struct {
-///     BEFloat32 x;
-///     BEFloat32 y;
-/// }
-/// ```
-pub const BE_POINT_F32: u32 = 70;
-/// A block of data representing 2D dimensions with 32-bit big-endian floating point width and height. It has the structure:
-///
-/// ```c
-/// struct {
-///     BEFloat32 width;
-///     BEFloat32 height;
-/// }
-/// ```
-pub const BE_DIMENSIONS_F32: u32 = 71;
-/// A block of data representing a 2D rectangle with 32-bit big-endian floating point x and y coordinates and a 32-bit big-endian floating point width and height size. It has the structure:
-///
-/// ```c
-/// struct {
-///     BEFloat32 x;
-///     BEFloat32 y;
-///     BEFloat32 width;
-///     BEFloat32 height;
-/// }
-/// ```
+/// Identifiers for flag atoms
 ///
-/// or the equivalent structure:
+/// Any identifier in here will be treated as having [`AtomData::Bool`] as its data type when parsing.
+/// See [`Ilst::set_flag`] for more information.
 ///
-/// ```c
-/// struct {
-///     PointF32 origin;
-///     DimensionsF32 size;
-/// }
-/// ```
-pub const BE_RECT_F32: u32 = 72;
-/// A big-endian 64-bit signed integer
-pub const BE_64BIT_SIGNED_INTEGER: u32 = 74;
-/// An 8-bit unsigned integer
-pub const UNSIGNED_8BIT_INTEGER: u32 = 75;
-/// A big-endian 16-bit unsigned integer
-pub const BE_16BIT_UNSIGNED_INTEGER: u32 = 76;
-/// A big-endian 32-bit unsigned integer
-pub const BE_32BIT_UNSIGNED_INTEGER: u32 = 77;
-/// A big-endian 64-bit unsigned integer
-pub const BE_64BIT_UNSIGNED_INTEGER: u32 = 78;
-/// A block of data representing a 3x3 transformation matrix. It has the structure:
-///
-/// ```c
-/// struct {
-///     BEFloat64 matrix[3][3];
-/// }
-/// ```
-pub const AFFINE_TRANSFORM_F64: u32 = 79;
+/// [`AtomData::Bool`]: crate::mp4::AtomData::Bool
+/// [`Ilst::set_flag`]: crate::mp4::Ilst::set_flag
+pub mod flags {
+	use crate::mp4::AtomIdent;
+
+	/// Podcast flag (`pcst`)
+	pub const PODCAST: AtomIdent<'_> = AtomIdent::Fourcc(*b"pcst");
+	/// Gapless playback flag (`pgap`)
+	pub const GAPLESS: AtomIdent<'_> = AtomIdent::Fourcc(*b"pgap");
+	/// Show work and movement flag (`shwm`)
+	pub const SHOW_WORK: AtomIdent<'_> = AtomIdent::Fourcc(*b"shwm");
+	/// HD video flag (`hdvd`)
+	pub const HD_VIDEO: AtomIdent<'_> = AtomIdent::Fourcc(*b"hdvd");
+	/// Compilation flag (`cpil`)
+	pub const COMPILATION: AtomIdent<'_> = AtomIdent::Fourcc(*b"cpil");
+}
+
+pub(crate) const WELL_KNOWN_TYPE_SET: u8 = 0;

lofty/src/mp4/ilst/mod.rs

@@ -64,6 +64,32 @@ macro_rules! impl_accessor {
 	}
 }
 
+macro_rules! impl_flag_accessors {
+	($($name:ident ($ident:ident)),+ $(,)?) => {
+		$(
+			paste::paste! {
+				#[doc = "Whether the `" $ident "` flag atom is set"]
+				///
+				/// # Examples
+				///
+				/// ```rust
+				#[doc = "use lofty::mp4::constants::flags::" $name ";"]
+				/// use lofty::mp4::{AtomIdent, Ilst};
+				///
+				/// let mut ilst = Ilst::new();
+				///
+				/// // I want to toggle this flag!
+				#[doc = "ilst.set_flag(" $name ", true);"]
+				///
+				#[doc = "assert!(ilst.is_" $name:lower "());"]
+				pub fn [<is_ $name:lower>](&self) -> bool {
+					self.get_flag(&constants::flags::$name).unwrap_or(false)
+				}
+			}
+		)+
+	};
+}
+
 /// ## Pictures
 ///
 /// Unlike other formats, ilst does not store a [`PictureType`]. All pictures will have
@@ -349,6 +375,53 @@ impl Ilst {
 			.retain(|a| !matches!(a.data().next(), Some(AtomData::Picture(_))))
 	}
 
+	/// Sets the value of a flag ([`AtomData::Bool`]) atom
+	///
+	/// For identifiers, see [`constants::flags`].
+	///
+	/// # Examples
+	///
+	/// ```rust
+	/// use lofty::mp4::constants::flags::COMPILATION;
+	/// use lofty::mp4::{AtomIdent, Ilst};
+	///
+	/// // This file part of a compilation!
+	/// let mut ilst = Ilst::new();
+	/// ilst.set_flag(COMPILATION, true);
+	///
+	/// assert!(ilst.is_compilation());
+	/// ```
+	pub fn set_flag(&mut self, ident: AtomIdent<'_>, value: bool) {
+		if !value {
+			// A flag with a value of `false` is equivalent to removing it.
+			let _ = self.remove(&ident);
+			return;
+		}
+
+		let data = AtomData::Bool(value);
+		self.replace_atom(Atom {
+			ident,
+			data: AtomDataStorage::Single(data),
+		});
+	}
+
+	fn get_flag(&self, ident: &AtomIdent<'_>) -> Option<bool> {
+		self.get(ident)
+			.and_then(|atom| atom.data().next())
+			.and_then(|data| match data {
+				AtomData::Bool(b) => Some(*b),
+				_ => None,
+			})
+	}
+
+	impl_flag_accessors!(
+		PODCAST(pcst),
+		GAPLESS(pgap),
+		SHOW_WORK(shwm),
+		HD_VIDEO(hdvd),
+		COMPILATION(cpil)
+	);
+
 	/// Returns the parental advisory rating according to the `rtng` atom
 	pub fn advisory_rating(&self) -> Option<AdvisoryRating> {
 		self.get(&ADVISORY_RATING)