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mod application;
mod graphiccontrol;
pub use graphiccontrol::{DisposalMethod, GraphicControl};
pub use self::application::Application;
pub enum Extension {
GraphicControl(GraphicControl),
Looping(u16),
Comment(Vec<u8>), // Plain Text
Application(Application),
}
impl From<&Extension> for Box<[u8]> {
fn from(ext: &Extension) -> Self {
let mut vec = vec![];
vec.push(0x21); // Push the extension introducer
match ext {
Extension::GraphicControl(gc) => {
vec.push(0xF9); // Graphic control label
vec.push(0x04); // Block size for this extension is always 4
vec.push(gc.packed);
vec.extend_from_slice(&gc.delay_time.to_le_bytes());
vec.push(gc.transparency_index);
}
Extension::Looping(count) => {
vec.push(0xFF); // Application extension label
vec.push(0x0B); // 11 bytes in this block
vec.extend_from_slice(b"NETSCAPE2.0"); // App. ident. and "auth code"
vec.push(0x03); // Sub-block length
vec.push(0x01); // Identifies netscape looping extension
vec.extend_from_slice(&count.to_le_bytes());
}
Extension::Comment(_) => todo!(),
Extension::Application(_) => todo!(),
}
vec.push(0x00); // Zero-length data block indicates end of extension
vec.into_boxed_slice()
}
}
impl From<GraphicControl> for Extension {
fn from(gce: GraphicControl) -> Self {
Extension::GraphicControl(gce)
}
}
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