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//! プレゼンテーション。pptx と ppt を開く
//!
//! ```no_run
//! use folio::presentation::Presentation;
//! use std::path::Path;
//!
//! let mut file = Presentation::open(Path::new("deck.pptx")).unwrap();
//!
//! for index in 0..file.count() {
//! println!("{}", file.read(index).unwrap().text());
//! }
//! ```
use crate::error::Error;
use crate::package::Package;
use crate::slide::{self, Slide};
use crate::xml::{Event, Reader};
use std::path::Path;
/// どちらの形式を開いたか
enum Origin {
/// pptx
Package(Package),
/// ppt。読み込んだスライドを持つ
Record(Vec<Slide>),
}
/// 読むために開いたプレゼンテーション
pub struct Presentation {
source: Origin,
main: String,
part: Vec<String>,
}
impl Presentation {
/// pptx か ppt を開く
///
/// 先頭のバイトを見て、どちらの形式かを決める。読む側は形式を気にしなくてよい。
pub fn open(path: &Path) -> Result<Presentation, Error> {
if crate::cfb::is_compound(path) {
return open_record(path);
}
let mut package = Package::open(path)?;
let main = package.main()?;
let listed = read_order(&mut package, &main)?;
let link = package.relationship(&main)?;
let mut part = Vec::with_capacity(listed.len());
for id in listed {
let Some(one) = link.iter().find(|one| one.id == id) else {
return Err(Error::at(format!("スライド {id} の指し先がありません"), &main));
};
part.push(one.target.clone());
}
Ok(Presentation {source: Origin::Package(package), main, part})
}
/// 何枚あるか
pub fn count(&self) -> usize {
match &self.source {
Origin::Package(_) => self.part.len(),
Origin::Record(slide) => slide.len(),
}
}
/// 旧形式かどうか
pub fn is_record(&self) -> bool {
matches!(self.source, Origin::Record(_))
}
/// スライドのパートの名前。並び順
pub fn slide(&self) -> &[String] {
&self.part
}
/// 本体のパートの名前
pub fn main(&self) -> &str {
&self.main
}
/// 包みそのもの。folio が読まないパートを自分で取り出すときに使う
///
/// 旧形式には包みがないので None を返す。
pub fn package(&mut self) -> Option<&mut Package> {
match &mut self.source {
Origin::Package(one) => Some(one),
Origin::Record(_) => None,
}
}
/// 1 枚読む。番号は 0 から
pub fn read(&mut self, index: usize) -> Result<Slide, Error> {
if let Origin::Record(all) = &self.source {
let Some(one) = all.get(index) else {
return Err(Error::new(format!("{index} 枚目はありません")));
};
return Ok(one.clone());
}
let Some(part) = self.part.get(index) else {
return Err(Error::new(format!("{index} 枚目はありません")));
};
let part = part.clone();
let Origin::Package(package) = &mut self.source else {
return Err(Error::new("包みがありません"));
};
let mut reader = package.reader(&part)?;
slide::read(&mut reader).map_err(|error| error.within(&part))
}
/// 全部の文字を、スライドごとに改行でつないで返す
pub fn text(&mut self) -> Result<String, Error> {
let mut result = String::new();
for index in 0..self.count() {
if index > 0 {
result.push('\n');
}
result.push_str(&self.read(index)?.text());
result.push('\n');
}
Ok(result)
}
}
/// ppt を開く
fn open_record(path: &Path) -> Result<Presentation, Error> {
let mut file = crate::cfb::Compound::open(path)?;
if !file.has("PowerPoint Document") {
return Err(Error::new("ppt の PowerPoint Document ストリームがありません"));
}
let main = file.read("PowerPoint Document")?;
let user = if file.has("Current User") {
file.read("Current User")?
} else {
Vec::new()
};
let slide = crate::ppt::read(&main, &user)?;
Ok(Presentation {
source: Origin::Record(slide),
main: "PowerPoint Document".to_string(),
part: Vec::new(),
})
}
/// presentation.xml から、スライドの並びを読む
fn read_order(package: &mut Package, main: &str) -> Result<Vec<String>, Error> {
let data = package.read(main)?;
let mut reader = Reader::over(data);
let mut result = Vec::new();
let mut inside = false;
while let Some(event) = reader.next().map_err(|error| error.within(main))? {
if event == Event::Close {
if reader.name() == "sldIdLst" {
inside = false;
}
continue;
}
if event == Event::Text {
continue;
}
match reader.name() {
"sldIdLst" => inside = event == Event::Open,
"sldId" if inside => result.push(reader.attribute("r:id").unwrap_or("").to_string()),
_ => {}
}
}
Ok(result)
}