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use crate::*;
/// Writer - has support for wrapping text, page layout, fonts, etc.
pub struct Writer {
/// Underlying Basic Writer
pub b: BasicPdfWriter,
/// Current Page
pub p: Page,
/// List of fonts
pub fonts: FontFamily,
/// Index into fonts
pub cur_font: usize,
/// Current font size, default is 10
pub font_size: Px,
/// Current sup ( raises text up off line ), use set_sup to adjust it
pub sup: Px,
/// Writing mode
pub mode: Mode,
/// PDF title
pub title: String,
/// List of Pages
pub pages: Vec<Page>,
/// Page is new ( not yet initialised )
pub new_page: bool,
/// Line padding ( space between lines ) default is 4
pub line_pad: Px,
/// Line margin ( left ), default is 20
pub margin_left: Px,
/// Line margin ( right ), default is 20
pub margin_right: Px,
/// Top margin, default is 20
pub margin_top: Px,
/// Bottom margin, default is 20
pub margin_bottom: Px,
/// Page width, default is 600
pub page_width: Px,
/// Page height, default is 800
pub page_height: Px,
/// Line used ( controls word-wrapping )
pub line_used: MPx,
/// Line items
pub line: Vec<Item>,
/// Largest font for current line
pub max_font_size: Px,
/// Default is zero, set to 1 to center output lines
pub center: bool,
/// For fetching fonts and images
pub fetcher: Option<Box<dyn Fetcher>>,
}
impl Default for Writer {
fn default() -> Self {
Self {
mode: Mode::Normal,
title: String::new(),
b: BasicPdfWriter::default(),
fonts: helvetica(),
cur_font: 0,
font_size: 10,
sup: 0,
p: Page::default(),
pages: Vec::new(),
new_page: true,
page_width: 600,
page_height: 800,
line_pad: 4,
margin_left: 20,
margin_right: 20,
margin_top: 20,
margin_bottom: 20,
line_used: 0,
line: Vec::new(),
max_font_size: 0,
center: false,
fetcher: None,
}
}
}
impl Writer {
fn init_page(&mut self) {
self.p.width = self.page_width;
self.p.height = self.page_height;
self.p.goto(
self.margin_left,
self.p.height - self.font_size - self.margin_top,
);
if self.sup != 0 {
self.p.set_sup(self.sup);
}
self.new_page = false;
}
/// Completes current page.
pub fn save_page(&mut self) {
let p = std::mem::take(&mut self.p);
self.pages.push(p);
self.new_page = true;
}
fn init_font(&mut self, x: usize) {
let f = &mut self.fonts[x];
f.init(&mut self.b);
}
fn width(&self, c: char) -> MPx {
let f = &self.fonts[self.cur_font];
f.width(c) * self.font_size as MPx
}
fn line_len(&self) -> MPx {
((self.page_width - self.margin_left - self.margin_right) as MPx) * 1000
}
fn wrap_init(&mut self) {
if self.new_page {
self.init_page();
}
}
fn wrap_text(&mut self, s: &str) {
self.wrap_init();
let mut width: MPx = 0;
for c in s.chars() {
width += self.width(c); // May depend on current font.
}
if self.line_used + width > self.line_len() {
self.output_line();
if s == " " {
return;
}
}
self.line_used += width;
self.init_font(self.cur_font);
if self.font_size > self.max_font_size {
self.max_font_size = self.font_size;
}
self.line.push(Item::Text(
s.to_string(),
self.cur_font,
self.font_size,
width,
));
}
fn wrap_image(&mut self, im: Image, width: Px, scale: f32) {
self.wrap_init();
let width = (width as MPx) * 1000; // Convert width to MPx
if self.line_used + width > self.line_len() {
self.output_line();
}
self.line_used += width;
self.line.push(Item::Img(im, width, scale));
}
/// Outputs current line ( consisting of items ).
pub fn output_line(&mut self) {
if self.new_page {
self.init_page();
} else {
let cx = if self.center {
((self.line_len() - self.line_used) / 2000) as Px
} else {
0
};
let h = self.max_font_size + self.line_pad;
if self.p.y >= h + self.margin_bottom {
self.p.td(self.margin_left + cx - self.p.x, -h);
} else {
self.save_page();
self.init_page();
}
}
let mut cx: MPx = 0;
for item in &self.line {
match item {
Item::Text(s, f, x, w) => {
let fp = &*self.fonts[*f];
self.p.text(fp, *x, s);
cx += w;
}
Item::Sup(x) => {
self.p.set_sup(*x);
}
Item::Img(im, width, scale) => {
self.p.flush_text();
let x: f32 = (self.p.x as f32) + (cx as f32 / 1000.0);
let y = self.p.y as f32;
im.draw(&mut self.p, x, y, *scale);
cx += width;
self.p.space(*width);
}
}
}
self.line.clear();
self.line_used = 0;
self.max_font_size = 0;
}
/// Writes word-wrapped text if mode is Normal, adds text to title if mode is Title.
pub fn text(&mut self, s: &str) {
match self.mode {
Mode::Normal => {
self.wrap_text(s);
}
Mode::Title => {
self.title += s;
}
Mode::Head => {}
}
}
/// Write image
pub fn image(&mut self, src: &str, awidth: Option<Px>, aheight: Option<Px>) {
let mut bf = std::mem::take(&mut self.fetcher);
if let Some(f) = &mut bf {
let im = f.image(self, src);
let mut width: Px = im.width;
let mut scale: f32 = 1.0;
if let Some(awidth) = awidth {
scale = awidth as f32 / width as f32;
width = awidth;
} else if let Some(aheight) = aheight {
scale = aheight as f32 / im.height as f32;
width = (width as f32 * scale) as Px;
}
self.wrap_image(im, width, scale);
} else {
self.text("error : no fetcher in pdf-min::Writer");
}
self.fetcher = bf;
}
/// Adds a space to text.
pub fn space(&mut self) {
self.text(" ");
}
/// Sets sup
pub fn set_sup(&mut self, sup: Px) {
self.line.push(Item::Sup(sup));
self.sup = sup;
}
/// Flushes output line, writes page footers, saves pages, sets title, returns finished PDF as byte slice.
pub fn finish(&mut self) -> &[u8] {
self.output_line();
self.init_font(0);
self.save_page();
let n = self.pages.len();
let mut pnum = 1;
let font_size = 8;
#[allow(clippy::explicit_counter_loop)]
for p in &mut self.pages {
p.goto(self.margin_left, self.line_pad);
p.text(
&*self.fonts[0],
font_size,
&format!("Page {} of {}", pnum, n),
);
p.finish();
pnum += 1;
}
self.b.finish(&self.pages, self.title.as_bytes());
&self.b.b
}
}
/// Writing mode (for html)
#[derive(Clone, Copy)]
pub enum Mode {
/// Normal
Normal,
/// Text output is suppressed
Head,
/// Text is appended to title
Title,
}
/// Items that define a line of text.
pub enum Item {
/// Text, font index, font size, width
Text(String, usize, Px, MPx),
/// Sup value ( raise text above base line )
Sup(Px),
/// Image, image, width, scale
Img(Image, MPx, f32),
}
/// Instances can fetch an image or font
pub trait Fetcher {
/// Fetch named image
fn image(&mut self, _w: &mut Writer, _name: &str) -> Image {
todo!()
}
/// Fetch specified font
fn font(&mut self, _w: &mut Writer, _name: &str) -> Box<dyn Font> {
todo!()
}
}