use crate::event;
use crate::native;
use std::collections::HashSet;
use wasm_bindgen::prelude::*;
use wasm_bindgen::JsCast;
use web_sys;
pub struct Renderer {
before: super::Node,
root: web_sys::Node,
}
impl Renderer {
pub fn new(virtual_node: super::Node, root_node: web_sys::Node) -> Self {
let root: web_sys::Node;
if let Some(node) = render(&virtual_node, None, Some(&root_node)) {
root = node;
} else {
root = native::create_text_node("").into();
}
let _ = root_node
.parent_node()
.expect("no parent node of root")
.replace_child(&root, &root_node);
Self {
before: virtual_node,
root,
}
}
pub fn update(&mut self, after: super::Node) {
if let Some(root) = render(&after, Some(&self.before), Some(&self.root)) {
let _ = self
.root
.parent_node()
.expect("no parent node of root")
.replace_child(&root, &self.root);
self.root = root;
}
self.before = after;
}
}
fn set_attribute_all(element: &web_sys::Element, attributes: &super::Attributes) {
for (a, v) in &attributes.attributes {
if v.is_empty() {
let _ = element.set_attribute(a, "");
} else if let Some(d) = attributes.delimiters.get(a) {
set_attribute_set(element, a, v, d);
} else {
set_attribute_set(element, a, v, "");
}
}
}
fn set_attribute_set(element: &web_sys::Element, a: &str, v: &HashSet<super::Value>, d: &str) {
let v = v.iter().map(|v| v.into()).collect::<Vec<String>>();
let v = v.iter().map(|v| &v as &str).collect::<Vec<&str>>().join(d);
if String::from("value") == String::from(a) {
if let Some(element) = element.dyn_ref::<web_sys::HtmlInputElement>() {
element.set_value(&v);
} else {
let _ = element.set_attribute(a, &v);
}
} else {
let _ = element.set_attribute(a, &v);
}
}
fn set_event_all(element: &web_sys::Element, events: &super::Events) {
for (t, hid) in &events.handlers {
let hid = *hid;
let h = Closure::once(move |e| {
event::dispatch(hid, e);
});
let event_target: &web_sys::EventTarget = element.as_ref();
let _ = event_target.add_event_listener_with_callback_and_add_event_listener_options(
&t,
h.as_ref().unchecked_ref(),
web_sys::AddEventListenerOptions::new().once(true),
);
h.forget();
}
}
fn set_attribute_diff(
element: &web_sys::Element,
after: &super::Attributes,
before: &super::Attributes,
) {
for (a, _) in &before.attributes {
if after.attributes.get(a).is_none() {
let _ = element.remove_attribute(a);
}
}
set_attribute_all(element, after);
}
fn render(
after: &super::Node,
before: Option<&super::Node>,
root: Option<&web_sys::Node>,
) -> Option<web_sys::Node> {
use super::Node;
match after {
Node::Text(text) => Some(native::create_text_node(&text).into()),
Node::Element(after) => {
if after.need_rerendering {
if let (Some(Node::Element(before)), Some(root)) = (before, root) {
if let Some(root) = root.dyn_ref::<web_sys::Element>() {
if after.tag_name == before.tag_name {
render_element_diff(after, before, root);
None
} else {
Some(render_element_force(after))
}
} else {
None
}
} else {
Some(render_element_force(after))
}
} else {
if let (Some(Node::Element(before)), Some(root)) = (before, root) {
render_element_lazy(after, before, root);
None
} else {
None
}
}
}
}
}
fn render_element_lazy(after: &super::Element, before: &super::Element, root: &web_sys::Node) {
let mut i: usize = 0;
for child in &after.children {
if let Some(b) = root.child_nodes().item(i as u32) {
if let Some(a) = render(&child, before.children.get(i), Some(&b)) {
let _ = root.replace_child(&a, &b);
}
}
i += 1;
}
}
fn render_element_force(after: &super::Element) -> web_sys::Node {
let el = new_element(&after.tag_name, &after.attributes, &after.events);
for child in &after.children {
if let Some(node) = render(&child, None, None) {
let _ = el.append_child(&node);
}
}
el.into()
}
fn render_element_diff(after: &super::Element, before: &super::Element, root: &web_sys::Element) {
for (_, hid) in &before.events.handlers {
event::remove(hid);
}
set_attribute_diff(&root, &after.attributes, &before.attributes);
set_event_all(&root, &after.events);
let mut i = (root.child_nodes().length() as i64) - (after.children.len() as i64);
while i > 0 {
if let Some(node) = root
.child_nodes()
.item((after.children.len() as i64 + i - 1) as u32)
{
let _ = root.remove_child(&node);
}
i -= 1;
}
let mut i: usize = 0;
for child in &after.children {
if let Some(old) = root.child_nodes().item(i as u32) {
if let Some(new) = render(&child, before.children.get(i), Some(&old)) {
let _ = root.replace_child(&new, &old);
}
} else {
if let Some(new) = render(&child, None, None) {
let _ = root.append_child(&new);
}
}
i += 1;
}
}
fn new_element(
tag_name: &str,
attributes: &super::Attributes,
events: &super::Events,
) -> web_sys::Element {
let element = native::create_element(tag_name);
set_attribute_all(&element, attributes);
set_event_all(&element, events);
element
}