use proc_macro2::TokenStream;
use proc_macro_error::{emit_call_site_error, emit_error};
use quote::quote;
use syn::Data;
use std::collections::HashMap;
use std::string::ToString;
use crate::attribute_parser::*;
use crate::util::*;
fn gen_set_template(source: &TemplateSource, crate_ident: &proc_macro2::Ident) -> TokenStream {
match source {
TemplateSource::File(file) => quote! {
#crate_ident::subclass::widget::WidgetClassSubclassExt::set_template_static(
klass,
include_bytes!(#file),
);
},
TemplateSource::Resource(resource) => quote! {
#crate_ident::subclass::widget::WidgetClassSubclassExt::set_template_from_resource(
klass,
&#resource,
);
},
TemplateSource::String(template) => quote! {
#crate_ident::subclass::widget::WidgetClassSubclassExt::set_template_static(
klass,
#template.as_bytes(),
);
},
}
}
fn check_template_fields(source: &TemplateSource, fields: &[AttributedField]) {
#[allow(unused_assignments)]
let xml = match source {
TemplateSource::String(template) => template,
_ => return,
};
let mut reader = quick_xml::Reader::from_str(xml);
let mut buf = Vec::new();
let mut ids_left = fields
.iter()
.map(|field| match field.attr.ty {
FieldAttributeType::TemplateChild => (field.id(), field.id_span()),
})
.collect::<HashMap<_, _>>();
loop {
use quick_xml::events::Event;
let event = reader.read_event(&mut buf);
let elem = match &event {
Ok(Event::Start(e)) => Some(e),
Ok(Event::Empty(e)) => Some(e),
Ok(Event::Eof) => break,
Err(e) => {
emit_call_site_error!(
"Failed reading template XML at position {}: {:?}",
reader.buffer_position(),
e
);
break;
}
_ => None,
};
if let Some(e) = elem {
let name = e.name();
if name == b"object" || name == b"template" {
let id = e
.attributes()
.find_map(|a| a.ok().and_then(|a| (a.key == b"id").then(|| a)));
let id = id.as_ref().and_then(|a| std::str::from_utf8(&a.value).ok());
if let Some(id) = id {
ids_left.remove(id);
}
}
}
buf.clear();
}
if let Some((name, span)) = ids_left.iter().next() {
emit_error!(
span,
"Template child with id `{}` not found in template XML",
name
);
}
}
fn gen_template_child_bindings(fields: &[AttributedField]) -> TokenStream {
let crate_ident = crate_ident_new();
let recurse = fields.iter().map(|field| match field.attr.ty {
FieldAttributeType::TemplateChild => {
let mut value_id = &field.ident.to_string();
let ident = &field.ident;
let mut value_internal = false;
field.attr.args.iter().for_each(|arg| match arg {
FieldAttributeArg::Id(value, _) => {
value_id = value;
}
FieldAttributeArg::Internal(internal) => {
value_internal = *internal;
}
});
quote! {
klass.bind_template_child_with_offset(
&#value_id,
#value_internal,
#crate_ident::offset_of!(Self => #ident),
);
}
}
});
quote! {
#(#recurse)*
}
}
fn gen_template_child_type_checks(fields: &[AttributedField]) -> TokenStream {
let crate_ident = crate_ident_new();
let recurse = fields.iter().map(|field| match field.attr.ty {
FieldAttributeType::TemplateChild => {
let ty = &field.ty;
let ident = &field.ident;
let type_err = format!("Template child with id `{}` has incompatible type. XML has {{:?}}, struct has {{:?}}", field.id());
quote! {
let ty = <<#ty as ::std::ops::Deref>::Target as #crate_ident::glib::StaticType>::static_type();
let child_ty = #crate_ident::glib::object::ObjectExt::type_(::std::ops::Deref::deref(&imp.#ident));
if !child_ty.is_a(ty) {
panic!(#type_err, child_ty, ty);
}
}
}
});
quote! {
#(#recurse)*
}
}
pub fn impl_composite_template(input: &syn::DeriveInput) -> TokenStream {
let name = &input.ident;
let crate_ident = crate_ident_new();
let template = match parse_template_source(input) {
Ok(v) => Some(v),
Err(e) => {
emit_call_site_error!(
"{}: derive(CompositeTemplate) requires #[template(...)] to specify 'file', 'resource', or 'string'",
e
);
None
}
};
let allow_without_attribute = template
.as_ref()
.map(|t| t.allow_template_child_without_attribute)
.unwrap_or(false);
let source = template.as_ref().map(|t| &t.source);
let set_template = source.map(|s| gen_set_template(s, &crate_ident));
let fields = match input.data {
Data::Struct(ref s) => Some(&s.fields),
_ => {
emit_call_site_error!("derive(CompositeTemplate) only supports structs");
None
}
};
let attributed_fields = match fields.map(|f| parse_fields(f, allow_without_attribute)) {
Some(Ok(fields)) => fields,
Some(Err(err)) => {
emit_error!(err.span(), err);
vec![]
}
None => vec![],
};
if let Some(source) = source {
check_template_fields(source, &attributed_fields);
}
let template_children = gen_template_child_bindings(&attributed_fields);
let checks = gen_template_child_type_checks(&attributed_fields);
quote! {
impl #crate_ident::subclass::widget::CompositeTemplate for #name {
fn bind_template(klass: &mut Self::Class) {
#set_template
unsafe {
#template_children
}
}
fn check_template_children(widget: &<Self as #crate_ident::glib::subclass::prelude::ObjectSubclass>::Type) {
let imp = #crate_ident::subclass::prelude::ObjectSubclassIsExt::imp(widget);
#checks
}
}
}
}