From 605cff3f834f77539d9ff8c92761d3642594b329 Mon Sep 17 00:00:00 2001
From: IdanArye <idanarye@gmail.com>
Date: Fri, 2 Apr 2021 23:51:25 +0300
Subject: [PATCH] Close #5 - allow `#[widget(recursive)]` on builder fields

---
 CHANGELOG.md                              |  1 +
 macros/src/widgets_from_builder_derive.rs | 26 +++++++++
 tests/four_texts.glade                    | 59 ++++++++++++++++++++
 tests/recusive_widgets_from_builder.rs    | 65 +++++++++++++++++++++++
 4 files changed, 151 insertions(+)
 create mode 100644 tests/four_texts.glade
 create mode 100644 tests/recusive_widgets_from_builder.rs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ede16e2265..616523d689 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - `woab::NamespacedSignalRouter` for routing signals from the same builder to
   different actors.
 - `BuilderConnector::with_object`.
+- `#[widget(nested)]` for nesting widget structs.
 
 ### Changed
 - [**BREAKING**] Updated Actix to 0.11 and Tokio to 1.14. Consequences:
diff --git a/macros/src/widgets_from_builder_derive.rs b/macros/src/widgets_from_builder_derive.rs
index c94c1c242d..bbab29de17 100644
--- a/macros/src/widgets_from_builder_derive.rs
+++ b/macros/src/widgets_from_builder_derive.rs
@@ -22,9 +22,19 @@ pub fn impl_widgets_from_builder_derive(ast: &syn::DeriveInput) -> Result<proc_m
         .iter()
         .map(|field| {
             /* Handle renaming */
+            let mut nested = false;
             let mut name = None;
             iter_attrs_parameters(&field.attrs, "widget", |attr_name, value| {
                 match path_to_single_string(&attr_name)?.as_str() {
+                    "nested" => {
+                        if nested {
+                            return Err(Error::new_spanned(value, "attribute `nested` can only be specified once"));
+                        }
+                        if value.is_some() {
+                            return Err(Error::new_spanned(value, "attribute `nested` cannot have a value"));
+                        }
+                        nested = true;
+                    }
                     "name" => {
                         let value = value.ok_or_else(|| Error::new_spanned(attr_name, "attribute `name` must have a value"))?;
                         if name.is_some() {
@@ -38,11 +48,27 @@ pub fn impl_widgets_from_builder_derive(ast: &syn::DeriveInput) -> Result<proc_m
                 }
                 Ok(())
             })?;
+            if nested && name.is_some() {
+                return Err(Error::new_spanned(field, "`nested` and `name` are mutually exclusive"));
+            }
 
             let field_ident = field
                 .ident
                 .as_ref()
                 .ok_or_else(|| Error::new(field.span(), "Nameless field"))?;
+
+            if nested {
+                // NOTE: Not using `?` because it `into`es the error and the type checker does not like that.
+                return Ok(quote! {
+                    #field_ident: {
+                        match std::convert::TryInto::try_into(builder) {
+                            Ok(ok) => ok,
+                            Err(err) => return Err(err),
+                        }
+                    },
+                })
+            }
+
             let field_type = &field.ty;
             let ident_as_str = match name {
                 Some(syn::Expr::Lit(syn::ExprLit {
diff --git a/tests/four_texts.glade b/tests/four_texts.glade
new file mode 100644
index 0000000000..656522d73a
--- /dev/null
+++ b/tests/four_texts.glade
@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.38.2 -->
+<interface>
+  <requires lib="gtk+" version="3.24"/>
+  <object class="GtkApplicationWindow" id="win_test">
+    <property name="can-focus">False</property>
+    <child>
+      <object class="GtkBox">
+        <property name="visible">True</property>
+        <property name="can-focus">False</property>
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="GtkEntry" id="text1">
+            <property name="visible">True</property>
+            <property name="can-focus">True</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">0</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkEntry" id="text2">
+            <property name="visible">True</property>
+            <property name="can-focus">True</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">1</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkEntry" id="text3">
+            <property name="visible">True</property>
+            <property name="can-focus">True</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">2</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkEntry" id="text4">
+            <property name="visible">True</property>
+            <property name="can-focus">True</property>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">3</property>
+          </packing>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>
diff --git a/tests/recusive_widgets_from_builder.rs b/tests/recusive_widgets_from_builder.rs
new file mode 100644
index 0000000000..808b1ade44
--- /dev/null
+++ b/tests/recusive_widgets_from_builder.rs
@@ -0,0 +1,65 @@
+use gtk::prelude::*;
+
+#[macro_use]
+mod util;
+
+#[derive(woab::WidgetsFromBuilder)]
+pub struct FlatWidgets {
+    text1: gtk::Entry,
+    text2: gtk::Entry,
+    text3: gtk::Entry,
+    text4: gtk::Entry,
+}
+
+#[derive(woab::WidgetsFromBuilder)]
+pub struct GroupedWidgets {
+    #[widget(nested)]
+    group_a: GroupA,
+    #[widget(nested)]
+    group_b: GroupB,
+}
+
+#[derive(woab::WidgetsFromBuilder)]
+pub struct GroupA {
+    text1: gtk::Entry,
+    text2: gtk::Entry,
+}
+
+#[derive(woab::WidgetsFromBuilder)]
+pub struct GroupB {
+    text3: gtk::Entry,
+    text4: gtk::Entry,
+}
+
+#[test]
+fn test_recusive_widgets_from_builder() -> anyhow::Result<()> {
+    let factory = woab::BuilderFactory::from(include_str!("four_texts.glade").to_owned());
+    gtk::init()?;
+    woab::run_actix_inside_gtk_event_loop()?;
+    let bld = factory.instantiate();
+
+    let flat_widgets: FlatWidgets = bld.widgets()?;
+    let grouped_widgets: GroupedWidgets = bld.widgets()?;
+
+    assert!(grouped_widgets.group_a.text1.get_text().is_empty());
+    assert!(grouped_widgets.group_a.text2.get_text().is_empty());
+    assert!(grouped_widgets.group_b.text3.get_text().is_empty());
+    assert!(grouped_widgets.group_b.text4.get_text().is_empty());
+
+    flat_widgets.text1.set_text("Text 1");
+    flat_widgets.text2.set_text("Text 2");
+    flat_widgets.text3.set_text("Text 3");
+    flat_widgets.text4.set_text("Text 4");
+
+    wait_for!(flat_widgets.text1.get_text() == "Text 1")?;
+    wait_for!(flat_widgets.text2.get_text() == "Text 2")?;
+    wait_for!(flat_widgets.text3.get_text() == "Text 3")?;
+    wait_for!(flat_widgets.text4.get_text() == "Text 4")?;
+
+    assert!(grouped_widgets.group_a.text1.get_text() == "Text 1");
+    assert!(grouped_widgets.group_a.text2.get_text() == "Text 2");
+    assert!(grouped_widgets.group_b.text3.get_text() == "Text 3");
+    assert!(grouped_widgets.group_b.text4.get_text() == "Text 4");
+
+    Ok(())
+}