subclass contrast preview

data/resources/style.css

@@ -28,7 +28,7 @@ entry selection{
   color: @foreground_color;
   padding-bottom: 6px;
 }
-.preview-comment {
+.preview-body {
   padding: 6px;
 }
 /* ChartBarWidget */

src/contrast_preview.rs

 use gettextrs::gettext;
+use glib::subclass;
+use glib::subclass::prelude::*;
+use glib::translate::*;
 use gtk::prelude::*;
+use gtk::subclass::prelude::{BoxImpl, ContainerImpl, WidgetImpl};
 
-pub struct ContrastPreview {
-    pub widget: gtk::Box,
+pub struct ContrastPreviewPrivate {
     head_label: gtk::Label,
-    comment_label: gtk::Label,
+    body_label: gtk::Label,
 }
 
-impl ContrastPreview {
-    pub fn new() -> ContrastPreview {
-        let widget = gtk::Box::new(gtk::Orientation::Vertical, 0);
+impl ObjectSubclass for ContrastPreviewPrivate {
+    const NAME: &'static str = "ContrastPreview";
+    type ParentType = gtk::Box;
+    type Instance = subclass::simple::InstanceStruct<Self>;
+    type Class = subclass::simple::ClassStruct<Self>;
 
-        let head_label = gtk::Label::new(Some(""));
-        let comment_label = gtk::Label::new(Some(""));
-        let preview = ContrastPreview { widget, head_label, comment_label };
+    glib_object_subclass!();
 
-        preview.setup_widget();
-        preview
+    fn new() -> Self {
+        let head_label = gtk::Label::new(None);
+        let body_label = gtk::Label::new(None);
+        Self { head_label, body_label }
     }
+}
+impl ObjectImpl for ContrastPreviewPrivate {
+    glib_object_impl!();
+
+    fn constructed(&self, obj: &glib::Object) {
+        self.parent_constructed(obj);
+        let self_ = obj.downcast_ref::<gtk::Box>().unwrap();
 
-    fn setup_widget(&self) {
-        self.widget.set_vexpand(true);
-        self.widget.set_valign(gtk::Align::Center);
-        self.widget.get_style_context().add_class("preview");
+        self_.set_orientation(gtk::Orientation::Vertical);
+        self_.set_vexpand(true);
+        self_.set_valign(gtk::Align::Center);
+        self_.get_style_context().add_class("preview");
 
         self.head_label.get_style_context().add_class("preview-head");
         self.head_label.set_halign(gtk::Align::Center);
         self.head_label.set_valign(gtk::Align::Start);
         self.head_label.show();
 
-        self.comment_label.get_style_context().add_class("preview-comment");
-        self.comment_label.set_halign(gtk::Align::Center);
-        self.comment_label.set_valign(gtk::Align::Start);
-        self.comment_label.show();
+        self.body_label.get_style_context().add_class("preview-body");
+        self.body_label.set_halign(gtk::Align::Center);
+        self.body_label.set_valign(gtk::Align::Start);
+        self.body_label.show();
+
+        self_.pack_start(&self.head_label, false, false, 0);
+        self_.pack_start(&self.body_label, false, false, 0);
+
+        self_.show();
+    }
+}
+
+impl WidgetImpl for ContrastPreviewPrivate {}
+impl ContainerImpl for ContrastPreviewPrivate {}
+impl BoxImpl for ContrastPreviewPrivate {}
+
+glib_wrapper! {
+    pub struct ContrastPreview(
+        Object<subclass::simple::InstanceStruct<ContrastPreviewPrivate>,
+        subclass::simple::ClassStruct<ContrastPreviewPrivate>,
+        BoxClass>)
+        @extends gtk::Widget, gtk::Container, gtk::Box;
 
-        self.widget.pack_start(&self.head_label, false, false, 0);
-        self.widget.pack_start(&self.comment_label, false, false, 0);
+    match fn {
+        get_type => || ContrastPreviewPrivate::get_type().to_glib(),
+    }
+}
 
-        self.widget.show();
+impl ContrastPreview {
+    pub fn new() -> Self {
+        glib::Object::new(ContrastPreview::static_type(), &[]).unwrap().downcast::<ContrastPreview>().unwrap()
     }
 
     pub fn set_contrast_level(&self, contrast_level: f64) {
+        let self_ = ContrastPreviewPrivate::from_instance(self);
         if 0.0 <= contrast_level && contrast_level < 3.0 {
-            self.head_label.set_text(&gettext("Nope"));
-            self.comment_label.set_text(&gettext("This color combination doesn’t have enough contrast to be legible."));
+            self_.head_label.set_text(&gettext("Nope"));
+            self_.body_label.set_text(&gettext("This color combination doesn’t have enough contrast to be legible."));
         } else if 3.0 <= contrast_level && contrast_level < 4.5 {
-            self.head_label.set_text(&gettext("Not bad"));
-            self.comment_label.set_text(&gettext("This color combination can work, but only at large text sizes."));
+            self_.head_label.set_text(&gettext("Not bad"));
+            self_.body_label.set_text(&gettext("This color combination can work, but only at large text sizes."));
         } else if 4.5 <= contrast_level && contrast_level < 7.0 {
-            self.head_label.set_text(&gettext("Pretty good"));
-            self.comment_label.set_text(&gettext("This color combination should work OK in most cases."));
+            self_.head_label.set_text(&gettext("Pretty good"));
+            self_.body_label.set_text(&gettext("This color combination should work OK in most cases."));
         } else if 7.0 <= contrast_level && contrast_level <= 21.0 {
-            self.head_label.set_text(&gettext("Awesome"));
-            self.comment_label.set_text(&gettext("This color combination has great contrast."));
+            self_.head_label.set_text(&gettext("Awesome"));
+            self_.body_label.set_text(&gettext("This color combination has great contrast."));
         }
     }
 }

src/window.rs

@@ -21,7 +21,7 @@ pub struct Window {
     reverse_btn: gtk::Button,
     pub state: Rc<RefCell<WindowState>>,
     pub levelbar: RefCell<ContrastLevelBar>,
-    pub preview: RefCell<ContrastPreview>,
+    pub preview: ContrastPreview,
     sender: glib::Sender<Action>,
 }
 
@@ -39,7 +39,7 @@ impl Window {
         let state = Rc::new(RefCell::new(WindowState::init(settings)));
 
         let levelbar = RefCell::new(ContrastLevelBar::new());
-        let preview = RefCell::new(ContrastPreview::new());
+        let preview = ContrastPreview::new();
 
         let window = Rc::new(Window {
             widget: window_widget,
@@ -64,7 +64,7 @@ impl Window {
         let contrast_level = colour::calc_contrast_level(&bg_rgba, &fg_rgba);
 
         self.levelbar.borrow_mut().set_contrast_level(contrast_level);
-        self.preview.borrow_mut().set_contrast_level(contrast_level);
+        self.preview.set_contrast_level(contrast_level);
 
         colour::compile_styles(&self.sender, fg_rgba, bg_rgba);
     }
@@ -140,7 +140,7 @@ impl Window {
         get_widget!(self.builder, libhandy::HeaderBar, headerbar);
         headerbar.set_custom_title(Some(&entries_container));
 
-        container.pack_start(&self.preview.borrow().widget, true, true, 12);
+        container.pack_start(&self.preview, true, true, 12);
         container.pack_start(&self.levelbar.borrow().widget, true, true, 12);
 
         self.widget.add(&container);