Allow for GtkApplication to be subclasses

This expands further upon the gio MR that does the same
for GApplictiona.

gtk-rs/gio#209

Cargo.toml

@@ -37,6 +37,7 @@ purge-lgpl-docs = ["gtk-rs-lgpl-docs", "gdk/purge-lgpl-docs"]
 embed-lgpl-docs = ["gtk-rs-lgpl-docs", "gdk/embed-lgpl-docs"]
 dox = ["gdk/dox", "gtk-sys/dox"]
 futures = ["futures-preview", "fragile", "gio/futures"]
+subclassing = ["glib/subclassing", "gio/subclassing"]
 
 [target.'cfg(target_os = "macos")'.build-dependencies]
 cc = "^1.0"

Gir.toml

@@ -426,6 +426,7 @@ status = "generate"
 name = "Gtk.Application"
 status = "generate"
 trait_name = "GtkApplicationExt"
+subclassing = true
 manual_traits = ["gio::ApplicationExtManual"]
     [[object.function]]
     name = "new"

src/lib.rs

@@ -272,6 +272,10 @@ mod tree_store;
 mod widget;
 mod window;
 
+#[macro_use]
+#[cfg(feature = "subclassing")]
+pub mod subclass;
+
 pub mod prelude;
 
 pub use auto::*;

src/subclass/application.rs

@@ -0,0 +1,81 @@
+use gtk_sys;
+
+use glib::translate::*;
+
+use glib::subclass::prelude::*;
+
+use Application;
+use ApplicationClass;
+use Window;
+
+pub trait ApplicationImpl: ApplicationImplExt + gio::subclass::prelude::ApplicationImpl + 'static {
+    fn window_added(&self, application: &Application, window: &Window) {
+        self.parent_window_added(application, window)
+    }
+
+    fn window_removed(&self, application: &Application, window: &Window) {
+        self.parent_window_removed(application, window)
+    }
+}
+
+pub trait ApplicationImplExt {
+    fn parent_window_added(&self, application: &Application, window: &Window);
+    fn parent_window_removed(&self, application: &Application, window: &Window);
+}
+
+impl<T: ApplicationImpl + ObjectImpl> ApplicationImplExt for T {
+    fn parent_window_added(&self, application: &Application, window: &Window) {
+        unsafe {
+            let data = self.get_type_data();
+            let parent_class = data.as_ref().get_parent_class() as *mut gtk_sys::GtkApplicationClass;
+            let f = (*parent_class)
+                .window_added
+                .expect("No parent class implementation for \"window_added\"");
+            f(application.to_glib_none().0, window.to_glib_none().0)
+        }
+    }
+
+    fn parent_window_removed(&self, application: &Application, window: &Window) {
+        unsafe {
+            let data = self.get_type_data();
+            let parent_class = data.as_ref().get_parent_class() as *mut gtk_sys::GtkApplicationClass;
+            let f = (*parent_class)
+                .window_removed
+                .expect("No parent class implementation for \"window_added\"");
+            f(application.to_glib_none().0, window.to_glib_none().0)
+        }
+    }
+}
+
+unsafe impl<T: ObjectSubclass + ApplicationImpl> IsSubclassable<T> for ApplicationClass {
+    fn override_vfuncs(&mut self) {
+        <gio::ApplicationClass as IsSubclassable<T>>::override_vfuncs(self);
+        unsafe {
+            let klass = &mut *(self as *mut Self as *mut gtk_sys::GtkApplicationClass);
+            klass.window_added = Some(application_window_added::<T>);
+            klass.window_removed = Some(application_window_removed::<T>);
+        }
+    }
+}
+
+unsafe extern "C" fn application_window_added<T: ObjectSubclass>(ptr: *mut gtk_sys::GtkApplication, wptr: *mut gtk_sys::GtkWindow)
+where
+    T: ApplicationImpl,
+{
+    let instance = &*(ptr as *mut T::Instance);
+    let imp = instance.get_impl();
+    let wrap: Application = from_glib_borrow(ptr);
+
+    imp.window_added(&wrap, &from_glib_borrow(wptr))
+}
+
+unsafe extern "C" fn application_window_removed<T: ObjectSubclass>(ptr: *mut gtk_sys::GtkApplication, wptr: *mut gtk_sys::GtkWindow)
+where
+    T: ApplicationImpl,
+{
+    let instance = &*(ptr as *mut T::Instance);
+    let imp = instance.get_impl();
+    let wrap: Application = from_glib_borrow(ptr);
+
+    imp.window_removed(&wrap, &from_glib_borrow(wptr))
+}

src/subclass/mod.rs

@@ -0,0 +1,5 @@
+// Copyright 2019, The Gtk-rs Project Developers.
+// See the COPYRIGHT file at the top-level directory of this distribution.
+// Licensed under the MIT license, see the LICENSE file or <http://opensource.org/licenses/MIT>
+
+pub mod application;