use droppable structure for unref things

source/tycho/main.rs

@@ -8,7 +8,7 @@ use glib_sys::*;
 use gobject_sys::*;
 use gtk_sys::*;
 use maraiah::{c_str, durandal::ffi};
-use std::{cell::RefCell, rc::Rc};
+use std::{cell::RefCell, marker::PhantomData, rc::Rc};
 
 /// Called when the application activates in order to set everything up.
 unsafe extern "C" fn app_activate(app: *mut GtkApplication, edit: gpointer)
@@ -20,40 +20,32 @@ unsafe extern "C" fn app_activate(app: *mut GtkApplication, edit: gpointer)
    setup_css();
 
    let path = c_str!("/net/greyserv/maraiah/tycho/ui");
-   let b    = gtk_builder_new_from_resource(path);
+   let b    = Refc::new(gtk_builder_new_from_resource(path));
 
-   setup_draw_area(b, edit.clone());
+   setup_draw_area(&b, edit.clone());
-   setup_win_map_view(b);
+   setup_win_map_view(&b);
-   setup_win_map_tools(b);
+   setup_win_map_tools(&b);
-   setup_win_map_prop(b);
+   setup_win_map_prop(&b);
-   setup_about_dlg(b);
+   setup_about_dlg(&b);
-   setup_win_main(b, app, edit.clone());
+   setup_win_main(&b, app, edit.clone());
-
-   g_object_unref(b as _);
 }
 
 /// Sets up the map view window's drawing area.
-unsafe fn setup_draw_area(b: *mut GtkBuilder, edit: Rc<MapEditorRef>)
+unsafe fn setup_draw_area(b: &Refc<GtkBuilder>, edit: Rc<MapEditorRef>)
 {
    /// All of the state necessary for the drawing area.
    struct RenderState
    {
-      im_nomap: *mut GdkPixbuf,
+      im_nomap: Refc<'static, GdkPixbuf>,
-      ax:       *mut GtkAdjustment,
+      ax:       Refc<'static, GtkAdjustment>,
-      ay:       *mut GtkAdjustment,
+      ay:       Refc<'static, GtkAdjustment>,
       edit:     Rc<MapEditorRef>,
    }
 
    /// Callback to finalize the drawing area.
    unsafe extern "C" fn c_done(_: *mut GtkWidget, rend: gpointer)
    {
-      let rend = Box::from_raw(rend as *mut RenderState);
+      Box::from_raw(rend as *mut RenderState);
-
-      g_object_unref(rend.im_nomap as gpointer as _);
-      g_object_unref(rend.ax as _);
-      g_object_unref(rend.ay as _);
-
-      // data is dropped and freed here
    }
 
    /// Callback to draw on the drawing area.
@@ -68,13 +60,13 @@ unsafe fn setup_draw_area(b: *mut GtkBuilder, edit: Rc<MapEditorRef>)
       let w = f64::from(gtk_widget_get_allocated_width(wid));
       let h = f64::from(gtk_widget_get_allocated_height(wid));
 
-      gtk_adjustment_set_lower(rend.ax, 0.0);
+      gtk_adjustment_set_lower(*rend.ax, 0.0);
-      gtk_adjustment_set_upper(rend.ax, w);
+      gtk_adjustment_set_upper(*rend.ax, w);
 
-      gtk_adjustment_set_lower(rend.ay, 0.0);
+      gtk_adjustment_set_lower(*rend.ay, 0.0);
-      gtk_adjustment_set_upper(rend.ay, h);
+      gtk_adjustment_set_upper(*rend.ay, h);
 
-      let im = CrImage(rend.im_nomap);
+      let im = CrImage(*rend.im_nomap);
       let mut dr = CrDrawArea::new(ctx, w, h);
 
       rend.edit.borrow().draw(&mut dr, &im);
@@ -87,13 +79,14 @@ unsafe fn setup_draw_area(b: *mut GtkBuilder, edit: Rc<MapEditorRef>)
    edit.borrow_mut().set_draw(wid as _);
 
    // get all of the necessary state and related objects
-   let ax: *mut GtkAdjustment = get_obj(b, c_str!("adj-map-horz"));
+   let ax = Refc::<GtkAdjustment>::new(get_obj(b, c_str!("adj-map-horz")));
-   let ay: *mut GtkAdjustment = get_obj(b, c_str!("adj-map-vert"));
+   let ay = Refc::<GtkAdjustment>::new(get_obj(b, c_str!("adj-map-vert")));
 
-   g_object_ref(ax as _);
+   g_object_ref(*ax as _);
-   g_object_ref(ay as _);
+   g_object_ref(*ay as _);
 
    let im_nomap = load_img(c_str!("/net/greyserv/maraiah/tycho/tycho1.png"));
+   let im_nomap = Refc::new(im_nomap);
 
    let rend = RenderState{im_nomap, ax, ay, edit};
    let rend = Box::into_raw(Box::new(rend));
@@ -103,7 +96,7 @@ unsafe fn setup_draw_area(b: *mut GtkBuilder, edit: Rc<MapEditorRef>)
 }
 
 /// Sets up the map view window.
-unsafe fn setup_win_map_view(b: *mut GtkBuilder)
+unsafe fn setup_win_map_view(b: &Refc<GtkBuilder>)
 {
    let win: *mut GtkWindow   = get_obj(b, c_str!("win-map-view"));
    let btn: *mut GtkMenuItem = get_obj(b, c_str!("btn-show-map-view"));
@@ -113,7 +106,7 @@ unsafe fn setup_win_map_view(b: *mut GtkBuilder)
 }
 
 /// Sets up the map tools window.
-unsafe fn setup_win_map_tools(b: *mut GtkBuilder)
+unsafe fn setup_win_map_tools(b: &Refc<GtkBuilder>)
 {
    let win: *mut GtkWindow   = get_obj(b, c_str!("win-map-tools"));
    let btn: *mut GtkMenuItem = get_obj(b, c_str!("btn-show-map-tools"));
@@ -123,7 +116,7 @@ unsafe fn setup_win_map_tools(b: *mut GtkBuilder)
 }
 
 /// Sets up the map properties window.
-unsafe fn setup_win_map_prop(b: *mut GtkBuilder)
+unsafe fn setup_win_map_prop(b: &Refc<GtkBuilder>)
 {
    let win: *mut GtkWindow   = get_obj(b, c_str!("win-map-prop"));
    let btn: *mut GtkMenuItem = get_obj(b, c_str!("btn-show-map-prop"));
@@ -133,7 +126,7 @@ unsafe fn setup_win_map_prop(b: *mut GtkBuilder)
 }
 
 /// Sets up the about dialogue.
-unsafe fn setup_about_dlg(b: *mut GtkBuilder)
+unsafe fn setup_about_dlg(b: &Refc<GtkBuilder>)
 {
    /// Callback to show the dialogue when the "About" button is pressed, and
    /// hide it when the "Close" button is pressed on it.
@@ -149,20 +142,19 @@ unsafe fn setup_about_dlg(b: *mut GtkBuilder)
    let it    = env!("CARGO_PKG_AUTHORS").split(';');
    let mut v = ffi::CStringVec::new_from_iter(it).unwrap();
    let img   = load_img(c_str!("/net/greyserv/maraiah/tycho/tycho2.png"));
+   let img   = Refc::new(img);
 
    gtk_about_dialog_set_authors(dlg, v.as_mut_ptr());
    gtk_about_dialog_set_version(dlg, c_str!(env!("CARGO_PKG_VERSION")));
    gtk_about_dialog_set_website(dlg, c_str!(env!("CARGO_PKG_HOMEPAGE")));
-   gtk_about_dialog_set_logo(dlg, img);
+   gtk_about_dialog_set_logo(dlg, *img);
 
    connect_hide(dlg as _);
    connect(btn as _, c_str!("activate"), c_show_act as _, dlg as _);
-
-   g_object_unref(img as gpointer as _);
 }
 
 /// Sets up explicit window finalization for the main window.
-unsafe fn setup_explicit_drop(b: *mut GtkBuilder, win: *mut GtkWindow)
+unsafe fn setup_explicit_drop(b: &Refc<GtkBuilder>, win: *mut GtkWindow)
 {
    /// Callback to explicitly finalize all windows on exit.
    unsafe extern "C" fn c_done(_: *mut GtkWidget, exp_del: gpointer)
@@ -179,7 +171,7 @@ unsafe fn setup_explicit_drop(b: *mut GtkBuilder, win: *mut GtkWindow)
    let mut exp_del = Vec::new();
 
    // so, we get all of the objects from the builder, and iterate through them
-   let head    = gtk_builder_get_objects(b);
+   let head    = gtk_builder_get_objects(**b);
    let mut lst = &*head;
 
    loop {
@@ -214,7 +206,7 @@ unsafe fn setup_explicit_drop(b: *mut GtkBuilder, win: *mut GtkWindow)
 }
 
 /// Sets up the main menu window.
-unsafe fn setup_win_main(b: *mut GtkBuilder,
+unsafe fn setup_win_main(b: &Refc<GtkBuilder>,
                          app: *mut GtkApplication,
                          edit: Rc<MapEditorRef>)
 {
@@ -277,14 +269,12 @@ unsafe fn setup_win_main(b: *mut GtkBuilder,
 unsafe fn setup_css()
 {
    let path = c_str!("/net/greyserv/maraiah/tycho/css");
-   let css  = gtk_css_provider_new();
+   let css  = Refc::new(gtk_css_provider_new());
-   gtk_css_provider_load_from_resource(css, path);
+   gtk_css_provider_load_from_resource(*css, path);
 
    let scr = gdk_screen_get_default();
    let pri = GTK_STYLE_PROVIDER_PRIORITY_APPLICATION as u32;
-   gtk_style_context_add_provider_for_screen(scr, css as _, pri);
+   gtk_style_context_add_provider_for_screen(scr, *css as _, pri);
-
-   g_object_unref(css as _);
 }
 
 /// Runs a modal OK/Cancel dialogue.
@@ -343,9 +333,9 @@ unsafe fn connect_show(btn: *mut GtkWidget, wid: *mut GtkWidget)
 }
 
 /// Gets an object from a `GtkBuilder`.
-unsafe fn get_obj<T>(b: *mut GtkBuilder, name: ffi::NT) -> *mut T
+unsafe fn get_obj<T>(b: &Refc<GtkBuilder>, name: ffi::NT) -> *mut T
 {
-   let obj = gtk_builder_get_object(b, name);
+   let obj = gtk_builder_get_object(**b, name);
    obj as _
 }
 
@@ -388,14 +378,14 @@ fn main()
 
       // create and run the app
       let name = c_str!("net.greyserv.maraiah.tycho");
-      let app  = gtk_application_new(name, 0);
+      let app  = Refc::new(gtk_application_new(name, 0));
 
-      connect(app as _, c_str!("activate"), app_activate as _, eptr as _);
+      connect(*app as _, c_str!("activate"), app_activate as _, eptr as _);
 
-      g_application_run(app as _, 0, ffi::null_mut());
+      g_application_run(*app as _, 0, ffi::null_mut());
 
       // ok, clean up all this crap now
-      g_object_unref(app as _);
+      drop(app);
 
       assert_eq!(Rc::strong_count(&edit), 1);
       drop(edit);
@@ -405,4 +395,32 @@ fn main()
    }
 }
 
+impl<T> std::ops::Deref for Refc<'_, T>
+{
+   type Target = *mut T;
+
+   fn deref(&self) -> &Self::Target {&self.p}
+}
+
+impl<T> Drop for Refc<'_, T>
+{
+   fn drop(&mut self)
+   {
+      unsafe {
+         g_object_unref(self.p as _);
+      }
+   }
+}
+
+impl<T> Refc<'_, T>
+{
+   fn new(p: *mut T) -> Self {Self{p, l: PhantomData}}
+}
+
+struct Refc<'a, T>
+{
+   p: *mut T,
+   l: PhantomData<&'a *mut T>,
+}
+
 // EOF