Use dedicated type DeviceMonitorFilterId

See https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/issues/174

Gir_Gst.toml

@@ -547,6 +547,11 @@ status = "generate"
     # Work-around for 1.14 switch from transfer-floating to transfer-full
     ignore = true
 
+    [[object.function]]
+    name = "add_filter"
+    # Return Option<DeviceMonitorFilterId>
+    ignore = true
+
     [[object.function]]
     name = "get_bus"
         [object.function.return]
@@ -559,8 +564,8 @@ status = "generate"
 
     [[object.function]]
     name = "remove_filter"
-        [object.function.return]
-        bool_return_is_error = "Failed to remove the filter"
+    # Use DeviceMonitorFilterId and return Result<(), glib::BoolError>
+    ignore = true
 
 [[object]]
 name = "Gst.Device"

gstreamer/src/auto/device_monitor.rs

@@ -3,7 +3,6 @@
 // DO NOT EDIT
 
 use Bus;
-use Caps;
 use Device;
 use Object;
 use ffi;
@@ -35,8 +34,6 @@ unsafe impl Sync for DeviceMonitor {}
 pub const NONE_DEVICE_MONITOR: Option<&DeviceMonitor> = None;
 
 pub trait DeviceMonitorExt: 'static {
-    fn add_filter<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b Caps>>>(&self, classes: P, caps: Q) -> u32;
-
     fn get_bus(&self) -> Bus;
 
     fn get_devices(&self) -> Vec<Device>;
@@ -45,8 +42,6 @@ pub trait DeviceMonitorExt: 'static {
 
     fn get_show_all_devices(&self) -> bool;
 
-    fn remove_filter(&self, filter_id: u32) -> Result<(), glib::error::BoolError>;
-
     fn set_show_all_devices(&self, show_all: bool);
 
     fn start(&self) -> Result<(), glib::error::BoolError>;
@@ -61,14 +56,6 @@ pub trait DeviceMonitorExt: 'static {
 }
 
 impl<O: IsA<DeviceMonitor>> DeviceMonitorExt for O {
-    fn add_filter<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b Caps>>>(&self, classes: P, caps: Q) -> u32 {
-        let classes = classes.into();
-        let caps = caps.into();
-        unsafe {
-            ffi::gst_device_monitor_add_filter(self.as_ref().to_glib_none().0, classes.to_glib_none().0, caps.to_glib_none().0)
-        }
-    }
-
     fn get_bus(&self) -> Bus {
         unsafe {
             from_glib_full(ffi::gst_device_monitor_get_bus(self.as_ref().to_glib_none().0))
@@ -93,12 +80,6 @@ impl<O: IsA<DeviceMonitor>> DeviceMonitorExt for O {
         }
     }
 
-    fn remove_filter(&self, filter_id: u32) -> Result<(), glib::error::BoolError> {
-        unsafe {
-            glib_result_from_gboolean!(ffi::gst_device_monitor_remove_filter(self.as_ref().to_glib_none().0, filter_id), "Failed to remove the filter")
-        }
-    }
-
     fn set_show_all_devices(&self, show_all: bool) {
         unsafe {
             ffi::gst_device_monitor_set_show_all_devices(self.as_ref().to_glib_none().0, show_all.to_glib());

gstreamer/src/device_monitor.rs

@@ -1,4 +1,4 @@
-// Copyright (C) 2018 Sebastian Dröge <sebastian@centricular.com>
+// Copyright (C) 2018-2019 Sebastian Dröge <sebastian@centricular.com>
 //
 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
@@ -6,10 +6,15 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use ffi;
-use glib::translate::*;
+use Caps;
 use DeviceMonitor;
 
+use glib;
+use glib::object::IsA;
+use glib::translate::*;
+
+use ffi;
+
 impl DeviceMonitor {
     pub fn new() -> DeviceMonitor {
         assert_initialized_main_thread!();
@@ -28,3 +33,72 @@ impl Default for DeviceMonitor {
         Self::new()
     }
 }
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct DeviceMonitorFilterId(libc::c_uint);
+
+impl ToGlib for DeviceMonitorFilterId {
+    type GlibType = libc::c_uint;
+
+    fn to_glib(&self) -> libc::c_uint {
+        self.0
+    }
+}
+
+impl FromGlib<libc::c_uint> for DeviceMonitorFilterId {
+    fn from_glib(val: libc::c_uint) -> DeviceMonitorFilterId {
+        skip_assert_initialized!();
+        assert_ne!(val, 0);
+        DeviceMonitorFilterId(val)
+    }
+}
+
+pub trait DeviceMonitorExtManual: 'static {
+    fn add_filter<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b Caps>>>(
+        &self,
+        classes: P,
+        caps: Q,
+    ) -> Option<DeviceMonitorFilterId>;
+
+    fn remove_filter(&self, filter_id: DeviceMonitorFilterId)
+        -> Result<(), glib::error::BoolError>;
+}
+
+impl<O: IsA<DeviceMonitor>> DeviceMonitorExtManual for O {
+    fn add_filter<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b Caps>>>(
+        &self,
+        classes: P,
+        caps: Q,
+    ) -> Option<DeviceMonitorFilterId> {
+        let classes = classes.into();
+        let caps = caps.into();
+        let id = unsafe {
+            ffi::gst_device_monitor_add_filter(
+                self.as_ref().to_glib_none().0,
+                classes.to_glib_none().0,
+                caps.to_glib_none().0,
+            )
+        };
+
+        if id == 0 {
+            None
+        } else {
+            Some(from_glib(id))
+        }
+    }
+
+    fn remove_filter(
+        &self,
+        filter_id: DeviceMonitorFilterId,
+    ) -> Result<(), glib::error::BoolError> {
+        unsafe {
+            glib_result_from_gboolean!(
+                ffi::gst_device_monitor_remove_filter(
+                    self.as_ref().to_glib_none().0,
+                    filter_id.to_glib()
+                ),
+                "Failed to remove the filter"
+            )
+        }
+    }
+}

gstreamer/src/lib.rs

@@ -210,6 +210,7 @@ pub use self::iterator::{Iterator, IteratorError, IteratorImpl};
 pub use bus::BusStream;
 pub use child_proxy::ChildProxyExtManual;
 pub use clock_time::ClockTime;
+pub use device_monitor::{DeviceMonitorExtManual, DeviceMonitorFilterId};
 pub use device_provider::DeviceProviderExtManual;
 pub use enums::{
     ClockError, ClockSuccess, FlowError, FlowSuccess, PadLinkError, PadLinkSuccess,
@@ -324,6 +325,7 @@ pub mod prelude {
     pub use buffer_pool::BufferPoolExtManual;
     pub use child_proxy::ChildProxyExtManual;
     pub use clock::ClockExtManual;
+    pub use device_monitor::DeviceMonitorExtManual;
     pub use device_provider::DeviceProviderExtManual;
     pub use gobject::GObjectExtManualGst;
     pub use object::GstObjectExtManual;