gstreamer/pad: Don't provide constructors anymore but instead a builder

This handles safely setting the pad functions during construction and
also has special support for ghost pads.

Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/issues/247

Gir_Gst.toml

@@ -827,9 +827,19 @@ manual_traits = ["PadExtManual"]
     # Use Result<FlowSuccess, FlowError>
     ignore = true
 
+    [[object.function]]
+    name = "new"
+    # Builder
+    ignore = true
+
+    [[object.function]]
+    name = "new_from_template"
+    # Builder
+    ignore = true
+
     [[object.function]]
     name = "new_from_static_template"
-    # Correct mutability
+    # Builder
     ignore = true
 
     [[object.function]]
@@ -929,13 +939,11 @@ status = "generate"
 
     [[object.function]]
     name = "new_no_target"
-        [object.function.return]
-        nullable_return_is_error = "Failed to create GhostPad"
+    ignore = true
 
     [[object.function]]
     name = "new_no_target_from_template"
-        [object.function.return]
-        nullable_return_is_error = "Failed to create GhostPad"
+    ignore = true
 
     [[object.function]]
     name = "construct"

gstreamer/src/auto/ghost_pad.rs

@@ -3,14 +3,11 @@
 // DO NOT EDIT
 
 use glib;
-use glib::object::Cast;
 use glib::object::IsA;
 use glib::translate::*;
 use gst_sys;
 use Object;
 use Pad;
-use PadDirection;
-use PadTemplate;
 use ProxyPad;
 
 glib_wrapper! {
@@ -21,38 +18,6 @@ glib_wrapper! {
     }
 }
 
-impl GhostPad {
-    pub fn new_no_target(
-        name: Option<&str>,
-        dir: PadDirection,
-    ) -> Result<GhostPad, glib::BoolError> {
-        assert_initialized_main_thread!();
-        unsafe {
-            Option::<Pad>::from_glib_none(gst_sys::gst_ghost_pad_new_no_target(
-                name.to_glib_none().0,
-                dir.to_glib(),
-            ))
-            .map(|o| o.unsafe_cast())
-            .ok_or_else(|| glib_bool_error!("Failed to create GhostPad"))
-        }
-    }
-
-    pub fn new_no_target_from_template(
-        name: Option<&str>,
-        templ: &PadTemplate,
-    ) -> Result<GhostPad, glib::BoolError> {
-        skip_assert_initialized!();
-        unsafe {
-            Option::<Pad>::from_glib_none(gst_sys::gst_ghost_pad_new_no_target_from_template(
-                name.to_glib_none().0,
-                templ.to_glib_none().0,
-            ))
-            .map(|o| o.unsafe_cast())
-            .ok_or_else(|| glib_bool_error!("Failed to create GhostPad"))
-        }
-    }
-}
-
 unsafe impl Send for GhostPad {}
 unsafe impl Sync for GhostPad {}
 

gstreamer/src/auto/pad.rs

@@ -39,28 +39,6 @@ glib_wrapper! {
     }
 }
 
-impl Pad {
-    pub fn new(name: Option<&str>, direction: PadDirection) -> Pad {
-        assert_initialized_main_thread!();
-        unsafe {
-            from_glib_none(gst_sys::gst_pad_new(
-                name.to_glib_none().0,
-                direction.to_glib(),
-            ))
-        }
-    }
-
-    pub fn from_template(templ: &PadTemplate, name: Option<&str>) -> Pad {
-        skip_assert_initialized!();
-        unsafe {
-            from_glib_none(gst_sys::gst_pad_new_from_template(
-                templ.to_glib_none().0,
-                name.to_glib_none().0,
-            ))
-        }
-    }
-}
-
 unsafe impl Send for Pad {}
 unsafe impl Sync for Pad {}
 

gstreamer/src/auto/versions.txt

@@ -1,2 +1,2 @@
 Generated by gir (https://github.com/gtk-rs/gir @ 5a5b8f5)
-from gir-files (https://github.com/gtk-rs/gir-files @ 2bd82b67)
+from gir-files (https://github.com/gtk-rs/gir-files @ 7e318657)

gstreamer/src/ghost_pad.rs

@@ -6,48 +6,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use glib::object::Cast;
 use glib::object::IsA;
 use glib::translate::*;
 use gst_sys;
 use GhostPad;
 use Object;
-use Pad;
 use PadMode;
-use PadTemplate;
 
 impl GhostPad {
-    pub fn new<Q: IsA<Pad>>(name: Option<&str>, target: &Q) -> Result<GhostPad, glib::BoolError> {
-        skip_assert_initialized!();
-        let name = name.to_glib_none();
-        unsafe {
-            Option::<Pad>::from_glib_none(gst_sys::gst_ghost_pad_new(
-                name.0,
-                target.as_ref().to_glib_none().0,
-            ))
-            .map(|o| Cast::unsafe_cast(o))
-            .ok_or_else(|| glib_bool_error!("Failed to create GhostPad"))
-        }
-    }
-
-    pub fn from_template<Q: IsA<Pad>>(
-        name: Option<&str>,
-        target: &Q,
-        templ: &PadTemplate,
-    ) -> Result<GhostPad, glib::BoolError> {
-        skip_assert_initialized!();
-        let name = name.to_glib_none();
-        unsafe {
-            Option::<Pad>::from_glib_none(gst_sys::gst_ghost_pad_new_from_template(
-                name.0,
-                target.as_ref().to_glib_none().0,
-                templ.to_glib_none().0,
-            ))
-            .map(|o| Cast::unsafe_cast(o))
-            .ok_or_else(|| glib_bool_error!("Failed to create GhostPad"))
-        }
-    }
-
     pub fn activate_mode_default<P: IsA<GhostPad>, Q: IsA<Object>>(
         pad: &P,
         parent: Option<&Q>,

gstreamer/src/lib.rs

@@ -204,6 +204,7 @@ mod gobject;
 mod iterator;
 mod object;
 mod pad;
+pub use pad::PadBuilder;
 mod parse_context;
 mod proxy_pad;
 mod tag_setter;

gstreamer/src/pad.rs

@@ -38,8 +38,8 @@ use std::ptr;
 use glib;
 use glib::object::{Cast, IsA};
 use glib::translate::{
-    from_glib, from_glib_borrow, from_glib_full, from_glib_none, mut_override, FromGlib,
-    FromGlibPtrBorrow, ToGlib, ToGlibPtr,
+    from_glib, from_glib_borrow, from_glib_full, from_glib_none, FromGlib, FromGlibPtrBorrow,
+    ToGlib, ToGlibPtr,
 };
 use glib::StaticType;
 use glib_sys;
@@ -49,18 +49,6 @@ use libc;
 
 use gst_sys;
 
-impl Pad {
-    pub fn from_static_template(templ: &StaticPadTemplate, name: Option<&str>) -> Pad {
-        assert_initialized_main_thread!();
-        unsafe {
-            from_glib_none(gst_sys::gst_pad_new_from_static_template(
-                mut_override(templ.to_glib_none().0),
-                name.to_glib_none().0,
-            ))
-        }
-    }
-}
-
 #[derive(Debug, PartialEq, Eq)]
 pub struct PadProbeId(NonZeroU64);
 
@@ -1557,6 +1545,330 @@ unsafe extern "C" fn destroy_closure_pad_task<F>(ptr: gpointer) {
     Box::<RefCell<F>>::from_raw(ptr as *mut _);
 }
 
+impl Pad {
+    pub fn new(name: Option<&str>, direction: ::PadDirection) -> Self {
+        skip_assert_initialized!();
+        Self::builder(name, direction).build()
+    }
+
+    pub fn builder(name: Option<&str>, direction: ::PadDirection) -> PadBuilder<Self> {
+        skip_assert_initialized!();
+        PadBuilder::new(name, direction)
+    }
+
+    pub fn from_static_template(templ: &StaticPadTemplate, name: Option<&str>) -> Self {
+        skip_assert_initialized!();
+        Self::builder_from_static_template(templ, name).build()
+    }
+
+    pub fn builder_from_static_template(
+        templ: &StaticPadTemplate,
+        name: Option<&str>,
+    ) -> PadBuilder<Self> {
+        skip_assert_initialized!();
+        PadBuilder::from_static_template(templ, name)
+    }
+
+    pub fn from_template(templ: &::PadTemplate, name: Option<&str>) -> Self {
+        skip_assert_initialized!();
+        Self::builder_from_template(templ, name).build()
+    }
+
+    pub fn builder_from_template(templ: &::PadTemplate, name: Option<&str>) -> PadBuilder<Self> {
+        skip_assert_initialized!();
+        PadBuilder::from_template(templ, name)
+    }
+}
+
+impl ::GhostPad {
+    pub fn new(name: Option<&str>, direction: ::PadDirection) -> Self {
+        skip_assert_initialized!();
+        Self::builder(name, direction).build()
+    }
+
+    pub fn builder(name: Option<&str>, direction: ::PadDirection) -> PadBuilder<Self> {
+        skip_assert_initialized!();
+        PadBuilder::new(name, direction)
+    }
+
+    pub fn from_static_template(templ: &StaticPadTemplate, name: Option<&str>) -> Self {
+        skip_assert_initialized!();
+        Self::builder_from_static_template(templ, name).build()
+    }
+
+    pub fn builder_from_static_template(
+        templ: &StaticPadTemplate,
+        name: Option<&str>,
+    ) -> PadBuilder<Self> {
+        skip_assert_initialized!();
+        PadBuilder::from_static_template(templ, name)
+    }
+
+    pub fn from_template(templ: &::PadTemplate, name: Option<&str>) -> Self {
+        skip_assert_initialized!();
+        Self::builder_from_template(templ, name).build()
+    }
+
+    pub fn builder_from_template(templ: &::PadTemplate, name: Option<&str>) -> PadBuilder<Self> {
+        skip_assert_initialized!();
+        PadBuilder::from_template(templ, name)
+    }
+}
+
+pub struct PadBuilder<T>(T);
+
+impl<T: IsA<Pad> + IsA<glib::Object>> PadBuilder<T> {
+    pub fn new(name: Option<&str>, direction: ::PadDirection) -> Self {
+        assert_initialized_main_thread!();
+
+        let pad = glib::Object::new(
+            T::static_type(),
+            &[("name", &name), ("direction", &direction)],
+        )
+        .expect("Failed to create pad")
+        .downcast::<T>()
+        .unwrap();
+
+        // Ghost pads are a bit special
+        if let Some(pad) = pad.dynamic_cast_ref::<::GhostPad>() {
+            unsafe {
+                let res = gst_sys::gst_ghost_pad_construct(pad.to_glib_none().0);
+                // This can't really fail...
+                assert_ne!(res, glib_sys::GFALSE, "Failed to construct ghost pad");
+            }
+        }
+
+        PadBuilder(pad)
+    }
+
+    pub fn from_static_template(templ: &StaticPadTemplate, name: Option<&str>) -> Self {
+        assert_initialized_main_thread!();
+
+        let templ = templ.get();
+        Self::from_template(&templ, name)
+    }
+
+    pub fn from_template(templ: &::PadTemplate, name: Option<&str>) -> Self {
+        assert_initialized_main_thread!();
+
+        use glib::ObjectExt;
+
+        let mut type_ = T::static_type();
+
+        // Since 1.14 templates can keep a pad GType with them, so we need to do some
+        // additional checks here now
+        if templ.has_property("gtype", Some(glib::Type::static_type())) {
+            let gtype = templ
+                .get_property("gtype")
+                .unwrap()
+                .get_some::<glib::Type>()
+                .unwrap();
+
+            if gtype == glib::Type::Unit {
+                // Nothing to be done, we can create any kind of pad
+            } else if gtype.is_a(&type_) {
+                // We were asked to create a parent type of the template type, e.g. a gst::Pad for
+                // a template that wants a gst_base::AggregatorPad. Not a problem: update the type
+                type_ = gtype;
+            } else {
+                // Otherwise the requested type must be a subclass of the template pad type
+                assert!(type_.is_a(&gtype));
+            }
+        }
+
+        let pad = glib::Object::new(
+            type_,
+            &[
+                ("name", &name),
+                ("direction", &templ.get_property_direction()),
+                ("template", templ),
+            ],
+        )
+        .expect("Failed to create pad")
+        .downcast::<T>()
+        .unwrap();
+
+        // Ghost pads are a bit special
+        if let Some(pad) = pad.dynamic_cast_ref::<::GhostPad>() {
+            unsafe {
+                let res = gst_sys::gst_ghost_pad_construct(pad.to_glib_none().0);
+                // This can't really fail...
+                assert_ne!(res, glib_sys::GFALSE, "Failed to construct ghost pad");
+            }
+        }
+
+        PadBuilder(pad)
+    }
+
+    pub fn activate_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>) -> Result<(), LoggableError> + Send + Sync + 'static,
+    {
+        unsafe {
+            self.0.set_activate_function(func);
+        }
+
+        self
+    }
+
+    pub fn activatemode_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, ::PadMode, bool) -> Result<(), LoggableError>
+            + Send
+            + Sync
+            + 'static,
+    {
+        unsafe {
+            self.0.set_activatemode_function(func);
+        }
+
+        self
+    }
+
+    pub fn chain_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, ::Buffer) -> Result<FlowSuccess, FlowError>
+            + Send
+            + Sync
+            + 'static,
+    {
+        unsafe {
+            self.0.set_chain_function(func);
+        }
+
+        self
+    }
+
+    pub fn chain_list_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, ::BufferList) -> Result<FlowSuccess, FlowError>
+            + Send
+            + Sync
+            + 'static,
+    {
+        unsafe {
+            self.0.set_chain_list_function(func);
+        }
+
+        self
+    }
+
+    pub fn event_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, ::Event) -> bool + Send + Sync + 'static,
+    {
+        unsafe {
+            self.0.set_event_function(func);
+        }
+
+        self
+    }
+
+    pub fn event_full_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, ::Event) -> Result<FlowSuccess, FlowError>
+            + Send
+            + Sync
+            + 'static,
+    {
+        unsafe {
+            self.0.set_event_full_function(func);
+        }
+
+        self
+    }
+
+    pub fn getrange_function<F>(self, func: F) -> Self
+    where
+        F: Fn(
+                &T,
+                Option<&::Object>,
+                u64,
+                Option<&mut ::BufferRef>,
+                u32,
+            ) -> Result<PadGetRangeSuccess, ::FlowError>
+            + Send
+            + Sync
+            + 'static,
+    {
+        unsafe {
+            self.0.set_getrange_function(func);
+        }
+
+        self
+    }
+
+    pub fn iterate_internal_links_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>) -> ::Iterator<Pad> + Send + Sync + 'static,
+    {
+        unsafe {
+            self.0.set_iterate_internal_links_function(func);
+        }
+
+        self
+    }
+
+    pub fn link_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, &Pad) -> Result<::PadLinkSuccess, ::PadLinkError>
+            + Send
+            + Sync
+            + 'static,
+    {
+        unsafe {
+            self.0.set_link_function(func);
+        }
+
+        self
+    }
+
+    pub fn query_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>, &mut ::QueryRef) -> bool + Send + Sync + 'static,
+    {
+        unsafe {
+            self.0.set_query_function(func);
+        }
+
+        self
+    }
+
+    pub fn unlink_function<F>(self, func: F) -> Self
+    where
+        F: Fn(&T, Option<&::Object>) + Send + Sync + 'static,
+    {
+        unsafe {
+            self.0.set_unlink_function(func);
+        }
+
+        self
+    }
+
+    pub fn flags(self, flags: PadFlags) -> Self {
+        self.0.set_pad_flags(flags);
+
+        self
+    }
+
+    pub fn build(self) -> T {
+        self.0
+    }
+}
+
+impl<T: IsA<::GhostPad> + IsA<Pad>> PadBuilder<T> {
+    pub fn build_with_target<P: IsA<Pad>>(self, target: &P) -> Result<T, glib::BoolError> {
+        use GhostPadExt;
+        use PadExt;
+
+        assert_eq!(self.0.get_direction(), target.get_direction());
+
+        self.0.set_target(Some(target))?;
+
+        Ok(self.0)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1568,25 +1880,24 @@ mod tests {
     fn test_event_chain_functions() {
         ::init().unwrap();
 
-        let pad = ::Pad::new(Some("sink"), ::PadDirection::Sink);
-
         let events = Arc::new(Mutex::new(Vec::new()));
         let events_clone = events.clone();
-        pad.set_event_function(move |_, _, event| {
-            let mut events = events_clone.lock().unwrap();
-            events.push(event);
-
-            true
-        });
-
         let buffers = Arc::new(Mutex::new(Vec::new()));
         let buffers_clone = buffers.clone();
-        pad.set_chain_function(move |_, _, buffer| {
-            let mut buffers = buffers_clone.lock().unwrap();
-            buffers.push(buffer);
+        let pad = ::Pad::builder(Some("sink"), ::PadDirection::Sink)
+            .event_function(move |_, _, event| {
+                let mut events = events_clone.lock().unwrap();
+                events.push(event);
 
-            Ok(FlowSuccess::Ok)
-        });
+                true
+            })
+            .chain_function(move |_, _, buffer| {
+                let mut buffers = buffers_clone.lock().unwrap();
+                buffers.push(buffer);
+
+                Ok(FlowSuccess::Ok)
+            })
+            .build();
 
         pad.set_active(true).unwrap();
 
@@ -1616,17 +1927,18 @@ mod tests {
     fn test_getrange_function() {
         ::init().unwrap();
 
-        let pad = ::Pad::new(Some("src"), ::PadDirection::Src);
-        pad.set_activate_function(|pad, _parent| {
-            pad.activate_mode(::PadMode::Pull, true)
-                .map_err(|err| err.into())
-        });
-        pad.set_getrange_function(|_pad, _parent, offset, _buffer, size| {
-            assert_eq!(offset, 0);
-            assert_eq!(size, 5);
-            let buffer = ::Buffer::from_slice(b"abcde");
-            Ok(PadGetRangeSuccess::NewBuffer(buffer))
-        });
+        let pad = ::Pad::builder(Some("src"), ::PadDirection::Src)
+            .activate_function(|pad, _parent| {
+                pad.activate_mode(::PadMode::Pull, true)
+                    .map_err(|err| err.into())
+            })
+            .getrange_function(|_pad, _parent, offset, _buffer, size| {
+                assert_eq!(offset, 0);
+                assert_eq!(size, 5);
+                let buffer = ::Buffer::from_slice(b"abcde");
+                Ok(PadGetRangeSuccess::NewBuffer(buffer))
+            })
+            .build();
         pad.set_active(true).unwrap();
 
         let buffer = pad.get_range(0, 5).unwrap();
@@ -1641,22 +1953,23 @@ mod tests {
         pad.set_active(false).unwrap();
         drop(pad);
 
-        let pad = ::Pad::new(Some("src"), ::PadDirection::Src);
-        pad.set_activate_function(|pad, _parent| {
-            pad.activate_mode(::PadMode::Pull, true)
-                .map_err(|err| err.into())
-        });
-        pad.set_getrange_function(|_pad, _parent, offset, buffer, size| {
-            assert_eq!(offset, 0);
-            assert_eq!(size, 5);
-            if let Some(buffer) = buffer {
-                buffer.copy_from_slice(0, b"fghij").unwrap();
-                Ok(PadGetRangeSuccess::FilledBuffer)
-            } else {
-                let buffer = ::Buffer::from_slice(b"abcde");
-                Ok(PadGetRangeSuccess::NewBuffer(buffer))
-            }
-        });
+        let pad = ::Pad::builder(Some("src"), ::PadDirection::Src)
+            .activate_function(|pad, _parent| {
+                pad.activate_mode(::PadMode::Pull, true)
+                    .map_err(|err| err.into())
+            })
+            .getrange_function(|_pad, _parent, offset, buffer, size| {
+                assert_eq!(offset, 0);
+                assert_eq!(size, 5);
+                if let Some(buffer) = buffer {
+                    buffer.copy_from_slice(0, b"fghij").unwrap();
+                    Ok(PadGetRangeSuccess::FilledBuffer)
+                } else {
+                    let buffer = ::Buffer::from_slice(b"abcde");
+                    Ok(PadGetRangeSuccess::NewBuffer(buffer))
+                }
+            })
+            .build();
         pad.set_active(true).unwrap();
 
         let buffer = pad.get_range(0, 5).unwrap();

gstreamer/src/subclass/element.rs

@@ -533,45 +533,6 @@ mod tests {
     }
 
     impl TestElement {
-        fn set_pad_functions(sinkpad: &::Pad, srcpad: &::Pad) {
-            sinkpad.set_chain_function(|pad, parent, buffer| {
-                TestElement::catch_panic_pad_function(
-                    parent,
-                    || Err(::FlowError::Error),
-                    |identity, element| identity.sink_chain(pad, element, buffer),
-                )
-            });
-            sinkpad.set_event_function(|pad, parent, event| {
-                TestElement::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |identity, element| identity.sink_event(pad, element, event),
-                )
-            });
-            sinkpad.set_query_function(|pad, parent, query| {
-                TestElement::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |identity, element| identity.sink_query(pad, element, query),
-                )
-            });
-
-            srcpad.set_event_function(|pad, parent, event| {
-                TestElement::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |identity, element| identity.src_event(pad, element, event),
-                )
-            });
-            srcpad.set_query_function(|pad, parent, query| {
-                TestElement::catch_panic_pad_function(
-                    parent,
-                    || false,
-                    |identity, element| identity.src_query(pad, element, query),
-                )
-            });
-        }
-
         fn sink_chain(
             &self,
             _pad: &::Pad,
@@ -609,11 +570,47 @@ mod tests {
 
         fn with_class(klass: &subclass::simple::ClassStruct<Self>) -> Self {
             let templ = klass.get_pad_template("sink").unwrap();
-            let sinkpad = ::Pad::from_template(&templ, Some("sink"));
-            let templ = klass.get_pad_template("src").unwrap();
-            let srcpad = ::Pad::from_template(&templ, Some("src"));
+            let sinkpad = ::Pad::builder_from_template(&templ, Some("sink"))
+                .chain_function(|pad, parent, buffer| {
+                    TestElement::catch_panic_pad_function(
+                        parent,
+                        || Err(::FlowError::Error),
+                        |identity, element| identity.sink_chain(pad, element, buffer),
+                    )
+                })
+                .event_function(|pad, parent, event| {
+                    TestElement::catch_panic_pad_function(
+                        parent,
+                        || false,
+                        |identity, element| identity.sink_event(pad, element, event),
+                    )
+                })
+                .query_function(|pad, parent, query| {
+                    TestElement::catch_panic_pad_function(
+                        parent,
+                        || false,
+                        |identity, element| identity.sink_query(pad, element, query),
+                    )
+                })
+                .build();
 
-            TestElement::set_pad_functions(&sinkpad, &srcpad);
+            let templ = klass.get_pad_template("src").unwrap();
+            let srcpad = ::Pad::builder_from_template(&templ, Some("src"))
+                .event_function(|pad, parent, event| {
+                    TestElement::catch_panic_pad_function(
+                        parent,
+                        || false,
+                        |identity, element| identity.src_event(pad, element, event),
+                    )
+                })
+                .query_function(|pad, parent, query| {
+                    TestElement::catch_panic_pad_function(
+                        parent,
+                        || false,
+                        |identity, element| identity.src_query(pad, element, query),
+                    )
+                })
+                .build();
 
             Self {
                 n_buffers: atomic::AtomicU32::new(0),