Add Success/Error variants of #[must_use] enums

And implement basically the Try trait for them. This will be replaced by
the Try trait once it is stable.

Fixes https://github.com/sdroege/gstreamer-rs/issues/44

examples/src/bin/appsrc.rs

@@ -73,7 +73,7 @@ fn main_loop() -> Result<(), utils::ExampleError> {
             }
         }
 
-        appsrc.end_of_stream();
+        let _ = appsrc.end_of_stream();
     });
 
     utils::set_state(&pipeline, gst::State::Playing)?;

gstreamer/src/enums.rs

@@ -0,0 +1,208 @@
+// Copyright (C) 2017 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
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use StateChangeReturn;
+use FlowReturn;
+use PadLinkReturn;
+use ClockReturn;
+
+impl StateChangeReturn {
+    pub fn into_result(self) -> Result<StateChangeSuccess, StateChangeError> {
+        match self {
+            StateChangeReturn::Success => Ok(StateChangeSuccess::Success),
+            StateChangeReturn::Async => Ok(StateChangeSuccess::Async),
+            StateChangeReturn::NoPreroll => Ok(StateChangeSuccess::NoPreroll),
+            StateChangeReturn::Failure => Err(StateChangeError),
+            _ => Err(StateChangeError),
+        }
+    }
+
+    pub fn from_error(_: StateChangeError) -> Self {
+        StateChangeReturn::Failure
+    }
+
+    pub fn from_ok(v: StateChangeSuccess) -> Self {
+        match v {
+            StateChangeSuccess::Success => StateChangeReturn::Success,
+            StateChangeSuccess::Async => StateChangeReturn::Async,
+            StateChangeSuccess::NoPreroll => StateChangeReturn::NoPreroll,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub enum StateChangeSuccess {
+    Success,
+    Async,
+    NoPreroll,
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+#[must_use]
+pub struct StateChangeError;
+
+impl FlowReturn {
+    pub fn into_result(self) -> Result<FlowSuccess, FlowError> {
+        match self {
+            FlowReturn::CustomSuccess2 => Ok(FlowSuccess::CustomSuccess2),
+            FlowReturn::CustomSuccess1 => Ok(FlowSuccess::CustomSuccess1),
+            FlowReturn::CustomSuccess => Ok(FlowSuccess::CustomSuccess),
+            FlowReturn::Ok => Ok(FlowSuccess::Ok),
+            FlowReturn::NotLinked => Err(FlowError::NotLinked),
+            FlowReturn::Flushing => Err(FlowError::Flushing),
+            FlowReturn::Eos => Err(FlowError::Eos),
+            FlowReturn::NotNegotiated => Err(FlowError::NotNegotiated),
+            FlowReturn::Error => Err(FlowError::Error),
+            FlowReturn::NotSupported => Err(FlowError::NotSupported),
+            FlowReturn::CustomError => Err(FlowError::CustomError),
+            FlowReturn::CustomError1 => Err(FlowError::CustomError1),
+            FlowReturn::CustomError2 => Err(FlowError::CustomError2),
+            _ => Err(FlowError::Error),
+        }
+    }
+
+    pub fn from_error(v: FlowError) -> Self {
+        match v {
+            FlowError::NotLinked => FlowReturn::NotLinked,
+            FlowError::Flushing => FlowReturn::Flushing,
+            FlowError::Eos => FlowReturn::Eos,
+            FlowError::NotNegotiated => FlowReturn::NotNegotiated,
+            FlowError::Error => FlowReturn::Error,
+            FlowError::NotSupported => FlowReturn::NotSupported,
+            FlowError::CustomError => FlowReturn::CustomError,
+            FlowError::CustomError1 => FlowReturn::CustomError1,
+            FlowError::CustomError2 => FlowReturn::CustomError2,
+        }
+    }
+
+    pub fn from_ok(v: FlowSuccess) -> Self {
+        match v {
+            FlowSuccess::CustomSuccess2 => FlowReturn::CustomSuccess2,
+            FlowSuccess::CustomSuccess1 => FlowReturn::CustomSuccess1,
+            FlowSuccess::CustomSuccess => FlowReturn::CustomSuccess,
+            FlowSuccess::Ok => FlowReturn::Ok,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub enum FlowSuccess {
+    CustomSuccess2,
+    CustomSuccess1,
+    CustomSuccess,
+    Ok,
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+#[must_use]
+pub enum FlowError {
+    NotLinked,
+    Flushing,
+    Eos,
+    NotNegotiated,
+    Error,
+    NotSupported,
+    CustomError,
+    CustomError1,
+    CustomError2,
+}
+
+impl PadLinkReturn {
+    pub fn into_result(self) -> Result<PadLinkSuccess, PadLinkError> {
+        match self {
+            PadLinkReturn::Ok => Ok(PadLinkSuccess),
+            PadLinkReturn::WrongHierarchy => Err(PadLinkError::WrongHierarchy),
+            PadLinkReturn::WasLinked => Err(PadLinkError::WasLinked),
+            PadLinkReturn::WrongDirection => Err(PadLinkError::WrongDirection),
+            PadLinkReturn::Noformat => Err(PadLinkError::Noformat),
+            PadLinkReturn::Nosched => Err(PadLinkError::Nosched),
+            PadLinkReturn::Refused => Err(PadLinkError::Refused),
+            _ => Err(PadLinkError::Refused),
+        }
+    }
+
+    pub fn from_error(v: PadLinkError) -> Self {
+        match v {
+            PadLinkError::WrongHierarchy => PadLinkReturn::WrongHierarchy,
+            PadLinkError::WasLinked => PadLinkReturn::WasLinked,
+            PadLinkError::WrongDirection => PadLinkReturn::WrongDirection,
+            PadLinkError::Noformat => PadLinkReturn::Noformat,
+            PadLinkError::Nosched => PadLinkReturn::Nosched,
+            PadLinkError::Refused => PadLinkReturn::Refused,
+        }
+    }
+
+    pub fn from_ok(_: PadLinkSuccess) -> Self {
+        PadLinkReturn::Ok
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub struct PadLinkSuccess;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+#[must_use]
+pub enum PadLinkError {
+    WrongHierarchy,
+    WasLinked,
+    WrongDirection,
+    Noformat,
+    Nosched,
+    Refused,
+}
+
+impl ClockReturn {
+    pub fn into_result(self) -> Result<ClockSuccess, ClockError> {
+        match self {
+            ClockReturn::Ok => Ok(ClockSuccess::Ok),
+            ClockReturn::Done => Ok(ClockSuccess::Done),
+            ClockReturn::Early => Err(ClockError::Early),
+            ClockReturn::Unscheduled => Err(ClockError::Unscheduled),
+            ClockReturn::Busy => Err(ClockError::Busy),
+            ClockReturn::Badtime => Err(ClockError::Badtime),
+            ClockReturn::Error => Err(ClockError::Error),
+            ClockReturn::Unsupported => Err(ClockError::Unsupported),
+            _ => Err(ClockError::Error),
+        }
+    }
+
+    pub fn from_error(v: ClockError) -> Self {
+        match v {
+            ClockError::Early => ClockReturn::Early,
+            ClockError::Unscheduled => ClockReturn::Unscheduled,
+            ClockError::Busy => ClockReturn::Busy,
+            ClockError::Badtime => ClockReturn::Badtime,
+            ClockError::Error => ClockReturn::Error,
+            ClockError::Unsupported => ClockReturn::Unsupported,
+        }
+    }
+
+    pub fn from_ok(v: ClockSuccess) -> Self {
+        match v {
+            ClockSuccess::Ok => ClockReturn::Ok,
+            ClockSuccess::Done => ClockReturn::Done,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub enum ClockSuccess {
+    Ok,
+    Done,
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+#[must_use]
+pub enum ClockError {
+    Early,
+    Unscheduled,
+    Busy,
+    Badtime,
+    Error,
+    Unsupported,
+}

gstreamer/src/lib.rs

@@ -101,6 +101,7 @@ mod tag_setter;
 mod iterator;
 mod device_provider;
 mod parse_context;
+mod enums;
 pub use object::GstObjectExtManual;
 pub use element::{ElementExtManual, ElementMessageType, NotifyWatchId};
 pub use element::{ELEMENT_METADATA_AUTHOR, ELEMENT_METADATA_DESCRIPTION, ELEMENT_METADATA_DOC_URI,
@@ -115,6 +116,7 @@ pub use device_provider::DeviceProviderExtManual;
 pub use parse_context::ParseContext;
 #[cfg(feature = "futures")]
 pub use bus::BusStream;
+pub use enums::{StateChangeSuccess, StateChangeError};
 
 mod value;
 pub use value::*;

tutorials/src/bin/basic-tutorial-5.rs

@@ -92,7 +92,10 @@ mod tutorial5 {
         let pipeline = playbin.clone();
         play_button.connect_clicked(move |_| {
             let pipeline = &pipeline;
-            pipeline.set_state(gst::State::Playing);
+            pipeline
+                .set_state(gst::State::Playing)
+                .into_result()
+                .unwrap();
         });
 
         let pause_button = gtk::Button::new_from_icon_name(
@@ -102,7 +105,10 @@ mod tutorial5 {
         let pipeline = playbin.clone();
         pause_button.connect_clicked(move |_| {
             let pipeline = &pipeline;
-            pipeline.set_state(gst::State::Paused);
+            pipeline
+                .set_state(gst::State::Paused)
+                .into_result()
+                .unwrap();
         });
 
         let stop_button = gtk::Button::new_from_icon_name(
@@ -112,7 +118,7 @@ mod tutorial5 {
         let pipeline = playbin.clone();
         stop_button.connect_clicked(move |_| {
             let pipeline = &pipeline;
-            pipeline.set_state(gst::State::Ready);
+            pipeline.set_state(gst::State::Ready).into_result().unwrap();
         });
 
         let slider = gtk::Scale::new_with_range(
@@ -313,7 +319,10 @@ mod tutorial5 {
             .unwrap();
 
         create_ui(&playbin);
-        playbin.set_state(gst::State::Playing);
+        playbin
+            .set_state(gst::State::Playing)
+            .into_result()
+            .unwrap();
 
         let bus = playbin.get_bus().unwrap();
         let pipeline = playbin.clone();
@@ -324,7 +333,7 @@ mod tutorial5 {
                 // We just set the pipeline to READY (which stops playback).
                 gst::MessageView::Eos(..) => {
                     println!("End-Of-Stream reached.");
-                    pipeline.set_state(gst::State::Ready);
+                    pipeline.set_state(gst::State::Ready).into_result().unwrap();
                 }
 
                 // This is called when an error message is posted on the bus
@@ -346,7 +355,7 @@ mod tutorial5 {
         });
 
         gtk::main();
-        playbin.set_state(gst::State::Null);
+        playbin.set_state(gst::State::Null).into_result().unwrap();
     }
 }
 

tutorials/src/bin/basic-tutorial-7.rs

@@ -55,7 +55,7 @@ fn main() {
         tee_audio_pad.get_name()
     );
     let queue_audio_pad = audio_queue.get_static_pad("sink").unwrap();
-    tee_audio_pad.link(&queue_audio_pad);
+    tee_audio_pad.link(&queue_audio_pad).into_result().unwrap();
 
     let tee_video_pad = tee.get_request_pad("src_%u").unwrap();
     println!(
@@ -63,14 +63,9 @@ fn main() {
         tee_video_pad.get_name()
     );
     let queue_video_pad = video_queue.get_static_pad("sink").unwrap();
-    tee_video_pad.link(&queue_video_pad);
+    tee_video_pad.link(&queue_video_pad).into_result().unwrap();
 
-    let ret = pipeline.set_state(gst::State::Playing);
+    pipeline.set_state(gst::State::Playing).into_result().expect("Unable to set the pipeline to the Playing state.");
-    assert_ne!(
-        ret,
-        gst::StateChangeReturn::Failure,
-        "Unable to set the pipeline to the Playing state."
-    );
     let bus = pipeline.get_bus().unwrap();
     while let Some(msg) = bus.timed_pop(gst::CLOCK_TIME_NONE) {
         use gst::MessageView;
@@ -89,12 +84,5 @@ fn main() {
         }
     }
 
-    pipeline.set_state(gst::State::Null);
+    pipeline.set_state(gst::State::Null).into_result().expect("Unable to set the pipeline to the Null state.");
-
-    let ret = pipeline.set_state(gst::State::Null);
-    assert_ne!(
-        ret,
-        gst::StateChangeReturn::Failure,
-        "Unable to set the pipeline to the Null state."
-    );
 }