gstreamer-video: Change functions from returning Option to Result

Partial work for:
https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/issues/216

gstreamer-video/src/video_event.rs

@@ -158,7 +158,7 @@ pub struct DownstreamForceKeyUnitEvent {
 
 pub fn parse_downstream_force_key_unit_event(
     event: &gst::EventRef,
-) -> Option<DownstreamForceKeyUnitEvent> {
+) -> Result<DownstreamForceKeyUnitEvent, glib::error::BoolError> {
     unsafe {
         let mut timestamp = mem::MaybeUninit::uninit();
         let mut stream_time = mem::MaybeUninit::uninit();
@@ -177,7 +177,7 @@ pub fn parse_downstream_force_key_unit_event(
             ),
         );
         if res {
-            Some(DownstreamForceKeyUnitEvent {
+            Ok(DownstreamForceKeyUnitEvent {
                 timestamp: from_glib(timestamp.assume_init()),
                 stream_time: from_glib(stream_time.assume_init()),
                 running_time: from_glib(running_time.assume_init()),
@@ -185,7 +185,7 @@ pub fn parse_downstream_force_key_unit_event(
                 count: count.assume_init(),
             })
         } else {
-            None
+            Err(glib_bool_error!("Failed to parse GstEvent"))
         }
     }
 }
@@ -252,7 +252,7 @@ pub struct UpstreamForceKeyUnitEvent {
 
 pub fn parse_upstream_force_key_unit_event(
     event: &gst::EventRef,
-) -> Option<UpstreamForceKeyUnitEvent> {
+) -> Result<UpstreamForceKeyUnitEvent, glib::error::BoolError> {
     unsafe {
         let mut running_time = mem::MaybeUninit::uninit();
         let mut all_headers = mem::MaybeUninit::uninit();
@@ -267,13 +267,13 @@ pub fn parse_upstream_force_key_unit_event(
             ),
         );
         if res {
-            Some(UpstreamForceKeyUnitEvent {
+            Ok(UpstreamForceKeyUnitEvent {
                 running_time: from_glib(running_time.assume_init()),
                 all_headers: from_glib(all_headers.assume_init()),
                 count: count.assume_init(),
             })
         } else {
-            None
+            Err(glib_bool_error!("Failed to parse GstEvent"))
         }
     }
 }
@@ -284,7 +284,9 @@ pub enum ForceKeyUnitEvent {
     Upstream(UpstreamForceKeyUnitEvent),
 }
 
-pub fn parse_force_key_unit_event(event: &gst::EventRef) -> Option<ForceKeyUnitEvent> {
+pub fn parse_force_key_unit_event(
+    event: &gst::EventRef,
+) -> Result<ForceKeyUnitEvent, glib::error::BoolError> {
     if event.is_upstream() {
         parse_upstream_force_key_unit_event(event).map(ForceKeyUnitEvent::Upstream)
     } else {
@@ -324,7 +326,9 @@ pub struct StillFrameEvent {
     pub in_still: bool,
 }
 
-pub fn parse_still_frame_event(event: &gst::EventRef) -> Option<StillFrameEvent> {
+pub fn parse_still_frame_event(
+    event: &gst::EventRef,
+) -> Result<StillFrameEvent, glib::error::BoolError> {
     unsafe {
         let mut in_still = mem::MaybeUninit::uninit();
 
@@ -333,11 +337,11 @@ pub fn parse_still_frame_event(event: &gst::EventRef) -> Option<StillFrameEvent>
             in_still.as_mut_ptr(),
         ));
         if res {
-            Some(StillFrameEvent {
+            Ok(StillFrameEvent {
                 in_still: from_glib(in_still.assume_init()),
             })
         } else {
-            None
+            Err(glib_bool_error!("Invalid still-frame event"))
         }
     }
 }

gstreamer-video/src/video_overlay_composition.rs

@@ -198,12 +198,14 @@ impl fmt::Debug for VideoOverlayCompositionRef {
 }
 
 impl VideoOverlayComposition {
-    pub fn new<'a, T: IntoIterator<Item = &'a VideoOverlayRectangle>>(rects: T) -> Option<Self> {
+    pub fn new<'a, T: IntoIterator<Item = &'a VideoOverlayRectangle>>(
+        rects: T,
+    ) -> Result<Self, glib::error::BoolError> {
         unsafe {
             let mut iter = rects.into_iter();
 
             let first = match iter.next() {
-                None => return None,
+                None => return Err(glib_bool_error!("Failed to create VideoOverlayComposition")),
                 Some(first) => first,
             };
 
@@ -218,7 +220,7 @@ impl VideoOverlayComposition {
                 );
             }
 
-            Some(composition)
+            Ok(composition)
         }
     }
 }
@@ -228,16 +230,19 @@ impl VideoOverlayCompositionRef {
         unsafe { gst_video_sys::gst_video_overlay_composition_n_rectangles(self.as_mut_ptr()) }
     }
 
-    pub fn get_rectangle(&self, idx: u32) -> Option<VideoOverlayRectangle> {
+    pub fn get_rectangle(&self, idx: u32) -> Result<VideoOverlayRectangle, glib::error::BoolError> {
         if idx >= self.n_rectangles() {
-            return None;
+            return Err(glib_bool_error!("Invalid index"));
         }
 
         unsafe {
-            from_glib_none(gst_video_sys::gst_video_overlay_composition_get_rectangle(
+            match from_glib_none(gst_video_sys::gst_video_overlay_composition_get_rectangle(
                 self.as_mut_ptr(),
                 idx,
-            ))
+            )) {
+                Some(r) => Ok(r),
+                None => Err(glib_bool_error!("Failed to get rectangle")),
+            }
         }
     }
 

gstreamer-video/src/video_time_code.rs

@@ -77,7 +77,7 @@ impl VideoTimeCode {
         dt: &glib::DateTime,
         flags: VideoTimeCodeFlags,
         field_count: u32,
-    ) -> Option<VideoTimeCode> {
+    ) -> Result<VideoTimeCode, glib::error::BoolError> {
         assert_initialized_main_thread!();
         assert!(*fps.denom() > 0);
         unsafe {
@@ -92,9 +92,9 @@ impl VideoTimeCode {
             );
 
             if res == glib_sys::GFALSE {
-                None
+                Err(glib_bool_error!("Failed to init video time code"))
             } else {
-                Some(VideoTimeCode(v.assume_init()))
+                Ok(VideoTimeCode(v.assume_init()))
             }
         }
     }
@@ -163,7 +163,7 @@ impl ValidVideoTimeCode {
         seconds: u32,
         frames: u32,
         field_count: u32,
-    ) -> Option<Self> {
+    ) -> Result<Self, glib::error::BoolError> {
         let tc = VideoTimeCode::new(
             fps,
             latest_daily_jam,
@@ -174,7 +174,10 @@ impl ValidVideoTimeCode {
             frames,
             field_count,
         );
-        tc.try_into().ok()
+        match tc.try_into() {
+            Ok(v) => Ok(v),
+            Err(_) => Err(glib_bool_error!("Failed to create new ValidVideoTimeCode")),
+        }
     }
 
     //    #[cfg(any(feature = "v1_16", feature = "dox"))]
@@ -195,12 +198,18 @@ impl ValidVideoTimeCode {
     }
 
     #[cfg(any(feature = "v1_12", feature = "dox"))]
-    pub fn add_interval(&self, tc_inter: &VideoTimeCodeInterval) -> Option<VideoTimeCode> {
+    pub fn add_interval(
+        &self,
+        tc_inter: &VideoTimeCodeInterval,
+    ) -> Result<VideoTimeCode, glib::error::BoolError> {
         unsafe {
-            from_glib_full(gst_video_sys::gst_video_time_code_add_interval(
+            match from_glib_full(gst_video_sys::gst_video_time_code_add_interval(
                 self.to_glib_none().0,
                 tc_inter.to_glib_none().0,
-            ))
+            )) {
+                Some(i) => Ok(i),
+                None => Err(glib_bool_error!("Failed to add interval")),
+            }
         }
     }
 
@@ -224,11 +233,16 @@ impl ValidVideoTimeCode {
         unsafe { gst_video_sys::gst_video_time_code_nsec_since_daily_jam(self.to_glib_none().0) }
     }
 
-    pub fn to_date_time(&self) -> Option<glib::DateTime> {
+    pub fn to_date_time(&self) -> Result<glib::DateTime, glib::error::BoolError> {
         unsafe {
-            from_glib_full(gst_video_sys::gst_video_time_code_to_date_time(
+            match from_glib_full(gst_video_sys::gst_video_time_code_to_date_time(
                 self.to_glib_none().0,
-            ))
+            )) {
+                Some(d) => Ok(d),
+                None => Err(glib_bool_error!(
+                    "Failed to convert VideoTimeCode to date time"
+                )),
+            }
         }
     }
 }
@@ -466,15 +480,15 @@ generic_impl!(ValidVideoTimeCode);
 
 #[cfg(any(feature = "v1_12", feature = "dox"))]
 impl str::FromStr for VideoTimeCode {
-    type Err = ();
+    type Err = glib::error::BoolError;
 
-    fn from_str(s: &str) -> Result<Self, ()> {
+    fn from_str(s: &str) -> Result<Self, glib::error::BoolError> {
         assert_initialized_main_thread!();
         unsafe {
             Option::<VideoTimeCode>::from_glib_full(
                 gst_video_sys::gst_video_time_code_new_from_string(s.to_glib_none().0),
             )
-            .ok_or(())
+            .ok_or_else(|| glib_bool_error!("Failed to create VideoTimeCode from string"))
         }
     }
 }

gstreamer-video/src/video_time_code_interval.rs

@@ -128,15 +128,15 @@ impl fmt::Display for VideoTimeCodeInterval {
 }
 
 impl str::FromStr for VideoTimeCodeInterval {
-    type Err = ();
+    type Err = glib::error::BoolError;
 
-    fn from_str(s: &str) -> Result<Self, ()> {
+    fn from_str(s: &str) -> Result<Self, glib::error::BoolError> {
         assert_initialized_main_thread!();
         unsafe {
             Option::<VideoTimeCodeInterval>::from_glib_full(
                 gst_video_sys::gst_video_time_code_interval_new_from_string(s.to_glib_none().0),
             )
-            .ok_or(())
+            .ok_or_else(|| glib_bool_error!("Failed to create VideoTimeCodeInterval from string"))
         }
     }
 }