gstreamer: Manually implement Object::set_property_from_str() to be able to catch deserialization errors

examples/src/bin/overlay-composition.rs

@@ -89,7 +89,7 @@ fn create_pipeline() -> Result<gst::Pipeline, Error> {
 
     // The videotestsrc supports multiple test patterns. In this example, we will use the
     // pattern with a white ball moving around the video's center point.
-    src.set_property_from_str("pattern", "ball");
+    src.set_property_from_str("pattern", "ball").unwrap();
 
     // The PangoFontMap represents the set of fonts available for a particular rendering system.
     let fontmap = pangocairo::FontMap::new().unwrap();

examples/src/bin/pango-cairo.rs

@@ -87,7 +87,7 @@ fn create_pipeline() -> Result<gst::Pipeline, Error> {
 
     // The videotestsrc supports multiple test patterns. In this example, we will use the
     // pattern with a white ball moving around the video's center point.
-    src.set_property_from_str("pattern", "ball");
+    src.set_property_from_str("pattern", "ball").unwrap();
 
     // The PangoFontMap represents the set of fonts available for a particular rendering system.
     let fontmap = pangocairo::FontMap::new().unwrap();

examples/src/bin/rtpfecclient.rs

@@ -135,7 +135,7 @@ fn example_main() -> Result<(), Error> {
             pipeline.add_many(&[&enc, &mux, &sink])?;
             gst::Element::link_many(&[&filter, &enc, &mux, &sink])?;
             sink.set_property("location", &"out.mkv")?;
-            enc.set_property_from_str("tune", "zerolatency");
+            enc.set_property_from_str("tune", "zerolatency")?;
             eprintln!("Recording to out.mkv");
         }
         _ => return Err(Error::from(UsageError(args[0].clone()))),

examples/src/bin/rtpfecserver.rs

@@ -151,14 +151,14 @@ fn example_main() -> Result<(), Error> {
 
     let video_caps = gst::Caps::new_simple("video/x-raw", &[]);
 
-    src.set_property_from_str("pattern", "ball");
+    src.set_property_from_str("pattern", "ball")?;
     sink.set_property("host", &"127.0.0.1")?;
     sink.set_property("sync", &true)?;
     enc.set_property("keyframe-max-dist", &30i32)?;
     enc.set_property("threads", &12i32)?;
     enc.set_property("cpu-used", &(-16i32))?;
     enc.set_property("deadline", &1i64)?;
-    enc.set_property_from_str("error-resilient", "default");
+    enc.set_property_from_str("error-resilient", "default")?;
     src.set_property("expose-all-streams", &false)?;
     src.set_property("caps", &video_caps)?;
     src.set_property("uri", &uri)?;

examples/src/bin/subclass.rs

@@ -273,7 +273,7 @@ fn create_pipeline() -> Result<gst::Pipeline, Error> {
     filter.link(&conv)?;
     conv.link(&sink)?;
 
-    src.set_property_from_str("wave", "white-noise");
+    src.set_property_from_str("wave", "white-noise").unwrap();
 
     // Create a windowed sinc lowpass filter at 1/64 sample rate,
     // i.e. 689Hz for 44.1kHz sample rate

gstreamer/src/gobject.rs

@@ -1,20 +1,52 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
+use crate::GstValueExt;
 use glib::prelude::*;
-use glib::translate::ToGlibPtr;
 
 pub trait GObjectExtManualGst: 'static {
-    fn set_property_from_str(&self, name: &str, value: &str);
+    #[doc(alias = "gst_util_set_object_arg")]
+    fn set_property_from_str(&self, name: &str, value: &str) -> Result<(), glib::BoolError>;
 }
 
 impl<O: IsA<glib::Object>> GObjectExtManualGst for O {
-    fn set_property_from_str(&self, name: &str, value: &str) {
-        unsafe {
-            ffi::gst_util_set_object_arg(
-                self.as_ref().to_glib_none().0,
-                name.to_glib_none().0,
-                value.to_glib_none().0,
-            );
+    fn set_property_from_str(&self, name: &str, value: &str) -> Result<(), glib::BoolError> {
+        let pspec = self.find_property(name).ok_or_else(|| {
+            glib::bool_error!("property '{}' of type '{}' not found", name, self.type_())
+        })?;
+
+        let value = {
+            if pspec.value_type() == crate::Structure::static_type() && value == "NULL" {
+                None::<crate::Structure>.to_value()
+            } else {
+                #[cfg(feature = "v1_20")]
+                {
+                    glib::Value::deserialize_with_pspec(value, &pspec)?
                 }
+                #[cfg(not(feature = "v1_20"))]
+                {
+                    glib::Value::deserialize(value, pspec.value_type())?
+                }
+            }
+        };
+
+        self.set_property_from_value(name, &value)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_set_property_from_str() {
+        crate::init().unwrap();
+
+        let fakesink = crate::ElementFactory::make("fakesink", None).unwrap();
+        fakesink
+            .set_property_from_str("state-error", "ready-to-paused")
+            .unwrap();
+        let v = fakesink.property("state-error").unwrap();
+        let e = glib::EnumValue::from_value(&v).unwrap();
+        assert_eq!(e.nick(), "ready-to-paused");
     }
 }

tutorials/src/bin/basic-tutorial-2.rs

@@ -21,7 +21,7 @@ fn tutorial_main() {
     source.link(&sink).expect("Elements could not be linked.");
 
     // Modify the source's properties
-    source.set_property_from_str("pattern", "smpte");
+    source.set_property_from_str("pattern", "smpte").unwrap();
 
     // Start playing
     pipeline

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

@@ -25,8 +25,8 @@ fn tutorial_main() {
     let pipeline = gst::Pipeline::new(Some("test-pipeline"));
 
     audio_source.set_property("freq", &215.0).unwrap();
-    visual.set_property_from_str("shader", "none");
-    visual.set_property_from_str("style", "lines");
+    visual.set_property_from_str("shader", "none").unwrap();
+    visual.set_property_from_str("style", "lines").unwrap();
 
     pipeline
         .add_many(&[

tutorials/src/bin/basic-tutorial-8.rs

@@ -64,8 +64,8 @@ fn main() {
 
     let pipeline = gst::Pipeline::new(Some("test-pipeline"));
 
-    visual.set_property_from_str("shader", "none");
-    visual.set_property_from_str("style", "lines");
+    visual.set_property_from_str("shader", "none").unwrap();
+    visual.set_property_from_str("style", "lines").unwrap();
 
     pipeline
         .add_many(&[