use Pad builders for optional name definition

Also, apply auto-naming in the following cases

* When building from a non wildcard-named template, the name of the template is
  automatically assigned to the Pad. User can override with a specific name by
  calling `name()` on the `PadBuilder`.
* When building with a target and no name was provided via the above, the
  GhostPad is named after the target.

See https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/issues/448
Auto-naming discussion: https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1255#note_1891181

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1197>

16 files changed, 64 insertions, 62 deletions

diff --git a/video/closedcaption/src/cea608overlay/imp.rs b/video/closedcaption/src/cea608overlay/imp.rs
index ce7988d33..c3cba0275 100644
--- a/video/closedcaption/src/cea608overlay/imp.rs
+++ b/video/closedcaption/src/cea608overlay/imp.rs
@@ -522,7 +522,7 @@ impl ObjectSubclass for Cea608Overlay {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 Cea608Overlay::catch_panic_pad_function(
                     parent,
@@ -542,7 +542,7 @@ impl ObjectSubclass for Cea608Overlay {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .flags(gst::PadFlags::PROXY_CAPS)
             .flags(gst::PadFlags::PROXY_ALLOCATION)
             .build();
diff --git a/video/closedcaption/src/cea608tocea708/imp.rs b/video/closedcaption/src/cea608tocea708/imp.rs
index 2a53c7cbb..bed384630 100644
--- a/video/closedcaption/src/cea608tocea708/imp.rs
+++ b/video/closedcaption/src/cea608tocea708/imp.rs
@@ -721,7 +721,7 @@ impl ObjectSubclass for Cea608ToCea708 {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 Cea608ToCea708::catch_panic_pad_function(
                     parent,
@@ -740,7 +740,7 @@ impl ObjectSubclass for Cea608ToCea708 {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .flags(gst::PadFlags::FIXED_CAPS)
             .build();
 
diff --git a/video/closedcaption/src/cea608tojson/imp.rs b/video/closedcaption/src/cea608tojson/imp.rs
index c513dff3a..4eda84720 100644
--- a/video/closedcaption/src/cea608tojson/imp.rs
+++ b/video/closedcaption/src/cea608tojson/imp.rs
@@ -780,7 +780,7 @@ impl ObjectSubclass for Cea608ToJson {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 Cea608ToJson::catch_panic_pad_function(
                     parent,
@@ -799,7 +799,7 @@ impl ObjectSubclass for Cea608ToJson {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .flags(gst::PadFlags::FIXED_CAPS)
             .build();
 
diff --git a/video/closedcaption/src/cea608tott/imp.rs b/video/closedcaption/src/cea608tott/imp.rs
index c265dc7a3..c781585b0 100644
--- a/video/closedcaption/src/cea608tott/imp.rs
+++ b/video/closedcaption/src/cea608tott/imp.rs
@@ -377,7 +377,7 @@ impl ObjectSubclass for Cea608ToTt {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 Cea608ToTt::catch_panic_pad_function(
                     parent,
@@ -396,7 +396,7 @@ impl ObjectSubclass for Cea608ToTt {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .flags(gst::PadFlags::FIXED_CAPS)
             .build();
 
diff --git a/video/closedcaption/src/jsontovtt/imp.rs b/video/closedcaption/src/jsontovtt/imp.rs
index 42e029409..d2c1549e2 100644
--- a/video/closedcaption/src/jsontovtt/imp.rs
+++ b/video/closedcaption/src/jsontovtt/imp.rs
@@ -536,7 +536,7 @@ impl ObjectSubclass for JsonToVtt {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 JsonToVtt::catch_panic_pad_function(
                     parent,
@@ -555,7 +555,7 @@ impl ObjectSubclass for JsonToVtt {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .flags(gst::PadFlags::FIXED_CAPS)
             .event_function(|pad, parent, event| {
                 JsonToVtt::catch_panic_pad_function(
diff --git a/video/closedcaption/src/mcc_enc/imp.rs b/video/closedcaption/src/mcc_enc/imp.rs
index 32656e888..bec2b9999 100644
--- a/video/closedcaption/src/mcc_enc/imp.rs
+++ b/video/closedcaption/src/mcc_enc/imp.rs
@@ -424,7 +424,7 @@ impl ObjectSubclass for MccEnc {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 MccEnc::catch_panic_pad_function(
                     parent,
@@ -438,7 +438,7 @@ impl ObjectSubclass for MccEnc {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .event_function(|pad, parent, event| {
                 MccEnc::catch_panic_pad_function(parent, || false, |enc| enc.src_event(pad, event))
             })
diff --git a/video/closedcaption/src/mcc_parse/imp.rs b/video/closedcaption/src/mcc_parse/imp.rs
index f994cc45e..6bbbf0d99 100644
--- a/video/closedcaption/src/mcc_parse/imp.rs
+++ b/video/closedcaption/src/mcc_parse/imp.rs
@@ -1072,7 +1072,7 @@ impl ObjectSubclass for MccParse {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .activate_function(|pad, parent| {
                 MccParse::catch_panic_pad_function(
                     parent,
@@ -1109,7 +1109,7 @@ impl ObjectSubclass for MccParse {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .event_function(|pad, parent, event| {
                 MccParse::catch_panic_pad_function(
                     parent,
diff --git a/video/closedcaption/src/scc_enc/imp.rs b/video/closedcaption/src/scc_enc/imp.rs
index 75107049e..60dab9460 100644
--- a/video/closedcaption/src/scc_enc/imp.rs
+++ b/video/closedcaption/src/scc_enc/imp.rs
@@ -355,7 +355,7 @@ impl ObjectSubclass for SccEnc {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 SccEnc::catch_panic_pad_function(
                     parent,
@@ -369,7 +369,7 @@ impl ObjectSubclass for SccEnc {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .event_function(|pad, parent, event| {
                 SccEnc::catch_panic_pad_function(parent, || false, |enc| enc.src_event(pad, event))
             })
diff --git a/video/closedcaption/src/scc_parse/imp.rs b/video/closedcaption/src/scc_parse/imp.rs
index 78fc6cf63..4cdc96d0a 100644
--- a/video/closedcaption/src/scc_parse/imp.rs
+++ b/video/closedcaption/src/scc_parse/imp.rs
@@ -951,7 +951,7 @@ impl ObjectSubclass for SccParse {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .activate_function(|pad, parent| {
                 SccParse::catch_panic_pad_function(
                     parent,
@@ -988,7 +988,7 @@ impl ObjectSubclass for SccParse {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .event_function(|pad, parent, event| {
                 SccParse::catch_panic_pad_function(
                     parent,
diff --git a/video/closedcaption/src/transcriberbin/imp.rs b/video/closedcaption/src/transcriberbin/imp.rs
index f974ae8f6..5673e5120 100644
--- a/video/closedcaption/src/transcriberbin/imp.rs
+++ b/video/closedcaption/src/transcriberbin/imp.rs
@@ -149,9 +149,8 @@ impl TranscriberBin {
                 .build(),
         );
 
-        let sinkpad = gst::GhostPad::with_target(Some("sink"), &queue.static_pad("sink").unwrap())?;
-        let srcpad =
-            gst::GhostPad::with_target(Some("src"), &converter.static_pad("src").unwrap())?;
+        let sinkpad = gst::GhostPad::with_target(&queue.static_pad("sink").unwrap()).unwrap();
+        let srcpad = gst::GhostPad::with_target(&converter.static_pad("src").unwrap()).unwrap();
         bin.add_pad(&sinkpad)?;
         bin.add_pad(&srcpad)?;
 
@@ -214,14 +213,11 @@ impl TranscriberBin {
 
         state.ccmux.set_property("latency", CEA608MUX_LATENCY);
 
-        let transcription_audio_sinkpad = gst::GhostPad::with_target(
-            Some("sink"),
-            &aqueue_transcription.static_pad("sink").unwrap(),
-        )?;
-        let transcription_audio_srcpad = gst::GhostPad::with_target(
-            Some("src"),
-            &state.transcription_valve.static_pad("src").unwrap(),
-        )?;
+        let transcription_audio_sinkpad =
+            gst::GhostPad::with_target(&aqueue_transcription.static_pad("sink").unwrap()).unwrap();
+        let transcription_audio_srcpad =
+            gst::GhostPad::with_target(&state.transcription_valve.static_pad("src").unwrap())
+                .unwrap();
 
         state
             .transcription_bin
@@ -260,22 +256,27 @@ impl TranscriberBin {
             .video_queue
             .link_pads(Some("src"), &state.cccombiner, Some("sink"))?;
 
-        let internal_audio_sinkpad = gst::GhostPad::with_target(
-            Some("audio_sink"),
-            &aclocksync.static_pad("sink").unwrap(),
-        )?;
-        let internal_audio_srcpad = gst::GhostPad::with_target(
-            Some("audio_src"),
+        let internal_audio_sinkpad =
+            gst::GhostPad::builder_with_target(&aclocksync.static_pad("sink").unwrap())
+                .unwrap()
+                .name("audio_sink")
+                .build();
+        let internal_audio_srcpad = gst::GhostPad::builder_with_target(
             &state.audio_queue_passthrough.static_pad("src").unwrap(),
-        )?;
-        let internal_video_sinkpad = gst::GhostPad::with_target(
-            Some("video_sink"),
-            &vclocksync.static_pad("sink").unwrap(),
-        )?;
-        let internal_video_srcpad = gst::GhostPad::with_target(
-            Some("video_src"),
-            &state.cccombiner.static_pad("src").unwrap(),
-        )?;
+        )
+        .unwrap()
+        .name("audio_src")
+        .build();
+        let internal_video_sinkpad =
+            gst::GhostPad::builder_with_target(&vclocksync.static_pad("sink").unwrap())
+                .unwrap()
+                .name("video_sink")
+                .build();
+        let internal_video_srcpad =
+            gst::GhostPad::builder_with_target(&state.cccombiner.static_pad("src").unwrap())
+                .unwrap()
+                .name("video_src")
+                .build();
 
         state.internal_bin.add_pad(&internal_audio_sinkpad)?;
         state.internal_bin.add_pad(&internal_audio_srcpad)?;
@@ -835,9 +836,9 @@ impl ObjectSubclass for TranscriberBin {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink_audio").unwrap();
-        let audio_sinkpad = gst::GhostPad::from_template(&templ, Some("sink_audio"));
+        let audio_sinkpad = gst::GhostPad::from_template(&templ);
         let templ = klass.pad_template("src_audio").unwrap();
-        let audio_srcpad = gst::GhostPad::builder_with_template(&templ, Some("src_audio"))
+        let audio_srcpad = gst::GhostPad::builder_from_template(&templ)
             .query_function(|pad, parent, query| {
                 TranscriberBin::catch_panic_pad_function(
                     parent,
@@ -848,7 +849,7 @@ impl ObjectSubclass for TranscriberBin {
             .build();
 
         let templ = klass.pad_template("sink_video").unwrap();
-        let video_sinkpad = gst::GhostPad::builder_with_template(&templ, Some("sink_video"))
+        let video_sinkpad = gst::GhostPad::builder_from_template(&templ)
             .event_function(|pad, parent, event| {
                 TranscriberBin::catch_panic_pad_function(
                     parent,
@@ -858,7 +859,7 @@ impl ObjectSubclass for TranscriberBin {
             })
             .build();
         let templ = klass.pad_template("src_video").unwrap();
-        let video_srcpad = gst::GhostPad::builder_with_template(&templ, Some("src_video"))
+        let video_srcpad = gst::GhostPad::builder_from_template(&templ)
             .query_function(|pad, parent, query| {
                 TranscriberBin::catch_panic_pad_function(
                     parent,
diff --git a/video/closedcaption/src/tttocea608/imp.rs b/video/closedcaption/src/tttocea608/imp.rs
index 9e85ca5eb..f4f916c14 100644
--- a/video/closedcaption/src/tttocea608/imp.rs
+++ b/video/closedcaption/src/tttocea608/imp.rs
@@ -977,7 +977,7 @@ impl ObjectSubclass for TtToCea608 {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 TtToCea608::catch_panic_pad_function(
                     parent,
@@ -996,7 +996,7 @@ impl ObjectSubclass for TtToCea608 {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .flags(gst::PadFlags::FIXED_CAPS)
             .build();
 
diff --git a/video/closedcaption/src/tttojson/imp.rs b/video/closedcaption/src/tttojson/imp.rs
index b8d4228e2..e4f98fe39 100644
--- a/video/closedcaption/src/tttojson/imp.rs
+++ b/video/closedcaption/src/tttojson/imp.rs
@@ -192,7 +192,7 @@ impl ObjectSubclass for TtToJson {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 TtToJson::catch_panic_pad_function(
                     parent,
@@ -210,7 +210,7 @@ impl ObjectSubclass for TtToJson {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src")).build();
+        let srcpad = gst::Pad::from_template(&templ);
 
         Self {
             srcpad,
diff --git a/video/ffv1/tests/ffv1dec.rs b/video/ffv1/tests/ffv1dec.rs
index d1ae38ad7..47410eb90 100644
--- a/video/ffv1/tests/ffv1dec.rs
+++ b/video/ffv1/tests/ffv1dec.rs
@@ -44,7 +44,7 @@ fn test_decode(name: &str) {
     .unwrap();
 
     let srcpad = bin.by_name("ffv1dec").unwrap().static_pad("src").unwrap();
-    let _ = bin.add_pad(&gst::GhostPad::with_target(Some("src"), &srcpad).unwrap());
+    let _ = bin.add_pad(&gst::GhostPad::with_target(&srcpad).unwrap());
 
     let mut h = gst_check::Harness::with_element(&bin, None, Some("src"));
 
diff --git a/video/gtk4/examples/gtksink.rs b/video/gtk4/examples/gtksink.rs
index 77855af75..2346a8cd3 100644
--- a/video/gtk4/examples/gtksink.rs
+++ b/video/gtk4/examples/gtksink.rs
@@ -48,11 +48,8 @@ fn create_ui(app: &gtk::Application) {
         sink.add(&gtksink).unwrap();
         convert.link(&gtksink).unwrap();
 
-        sink.add_pad(
-            &gst::GhostPad::with_target(Some("sink"), &convert.static_pad("sink").unwrap())
-                .unwrap(),
-        )
-        .unwrap();
+        sink.add_pad(&gst::GhostPad::with_target(&convert.static_pad("sink").unwrap()).unwrap())
+            .unwrap();
 
         (src, sink.upcast())
     };
diff --git a/video/videofx/src/videocompare/mod.rs b/video/videofx/src/videocompare/mod.rs
index 67bccd4f1..a31493ace 100644
--- a/video/videofx/src/videocompare/mod.rs
+++ b/video/videofx/src/videocompare/mod.rs
@@ -200,7 +200,9 @@ mod test {
 
         let mut message = VideoCompareMessage::default();
         message.pad_distances.push(PadDistance {
-            pad: gst::Pad::new(Some("sink_0"), gst::PadDirection::Sink),
+            pad: gst::Pad::builder(gst::PadDirection::Sink)
+                .name("sink_0")
+                .build(),
             distance: 42_f64,
         });
         message.running_time = Some(running_time);
@@ -236,7 +238,9 @@ mod test {
                 gst::Array::from_iter([gst::Structure::builder("pad-distance")
                     .field(
                         "pad",
-                        gst::Pad::new(Some("sink_0"), gst::PadDirection::Sink),
+                        gst::Pad::builder(gst::PadDirection::Sink)
+                            .name("sink_0")
+                            .build(),
                     )
                     .field("distance", 42f64)
                     .build()
diff --git a/video/webp/src/dec/imp.rs b/video/webp/src/dec/imp.rs
index b5f97e56e..8e70c950b 100644
--- a/video/webp/src/dec/imp.rs
+++ b/video/webp/src/dec/imp.rs
@@ -273,7 +273,7 @@ impl ObjectSubclass for WebPDec {
 
     fn with_class(klass: &Self::Class) -> Self {
         let templ = klass.pad_template("sink").unwrap();
-        let sinkpad = gst::Pad::builder_with_template(&templ, Some("sink"))
+        let sinkpad = gst::Pad::builder_from_template(&templ)
             .chain_function(|pad, parent, buffer| {
                 WebPDec::catch_panic_pad_function(
                     parent,
@@ -291,7 +291,7 @@ impl ObjectSubclass for WebPDec {
             .build();
 
         let templ = klass.pad_template("src").unwrap();
-        let srcpad = gst::Pad::builder_with_template(&templ, Some("src"))
+        let srcpad = gst::Pad::builder_from_template(&templ)
             .event_function(|pad, parent, event| {
                 WebPDec::catch_panic_pad_function(parent, || false, |dec| dec.src_event(pad, event))
             })