Add Element::get_metadata(), get_pad_template(), get_pad_template_list() and DeviceProvider::get_metadata()

As wrapper around the C class functions.

Fixes https://github.com/sdroege/gstreamer-rs/issues/28

gstreamer/src/device_provider.rs

@@ -0,0 +1,38 @@
+// 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 DeviceProvider;
+
+use glib::IsA;
+use glib::translate::ToGlibPtr;
+
+use std::ffi::CStr;
+
+use ffi;
+use gobject_ffi;
+
+pub trait DeviceProviderExtManual {
+    fn get_metadata(&self, key: &str) -> Option<&'static str>;
+}
+
+impl<O: IsA<DeviceProvider>> DeviceProviderExtManual for O {
+    fn get_metadata(&self, key: &str) -> Option<&'static str> {
+        unsafe {
+            let klass = (*(self.to_glib_none().0 as *mut gobject_ffi::GTypeInstance)).g_class as
+                *mut ffi::GstDeviceProviderClass;
+
+            let ptr = ffi::gst_device_provider_class_get_metadata(klass, key.to_glib_none().0);
+
+            if ptr.is_null() {
+                None
+            } else {
+                Some(CStr::from_ptr(ptr).to_str().unwrap())
+            }
+        }
+    }
+}

gstreamer/src/element.rs

@@ -10,12 +10,16 @@ use Element;
 
 use glib;
 use glib::IsA;
-use glib::translate::{from_glib, ToGlibPtr};
+use glib::translate::{from_glib, from_glib_none, FromGlibPtrContainer, ToGlibPtr};
 use QueryRef;
 use Event;
+use PadTemplate;
 use miniobject::MiniObject;
 
+use std::ffi::CStr;
+
 use ffi;
+use gobject_ffi;
 
 impl Element {
     pub fn link_many<E: IsA<Element>>(elements: &[&E]) -> Result<(), glib::BoolError> {
@@ -47,6 +51,11 @@ pub trait ElementExtManual {
     fn query(&self, query: &mut QueryRef) -> bool;
 
     fn send_event(&self, event: Event) -> bool;
+
+    fn get_metadata(&self, key: &str) -> Option<&'static str>;
+
+    fn get_pad_template(&self, name: &str) -> Option<PadTemplate>;
+    fn get_pad_template_list(&self) -> Vec<PadTemplate>;
 }
 
 impl<O: IsA<Element>> ElementExtManual for O {
@@ -67,4 +76,51 @@ impl<O: IsA<Element>> ElementExtManual for O {
             ))
         }
     }
+
+    fn get_metadata(&self, key: &str) -> Option<&'static str> {
+        unsafe {
+            let klass = (*(self.to_glib_none().0 as *mut gobject_ffi::GTypeInstance)).g_class as
+                *mut ffi::GstElementClass;
+
+            let ptr = ffi::gst_element_class_get_metadata(klass, key.to_glib_none().0);
+
+            if ptr.is_null() {
+                None
+            } else {
+                Some(CStr::from_ptr(ptr).to_str().unwrap())
+            }
+        }
+    }
+
+    fn get_pad_template(&self, name: &str) -> Option<PadTemplate> {
+        unsafe {
+            let klass = (*(self.to_glib_none().0 as *mut gobject_ffi::GTypeInstance)).g_class as
+                *mut ffi::GstElementClass;
+
+            from_glib_none(ffi::gst_element_class_get_pad_template(
+                klass,
+                name.to_glib_none().0,
+            ))
+        }
+    }
+
+    fn get_pad_template_list(&self) -> Vec<PadTemplate> {
+        unsafe {
+            let klass = (*(self.to_glib_none().0 as *mut gobject_ffi::GTypeInstance)).g_class as
+                *mut ffi::GstElementClass;
+
+            FromGlibPtrContainer::from_glib_none(
+                ffi::gst_element_class_get_pad_template_list(klass),
+            )
+        }
+    }
+}
+
+lazy_static!{
+    pub static ref ELEMENT_METADATA_AUTHOR: &'static str = unsafe { CStr::from_ptr(ffi::GST_ELEMENT_METADATA_AUTHOR).to_str().unwrap() };
+    pub static ref ELEMENT_METADATA_DESCRIPTION: &'static str = unsafe { CStr::from_ptr(ffi::GST_ELEMENT_METADATA_DESCRIPTION).to_str().unwrap() };
+    pub static ref ELEMENT_METADATA_DOC_URI: &'static str = unsafe { CStr::from_ptr(ffi::GST_ELEMENT_METADATA_DOC_URI).to_str().unwrap() };
+    pub static ref ELEMENT_METADATA_ICON_NAME: &'static str = unsafe { CStr::from_ptr(ffi::GST_ELEMENT_METADATA_ICON_NAME).to_str().unwrap() };
+    pub static ref ELEMENT_METADATA_KLASS: &'static str = unsafe { CStr::from_ptr(ffi::GST_ELEMENT_METADATA_KLASS).to_str().unwrap() };
+    pub static ref ELEMENT_METADATA_LONGNAME: &'static str = unsafe { CStr::from_ptr(ffi::GST_ELEMENT_METADATA_LONGNAME).to_str().unwrap() };
 }

gstreamer/src/lib.rs

@@ -85,13 +85,23 @@ mod ghost_pad;
 mod child_proxy;
 mod tag_setter;
 mod iterator;
+mod device_provider;
 pub use element::ElementExtManual;
+pub use element::{
+    ELEMENT_METADATA_AUTHOR,
+    ELEMENT_METADATA_DESCRIPTION,
+    ELEMENT_METADATA_DOC_URI,
+    ELEMENT_METADATA_ICON_NAME,
+    ELEMENT_METADATA_KLASS,
+    ELEMENT_METADATA_LONGNAME,
+};
 pub use bin::BinExtManual;
 pub use pad::{PadExtManual, PadProbeData, PadProbeId, PadProbeInfo, PAD_PROBE_ID_INVALID};
 pub use gobject::GObjectExtManualGst;
 pub use child_proxy::ChildProxyExtManual;
 pub use tag_setter::TagSetterExtManual;
 pub use self::iterator::Iterator;
+pub use device_provider::DeviceProviderExtManual;
 
 mod value;
 pub use value::*;