Structure: Add Accessor for GstValueList Fields

src/org/freedesktop/gstreamer/Structure.java

@@ -21,17 +21,18 @@
 
 import com.sun.jna.Pointer;
 import com.sun.jna.ptr.PointerByReference;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-import org.freedesktop.gstreamer.lowlevel.GType;
-import org.freedesktop.gstreamer.lowlevel.GValueAPI;
 import org.freedesktop.gstreamer.glib.NativeObject;
 import org.freedesktop.gstreamer.glib.Natives;
 import org.freedesktop.gstreamer.lowlevel.GPointer;
+import org.freedesktop.gstreamer.lowlevel.GType;
+import org.freedesktop.gstreamer.lowlevel.GValueAPI;
 import org.freedesktop.gstreamer.lowlevel.GValueAPI.GValue;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static org.freedesktop.gstreamer.lowlevel.GValueAPI.GVALUE_API;
 import static org.freedesktop.gstreamer.lowlevel.GstStructureAPI.GSTSTRUCTURE_API;
 import static org.freedesktop.gstreamer.lowlevel.GstValueAPI.GSTVALUE_API;
 
@@ -210,7 +211,7 @@ public double[] getDoubles(String fieldName, double[] array) {
             }
         }
     }
-    
+
     /**
      * Get the number of fields in the {@link Structure}.
      *
@@ -435,16 +436,37 @@ public Object getValue(String fieldName) {
      * Throws {@link InvalidFieldException} if the field does not exist, or the
      * field values cannot be converted to type T.
      * <p>
-     * This method only currently supports lists of values inside a GValueArray
-     * - other native list types will be supported in future.
+     * This method currently supports lists of values inside a GValueArray or
+     * GstValueList.
      *
      * @param <T>
      * @param type type of values
      * @param fieldName name of field
      * @return List of values from the named field
      */
     public <T> List<T> getValues(Class<T> type, String fieldName) {
-        Object val = getValue(fieldName);
+        GValue gValue = GSTSTRUCTURE_API.gst_structure_get_value(this, fieldName);
+        if (gValue == null) {
+            throw new InvalidFieldException(type.getSimpleName(), fieldName);
+        }
+
+        GType gType = gValue.getType();
+        if (gType.equals(GSTVALUE_API.gst_value_list_get_type())) {
+            int size = GSTVALUE_API.gst_value_list_get_size(gValue);
+            ArrayList<T> values = new ArrayList<>(size);
+            for (int i = 0; i <size; i++) {
+                Object o = GSTVALUE_API.gst_value_list_get_value(gValue, i).getValue();
+                if (type.isInstance(o)) {
+                    values.add(type.cast(o));
+                } else {
+                    throw new InvalidFieldException(type.getSimpleName(), fieldName);
+                }
+            }
+
+            return values;
+        }
+
+        Object val = gValue.getValue();
         if (val instanceof GValueAPI.GValueArray) {
             GValueAPI.GValueArray arr = (GValueAPI.GValueArray) val;
             int count = arr.getNValues();

test/org/freedesktop/gstreamer/StructureTest.java

@@ -1,15 +1,17 @@
 package org.freedesktop.gstreamer;
 
-import java.util.List;
-import static org.junit.Assert.*;
-
 import org.freedesktop.gstreamer.lowlevel.GType;
 import org.freedesktop.gstreamer.lowlevel.GValueAPI;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.*;
+
 public class StructureTest {
 	private Structure structure;
 
@@ -151,4 +153,24 @@ public void testFraction() {
 		assertEquals(17, structure.getFraction("fraction").getNumerator());
 		assertEquals(10, structure.getFraction("fraction").getDenominator());
 	}
+
+    @Test
+    public void testValueListInteger() {
+        Caps caps = Caps.fromString("audio/x-raw,rate={44100,48000}");
+        List<Integer> rates = caps.getStructure(0).getValues(Integer.class, "rate");
+        assertEquals(Arrays.asList(44100, 48000), rates);
+    }
+
+    @Test
+    public void testValueListStrings() {
+        Caps caps = Caps.fromString("video/x-raw,format={RGB, BGR, RGBx, BGRx}");
+        List<String> formats = caps.getStructure(0).getValues(String.class, "format");
+        assertEquals(Arrays.asList("RGB", "BGR", "RGBx","BGRx"), formats);
+    }
+
+    @Test(expected = Structure.InvalidFieldException.class)
+    public void testValueListChecksType() {
+        Caps caps = Caps.fromString("video/x-raw,format={RGB, BGR, RGBx, BGRx}");
+        caps.getStructure(0).getValues(Integer.class, "format");
+    }
 }