Add basic sorting implementation and API

Change-Id: Ic1fded7f26e3f63c234c6e5bebf8f8fed22e6365

server/src/main/java/com/vaadin/tokka/server/communication/data/DataCommunicator.java

@@ -171,14 +171,14 @@ public class DataCommunicator<T> extends AbstractExtension {
     protected ActiveDataHandler handler = new ActiveDataHandler();
     protected DataCommunicatorClientRpc rpc;
 
-    protected DataSource<T> dataSource;
+    protected DataSource<T, ?> dataSource;
     private DataKeyMapper<T> keyMapper;
 
     private boolean reset = false;
     private final Set<T> updatedData = new HashSet<T>();
     private Range pushRows = Range.withLength(0, 40);
 
-    public DataCommunicator(DataSource<T> dataSource) {
+    public DataCommunicator(DataSource<T, ?> dataSource) {
         addDataGenerator(handler);
         this.dataSource = dataSource;
         rpc = getRpcProxy(DataCommunicatorClientRpc.class);

server/src/main/java/com/vaadin/tokka/server/communication/data/DataSource.java

@@ -33,9 +33,18 @@ import com.vaadin.tokka.event.Registration;
  * @param <T>
  *            data type
  */
-public interface DataSource<T> extends Function<Object, Stream<T>>,
+public interface DataSource<T, SORT> extends Function<Object, Stream<T>>,
         Serializable {
 
+    /**
+     * Sets a default sorting order to the data source.
+     * 
+     * @param sortOrder
+     *            an object providing the needed sorting information
+     * @return new data source with modified sorting
+     */
+    DataSource<T, SORT> sortingBy(SORT sortOrder);
+
     /**
      * This method creates a new {@link InMemoryDataSource} from a given
      * Collection. The InMemoryDataSource creates a protective List copy of all

server/src/main/java/com/vaadin/tokka/server/communication/data/InMemoryDataSource.java

@@ -17,6 +17,7 @@ package com.vaadin.tokka.server.communication.data;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Comparator;
 import java.util.List;
 import java.util.function.Function;
 import java.util.stream.Stream;
@@ -27,7 +28,7 @@ import java.util.stream.Stream;
  * @param <T>
  *            data type
  */
-public class InMemoryDataSource<T> implements DataSource<T> {
+public class InMemoryDataSource<T> implements DataSource<T, Comparator<T>> {
 
     // FIXME: Missing Query object
     private Function<Object, Stream<T>> request;
@@ -44,8 +45,26 @@ public class InMemoryDataSource<T> implements DataSource<T> {
         request = query -> backend.stream();
     }
 
+    /**
+     * Chaining constructor for making modified {@link InMemoryDataSource}s.
+     * This Constructor is used internally for making sorted and filtered
+     * variants of a base data source with actual data.
+     * 
+     * @param request
+     *            request for the new data source
+     */
+    protected InMemoryDataSource(Function<Object, Stream<T>> request) {
+        this.request = request;
+    }
+
     @Override
     public Stream<T> apply(Object query) {
         return request.apply(query);
     }
+
+    @Override
+    public DataSource<T, Comparator<T>> sortingBy(Comparator<T> sortOrder) {
+        return new InMemoryDataSource<T>(q -> request.apply(q)
+                .sorted(sortOrder));
+    }
 }

server/src/main/java/com/vaadin/tokka/ui/components/Listing.java

@@ -35,7 +35,7 @@ public interface Listing<T> extends Serializable {
      * @param data
      *            data source
      */
-    void setDataSource(DataSource<T> data);
+    void setDataSource(DataSource<T, ?> data);
 
     /**
      * Sets the options available for this Listing.
@@ -62,7 +62,7 @@ public interface Listing<T> extends Serializable {
      * 
      * @return data source
      */
-    DataSource<T> getDataSource();
+    DataSource<T, ?> getDataSource();
 
     /**
      * Gets the {@link SelectionModel} for this Listing.

server/src/main/java/com/vaadin/tokka/ui/components/grid/Grid.java

@@ -26,7 +26,7 @@ import com.vaadin.tokka.ui.components.AbstractListing;
 
 public class Grid<T> extends AbstractListing<T> {
 
-    private DataSource<T> dataSource;
+    private DataSource<T, ?> dataSource;
     private Map<String, Column<T, ?>> columns = new LinkedHashMap<>();
 
     public Grid() {
@@ -34,13 +34,13 @@ public class Grid<T> extends AbstractListing<T> {
     }
 
     @Override
-    public void setDataSource(DataSource<T> data) {
+    public void setDataSource(DataSource<T, ?> data) {
         this.dataSource = data;
         setDataCommunicator(new DataCommunicator<>(data));
     }
 
     @Override
-    public DataSource<T> getDataSource() {
+    public DataSource<T, ?> getDataSource() {
         return dataSource;
     }
 

server/src/main/java/com/vaadin/tokka/ui/components/nativeselect/NativeSelect.java

@@ -28,7 +28,7 @@ import elemental.json.JsonObject;
 
 public class NativeSelect<T> extends AbstractListing<T> {
 
-    private DataSource<T> dataSource;
+    private DataSource<T, ?> dataSource;
     private Function<T, String> nameProvider = T::toString;
 
     public NativeSelect() {
@@ -47,13 +47,13 @@ public class NativeSelect<T> extends AbstractListing<T> {
         });
     }
 
-    public NativeSelect(DataSource<T> dataSource) {
+    public NativeSelect(DataSource<T, ?> dataSource) {
         this();
         setDataSource(dataSource);
     }
 
     @Override
-    public void setDataSource(DataSource<T> data) {
+    public void setDataSource(DataSource<T, ?> data) {
         dataSource = data;
         if (dataSource != null) {
             setDataCommunicator(new DataCommunicator<>(dataSource));
@@ -63,7 +63,7 @@ public class NativeSelect<T> extends AbstractListing<T> {
     }
 
     @Override
-    public DataSource<T> getDataSource() {
+    public DataSource<T, ?> getDataSource() {
         return dataSource;
     }
 }

server/src/test/java/com/vaadin/tokka/data/datasource/InMemoryDataSourceTest.java

@@ -2,10 +2,11 @@ package com.vaadin.tokka.data.datasource;
 
 import static org.junit.Assert.assertTrue;
 
-import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
-import java.util.stream.Stream;
+import java.util.stream.Collectors;
 
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -14,30 +15,12 @@ import com.vaadin.tokka.server.communication.data.InMemoryDataSource;
 
 public class InMemoryDataSourceTest {
 
-    private static class StrBean {
-
-        private String value;
-
-        public StrBean(String value) {
-            this.value = value;
-        }
-
-        public String getValue() {
-            return value;
-        }
-
-        public void setValue(String value) {
-            this.value = value;
-        }
-
-    }
-
     private InMemoryDataSource<StrBean> dataSource;
     private List<StrBean> data;
 
     @Before
     public void setUp() {
-        data = createData();
+        data = StrBean.generateRandomBeans(100);
         dataSource = DataSource.create(data);
     }
 
@@ -46,10 +29,47 @@ public class InMemoryDataSourceTest {
         dataSource.apply(null).forEach(str -> assertTrue(data.contains(str)));
     }
 
-    private List<StrBean> createData() {
-        List<StrBean> list = new ArrayList<>();
-        Stream.of("Foo", "Bar", "Baz").map(StrBean::new).forEach(list::add);
-        return list;
+    @Test
+    public void testSortByComparatorListsDiffer() {
+        Comparator<StrBean> comp = Comparator.comparing(StrBean::getValue)
+                .thenComparing(StrBean::getRandomNumber)
+                .thenComparing(StrBean::getId);
+        List<StrBean> list = dataSource.sortingBy(comp).apply(null)
+                .collect(Collectors.toList());
+
+        // First value in data is { Xyz, 10, 100 } which should be last in list
+        Assert.assertNotEquals("First value should not match", data.get(0),
+                list.get(0));
+
+        data.sort(comp);
+        for (int i = 0; i < data.size(); ++i) {
+            Assert.assertEquals("Sorting result differed", data.get(i),
+                    list.get(i));
+        }
     }
 
+    @Test
+    public void testDefatulSortWithSpecifiedPostSort() {
+        Comparator<StrBean> comp = Comparator.comparing(StrBean::getValue)
+                .thenComparing(Comparator.comparing(StrBean::getId).reversed());
+        List<StrBean> list = dataSource.sortingBy(comp).apply(null)
+                // The sort here should come e.g from a Component
+                .sorted(Comparator.comparing(StrBean::getRandomNumber))
+                .collect(Collectors.toList());
+
+        for (int i = 1; i < list.size(); ++i) {
+            StrBean prev = list.get(i - 1);
+            StrBean cur = list.get(i);
+            // Test specific sort
+            Assert.assertTrue(prev.getRandomNumber() <= cur.getRandomNumber());
+
+            if (prev.getRandomNumber() == cur.getRandomNumber()) {
+                // Test default sort
+                Assert.assertTrue(prev.getValue().compareTo(cur.getValue()) <= 0);
+                if (prev.getValue().equals(cur.getValue())) {
+                    Assert.assertTrue(prev.getId() > cur.getId());
+                }
+            }
+        }
+    }
 }

server/src/test/java/com/vaadin/tokka/data/datasource/StrBean.java

@@ -0,0 +1,49 @@
+package com.vaadin.tokka.data.datasource;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+class StrBean implements Serializable {
+
+    private static String[] values = new String[] { "Foo", "Bar", "Baz" };
+
+    private String value;
+    private final int id;
+    private final int randomNumber;
+
+    public StrBean(String value, int id, int randomNumber) {
+        this.value = value;
+        this.id = id;
+        this.randomNumber = randomNumber;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public int getRandomNumber() {
+        return randomNumber;
+    }
+
+    public static List<StrBean> generateRandomBeans(int max) {
+        List<StrBean> data = new ArrayList<StrBean>();
+        Random r = new Random(13337);
+        data.add(new StrBean("Xyz", 10, max));
+        for (int i = 0; i < max - 1; ++i) {
+            data.add(new StrBean(values[r.nextInt(values.length)], i, r
+                    .nextInt(10)));
+        }
+        return data;
+    }
+
+    @Override
+    public String toString() {
+        return "{ " + value + ", " + randomNumber + ", " + id + " }";
+    }
+}

server/src/test/java/com/vaadin/tokka/ui/components/AbstractListingTest.java

@@ -29,16 +29,16 @@ public class AbstractListingTest {
 
     AbstractListing<String> testComponent = new AbstractListing<String>() {
 
-        DataSource<String> data;
+        DataSource<String, ?> data;
 
         @Override
-        public void setDataSource(DataSource<String> data) {
+        public void setDataSource(DataSource<String, ?> data) {
             this.data = data;
             setDataCommunicator(new DataCommunicator<>(data));
         }
 
         @Override
-        public DataSource<String> getDataSource() {
+        public DataSource<String, ?> getDataSource() {
             return data;
         }
     };

uitest/src/main/java/com/vaadin/tokka/tests/components/ListingTestUI.java

@@ -1,6 +1,7 @@
 package com.vaadin.tokka.tests.components;
 
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Random;
 
@@ -80,7 +81,7 @@ public class ListingTestUI extends AbstractTestUI {
                 .getSelectionModel().getSelected()
                 .forEach(s -> Notification.show(s))));
         hLayout.addComponent(new Button("Random select", e -> {
-            DataSource<String> ds = select.getDataSource();
+            DataSource<String, ?> ds = select.getDataSource();
             int skip = r.nextInt((int) ds.apply(null).count());
             ds.apply(null).skip(skip).findFirst()
                     .ifPresent(select.getSelectionModel()::select);
@@ -100,7 +101,8 @@ public class ListingTestUI extends AbstractTestUI {
         grid.addColumn("String Value", Bean::getValue);
         grid.addColumn("Integer Value", Bean::getIntVal);
         grid.addColumn("toString", Bean::toString);
-        grid.setDataSource(DataSource.create(Bean.generateRandomBeans()));
+        grid.setDataSource(DataSource.create(Bean.generateRandomBeans())
+                .sortingBy(Comparator.comparing(Bean::getValue)));
 
         addComponent(new Button("Toggle Grid Selection",
                 new Button.ClickListener() {