feat: Add lazy support to available items grid

Close #130

pom.xml

@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.flowingcode.vaadin.addons</groupId>
 	<artifactId>twincolgrid</artifactId>
-	<version>2.9.3-SNAPSHOT</version>
+	<version>3.0.0-SNAPSHOT</version>
 	<name>TwinColGrid add-on</name>
     <properties>
         <vaadin.version>14.8.1</vaadin.version>

src/main/java/com/flowingcode/vaadin/addons/twincolgrid/EagerFilterableColumn.java

@@ -0,0 +1,23 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.component.ItemLabelGenerator;
+import com.vaadin.flow.function.SerializableBiPredicate;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Setter;
+import lombok.experimental.Accessors;
+
+@RequiredArgsConstructor
+@Getter
+@Setter
+@Accessors(fluent = true)
+public class EagerFilterableColumn<T> {
+
+  private final ItemLabelGenerator<T> itemLabelGenerator;
+  private final String header;
+  private final String filterPlaceholder;
+  private final boolean enableClearButton;
+  private final SerializableBiPredicate<T, String> filterCondition;
+  private String key;
+
+}

src/main/java/com/flowingcode/vaadin/addons/twincolgrid/EagerTwinColModel.java

@@ -0,0 +1,187 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.component.ComponentEventListener;
+import com.vaadin.flow.component.grid.Grid;
+import com.vaadin.flow.component.grid.Grid.Column;
+import com.vaadin.flow.component.grid.HeaderRow;
+import com.vaadin.flow.component.grid.ItemDoubleClickEvent;
+import com.vaadin.flow.component.grid.dnd.GridDropLocation;
+import com.vaadin.flow.component.html.Label;
+import com.vaadin.flow.component.orderedlayout.VerticalLayout;
+import com.vaadin.flow.component.textfield.TextField;
+import com.vaadin.flow.data.provider.DataProvider;
+import com.vaadin.flow.data.provider.ListDataProvider;
+import com.vaadin.flow.data.renderer.TextRenderer;
+import com.vaadin.flow.data.value.ValueChangeMode;
+import com.vaadin.flow.shared.Registration;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+import lombok.NonNull;
+
+public class EagerTwinColModel<T> implements TwinColModel<T> {
+
+  private final Grid<T> grid;
+  private final Label columnLabel = new Label();
+  private final VerticalLayout layout;
+  private HeaderRow headerRow;
+  private boolean droppedInsideGrid = false;
+  private boolean allowReordering = false;
+  private Registration moveItemsByDoubleClick;
+
+  EagerTwinColModel(@NonNull Grid<T> grid, String className) {
+    this.grid = grid;
+    this.grid.setDataProvider(DataProvider.ofCollection(new ArrayList<>()));
+
+    layout = new VerticalLayout(columnLabel, grid);
+
+    layout.setClassName(className);
+    grid.setClassName("twincol-grid-items");
+    columnLabel.setClassName("twincol-grid-label");
+  }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public ListDataProvider<T> getDataProvider() {
+    return (ListDataProvider<T>) grid.getDataProvider();
+  }
+
+  @Override
+  public boolean isReorderingEnabled() {
+    return allowReordering && grid.getSortOrder().isEmpty();
+  }
+
+  @Override
+  public Grid<T> getGrid() {
+    return grid;
+  }
+
+  @Override
+  public Label getColumnLabel() {
+    return columnLabel;
+  }
+
+  @Override
+  public boolean isDroppedInsideGrid() {
+    return droppedInsideGrid;
+  }
+
+  @Override
+  public void setDroppedInsideGrid(boolean droppedInsideGrid) {
+    this.droppedInsideGrid = droppedInsideGrid;
+  }
+
+  @Override
+  public void setAllowReordering(boolean allowReordering) {
+    this.allowReordering = allowReordering;
+  }
+
+  @Override
+  public boolean isAllowReordering() {
+    return allowReordering;
+  }
+
+  @Override
+  public HeaderRow getHeaderRow() {
+    return headerRow;
+  }
+
+  @Override
+  public void setHeaderRow(HeaderRow headerRow) {
+    this.headerRow = headerRow;
+  }
+
+  @Override
+  public Registration getMoveItemsByDoubleClick() {
+    return moveItemsByDoubleClick;
+  }
+
+  @Override
+  public Registration addItemDoubleClickListener(
+      ComponentEventListener<ItemDoubleClickEvent<T>> listener) {
+    moveItemsByDoubleClick = grid.addItemDoubleClickListener(listener);
+    return moveItemsByDoubleClick;
+  }
+
+  @Override
+  public void removeItemDoubleClickListener() {
+    if (moveItemsByDoubleClick != null) {
+      moveItemsByDoubleClick.remove();
+      moveItemsByDoubleClick = null;
+    }
+  }
+
+  @Override
+  public VerticalLayout getLayout() {
+    return layout;
+  }
+
+  @Override
+  public void addAll(Collection<T> items) {
+    getDataProvider().getItems().addAll(items);
+  }
+
+  @Override
+  public void removeAll(Collection<T> items) {
+    getDataProvider().getItems().removeAll(items);
+  }
+
+  @Override
+  public void clear() {
+    getDataProvider().getItems().clear();
+  }
+
+  public void addFilterableColumn(EagerFilterableColumn<T> filter) {
+    Column<T> column =
+        grid.addColumn(new TextRenderer<>(filter.itemLabelGenerator())).setHeader(filter.header());
+
+    Optional.ofNullable(filter.key()).ifPresent(column::setKey);
+
+    TextField filterField = new TextField();
+    filterField.setClearButtonVisible(filter.enableClearButton());
+
+    filterField.addValueChangeListener(
+        event -> getDataProvider()
+            .addFilter(item -> filter.filterCondition().test(item, filterField.getValue())));
+
+    if (headerRow == null) {
+      setHeaderRow(grid.appendHeaderRow());
+    }
+
+    headerRow.getCell(column).setComponent(filterField);
+    filterField.setValueChangeMode(ValueChangeMode.EAGER);
+    filterField.setSizeFull();
+    filterField.setPlaceholder(filter.filterPlaceholder());
+  }
+
+  public void addItems(Collection<T> draggedItems,
+      T dropOverItem, GridDropLocation dropLocation) {
+    if (dropOverItem != null) {
+      Collection<T> collection = getDataProvider().getItems();
+      List<T> list = new ArrayList<>(collection);
+      int dropIndex = list.indexOf(dropOverItem) + (dropLocation == GridDropLocation.BELOW ? 1 : 0);
+      list.addAll(dropIndex, draggedItems);
+      clear();
+      addAll(list);
+    } else {
+      addAll(draggedItems);
+    }
+    grid.getDataProvider().refreshAll();
+  }
+
+  public Collection<T> getItems() {
+    return getDataProvider().getItems();
+  }
+
+  @Override
+  public TwinColModelMode getMode() {
+    return TwinColModelMode.EAGER;
+  }
+
+  @Override
+  public boolean supportsAddAll() {
+    return true;
+  }
+
+}

src/main/java/com/flowingcode/vaadin/addons/twincolgrid/LazyFilter.java

@@ -0,0 +1,14 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import java.util.Collection;
+import java.util.HashSet;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class LazyFilter<T> {
+
+  private Collection<T> excludedItems = new HashSet<>();
+
+}

src/main/java/com/flowingcode/vaadin/addons/twincolgrid/LazyFilterableColumn.java

@@ -0,0 +1,30 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.component.ItemLabelGenerator;
+import com.vaadin.flow.function.SerializableBiPredicate;
+import com.vaadin.flow.function.SerializableConsumer;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Setter;
+import lombok.experimental.Accessors;
+
+@RequiredArgsConstructor
+@Getter
+@Accessors(fluent = true)
+@Setter
+public class LazyFilterableColumn<T> {
+
+  private final ItemLabelGenerator<T> itemLabelGenerator;
+  private final String header;
+  private final String filterPlaceholder;
+  private final boolean enableClearButton;
+  private String key;
+  private SerializableConsumer<String> lazyFilterAttribute;
+  private SerializableBiPredicate<T, String> eagerFilterCondition;
+
+  public EagerFilterableColumn<T> asEager() {
+    return new EagerFilterableColumn<>(itemLabelGenerator, header, filterPlaceholder,
+        enableClearButton, eagerFilterCondition);
+  }
+
+}