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/BaseLazyFilter.java

@@ -0,0 +1,19 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.data.provider.SortOrder;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class BaseLazyFilter<T> implements LazyFilter<T> {
+
+  private Collection<T> selectedItems = new HashSet<>();
+
+  private List<SortOrder<String>> sorting = new ArrayList<>();
+
+}

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

@@ -0,0 +1,21 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.flowingcode.vaadin.addons.twincolgrid.TwinColModel.TwinColModelMode;
+
+public class EagerFilterConfiguration<T> extends FilterConfiguration<T, EagerFilterableColumn<T>> {
+
+  @SafeVarargs
+  public EagerFilterConfiguration(EagerFilterableColumn<T>... columns) {
+    super(columns);
+  }
+
+  void apply(TwinColGrid<T> grid) {
+    filteredColumns.forEach(grid::addFilterableColumn);
+  }
+
+  @Override
+  boolean supports(TwinColModelMode mode) {
+    return TwinColModelMode.EAGER.equals(mode);
+  }
+
+}

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

@@ -0,0 +1,25 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.function.SerializableBiPredicate;
+import lombok.Getter;
+
+/**
+ * Enables in memory filtering support to column.
+ *
+ * @param <T>
+ */
+@Getter
+public class EagerFilterableColumn<T> extends FilterableColumn<T> {
+
+  /**
+   * filter condition to apply to column values.
+   */
+  private final SerializableBiPredicate<T, String> filterCondition;
+
+  public EagerFilterableColumn(TwinColumn<T> column, String filterPlaceholder,
+      boolean enableClearButton, SerializableBiPredicate<T, String> filterCondition) {
+    super(column, filterPlaceholder, enableClearButton);
+    this.filterCondition = filterCondition;
+  }
+
+}

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

@@ -0,0 +1,95 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.component.grid.Grid;
+import com.vaadin.flow.component.grid.Grid.Column;
+import com.vaadin.flow.component.grid.dnd.GridDropLocation;
+import com.vaadin.flow.component.textfield.TextField;
+import com.vaadin.flow.data.provider.DataProvider;
+import com.vaadin.flow.data.provider.InMemoryDataProvider;
+import com.vaadin.flow.data.provider.ListDataProvider;
+import com.vaadin.flow.data.value.ValueChangeMode;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import lombok.NonNull;
+
+/**
+ * Model that supports {@link InMemoryDataProvider} for {@link TwinColGrid} available and selection
+ * grids.
+ *
+ * @param <T>
+ */
+class EagerTwinColModel<T> extends TwinColModel<T, EagerFilterableColumn<T>> {
+
+  EagerTwinColModel(@NonNull Grid<T> grid, String className) {
+    super(grid, className);
+    this.grid.setDataProvider(DataProvider.ofCollection(new ArrayList<>()));
+  }
+
+  @Override
+  @SuppressWarnings("unchecked")
+  ListDataProvider<T> getDataProvider() {
+    return (ListDataProvider<T>) grid.getDataProvider();
+  }
+
+  @Override
+  void addAll(Collection<T> items) {
+    getDataProvider().getItems().addAll(items);
+  }
+
+  @Override
+  void removeAll(Collection<T> items) {
+    getDataProvider().getItems().removeAll(items);
+  }
+
+  @Override
+  void addFilterableColumn(Column<T> column, EagerFilterableColumn<T> filter) {
+    TextField filterField = new TextField();
+    filterField.setClearButtonVisible(filter.isEnableClearButton());
+    filterField.setValueChangeMode(ValueChangeMode.EAGER);
+    filterField.setSizeFull();
+    filterField.setPlaceholder(filter.getFilterPlaceholder());
+    filterField.addValueChangeListener(
+        event -> getDataProvider()
+            .addFilter(item -> filter.getFilterCondition().test(item, filterField.getValue())));
+
+    if (headerRow == null) {
+      setHeaderRow(grid.appendHeaderRow());
+    }
+
+    headerRow.getCell(column).setComponent(filterField);
+  }
+
+  void clear() {
+    getDataProvider().getItems().clear();
+  }
+
+  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);
+      getDataProvider().getItems().clear();
+      addAll(list);
+    } else {
+      addAll(draggedItems);
+    }
+    getDataProvider().refreshAll();
+  }
+
+  Collection<T> getItems() {
+    return getDataProvider().getItems();
+  }
+
+  @Override
+  TwinColModelMode getMode() {
+    return TwinColModelMode.EAGER;
+  }
+
+  @Override
+  boolean supportsAddAll() {
+    return true;
+  }
+
+}

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

@@ -0,0 +1,36 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.flowingcode.vaadin.addons.twincolgrid.TwinColModel.TwinColModelMode;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+
+public abstract class FilterConfiguration<T, C extends FilterableColumn<T>> {
+
+  protected final Collection<C> filteredColumns = new ArrayList<>();
+
+  @SafeVarargs
+  public FilterConfiguration(C... columns) {
+    filteredColumns.addAll(Arrays.asList(columns));
+  }
+
+  public void addFilteredColumn(C column) {
+    filteredColumns.add(column);
+  }
+
+  /**
+   * Applies this {@link FilterConfiguration} to grid.
+   * 
+   * @param grid
+   */
+  abstract void apply(TwinColGrid<T> grid);
+
+  /**
+   * Checks if {@link FilterConfiguration} supports the given {@link TwinColModelMode}
+   * 
+   * @param mode mode to check.
+   * @return true mode is supported.
+   */
+  abstract boolean supports(TwinColModelMode mode);
+
+}

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

@@ -0,0 +1,14 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+@Getter
+public abstract class FilterableColumn<T> {
+
+  private final TwinColumn<T> column;
+  private final String filterPlaceholder;
+  private final boolean enableClearButton;
+
+}

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

@@ -0,0 +1,23 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.data.provider.SortOrder;
+import java.util.Collection;
+import java.util.List;
+
+public interface LazyFilter<T> {
+
+  /**
+   * Items already selected.
+   * 
+   * @return
+   */
+  Collection<T> getSelectedItems();
+
+  /**
+   * Sorting criterias.
+   * 
+   * @return
+   */
+  List<SortOrder<String>> getSorting();
+
+}

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

@@ -0,0 +1,28 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.flowingcode.vaadin.addons.twincolgrid.TwinColModel.TwinColModelMode;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+public class LazyFilterConfiguration<T> extends FilterConfiguration<T, LazyFilterableColumn<T>> {
+
+  private final LazyFilter<T> lazyFilter;
+
+  @SafeVarargs
+  public LazyFilterConfiguration(LazyFilter<T> lazyFilter, LazyFilterableColumn<T>... columns) {
+    super(columns);
+    this.lazyFilter = lazyFilter;
+  }
+
+  @Override
+  void apply(TwinColGrid<T> grid) {
+    filteredColumns.forEach(grid::addFilterableColumn);
+    grid.setLazyFilter(lazyFilter);
+  }
+
+  @Override
+  boolean supports(TwinColModelMode mode) {
+    return TwinColModelMode.LAZY.equals(mode);
+  }
+
+}

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

@@ -0,0 +1,38 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.function.SerializableBiPredicate;
+import com.vaadin.flow.function.SerializableConsumer;
+import lombok.Getter;
+
+/**
+ * Enables lazy filtering support to column.
+ *
+ * @param <T>
+ */
+@Getter
+public class LazyFilterableColumn<T> extends FilterableColumn<T> {
+
+  /**
+   * filter bean field to store the query string.
+   */
+  private final SerializableConsumer<String> lazyFilterField;
+
+  /**
+   * filter condition to apply to column values in selection grid.
+   */
+  private final SerializableBiPredicate<T, String> eagerFilterCondition;
+
+  public LazyFilterableColumn(TwinColumn<T> column, String filterPlaceholder,
+      boolean enableClearButton, SerializableConsumer<String> lazyFilterField,
+      SerializableBiPredicate<T, String> eagerFilterCondition) {
+    super(column, filterPlaceholder, enableClearButton);
+    this.lazyFilterField = lazyFilterField;
+    this.eagerFilterCondition = eagerFilterCondition;
+  }
+
+  public EagerFilterableColumn<T> asEager() {
+    return new EagerFilterableColumn<>(super.getColumn(), super.getFilterPlaceholder(),
+        super.isEnableClearButton(), eagerFilterCondition);
+  }
+
+}