Refactor PagingListView to improve list handling

Reorganized list handling by introducing InnerListViewSkin usage in PagingListView and reducing redundancy in PagingListViewSkin. Moved functionality to PagingListView, ensuring cleaner code structure and better separation of concerns. Added support for multiple selection mode and improved the update mechanism with a weak listener.

gemsfx/src/main/java/com/dlsc/gemsfx/PagingListView.java

@@ -1,7 +1,10 @@
 package com.dlsc.gemsfx;
 
+import com.dlsc.gemsfx.skins.InnerListViewSkin;
 import com.dlsc.gemsfx.skins.PagingListViewSkin;
 import javafx.beans.InvalidationListener;
+import javafx.beans.Observable;
+import javafx.beans.WeakInvalidationListener;
 import javafx.beans.property.BooleanProperty;
 import javafx.beans.property.ObjectProperty;
 import javafx.beans.property.SimpleBooleanProperty;
@@ -15,6 +18,7 @@
 import javafx.scene.control.ListCell;
 import javafx.scene.control.ListView;
 import javafx.scene.control.MultipleSelectionModel;
+import javafx.scene.control.SelectionMode;
 import javafx.scene.control.Skin;
 import javafx.util.Callback;
 
@@ -30,9 +34,23 @@ public class PagingListView<T> extends PagingControlBase {
 
     private final ObservableList<T> unmodifiableItems = FXCollections.unmodifiableObservableList(items);
 
+    private final ListView<T> listView = new ListView<>(items);
+
+    private final InnerListViewSkin<T> innerListViewSkin;
+
+    private final InvalidationListener updateListener = (Observable it) -> updateItems();
+
+    private final WeakInvalidationListener weakUpdateListener = new WeakInvalidationListener(updateListener);
+
     public PagingListView() {
         getStyleClass().add("paging-list-view");
 
+        listView.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
+        listView.cellFactoryProperty().bind(cellFactoryProperty());
+
+        innerListViewSkin = new InnerListViewSkin<>(listView, this);
+        listView.setSkin(innerListViewSkin);
+
         loadingService.setOnSucceeded(evt -> {
             List<T> newList = loadingService.getValue();
             if (newList != null) {
@@ -60,6 +78,13 @@ protected void updateItem(T item, boolean empty) {
                 }
             }
         });
+
+        getUnmodifiableItems().addListener(weakUpdateListener);
+        pageSizeProperty().addListener(weakUpdateListener);
+        pageProperty().addListener(weakUpdateListener);
+        cellFactoryProperty().addListener(weakUpdateListener);
+
+        updateItems();
     }
 
     @Override
@@ -72,6 +97,10 @@ public String getUserAgentStylesheet() {
         return Objects.requireNonNull(PagingListView.class.getResource("paging-list-view.css")).toExternalForm();
     }
 
+    public final ListView<T> getListView() {
+        return listView;
+    }
+
     private class LoadingService extends Service<List<T>> {
 
         @Override
@@ -219,4 +248,8 @@ public final ObjectProperty<Callback<ListView<T>, ListCell<T>>> cellFactoryPrope
         }
         return cellFactory;
     }
+
+    private void updateItems() {
+        innerListViewSkin.updateItems();
+    }
 }

gemsfx/src/main/java/com/dlsc/gemsfx/skins/PagingListViewSkin.java

@@ -44,28 +44,16 @@ public Orientation getContentBias() {
         }
     };
 
-    private final InvalidationListener updateListener = (Observable it) -> updateItems();
-
-    private final WeakInvalidationListener weakUpdateListener = new WeakInvalidationListener(updateListener);
-
-    private final InnerListViewSkin<T> innerListViewSkin;
 
     private final ListView<T> innerListView;
 
     public PagingListViewSkin(PagingListView<T> pagingListView) {
         super(pagingListView);
 
-        innerListView = new ListView<>();
-        innerListView.setPrefHeight(Region.USE_COMPUTED_SIZE);
-        innerListView.cellFactoryProperty().bind(pagingListView.cellFactoryProperty());
-        innerListView.setItems(pagingListView.getUnmodifiableItems());
-        innerListView.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
+        innerListView = pagingListView.getListView();
 
         pagingListView.selectionModelProperty().bindBidirectional(innerListView.selectionModelProperty());
 
-        innerListViewSkin = new InnerListViewSkin<>(innerListView, pagingListView);
-        innerListView.setSkin(innerListViewSkin);
-
         pagingControls.pageProperty().bindBidirectional(pagingListView.pageProperty());
         pagingControls.totalItemCountProperty().bindBidirectional(pagingListView.totalItemCountProperty());
         pagingControls.pageSizeProperty().bind(pagingListView.pageSizeProperty());
@@ -84,19 +72,13 @@ public PagingListViewSkin(PagingListView<T> pagingListView) {
         // when the underlying data list changes, then we have to recreate the binding for the placeholder
         pagingListView.getUnmodifiableItems().addListener((Observable it) -> bindPlaceholder(null, pagingListView.getPlaceholder()));
 
-        pagingListView.getUnmodifiableItems().addListener(weakUpdateListener);
-        pagingListView.pageSizeProperty().addListener(weakUpdateListener);
-        pagingListView.pageProperty().addListener(weakUpdateListener);
-        pagingListView.cellFactoryProperty().addListener(weakUpdateListener);
-
         pagingListView.usingScrollPaneProperty().addListener(it -> updateView());
         pagingListView.placeholderProperty().addListener(it -> updateView());
 
         getChildren().setAll(stackPane);
 
         updateStyleClass();
         updateView();
-        updateItems();
     }
 
     private void updateStyleClass() {
@@ -150,8 +132,4 @@ private Node wrapInScrollPane(Node node) {
         scrollPane.setHbarPolicy(ScrollPane.ScrollBarPolicy.NEVER);
         return scrollPane;
     }
-
-    private void updateItems() {
-        innerListViewSkin.updateItems();
-    }
 }