在 JFXListView 上启用平滑滚动 (#4809)

HMCL/src/main/java/com/jfoenix/skins/JFXListViewSkin.java

@@ -26,6 +26,7 @@ import com.jfoenix.effects.JFXDepthManager;
 import javafx.scene.control.ListCell;
 import javafx.scene.control.skin.VirtualFlow;
 import javafx.scene.layout.Region;
+import org.jackhuang.hmcl.ui.FXUtils;
 
 // https://github.com/HMCL-dev/HMCL/issues/4720
 public class JFXListViewSkin<T> extends ListViewSkin<T> {
@@ -38,6 +39,7 @@ public class JFXListViewSkin<T> extends ListViewSkin<T> {
         flow = (VirtualFlow<ListCell<T>>) getChildren().get(0);
         JFXDepthManager.setDepth(flow, listView.depthProperty().get());
         listView.depthProperty().addListener((o, oldVal, newVal) -> JFXDepthManager.setDepth(flow, newVal));
+        FXUtils.smoothScrolling(flow);
     }
 
     @Override

HMCL/src/main/java/org/jackhuang/hmcl/ui/FXUtils.java

@@ -42,6 +42,7 @@ import javafx.scene.Scene;
 import javafx.scene.control.Label;
 import javafx.scene.control.ScrollPane;
 import javafx.scene.control.*;
+import javafx.scene.control.skin.VirtualFlow;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.input.*;
@@ -394,6 +395,11 @@ public final class FXUtils {
             ScrollUtils.addSmoothScrolling(scrollPane);
     }
 
+    public static void smoothScrolling(VirtualFlow<?> virtualFlow) {
+        if (AnimationUtils.isAnimationEnabled())
+            ScrollUtils.addSmoothScrolling(virtualFlow);
+    }
+
     /// If the current environment is JavaFX 23 or higher, this method returns [Labeled#textTruncatedProperty()];
     /// Otherwise, it returns `null`.
     public static @Nullable ReadOnlyBooleanProperty textTruncatedProperty(Labeled labeled) {

HMCL/src/main/java/org/jackhuang/hmcl/ui/ScrollUtils.java

@@ -25,7 +25,9 @@ import javafx.animation.Animation.Status;
 import javafx.animation.KeyFrame;
 import javafx.animation.Timeline;
 import javafx.event.EventHandler;
+import javafx.scene.control.IndexedCell;
 import javafx.scene.control.ScrollPane;
+import javafx.scene.control.skin.VirtualFlow;
 import javafx.scene.input.MouseEvent;
 import javafx.scene.input.ScrollEvent;
 import javafx.util.Duration;
@@ -139,6 +141,21 @@ final class ScrollUtils {
         smoothScroll(scrollPane, speed, trackPadAdjustment);
     }
 
+    /// @author Glavo
+    public static void addSmoothScrolling(VirtualFlow<?> virtualFlow) {
+        addSmoothScrolling(virtualFlow, 1);
+    }
+
+    /// @author Glavo
+    public static void addSmoothScrolling(VirtualFlow<?> virtualFlow, double speed) {
+        addSmoothScrolling(virtualFlow, speed, 7);
+    }
+
+    /// @author Glavo
+    public static void addSmoothScrolling(VirtualFlow<?> virtualFlow, double speed, double trackPadAdjustment) {
+        smoothScroll(virtualFlow, speed, trackPadAdjustment);
+    }
+
     private static final double[] FRICTIONS = {0.99, 0.1, 0.05, 0.04, 0.03, 0.02, 0.01, 0.04, 0.01, 0.008, 0.008, 0.008, 0.008, 0.0006, 0.0005, 0.00003, 0.00001};
     private static final Duration DURATION = Duration.millis(3);
 
@@ -207,4 +224,58 @@ final class ScrollUtils {
         timeline.setCycleCount(Animation.INDEFINITE);
     }
 
+    /// @author Glavo
+    private static void smoothScroll(VirtualFlow<?> virtualFlow, double speed, double trackPadAdjustment) {
+        if (!virtualFlow.isVertical())
+            return;
+
+        final double[] derivatives = new double[FRICTIONS.length];
+
+        Timeline timeline = new Timeline();
+        Holder<ScrollDirection> scrollDirectionHolder = new Holder<>();
+        final EventHandler<MouseEvent> mouseHandler = event -> timeline.stop();
+        final EventHandler<ScrollEvent> scrollHandler = event -> {
+            if (event.getEventType() == ScrollEvent.SCROLL) {
+                ScrollDirection scrollDirection = determineScrollDirection(event);
+                if (scrollDirection == ScrollDirection.LEFT || scrollDirection == ScrollDirection.RIGHT) {
+                    return;
+                }
+                scrollDirectionHolder.value = scrollDirection;
+                double currentSpeed = isTrackPad(event, scrollDirection) ? speed / trackPadAdjustment : speed;
+
+                derivatives[0] += scrollDirection.intDirection * currentSpeed;
+                if (timeline.getStatus() == Status.STOPPED) {
+                    timeline.play();
+                }
+                event.consume();
+            }
+        };
+        virtualFlow.addEventHandler(MouseEvent.MOUSE_PRESSED, mouseHandler);
+        virtualFlow.addEventFilter(ScrollEvent.ANY, scrollHandler);
+
+        timeline.getKeyFrames().add(new KeyFrame(DURATION, event -> {
+            for (int i = 0; i < derivatives.length; i++) {
+                derivatives[i] *= FRICTIONS[i];
+            }
+            for (int i = 1; i < derivatives.length; i++) {
+                derivatives[i] += derivatives[i - 1];
+            }
+
+            double dy = derivatives[derivatives.length - 1];
+
+            int cellCount = virtualFlow.getCellCount();
+            IndexedCell<?> firstVisibleCell = virtualFlow.getFirstVisibleCell();
+            double height = firstVisibleCell != null ? firstVisibleCell.getHeight() * cellCount : 0.0;
+
+            double delta = height > 0.0
+                    ? dy / height
+                    : (scrollDirectionHolder.value == ScrollDirection.DOWN ? 0.001 : -0.001);
+            virtualFlow.setPosition(Math.min(Math.max(virtualFlow.getPosition() + delta, 0), 1));
+
+            if (Math.abs(dy) < 0.001) {
+                timeline.stop();
+            }
+        }));
+        timeline.setCycleCount(Animation.INDEFINITE);
+    }
 }