Add drag finished listener unit test (#4199)

Author: shai-almog

maven/core-unittests/src/test/java/com/codename1/testing/TestCodenameOneImplementation.java

@@ -1308,6 +1308,30 @@ public void dispatchPointerRelease(int x, int y) {
         sendPointerEventToCurrentForm(false, x, y);
     }
 
+    public void dispatchPointerDrag(final int x, final int y) {
+        final Display display = Display.getInstance();
+        if (display == null) {
+            return;
+        }
+
+        Runnable r = new Runnable() {
+            public void run() {
+                Form current = display.getCurrent();
+                if (current == null) {
+                    return;
+                }
+
+                current.pointerDragged(x, y);
+            }
+        };
+
+        if (display.isEdt()) {
+            r.run();
+        } else {
+            display.callSeriallyAndWait(r);
+        }
+    }
+
     public void dispatchPointerPressAndRelease(int x, int y) {
         dispatchPointerPress(x, y);
         dispatchPointerRelease(x, y);

maven/core-unittests/src/test/java/com/codename1/ui/DragFinishedListener3056Test.java

@@ -0,0 +1,81 @@
+package com.codename1.ui;
+
+import com.codename1.junit.FormTest;
+import com.codename1.junit.UITestBase;
+import com.codename1.testing.TestCodenameOneImplementation;
+import com.codename1.ui.events.ActionEvent;
+import com.codename1.ui.events.ActionListener;
+import com.codename1.ui.geom.Dimension;
+import com.codename1.ui.layouts.BoxLayout;
+import static org.junit.jupiter.api.Assertions.*;
+
+class DragFinishedListener3056Test extends UITestBase {
+
+    @FormTest
+    void dragFinishedListenerFiresForLeadComponent() {
+        implementation.setBuiltinSoundsEnabled(false);
+        Form form = Display.getInstance().getCurrent();
+        form.removeAll();
+        form.setLayout(new BoxLayout(BoxLayout.Y_AXIS));
+
+        Container container = new Container(new BoxLayout(BoxLayout.Y_AXIS));
+        container.setPreferredSize(new Dimension(160, 160));
+
+        Label draggableIcon = new Label();
+        FontImage.setMaterialIcon(draggableIcon, FontImage.MATERIAL_3D_ROTATION, 10);
+        draggableIcon.setPreferredSize(new Dimension(100, 100));
+        draggableIcon.setDraggable(true);
+
+        Label secondary = new Label("Another label in the container");
+
+        container.add(draggableIcon);
+        container.add(secondary);
+        container.putClientProperty("isTest", Boolean.TRUE);
+        container.setLeadComponent(draggableIcon);
+        container.setDraggable(true);
+
+        final int[] dragCount = {0};
+        final boolean[] dragFinishedCalled = {false};
+        final int[] finished = {-1, -1};
+        final Component[] eventSource = {null};
+
+        draggableIcon.addPointerDraggedListener(new ActionListener() {
+            public void actionPerformed(ActionEvent evt) {
+                dragCount[0]++;
+            }
+        });
+
+        draggableIcon.addDragFinishedListener(new ActionListener() {
+            public void actionPerformed(ActionEvent evt) {
+                dragFinishedCalled[0] = true;
+                finished[0] = evt.getX();
+                finished[1] = evt.getY();
+                eventSource[0] = (Component) evt.getSource();
+            }
+        });
+
+        form.add(container);
+        form.revalidate();
+
+        TestCodenameOneImplementation impl = implementation;
+        int startX = draggableIcon.getAbsoluteX() + draggableIcon.getWidth() / 2;
+        int startY = draggableIcon.getAbsoluteY() + draggableIcon.getHeight() / 2;
+        int dragX = startX + 15;
+        int dragY = startY + 15;
+        int releaseX = startX + 25;
+        int releaseY = startY + 20;
+
+        impl.dispatchPointerPress(startX, startY);
+        impl.dispatchPointerDrag(dragX, dragY);
+        impl.dispatchPointerDrag(releaseX, releaseY);
+        impl.dispatchPointerRelease(releaseX, releaseY);
+
+        assertEquals(Boolean.TRUE, container.getClientProperty("isTest"),
+                "Container should preserve client property used by the sample");
+        assertTrue(dragCount[0] > 0, "Pointer dragged listener should be invoked while dragging");
+        assertTrue(dragFinishedCalled[0], "Drag finished listener should fire after releasing drag");
+        assertSame(draggableIcon, eventSource[0], "Event source should match the draggable lead component");
+        assertTrue(finished[0] >= 0 && finished[1] >= 0,
+                "Drag finished coordinates should be provided with non-negative values");
+    }
+}