Further tweaks to ComboBox popup positioning. (#11910) (#11921)

* Further tweaks to ComboBox popup positioning.

- Updated a comment and renamed a private method for better clarity.
- Blocked unnecessary position updates.
- Added a test for #11866 / #11894.

2 files changed, 67 insertions, 0 deletions

diff --git a/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxAtBottomEdgeWithinHorizontalLayout.java b/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxAtBottomEdgeWithinHorizontalLayout.java
new file mode 100644
index 0000000000..5c619bafc4
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxAtBottomEdgeWithinHorizontalLayout.java
@@ -0,0 +1,38 @@
+package com.vaadin.tests.components.combobox;
+
+import java.util.Arrays;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Alignment;
+import com.vaadin.ui.ComboBox;
+import com.vaadin.ui.HorizontalLayout;
+
+public class ComboBoxAtBottomEdgeWithinHorizontalLayout extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        ComboBox<Integer> comboBox = new ComboBox<>();
+        comboBox.setItems(Arrays.asList(100, 200, 300, 400, 500));
+
+        HorizontalLayout horizontalLayout = new HorizontalLayout();
+        horizontalLayout.addComponent(comboBox);
+
+        getLayout().addComponent(horizontalLayout);
+        getLayout().setComponentAlignment(horizontalLayout,
+                Alignment.BOTTOM_RIGHT);
+        getLayout().setSizeFull();
+        getLayout().getParent().setSizeFull();
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 11866;
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "ComboBox at bottom edge should open popup above "
+                + "even when within HorizontalLayout.";
+    }
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/combobox/ComboBoxAtBottomEdgeWithinHorizontalLayoutTest.java b/uitest/src/test/java/com/vaadin/tests/components/combobox/ComboBoxAtBottomEdgeWithinHorizontalLayoutTest.java
new file mode 100644
index 0000000000..f169e56ab5
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/combobox/ComboBoxAtBottomEdgeWithinHorizontalLayoutTest.java
@@ -0,0 +1,29 @@
+package com.vaadin.tests.components.combobox;
+
+import org.junit.Test;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.testbench.elements.ComboBoxElement;
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+public class ComboBoxAtBottomEdgeWithinHorizontalLayoutTest
+        extends MultiBrowserTest {
+
+    @Test
+    public void ensurePopupInView() {
+        openTestURL();
+
+        ComboBoxElement cb = $(ComboBoxElement.class).first();
+        cb.openPopup();
+        WebElement popup = cb.getSuggestionPopup();
+
+        int cbBottom = cb.getLocation().getY() + cb.getSize().getHeight();
+        int popupBottom = popup.getLocation().getY()
+                + popup.getSize().getHeight();
+        assertGreaterOrEqual(String.format(
+                "Popup should not open below the ComboBox at the "
+                        + "bottom edge of the viewport. ComboBox: %s, Popup: %s",
+                cbBottom, popupBottom), cbBottom, popupBottom);
+    }
+
+}