Clicking on slider makes handler move (#11519)

* Clicking on slider makes handler move

Fixes #1496

* Introducing control over clicking behaviour

- User will have to enable process of the click event on handle calling `slider.setEnableClickHandler(true);`
- Clean-up the handler logic in VSlider.java
- Renaming the property to `updateValueOnClick`
- Added JavaDocs
- Fixing tests

2 files changed, 97 insertions, 0 deletions

diff --git a/uitest/src/main/java/com/vaadin/tests/components/slider/SliderHandleBaseClick.java b/uitest/src/main/java/com/vaadin/tests/components/slider/SliderHandleBaseClick.java
new file mode 100644
index 0000000000..837f22056a
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/slider/SliderHandleBaseClick.java
@@ -0,0 +1,38 @@
+package com.vaadin.tests.components.slider;
+
+import com.vaadin.annotations.Widgetset;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Slider;
+import com.vaadin.ui.Button;
+
+@Widgetset("com.vaadin.DefaultWidgetSet")
+public class SliderHandleBaseClick extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        Slider slider = new Slider();
+        slider.setWidth(500, Unit.PIXELS);
+        slider.setMin(0);
+        slider.setMax(10);
+        slider.setValue(3.0);
+        slider.setUpdateValueOnClick(true);
+        addComponent(slider);
+        Button toggleHandling = new Button("Apply/remove click action", e -> {
+            slider.setUpdateValueOnClick(!slider.isUpdateValueOnClick());
+        });
+        toggleHandling.setId("toggleHandling");
+        addComponent(toggleHandling);
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "Slider should update its value, when clicked on the base";
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 1496;
+    }
+
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/slider/SliderHandleBaseClickTest.java b/uitest/src/test/java/com/vaadin/tests/components/slider/SliderHandleBaseClickTest.java
new file mode 100644
index 0000000000..8de82a590f
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/slider/SliderHandleBaseClickTest.java
@@ -0,0 +1,59 @@
+package com.vaadin.tests.components.slider;
+
+import com.vaadin.tests.tb3.MultiBrowserTest;
+import org.junit.Before;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.interactions.Actions;
+
+import static org.junit.Assert.assertEquals;
+
+public class SliderHandleBaseClickTest extends MultiBrowserTest {
+    private WebElement base;
+    private int offsetStep;
+
+    @Before
+    public void setUp() throws Exception {
+        super.setup();
+        openTestURL();
+        base = findElement(By.className("v-slider-base"));
+        offsetStep = base.getSize().getWidth() / 10;
+    }
+
+    @Test
+    public void testHandlerHasMoved() {
+        // dragAndDropBy function starts calculating click position from the
+        // middle of the component .
+        // So the click will always be at the position (center + offsetStep)px
+
+        // Will move by one from the middle
+        new Actions(driver).dragAndDropBy(base, offsetStep, 0).perform();
+        sleep(100);
+        assertEquals("The Slider value should be 6 after moving by one offset",
+                6, getSliderValue(), 0);
+        // Will move by two from the middle, in this case from 5
+        new Actions(driver).dragAndDropBy(base, offsetStep * 2, 0).perform();
+        sleep(100);
+        assertEquals("The Slider value should be 7 after moving by two offsets",
+                7, getSliderValue(), 0);
+    }
+
+    private double getSliderValue() {
+        return Double.valueOf(
+                findElement(By.className("v-slider-feedback")).getText());
+    }
+
+    @Test
+    public void testHandlerNotMoved() {
+        // Disable click event handling
+        findElement(By.id("toggleHandling")).click();
+        new Actions(driver).dragAndDropBy(base, offsetStep, 0).perform();
+        sleep(100);
+        assertEquals(String.format(
+                "Slider value should not have changed. Expected 3.0 , but was %f",
+                getSliderValue()), 3.0,getSliderValue(), 0.0);
+        // Enable click event handling
+        findElement(By.id("toggleHandling")).click();
+    }
+}