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Overview

HasStyleElement is a mixin interface for Vaadin components that expose styling through CSS classes. This interface provides methods to retrieve and assert CSS class attributes.

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Methods

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getCssClass

default String getCssClass()
Gets the raw class attribute value from the component. Returns: The value of the class attribute as a string, or null if not present

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assertCssClass

default void assertCssClass(String... classnames)
Asserts that the component has exactly the provided class names. When null is passed, asserts that no classes are present.
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classnames
String...
The expected class names, or null to assert no classes are present

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Implementation Details

This interface extends HasLocatorElement and provides default implementations for all methods. The assertCssClass() method behavior:
  • When class names are provided: asserts the component has exactly those classes
  • When null is passed: asserts the component has no classes by checking that the class attribute doesn’t match any pattern

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Implementing Classes

This interface is implemented by many Vaadin component wrappers, including:

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Layout Components

  • AccordionElement
  • CardElement
  • DetailsElement
  • SplitLayoutElement
  • MenuBarElement
  • MenuElement
  • MenuItemElement
  • ContextMenuElement

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Data Display Components

  • GridElement
  • ListBoxElement
  • MessageListElement
  • VirtualListElement

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Feedback Components

  • DialogElement
  • NotificationElement
  • PopoverElement
  • ProgressBarElement

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Input Components

  • MessageInputElement
  • All components implementing HasInputFieldElement (via inheritance)

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Other Components

  • AvatarElement

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Usage Example

import org.vaadin.addons.dramafinder.element.ButtonElement;

// Get a button by text
ButtonElement saveButton = ButtonElement.getByText(page, "Save");

// Get the CSS class attribute
String classes = saveButton.getCssClass();
System.out.println("Classes: " + classes);

// Assert specific classes are present
saveButton.assertCssClass("primary", "large");

// Assert no classes are present
ButtonElement plainButton = ButtonElement.getByText(page, "Cancel");
plainButton.assertCssClass(null);

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Usage with Custom Styling

// In your Vaadin application
Button button = new Button("Styled Button");
button.addClassName("custom-style");
button.addClassName("highlighted");

// In your test
ButtonElement button = ButtonElement.getByText(page, "Styled Button");
button.assertCssClass("custom-style", "highlighted");

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See Also

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