API of Components - CUBA Platform. Developer’s Manual

5.5.2.4. API of Components

API DOCS

Common

unwrap() - returns client-specific component instance (Vaadin or Swing component). Can be used in client module to simplify invocation of underlying API, see Working with Vaadin Components section.
```
com.vaadin.ui.TextField vTextField = textField.unwrap(com.vaadin.ui.TextField.class);
```
unwrapComposition() - returns the outmost external container of client-specific component instance. Can be used in client module to simplify invocation of underlying API.

Available for all components.

Component.Buffered

commit() - updates all changes made since the previous commit to the data source.

discard() - discards all changes since last commit. The object updates its value from the data source.

isModified() - returns true if the object value has been modified since it was last updated from the data source.

if (textArea.isModified()) {
    textArea.commit();
}

Available for components:

CheckBox - CurrencyField - DateField - FileUploadField - LookupField - LookupPickerField - PickerField - TextArea - TextField - TimeField

Component.Collapsable

addExpandedStateChangeListener() - adds the listener implementing the ExpandedStateChangeListener interface to intercept the component’s expanded state change events.
```
groupBox.addExpandedStateChangeListener(e ->
        showNotification("Expanded: " + groupBox.isExpanded()));
```
Available for components:

Filter - GroupBoxLayout

Component.Container

add() - adds child component to the container.

remove() - removes the child component from the container.

removeAll() - removes all children components from te container.

getOwnComponent() - returns the component directly owned by this container.

getComponent() - returns the component belonging to the whole components tree below this container.

getComponentNN() - returns the component belonging to the whole components tree below this container. Throws an exception if not found.

getOwnComponents() - returns all components directly owned by this container.

getComponents() - returns all components belonging to the whole components tree below this container.

Available for components:

Accordion - BoxLayout - CssLayout - Frame - GridLayout - GroupBoxLayout - HtmlBoxLayout - ScrollBoxLayout - SplitPanel - TabSheet

Component.OrderedContainer

indexOf() - returns the index of a given component in an ordered container.

Available for components:

BoxLayout - CssLayout - Frame - GroupBoxLayout - ScrollBoxLayout -

Component.HasContextHelp

setContextHelpIconClickHandler() - sets a context help icon click handler. Click handler has priority over context help text, i.e. no tooltip with context help text will be shown if the click handler is set.

textArea.setContextHelpIconClickHandler(event ->
        showMessageDialog("Title", "Body message",
                MessageType.CONFIRMATION_HTML
                        .modal(false)));

Available for components:

Component.HasSettings

applySettings() - restores the last user settings for this component.
saveSettings() - saves current user settings for this component.

Available for components:

DataGrid - Filter - GroupBoxLayout - SplitPanel - Table - TextArea

Component.HasValue

addValueChangeListener() - adds the listener implementing the ValueChangeListener interface to intercept the component’s value changes. If the component is bound to a datasource, in terms of the screen lifecycle, it is often preferable to use a datasource listener instead.
```
textField.addValueChangeListener(e ->
        showNotification("Before: " + e.getPrevValue() + ". After: " + e.getValue()));
```

Available for components:

Component.LayoutClickNotifier

addLayoutClickListener() - adds the listener implementing the LayoutClickListener interface to intercept the clicks on the component area.
```
vbox.addLayoutClickListener(event ->
                showNotification("Clicked"));
```

Available for components:

ButtonsPanel - BoxLayout - CssLayout - GridLayout

Component.Margin

setMargin() - sets the margins for the component.
- Sets margins on all sides of the component:
  vbox.setMargin(true);
- Sets margins only on the top and the bottom of the component:
  vbox.setMargin(true, false, true, false);
- Creates new instance of MarginInfo configuration class:
  vbox.setMargin(new MarginInfo(true, false, false, true));
getMargin() - returns margin configuration as an instance of MarginInfo class.

BoxLayout - Filter - Frame - GridLayout ScrollBoxLayout

Component.OuterMargin

setOuterMargin() - sets the outer margins outside the border of the component.
- Sets outer margins on all sides of the component:
  groupBox.setOuterMargin(true);
- Sets outer margins only on the top and the bottom of the component:
  groupBox.setOuterMargin(true, false, true, false);
- Creates new instance of MarginInfo configuration class:
  groupBox.setOuterMargin(new MarginInfo(true, false, false, true));
getOuterMargin() - returns outer margin configuration as an instance of MarginInfo class.

Available for component:

GroupBoxLayout

Component.ShortcutNotifier

addShortcutAction() - adds an action which is triggered when the user presses a given key combination.

cssLayout.addShortcutAction(new ShortcutAction("SHIFT-A", shortcutTriggeredEvent ->
        showNotification("SHIFT-A action" )));

Available for components:

BoxLayout - ButtonsPanel - CssLayout - GridLayout - GroupBoxLayout - ScrollBoxLayout

Component.Spacing

setSpacing() - adds space between the component and its child components.
```
vbox.setSpacing(true);
```

Available for components:

BoxLayout - ButtonsPanel - Frame - GridLayout GroupBoxLayout - ScrollBoxLayout