Package com.jbstrap.ui.components.button

Class DropDownButton

java.lang.Object

com.jbstrap.core.messagebus.MessageBus

com.jbstrap.ui.Component<DropDownButton>

com.jbstrap.ui.components.button.DropDownButton

All Implemented Interfaces:

Animatable<DropDownButton>, CanDrop<DropDownButton>, Clickable<DropDownButton>, Draggable<DropDownButton>, HandleHotKey<DropDownButton>, HandleMouseEvents<DropDownButton>, Touchable<DropDownButton>

public class DropDownButton
extends Component<DropDownButton>
implements Animatable<DropDownButton>, Clickable<DropDownButton>, HandleMouseEvents<DropDownButton>, Touchable<DropDownButton>, HandleHotKey<DropDownButton>, CanDrop<DropDownButton>, Draggable<DropDownButton>

DropDownButton component

With this component, a button can be placed on the interface. The button can be customized, and it can have an icon and/or text on it. The click event handler can be implemented on the server side.

Other menu items can be placed on the button, and they will appear to the user when they press the button. The menu items have their own individual click events, that can be programmed individually.

The button component supports the use of animations, that can be used when the button appears or disappears. The animation can be set by using the setAnimation method. For the types of animation, see the Animation enum.

A counter can also be placed on the right side of the button. The counter can have any integer number in it. This can be used to count content, for example, the amount of unread messages

Supported events:

AnimationStart AnimationEnd, Click, DoubleClick, MouseDown, MouseDown, MouseLeave, MouseMove, MouseOver, MouseOut, MouseUp, Wheel, TouchCancel, TouchEnd, TouchMove, TouchStart, HotKey Drop, DragStart, DragEnd

Since:

4.0

Author:

JBStrap

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	DropDownButton.DropDownMenuItem	Dropdown menu item.

Field Summary

Fields inherited from class com.jbstrap.ui.Component

animation, attributes, backgroundColor, borderColor, color, defaultHotKeyHandler, handlers, hotKeys, styleClasses, textAlign, toolTip, toolTipPosition

Constructor Summary

Constructors

Constructor	Description
DropDownButton(Icon icon)	creates a button with the specified icon
DropDownButton(Icon icon, String text)	Creates a button with the specified icon and text
DropDownButton(Icon icon, String text, StyleElement... styles)	Creates a button with the specified icon, text and style(s).
DropDownButton(String text)	Creates a button with the specified text
DropDownButton(String text, StyleElement... styles)	Creates a button with the specified text and style(s).
DropDownButton(String id, Icon icon)	Creates a button with the specified icon
DropDownButton(String id, Icon icon, String text)	Creates a button with the specified icon and text
DropDownButton(String id, Icon icon, String text, StyleElement... styles)	Creates a button with the specified icon, text and style(s).
DropDownButton(String id, String text)	Creates a button with the specified text

Method Summary

Modifier and Type	Method	Description
DropDownButton	addAnimationEndHandler(AnimationEndEventHandler handler)	Adds an animation end event handler to the component.
DropDownButton	addAnimationStartHandler(AnimationStartEventHandler handler)	Adds an animation start event handler to the component.
DropDownButton	addClickHandler(ClickEventHandler handler)	Adds a click event handler to the button.
DropDownButton	addComponent(Component<?> component)	Adds a component to the dropdown menu.
final DropDownButton	addDivider()	Adds a divider to the button drop down menu.
DropDownButton	addDoubleClickHandler(DoubleClickEventHandler handler)	Adds a double click event handler to the button.
DropDownButton	addHeader(String text)	Adds a header to the dropdown menu.
DropDownButton	addHotKey(int hotKey)	Adds the specified hot key to the component.
DropDownButton	addHotKey(int hotKey, HotKeyEventHandler handler)	Adds the specified hot key to the component.
DropDownButton	addMenuItem(Icon icon, String text, int hotKey, ClickEventHandler clickHandler)	Adds a menu item with the specified icon, text, hot key and click handler to the button's drop down menu
final DropDownButton	addMenuItem(Icon icon, String text, ClickEventHandler handler)	Adds a menu item with the specified icon, text and click handler to the button's drop down menu
DropDownButton	addMouseDownHandler(MouseDownEventHandler handler)	Adds a mouse button down event handler to the component.
DropDownButton	addMouseEnterHandler(MouseEnterEventHandler handler)	Adds a mouse enter event handler to the component.
DropDownButton	addMouseLeaveHandler(MouseLeaveEventHandler handler)	Adds a mouse leave event handler to the component.
DropDownButton	addMouseMoveHandler(MouseMoveEventHandler handler)	Adds a mouse move event handler to the component.
DropDownButton	addMouseOutHandler(MouseOutEventHandler handler)	Adds a mouse out event handler to the component.
DropDownButton	addMouseOverHandler(MouseOverEventHandler handler)	Adds a mouse over event handler to the component.
DropDownButton	addMouseUpHandler(MouseUpEventHandler handler)	Adds a mouse up event handler to the component.
DropDownButton	addMouseWheelHandler(MouseWheelEventHandler handler)	Adds a mouse wheel event handler to the component.
DropDownButton	addTouchCancelHandler(TouchCancelEventHandler handler)	Adds a touch cancel event handler to the component.
DropDownButton	addTouchEndHandler(TouchEndEventHandler handler)	Adds a touch end event handler to the component.
DropDownButton	addTouchMoveHandler(TouchMoveEventHandler handler)	Adds a touch move event handler.
DropDownButton	addTouchStartHandler(TouchStartEventHandler handler)	Adds a touch start event handler to the component.
final DropDownButton	clear()	Removes all components, headers, borders and menu items from the dropdown menu.
Animation	getAnimation()	Gets the component's animation type
final long	getCounter()	Gets the counter value
DropDownDirection	getDirection()	Gets the dropdown direction.
Icon	getIcon()	Gets the button icon
DropDownButton.DropDownMenuItem	getItem(int index)	Gets a menu item by referencing its index.
DropDownAlignament	getMenuAlignament()	Gets the dropdown menu alignment.
String	getText()	Gets the button text
void	init()	The component initialization method.
DropDownButton	removeAnimation()	Removes animation from the component
DropDownButton	removeHotKey(int hotKey)	Removes the specified hot key from the component
DropDownButton	removeHotKeys()	Removes every hot key from the component
DropDownButton	setAnimation(Animation animation)	Sets the animation type on the component
final DropDownButton	setCounter(long value)	Adds a counter to the right side of the button.
DropDownButton	setDirection(DropDownDirection direction)	Sets the dropdown direction.
DropDownButton	setIcon(Icon icon)	Sets the button icon
DropDownButton	setImage(Image image)	Places an image on the button
DropDownButton	setMenuAlignament(DropDownAlignament align)	Dropdown menu alignment relative to the button.
DropDownButton	setMenuOffset(int offsetX, int offsetY)	Sets the X and Y axis offset of the dropdown menu.
DropDownButton	setSize(ButtonSize size)	Stets the button size
DropDownButton	setText(String text)	Sets the button text
DropDownButton	setType(ButtonType type)	Sets the button size
boolean	writeHTML(StringWriter writer)	Creates the component's HTML equivalent

Methods inherited from class com.jbstrap.ui.Component

_hide, _setAttribute, addAllowedRole, addComponent, addComponents, addDeniedRole, addHandler, addStyle, addStyleClass, addStyleClasses, afterDraw, clearfix, closeTag, combinateAccess, containsStyle, containsStyleClass, draw, drawSubComponents, error, flattendComponentTree, getAccess, getAccessMode, getAllowedRoles, getAttribute, getAttributes, getBackgroundColor, getBorderColor, getClient, getComponentById, getComponents, getComponents, getComponentsByClass, getData, getDeniedRoles, getHandlers, getId, getLanguageCode, getName, getParent, getParent, getRegisteredEvents, getStyle, getStyleClasses, getTextAlign, getTextColor, getToolTip, getToolTipPosition, getTypeName, getUI, insertComponentAfter, insertComponentBefore, isAccess, isDrawn, isEnabled, isEventBubbling, isVisible, onHide, onHotKeyEventHandler, onShow, openTag, redraw, removeAllComponents, removeAllowedRole, removeAllStyleClasses, removeAttribute, removeComponent, removeComponent, removeComponents, removeDeniedRole, removeHandler, removeStyle, removeStyle, removeStyleClass, removeStyleClasses, replaceComponent, replaceStyleClass, runAfterDraw, runJavaScript, runJavaScript, runJavaScript, runOnHide, runOnShow, say, setAttribute, setBackgroundColor, setBorder, setBorderColor, setData, setDisplayType, setEnabled, setEventBubbling, setFlex, setFloating, setHeight100, setHeight25, setHeight50, setHeight75, setHeightAuto, setLanguage, setMargin, setName, setOverflow, setPadding, setParent, setScrollable, setSelectionType, setShadow, setStyle, setTextAlign, setTextColor, setToolTip, setToolTipPosition, setVisible, setWidth100, setWidth25, setWidth50, setWidth75, setWidthAuto, showNotification, showNotification, showProcessIndicator, toggleStyleClass

Methods inherited from class com.jbstrap.core.messagebus.MessageBus

closeMessageBus, messageBusOpened, openMessageBus, renewSubscription, sendMessageToMessageBus, subscribeMessageBus, unsubscribeAllListeners, unsubscribeMessageBus

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.jbstrap.ui.CanDrop

addDropEventHandler

Methods inherited from interface com.jbstrap.ui.Draggable

addDragEndEventHandler, addDragStartEventHandler, setDraggable

Constructor Details

DropDownButton

public DropDownButton(Icon icon)

creates a button with the specified icon

Parameters:

icon - the icon of the button. for the applicable icons, see the Icon enum.

Throws:

illegalstateexception - if the component is set to be both private and public, through an annotation.

DropDownButton

public DropDownButton(String id,
 Icon icon)

Creates a button with the specified icon

Parameters:

id - The component ID. The ID specified here will appear in the HTML tag as an ID attribute. If there are multiple components displayed, that have the same ID, the ID numbers will be numbered, in the order they are displayed. (For example, if the ID is 'COMPONENT' then it will be numbered like this: COMPONENT, COMPONENT_1, COMPONENT_2 etc.)

icon - The icon of the button. For the applicable icons, see the Icon enum.

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(String text)

Creates a button with the specified text

Parameters:

text - The button text

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(String id,
 String text)

Creates a button with the specified text

Parameters:

id - The component ID. The ID specified here will appear in the HTML tag as an ID attribute. If there are multiple components displayed, that have the same ID, the ID numbers will be numbered, in the order they are displayed. (For example, if the ID is 'COMPONENT' then it will be numbered like this: COMPONENT, COMPONENT_1, COMPONENT_2 etc.)

text - The button text

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(Icon icon,
 String text)

Creates a button with the specified icon and text

Parameters:

icon - The icon of the button. For the applicable icons, see the Icon enum.

text - The button text

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(String id,
 Icon icon,
 String text)

Creates a button with the specified icon and text

Parameters:

id - The component ID. The ID specified here will appear in the HTML tag as an ID attribute. If there are multiple components displayed, that have the same ID, the ID numbers will be numbered, in the order they are displayed. (For example, if the ID is 'COMPONENT' then it will be numbered like this: COMPONENT, COMPONENT_1, COMPONENT_2 etc.)

icon - The icon of the button. For the applicable icons, see the Icon enum.

text - The button text

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(String text,
 StyleElement... styles)

Creates a button with the specified text and style(s).

Parameters:

text - The button text

styles - The style (type and/or size) of the button. For the applicable types, see the ButtonType enum. For the applicable sizes, see the ButtonSize enum.

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(Icon icon,
 String text,
 StyleElement... styles)

Creates a button with the specified icon, text and style(s).

Parameters:

icon - The icon of the button. For the applicable icons, see the Icon enum.

text - The button text

styles - The style (type and/or size) of the button. For the applicable types, see the ButtonType enum. For the applicable sizes, see the ButtonSize enum.

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

DropDownButton

public DropDownButton(String id,
 Icon icon,
 String text,
 StyleElement... styles)

Creates a button with the specified icon, text and style(s).

Parameters:

id - The component ID. The ID specified here will appear in the HTML tag as an ID attribute. If there are multiple components displayed, that have the same ID, the ID numbers will be numbered, in the order they are displayed. (For example, if the ID is 'COMPONENT' then it will be numbered like this: COMPONENT, COMPONENT_1, COMPONENT_2 etc.)

icon - The icon of the button. For the applicable icons, see the Icon enum.

text - The button text

styles - The style (type and/or size) of the button. For the applicable types, see the ButtonType enum. For the applicable sizes, see the ButtonSize enum.

Throws:

IllegalStateException - If the component is set to be both Private and Public, through an annotation.

Method Details

init

public void init()
          throws JavaScriptLoadError

Description copied from class: Component

The component initialization method.

Empty method, only needs to be overwritten when making a custom component, that needs to call an initializing JavaScript on the client side. The method is called by the framework after the component is drawn, but before the afterDraw() method. The use of this method during application development is not allowed. This method is meant for inner use only.

Overrides:

init in class Component<DropDownButton>

Throws:

JavaScriptLoadError - If there was a JavaScript error during the initialization.

setText

public DropDownButton setText(String text)

Sets the button text

Parameters:

text - The button text

Returns:

The button component

getText

public String getText()

Gets the button text

Returns:

The current button text. If it has no text, returns with null

setIcon

public DropDownButton setIcon(Icon icon)

Sets the button icon

Parameters:

icon - The icon of the button. For the applicable icons, see the Icon enum.

Returns:

The button component

getIcon

public Icon getIcon()

Gets the button icon

Returns:

The current button icon. If it has no icon, returns with null

setImage

public DropDownButton setImage(Image image)

Places an image on the button

Parameters:

image - The image that will be on the button. If specified as null, nothing will be placed.

Returns:

The button component

setType

public DropDownButton setType(ButtonType type)

Sets the button size

Parameters:

type - The size of the button. For the applicable types, see the ButtonType enum.

Returns:

The button

setSize

public DropDownButton setSize(ButtonSize size)

Stets the button size

Parameters:

size - The style size of the button. For the applicable types, see the ButtonSize enum.

Returns:

The button

setCounter

public final DropDownButton setCounter(long value)

Adds a counter to the right side of the button.

Parameters:

value - The counter value

Returns:

The button component

getCounter

public final long getCounter()

Gets the counter value

Returns:

The current value on the button counter. If the button has no counter, returns with -1.

setDirection

public DropDownButton setDirection(DropDownDirection direction)

Sets the dropdown direction. By default, a dropdown menu opens downwards, but you can use this method to modify it upwards or left/right.

Parameters:

direction - Dropdown direction If null is specified, the dropdown menu opens downwards. Available directions are listed in the enum DropDownDirection

Returns:

Button component

getDirection

public DropDownDirection getDirection()

Gets the dropdown direction.

Returns:

Dropdown direction

addMenuItem

public final DropDownButton addMenuItem(Icon icon,
 String text,
 ClickEventHandler handler)

Adds a menu item with the specified icon, text and click handler to the button's drop down menu

Parameters:

icon - The icon of the button. For the applicable icons, see the Icon enum.

text - The button text

handler - The click even handler implementation

Returns:

The button component

addMenuItem

public DropDownButton addMenuItem(Icon icon,
 String text,
 int hotKey,
 ClickEventHandler clickHandler)

Adds a menu item with the specified icon, text, hot key and click handler to the button's drop down menu

Parameters:

icon - The icon of the button. For the applicable icons, see the Icon enum.

text - The button text

hotKey - The menu hot key. This can be specified by using one of the Key class' constants. For example, adding CTRL+S: Key.CRTL + Key.KEY_S

clickHandler - The click even handler implementation

Returns:

The button component

addDivider

public final DropDownButton addDivider()

Adds a divider to the button drop down menu.

Returns:

The button component

addHeader

public DropDownButton addHeader(String text)

Adds a header to the dropdown menu. Users cannot click on a header, it is only displayed as an information box.

Parameters:

text - Header text

Returns:

Button component

addComponent

public DropDownButton addComponent(Component<?> component)

Adds a component to the dropdown menu.

Overrides:

addComponent in class Component<DropDownButton>

Parameters:

component - The component to be added

Returns:

The component

getItem

public DropDownButton.DropDownMenuItem getItem(int index)

Gets a menu item by referencing its index.

Parameters:

index - Menu item index

Returns:

Menu item component or null, if there is no menu item with the specified index

setAnimation

public DropDownButton setAnimation(Animation animation)

Description copied from interface: Animatable

Sets the animation type on the component

Specified by:

setAnimation in interface Animatable<DropDownButton>

Parameters:

animation - The animation type. The usable animation types can be found in the Animation enum

Returns:

The component

getAnimation

public Animation getAnimation()

Description copied from interface: Animatable

Gets the component's animation type

Specified by:

getAnimation in interface Animatable<DropDownButton>

Returns:

The animation type that is assigned to the component

removeAnimation

public DropDownButton removeAnimation()

Description copied from interface: Animatable

Removes animation from the component

Specified by:

removeAnimation in interface Animatable<DropDownButton>

Returns:

The component

addAnimationStartHandler

public DropDownButton addAnimationStartHandler(AnimationStartEventHandler handler)

Description copied from interface: Animatable

Adds an animation start event handler to the component. This handler is used, when the animation has starts.

Specified by:

addAnimationStartHandler in interface Animatable<DropDownButton>

Parameters:

handler - The AnimationStartEventHandler implementation

Returns:

The component

See Also:

• AnimationEvent

addAnimationEndHandler

public DropDownButton addAnimationEndHandler(AnimationEndEventHandler handler)

Description copied from interface: Animatable

Adds an animation end event handler to the component. This handler is used, when the animation has ended.

Specified by:

addAnimationEndHandler in interface Animatable<DropDownButton>

Parameters:

handler - The AnimationEndEventHandler implementation

Returns:

The component

See Also:

• AnimationEvent

addClickHandler

public DropDownButton addClickHandler(ClickEventHandler handler)

Adds a click event handler to the button.

If you add a click event handler to the dropdown menu item, the menu opens only by clicking on the dropdown icon. If you click on the button, only the specified event handler runs.

Specified by:

addClickHandler in interface Clickable<DropDownButton>

Parameters:

handler - The ClickEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addDoubleClickHandler

public DropDownButton addDoubleClickHandler(DoubleClickEventHandler handler)

Adds a double click event handler to the button.

If you add a click event handler to the dropdown menu item, the menu opens only by clicking on the dropdown icon. If you click on the button, only the specified event handler runs.

Specified by:

addDoubleClickHandler in interface Clickable<DropDownButton>

Parameters:

handler - A DoubleClickEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addHotKey

public DropDownButton addHotKey(int hotKey)

Description copied from interface: HandleHotKey

Adds the specified hot key to the component. If the user presses the hot key, the component's Click event handler will be fired. If the hot key was assigned to an input field, the field will gain focus.

Specified by:

addHotKey in interface HandleHotKey<DropDownButton>

Parameters:

hotKey - The button combination, that will be assigned to the component. This button combination can be specified, by using the Key class' constants. If the hot key is a combination of two buttons, then the values must be added. For example, the CTRL+S combination is specified as KEY.CTRL + KEY.KEY_S

Returns:

The component

addHotKey

public DropDownButton addHotKey(int hotKey,
 HotKeyEventHandler handler)

Description copied from interface: HandleHotKey

Adds the specified hot key to the component. If the user presses the hot key, the specified event handler will be fired

Specified by:

addHotKey in interface HandleHotKey<DropDownButton>

Parameters:

hotKey - The button combination, that will be assigned to the component. This button combination can be specified, by using the Key class' constants. If the hot key is a combination of two buttons, then the values must be added. For example, the CTRL+S combination is specified as KEY.CTRL + KEY.KEY_S

handler - The HotKeyEventHandler implementation

Returns:

The component

See Also:

• HotKeyEvent

removeHotKey

public DropDownButton removeHotKey(int hotKey)

Description copied from interface: HandleHotKey

Removes the specified hot key from the component

Specified by:

removeHotKey in interface HandleHotKey<DropDownButton>

Parameters:

hotKey - The button combination assigned to the component. This button combination can be specified, by using the Key class' constants. If the hot key is a combination of two buttons, then the values must be added. For example, the CTRL+S combination is specified as KEY.CTRL + KEY.KEY_S

Returns:

The component

removeHotKeys

public DropDownButton removeHotKeys()

Description copied from interface: HandleHotKey

Removes every hot key from the component

Specified by:

removeHotKeys in interface HandleHotKey<DropDownButton>

Returns:

The component

addMouseDownHandler

public DropDownButton addMouseDownHandler(MouseDownEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse button down event handler to the component. The handler will run when the user presses a mouse button while having the mouse in the component

Specified by:

addMouseDownHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseDownEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseEnterHandler

public DropDownButton addMouseEnterHandler(MouseEnterEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse enter event handler to the component. The handler will run when the mouse cursor enters the component, i.e. when the user hovers with the mouse over the component.

Specified by:

addMouseEnterHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseEnterEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseLeaveHandler

public DropDownButton addMouseLeaveHandler(MouseLeaveEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse leave event handler to the component. The handler will run when the mouse cursor leaves the component.

Specified by:

addMouseLeaveHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseLeaveEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseMoveHandler

public DropDownButton addMouseMoveHandler(MouseMoveEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse move event handler to the component. The handler will run when the mouse cursor moves inside the component area.

Specified by:

addMouseMoveHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseMoveEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseOutHandler

public DropDownButton addMouseOutHandler(MouseOutEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse out event handler to the component. The handler will run when the mouse cursor moves out of a component

Specified by:

addMouseOutHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseOutEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseOverHandler

public DropDownButton addMouseOverHandler(MouseOverEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse over event handler to the component. The handler will run when the mouse cursor moves over a component

Specified by:

addMouseOverHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseOverEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseUpHandler

public DropDownButton addMouseUpHandler(MouseUpEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse up event handler to the component. The handler will run when the mouse button is released, while the cursor is in a component.

Specified by:

addMouseUpHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseUpEventHandler implementation

Returns:

The component

See Also:

• MouseEvent

addMouseWheelHandler

public DropDownButton addMouseWheelHandler(MouseWheelEventHandler handler)

Description copied from interface: HandleMouseEvents

Adds a mouse wheel event handler to the component. The handler will run when the mouse wheel is used (scrolling), while the cursor is in a component

Specified by:

addMouseWheelHandler in interface HandleMouseEvents<DropDownButton>

Parameters:

handler - The MouseWheelEventHandler implementation

Returns:

The component

See Also:

• WheelEvent

addTouchCancelHandler

public DropDownButton addTouchCancelHandler(TouchCancelEventHandler handler)

Description copied from interface: Touchable

Adds a touch cancel event handler to the component. The event is fired when the touch event is cancelled by the device. Each device cancels the touch event differently, and certain devices use this event. If the device fires the event, the event handler will also be called.

Specified by:

addTouchCancelHandler in interface Touchable<DropDownButton>

Parameters:

handler - The TouchCancelEventHandler implementation

Returns:

The component

See Also:

• TouchEvent

addTouchEndHandler

public DropDownButton addTouchEndHandler(TouchEndEventHandler handler)

Description copied from interface: Touchable

Adds a touch end event handler to the component. The specified handler will be used, when the user takes their finger off the component.

Specified by:

addTouchEndHandler in interface Touchable<DropDownButton>

Parameters:

handler - The TouchEndEventHandler implementation

Returns:

The component

See Also:

• TouchEvent

addTouchMoveHandler

public DropDownButton addTouchMoveHandler(TouchMoveEventHandler handler)

Description copied from interface: Touchable

Adds a touch move event handler. The handler will be used, when the user moves their finger on the screen.

Specified by:

addTouchMoveHandler in interface Touchable<DropDownButton>

Parameters:

handler - The TouchMoveEventHandler implementation

Returns:

The component

See Also:

• TouchEvent

addTouchStartHandler

public DropDownButton addTouchStartHandler(TouchStartEventHandler handler)

Description copied from interface: Touchable

Adds a touch start event handler to the component. The handler will be used, when the user touches component.

Specified by:

addTouchStartHandler in interface Touchable<DropDownButton>

Parameters:

handler - The TouchStartEventHandler implementation

Returns:

The component

See Also:

• TouchEvent

setMenuOffset

public DropDownButton setMenuOffset(int offsetX,
 int offsetY)

Sets the X and Y axis offset of the dropdown menu.

Parameters:

offsetX - X axis offset in pixels

offsetY - Y axis offset in pixels

Returns:

Button component

setMenuAlignament

public DropDownButton setMenuAlignament(DropDownAlignament align)

Dropdown menu alignment relative to the button. By default, the dropdown menu is displayed to the left from the button.

Parameters:

align - Dropdown menu alignment If null is specified, the menu opens on the left side of the button. Available alignment types are listed in the enum DropDownAlignament

Returns:

Button component

getMenuAlignament

public DropDownAlignament getMenuAlignament()

Gets the dropdown menu alignment.

Returns:

Dropdown menu alignment

clear

public final DropDownButton clear()

Removes all components, headers, borders and menu items from the dropdown menu.

writeHTML

public boolean writeHTML(StringWriter writer)

Description copied from class: Component

Creates the component's HTML equivalent

This method doesn't need to be used during application development. This method is used when developing a custom component. When creating a custom component, this method needs to be implemented. In the parameter (StringWriter class) the component's HTML equivalent must be specified, and the method has to return with a Boolean value. This boolean value determines if the component was drawn. If the user doesn't have access right to the component, or if the component couldn't be drawn, it should return with false. Otherwise, it must return with true.

Specified by:

writeHTML in class Component<DropDownButton>

Returns:

If the componentwas drawn, true, otherwise false