Class Widget

Object
   |
   +--Widget

Direct Known Subclasses:

ToolbarLine, TextArea, Icon, RootWidget, RadioButton, ToolbarButton, TabbedPane.Tab, Select, Container, Link, TableColumn, Reset, Text, TabbedPane, CheckBox, Splitter.Bar, Picture, HiddenVar, Button, MenuItem, Submit, Label, Spacer, TitledViewer, Item, ListItem

class Widget

Raises:

beforedragstart

whenever a draggable widget is about to be dragged. Listeners receive an instance of DragEvent. Setting the continueDrag property of the DragEvent to false will prevent the drag operation from starting. (See DragEvent.continueDrag.)

beforedragmove

whenever the user moves the mouse during a drag operation, but before the dragged-widget's position is updated. Listeners are passed an instance of DragEvent. Once this event has been raised, the dragged-widget's position is updated to match the widget property of the DragEvent that was passed to the beforedragmove listeners. Therefor, modifying the widget property will affect the new position of the dragged widget. Listeners can thus constrain the region inside which the dragged-widget can be dragged. (See DragEvent.widget.)

afterdragmove

whenever the user moves the mouse during a drag operation, but after the dragged-widget's position has been updated. Listeners are passed the same instance of DragEvent that was passed to the matching beforedragmove event. Modifying the members of the DragEvent during an afterdragmove event has no effect.

afterdragstop

whenever a drag operation terminates normally on a draggable widget (ie. the user 'dropped' the widget). Listeners are passed an instance of DragEvent. The mouse property of the DragEvent reflects the co-ordinates of the mouse at the time of the drop, and the widget property represents the co-ordinates of the dragged-widget at the time of the drop. (See DragEvent.mouse and DragEvent.widget.)

afterdragcancel

whenever a drag operation is cancelled by the user (probably by pressing the escape key). Listeners are passed an instance of DragEvent. In the case of an afterdragcancel event, the mouse property of the DragEvent reflects the co-ordinates that the mouse would have been at had it been a mouse event that caused the drag operation to be cancelled. Also, the widget property is the co-ordinates where the dragged-widget has been placed because of the cancellation. Together, this means that the same listener could be attached to both afterdragstop and afterdragcancel because the members of the DragEvent are consistent between the two events. (See DragEvent.mouse and DragEvent.widget.)

Field Detail

eventTable

<final> EventTable eventTable

html

DOMNode html

This widget's HTML node. Ideally this property should be treated as read-only, but subclassers may need to access the properties of html (such as the style property).

id

<final> string id

layoutData

LayoutData layoutData

parent

Widget parent

DISPOSE_COUNT

<static> int DISPOSE_COUNT

NEXT_WIDGET_ID

<static> int NEXT_WIDGET_ID

Widget

function Widget(<DOMNode> html, <Widget> parent)

The base widget class. Widgets are visual interface items, and are realised as nodes in the HTML tree.

Parameters:
html - an HTML node to use as this widget's representation.
parent - a Widget that contains this widget. Use of this parameter is deprecated and it will hopefully be removed in a codebase cleanup.

addEventListener

boolean addEventListener(eventName, listener)

blur

void blur()

createEventTable

void createEventTable(eventList)

dispose

void dispose()

focus

void focus()

getAbsoluteBottom

Pixels getAbsoluteBottom()

Returns the y-coordinate of the bottom of this widget relative to the screen, rather than the widget's parent.

Returns:
the y-coordinate of the widget's bottom edge

getAbsoluteLeft

Pixels getAbsoluteLeft()

getAbsoluteRight

Pixels getAbsoluteRight()

getAbsoluteTop

Pixels getAbsoluteTop()

getBottom

Pixels getBottom()

getBounds

Point getBounds()

getClientHeight

Pixels getClientHeight()

getClientWidth

Pixels getClientWidth()

getCorner

Point getCorner()

getHeight

Pixels getHeight()

getLeft

Pixels getLeft()

getPixelsPerEm

float getPixelsPerEm()

getRight

Pixels getRight()

getToolTip

string getToolTip()

getTop

Pixels getTop()

getWidth

Pixels getWidth()

installContextMenu

void installContextMenu(<Menu> menu)

Installs the given menu as a context menu for this widget. Only available after including menu.js.

Parameters:
menu - the menu to use as a context menu. Pass null to block context menus without providing an alternative.

installDefaultContextMenu

void installDefaultContextMenu()

Installs the default context menu on the widget. In other words, the context menu associated with this widget will be the browser-supplied default. Calling installDefaultContextMenu is necessary if this widget should use the browser-supplied default context menu, but at least one of the widget's ancestors uses a custom context menu or blocks context menus. This necessity derives from the DOM event model because context menu requests on this widget will "bubble" up to the nearest ancestor that handles them. If there's no such ancestor then the default behaviour is invoked and the user sees the default context menu. However, if any of the ancestors have installed non-default context menus, the nearest one will handle the menu request and show its non-default one, thus defeating this widget's desired default menu. This method is mostly useful for built-in widgets like text boxes that have context menus containing useful functions like 'Copy', and 'Paste'. Only available after including menu.js.

isDisposed

boolean isDisposed()

isDraggable

boolean isDraggable()

Returns true or false to indicate whether or not the user can drag this widget.

Returns:
true if this widget can be dragged by the user, false otherwise

See:
- Widget.setDraggable()

isEnabled

boolean isEnabled(<boolean> dontCheckParent)

Returns true if the widget is enabled, false otherwise.

Parameters:
dontCheckParent - (optional) - If true then ignore the parent when doing the disabled check.

Returns:
the enabled state of this widget

layout

void layout(<boolean> flushCache)

Causes the widget to redraw itself and any children it may have.

Parameters:
flushCache - if flushCache is true then the layout manager should ignore any cached values it may have and recompute everything

moveTo

void moveTo(x, y)

moveToAbsolute

void moveToAbsolute(x, y)

raiseEvent

void raiseEvent(eventName, event)

registerEventType

void registerEventType(eventName)

removeEventListener

boolean removeEventListener(eventName, listener)

setAbsoluteBottom

void setAbsoluteBottom(bottom)

setAbsoluteLeft

void setAbsoluteLeft(left)

setAbsoluteRight

void setAbsoluteRight(right)

setAbsoluteTop

void setAbsoluteTop(top)

setBottom

void setBottom(<Quantity> bottom)

Sets this widget's bottom co-ordinate.

Parameters:
bottom - the co-ordinate at which to place the bottom edge of this widget. bottom must be a Quantity (unlike setWidth(), setTop(), setLeft(), or setHeight()) because setBottom must delegate to setTop.

setBounds

void setBounds(x, y)

setDraggable

void setDraggable(newDraggable)

Reconfigures this widget to be either draggable or not draggable. If newDraggable is true, then mouse and key listeners will be registered in the appropriate places to simulate traditional drag-and-drop behaviour.

Parameters:
newDraggable - true or false.

See:
- DND

setEnabled

void setEnabled(<boolean> isEnabled)

Set the enabled state of this widget.

Parameters:
isEnabled - a boolean indicating whether or not to enable the widget. true enables the widget and false disables it.

setHeight

void setHeight(<Object> height)

Sets this widget's height.

Parameters:
height - the height to make this widget. height is used almost directly to set the style.height property of the underlying HTML node, so height can be any value whose toString() returns something that is a valid CSS height.

setLeft

void setLeft(<Object> left)

Sets this widget's left co-ordinate.

Parameters:
left - the point at which to place the left edge of this widget. left is used almost directly to set the style.left property of the underlying HTML node, so left can be any value whose toString() returns something that is a valid CSS left.

setParent

void setParent(<Widget> parent)

Sets this widget's parent to parent.

Parameters:
parent - this widget's new parent

setRight

void setRight(<Quantity> right)

Sets this widget's right co-ordinate.

Parameters:
right - the co-ordinate at which to place the right edge of this widget. right must be a Quantity (unlike setWidth(), setTop(), setLeft(), or setHeight()) because setRight must delegate to setLeft.

setToolTip

void setToolTip(tip)

setTop

void setTop(<Object> top)

Sets this widget's top co-ordinate.

Parameters:
top - the point at which to place the top of this widget. top is used almost directly to set the style.top property of the underlying HTML node, so top can be any value whose toString() returns something that is a valid CSS top.

setWidth

void setWidth(<Object> width)

Sets this widget's width.

Parameters:
width - the width to make this widget. width is used almost directly to set the style.width property of the underlying HTML node, so width can be any value whose toString() returns something that is a valid CSS width.

toString

string toString()

Returns a string representation of this widget.

Returns:
this widget's constructor's name plus this widget's ID.

uninstallContextMenu

void uninstallContextMenu()

If this widget has a context menu, uninstalls it. Only available after including menu.js.