Class: Menu

Constructor

new Menu()

A basic menu class.

Extends: Blockly.Component

Methods

addChild

package

addChild(child, opt_render)

Adds the specified component as the last child of this component. See Blockly.Component#addChildAt for detailed semantics.

Parameter
child	The new child component.
opt_render	Optional If true, the child component will be rendered into the parent.

Parameter

child

The new child component.

opt_render

Optional

If true, the child component will be rendered into the parent.

Inherited from: Blockly.Component#addChild
See also: Blockly.Component#addChildAt

addChildAt

protected

addChildAt(child, index, opt_render)

Adds the specified component as a child of this component at the given 0-based index.

Both addChild and addChildAt assume the following contract between parent and child components:

the child component's element must be a descendant of the parent component's element, and
the DOM state of the child component must be consistent with the DOM state of the parent component (see `isInDocument`) in the steady state -- the exception is to addChildAt(child, i, false) and then immediately decorate/render the child.

In particular, parent.addChild(child) will throw an error if the child component is already in the document, but the parent isn't.

Clients of this API may call addChild and addChildAt with opt_render set to true. If opt_render is true, calling these methods will automatically render the child component's element into the parent component's element. If the parent does not yet have an element, then createDom will automatically be invoked on the parent before rendering the child.

Invoking {@code parent.addChild(child, true)} will throw an error if the child component is already in the document, regardless of the parent's DOM state.

If opt_render is true and the parent component is not already in the document, enterDocument will not be called on this component at this point.

Finally, this method also throws an error if the new child already has a different parent, or the given index is out of bounds.

Parameter
child	The new child component.
index	0-based index at which the new child component is to be added; must be between 0 and the current child count (inclusive).
opt_render	Optional If true, the child component will be rendered into the parent.

Parameter

child

The new child component.

index

0-based index at which the new child component is to be added; must be between 0 and the current child count (inclusive).

opt_render

Optional

If true, the child component will be rendered into the parent.

Inherited from: Blockly.Component#addChildAt
See also: Blockly.Component#addChild

blur

package

blur()

Blur the menu element.

canHighlightItem

protected

canHighlightItem(item) returns boolean

Returns whether the given item can be highlighted.

Parameter
item	Blockly.MenuItem The item to check.

Returns: boolean Whether the item can be highlighted.

clearHighlighted

protected

clearHighlighted()

Clears the currently highlighted item.

createDom

protected

createDom()

Creates the menu DOM.

Inherited from: Blockly.Menu#createDom

dispose

protected

dispose()

Disposes of the object. If the object hasn't already been disposed of, calls #disposeInternal.

Inherited from: Blockly.Component#dispose

disposeInternal

protected

disposeInternal()

Disposes of the component. Calls exitDocument, which is expected to remove event handlers and clean up the component. Propagates the call to the component's children, if any. Removes the component's DOM from the document.

Inherited from: Blockly.Menu#disposeInternal

enterDocument

protected

enterDocument()

Called when the component's element is known to be in the document. Anything using document.getElementById etc. should be done at this stage.

If the component contains child components, this call is propagated to its children.

Inherited from: Blockly.Menu#enterDocument

exitDocument

protected

exitDocument()

Cleans up the container before its DOM is removed from the document, and removes event handlers. Overrides Blockly.Component#exitDocument.

Inherited from: Blockly.Menu#exitDocument

focus

package

focus()

Focus the menu element.

forEachChild

protected

forEachChild(f, opt_obj)

Calls the given function on each of this component's children in order. If opt_obj is provided, it will be used as the 'this' object in the function when called. The function should take two arguments: the child component and its 0-based index. The return value is ignored.

Parameter
f	The function to call for every child component; should take 2 arguments (the child and its index).
opt_obj	Optional Used as the 'this' object in f when called.

Parameter

The function to call for every child component; should take 2 arguments (the child and its index).

opt_obj

Optional

Used as the 'this' object in f when called.

Inherited from: Blockly.Component#forEachChild

getChild

protected

getChild(id) returns Blockly.Component

Returns the child with the given ID, or null if no such child exists.

Parameter
id	Child component ID.

Inherited from: Blockly.Component#getChild
Returns: The child with the given ID; null if none.

getChildAt

protected

getChildAt(index) returns Blockly.Component

Returns the child at the given index, or null if the index is out of bounds.

Parameter
index	0-based index.

Inherited from: Blockly.Component#getChildAt
Returns: The child at the given index; null if none.

getChildCount

protected

getChildCount() returns number

Returns the number of children of this component.

Inherited from: Blockly.Component#getChildCount
Returns: The number of children.

getContentElement

protected

getContentElement() returns Element

Returns the DOM element into which child components are to be rendered, or null if the component itself hasn't been rendered yet. This default implementation returns the component's root element. Subclasses with complex DOM structures must override this method.

Inherited from: Blockly.Component#getContentElement
Returns: Element to contain child elements (null if none).

getElement

package

getElement() returns Element

Gets the component's element.

Inherited from: Blockly.Component#getElement
Returns: The element for the component.

getHighlighted

protected

getHighlighted() returns Blockly.Component

Returns the currently highlighted item (if any).

Returns: nullable Blockly.Component Highlighted item (null if none).

getId

package

getId() returns string

Gets the unique ID for the instance of this component. If the instance doesn't already have an ID, generates one on the fly.

Inherited from: Blockly.Component#getId
Returns: Unique component ID.

getMenuItem

protected

getMenuItem(node) returns Blockly.MenuItem

Returns the child menuitem that owns the given DOM node, or null if no such menuitem is found.

Parameter
node	Node DOM node whose owner is to be returned.

Returns: nullable Blockly.MenuItem menuitem for which the DOM node belongs to.

getParent

protected

getParent() returns Blockly.Component

Returns the component's parent, if any.

Inherited from: Blockly.Component#getParent
Returns: The parent component.

handleKeyEvent

protected

handleKeyEvent(e) returns boolean

Attempts to handle a keyboard event, if the menuitem is enabled, by calling handleKeyEventInternal. Considered protected; should only be used within this package and by subclasses.

Parameter
e	Event Key event to handle.

Returns: boolean Whether the key event was handled.

handleKeyEventInternal

protected

handleKeyEventInternal(e) returns boolean

Attempts to handle a keyboard event; returns true if the event was handled, false otherwise. If the container is enabled, and a child is highlighted, calls the child menuitem's handleKeyEvent method to give the menuitem a chance to handle the event first.

Parameter
e	Event Key event to handle.

Returns: boolean Whether the event was handled by the container (or one of its children).

hasChildren

protected

hasChildren() returns boolean

Returns true if the component has children.

Inherited from: Blockly.Component#hasChildren
Returns: True if the component has children.

highlightHelper

protected

highlightHelper(fn, startIndex) returns boolean

Helper function that manages the details of moving the highlight among child menuitems in response to keyboard events.

Parameter
fn	function(number, number) Function that accepts the current and maximum indices, and returns the next index to check.
startIndex	number Start index.

Parameter

function(number, number)

Function that accepts the current and maximum indices, and returns the next index to check.

startIndex

number

Start index.

Returns: boolean Whether the highlight has changed.

highlightNext

package

highlightNext()

Highlights the next highlightable item (or the first if nothing is currently highlighted).

highlightPrevious

package

highlightPrevious()

Highlights the previous highlightable item (or the last if nothing is currently highlighted).

indexOfChild

protected

indexOfChild(child) returns number

Returns the 0-based index of the given child component, or -1 if no such child is found.

Parameter
child	The child component. Value may be null.

Parameter

child

The child component.

Value may be null.

Inherited from: Blockly.Component#indexOfChild
Returns: 0-based index of the child component; -1 if not found.

isInDocument

protected

isInDocument() returns boolean

Determines whether the component has been added to the document.

Inherited from: Blockly.Component#isInDocument
Returns: TRUE if rendered. Otherwise, FALSE.

isRightToLeft

protected

isRightToLeft() returns boolean

Returns true if the component is rendered right-to-left, false otherwise. The first time this function is invoked, the right-to-left rendering property is set if it has not been already.

Inherited from: Blockly.Component#isRightToLeft
Returns: Whether the control is rendered right-to-left.

render

package

render(opt_parentElement)

Renders the component. If a parent element is supplied, the component's element will be appended to it. If there is no optional parent element and the element doesn't have a parentNode then it will be appended to the document body.

If this component has a parent component, and the parent component is not in the document already, then this will not call enterDocument on this component.

Throws an Error if the component is already rendered.

Parameter
opt_parentElement	Optional Optional parent element to render the component into.

Parameter

opt_parentElement

Optional

Optional parent element to render the component into.

Inherited from: Blockly.Component#render

renderBefore

protected

renderBefore(sibling)

Renders the component before another element. The other element should be in the document already.

Throws an Error if the component is already rendered.

Parameter
sibling	Node to render the component before.

Inherited from: Blockly.Component#renderBefore

setElementInternal

protected

setElementInternal(element)

Sets the component's root element to the given element. Considered protected and final.

This should generally only be called during createDom. Setting the element does not actually change which element is rendered, only the element that is associated with this UI component.

This should only be used by subclasses and its associated renderers.

Parameter
element	Root element for the component.

Inherited from: Blockly.Component#setElementInternal

setHighlighted

protected

setHighlighted(item)

Highlights the given item if it exists and is a child of the container; otherwise un-highlights the currently highlighted item.

Parameter
item	Blockly.MenuItem Item to highlight.

setHighlightedIndex

protected

setHighlightedIndex(index)

Highlights the item at the given 0-based index (if any). If another item was previously highlighted, it is un-highlighted.

Parameter
index	number Index of item to highlight (-1 removes the current highlight).

Parameter

index

number

Index of item to highlight (-1 removes the current highlight).

setParent

protected

setParent(parent)

Sets the parent of this component to use for event bubbling. Throws an error if the component already has a parent or if an attempt is made to add a component to itself as a child.

Parameter
parent	The parent component.

Inherited from: Blockly.Component#setParent

setRightToLeft

package

setRightToLeft(rightToLeft)

Set is right-to-left. This function should be used if the component needs to know the rendering direction during DOM creation (i.e. before #enterDocument is called and is right-to-left is set).

Parameter
rightToLeft	Whether the component is rendered right-to-left.

Inherited from: Blockly.Component#setRightToLeft

setRole

package

setRole(roleName)

Set the menu accessibility role.

Parameter
roleName	(non-null Blockly.utils.aria.Role or string) role name.

Parameter

roleName

(non-null Blockly.utils.aria.Role or string)

role name.

unhighlightCurrent

protected

unhighlightCurrent()

Unhighlight the current highlighted item.