Class: FieldDropdown

Constructor

FieldDropdown

new FieldDropdown(menuGenerator, opt_validator)

Class for an editable dropdown field.

Parameter
menuGenerator	(non-null Array of non-null Array or non-null function()) An array of options for a dropdown list, or a function which generates these options.
opt_validator	Optional function() A function that is executed when a new option is selected, with the newly selected value as its sole argument. If it returns a value, that value (which must be one of the options) will become selected in place of the newly selected option, unless the return value is null, in which case the change is aborted.

Parameter

menuGenerator

(non-null Array of non-null Array or non-null function())

An array of options for a dropdown list, or a function which generates these options.

opt_validator

Optional

function()

A function that is executed when a new option is selected, with the newly selected value as its sole argument. If it returns a value, that value (which must be one of the options) will become selected in place of the newly selected option, unless the return value is null, in which case the change is aborted.

Extends: Blockly.Field

Properties

ARROW_CHAR

static

Android can't (in 2014) display "▾", so use "▼" instead.

CHECKMARK_OVERHANG

static

Horizontal distance that a checkmark overhangs the dropdown.

MAX_MENU_HEIGHT_VH

static

Maximum height of the dropdown menu, as a percentage of the viewport height.

CURSOR

Mouse cursor style when over the hotspot that initiates the editor.

EDITABLE

Editable fields are saved by the XML renderer, non-editable fields are not.

Inherited from: Blockly.Field#EDITABLE

fieldGroup_

unknown

Inherited from: Blockly.Field#fieldGroup_

maxDisplayLength

unknown

Maximum characters of text to display before adding an ellipsis.

Inherited from: Blockly.Field#maxDisplayLength

menuGenerator_

non-null Array of non-null Array of string

name

unknown

Name of field. Unique within each block. Static labels are usually unnamed.

Inherited from: Blockly.Field#name

sourceBlock_

protected

unknown

Block this field is attached to. Starts as null, then set in init.

Inherited from: Blockly.Field#sourceBlock_

text_

protected

unknown

Visible text to display.

Inherited from: Blockly.Field#text_

textElement_

unknown

Inherited from: Blockly.Field#textElement_

validator_

protected

unknown

Validation function called when user edits an editable field.

Inherited from: Blockly.Field#validator_

value_

protected

(string or non-null Object)

Language-neutral currently selected string or image object.

visible_

protected

unknown

Is the field visible, or hidden due to the block being collapsed?

Inherited from: Blockly.Field#visible_

Methods

applyTrim_

static

applyTrim_(options, prefixLength, suffixLength) returns Array of non-null Array

Use the calculated prefix and suffix lengths to trim all of the options in the given array.

Parameter
options	Array of non-null Array Array of option tuples: (human-readable text or image, language-neutral name). Value must not be null.
prefixLength	number The length of the common prefix.
suffixLength	number The length of the common suffix

Parameter

options

Array of non-null Array

Array of option tuples: (human-readable text or image, language-neutral name).

Value must not be null.

prefixLength

number

The length of the common prefix.

suffixLength

number

The length of the common suffix

Returns: non-null Array of non-null Array A new array with all of the option text trimmed.

fromJson

package static

fromJson(options) returns Blockly.FieldDropdown

Construct a FieldDropdown from a JSON arg object.

Parameter
options	Object A JSON object with options (options). Value must not be null.

Parameter

options

Object

A JSON object with options (options).

Value must not be null.

Returns: non-null Blockly.FieldDropdown The new field instance.

callValidator

callValidator(text) returns string

Calls the validation function for this field, as well as all the validation function for the field's class and its parents.

Parameter
text	Proposed text.

Inherited from: Blockly.Field#callValidator
Returns: Revised text, or null if invalid.

classValidator

classValidator(text) returns string

Validates a change. Does nothing. Subclasses may override this.

Parameter
text	The user's text.

Inherited from: Blockly.Field#classValidator
Returns: No change needed.

dispose

dispose()

Close the dropdown menu if this input is being deleted.

forceRerender

package

forceRerender()

Force a rerender of the block that this field is installed on, which will rerender this field and adjust for any sizing changes. Other fields on the same block will not rerender, because their sizes have already been recorded.

Inherited from: Blockly.Field#forceRerender

getDisplayText_

protected

getDisplayText_() returns string

Get the text from this field as displayed on screen. May differ from getText due to ellipsis, and other formatting.

Inherited from: Blockly.Field#getDisplayText_
Returns: Currently displayed text.

getOptions

getOptions() returns Array of non-null Array

Return a list of the options for this dropdown.

Throws: If generated options are incorrectly structured.
Returns: non-null Array of non-null Array Array of option tuples: (human-readable text or image, language-neutral name).

getScaledBBox_

protected

getScaledBBox_() returns Object

Returns the bounding box of the rendered field, accounting for workspace scaling.

Inherited from: Blockly.Field#getScaledBBox_
Returns: An object with top, bottom, left, and right in pixels relative to the top left corner of the page (window coordinates).

getSize

getSize() returns goog.math.Size

Returns the height and width of the field.

Inherited from: Blockly.Field#getSize
Returns: Height and width.

getSvgRoot

getSvgRoot() returns Element

Gets the group element for this editable field. Used for measuring the size and for positioning.

Inherited from: Blockly.Field#getSvgRoot
Returns: The group element.

getText

getText() returns string

Get the text from this field.

Inherited from: Blockly.Field#getText
Returns: Current text.

getValidator

getValidator() returns function()

Gets the validation function for editable fields, or null if not set.

Inherited from: Blockly.Field#getValidator
Returns: Validation function, or null.

getValue

getValue() returns string

Get the language-neutral value from this dropdown menu.

Returns: string Current text.

init

init()

Install this dropdown on a block.

initModel

initModel()

Initializes the model of the field after it has been installed on a block. No-op by default.

Inherited from: Blockly.Field#initModel

isCurrentlyEditable

isCurrentlyEditable() returns boolean

Check whether this field is currently editable. Some fields are never editable (e.g. text labels). Those fields are not serialized to XML. Other fields may be editable, and therefore serialized, but may exist on non-editable blocks.

Inherited from: Blockly.Field#isCurrentlyEditable
Returns: Whether this field is editable and on an editable block

isOptionListDynamic

isOptionListDynamic() returns boolean

Returns: boolean True if the option list is generated by a function. Otherwise false.

isVisible

isVisible() returns boolean

Gets whether this editable field is visible or not.

Inherited from: Blockly.Field#isVisible
Returns: True if visible.

onItemSelected

onItemSelected(menu, menuItem)

Handle the selection of an item in the dropdown menu.

Parameter
menu	goog.ui.Menu The Menu component clicked. Value must not be null.
menuItem	goog.ui.MenuItem The MenuItem selected within menu. Value must not be null.

Parameter

goog.ui.Menu

The Menu component clicked.

Value must not be null.

menuItem

goog.ui.MenuItem

The MenuItem selected within menu.

Value must not be null.

onMouseDown_

protected

onMouseDown_(e)

Handle a mouse down event on a field.

Parameter
e	Mouse down event. Value must not be null.

Inherited from: Blockly.Field#onMouseDown_

referencesVariables

package

referencesVariables() returns boolean

Whether this field references any Blockly variables. If true it may need to be handled differently during serialization and deserialization. Subclasses may override this.

Inherited from: Blockly.Field#referencesVariables
Returns: True if this field has any variable references.

setSourceBlock

setSourceBlock(block)

Attach this field to a block.

Parameter
block	The block containing this field. Value must not be null.

Parameter

block

The block containing this field.

Value must not be null.

Inherited from: Blockly.Field#setSourceBlock

setText

setText(newText)

Set the text in this field. Trigger a rerender of the source block.

Parameter
newText	New text.

Inherited from: Blockly.Field#setText

setTooltip

setTooltip(_newTip)

Change the tooltip text for this field.

Parameter
_newTip	Text for tooltip or a parent element to link to for its tooltip.

Inherited from: Blockly.Field#setTooltip

setValidator

setValidator(handler)

Sets a new validation function for editable fields, or clears a previously set validator.

The validator function takes in the text form of the users input, and optionally returns the accepted field text. Alternatively, if the function returns null, the field value change aborts. If the function does not return anything (or returns undefined), the input value is accepted as valid. This is a shorthand for fields using the validator function call as a field-level change event notification.

Parameter
handler	The validator function or null to clear a previous validator. Value may be null.

Parameter

handler

The validator function or null to clear a previous validator.

Value may be null.

Inherited from: Blockly.Field#setValidator

setValue

setValue(newValue)

Set the language-neutral value for this dropdown menu.

Parameter
newValue	string New value to set.

Parameter

newValue

string

New value to set.

setVisible

setVisible(visible)

Sets whether this editable field is visible or not.

Parameter
visible	True if visible.

Inherited from: Blockly.Field#setVisible

updateEditable

updateEditable()

Add or remove the UI indicating if this field is editable or not.

Inherited from: Blockly.Field#updateEditable

updateWidth

updateWidth()

Updates the width of the field. Overrides field.prototype.updateWidth to deal with image selections on IE and Edge. If the selected item is not an image, or if the browser is not IE / Edge, this simply calls the parent implementation.

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Last updated April 23, 2019.