An element, much like a button, that is placed on a menubar. When the user clicks the menu element, the child menupopup of the menu will be displayed. This element is also used to create submenus.

More information is available in the XUL tutorial.

Attributes
acceltext, accesskey, allowevents, command, crop, disabled, image, label, menuactive, open, sizetopopup, tabindex, value
Properties
accessibleType, accessKey, command, control, crop, disabled, image, itemCount, label, labelElement, menupopup, open, parentContainer, selected, tabIndex, value
Methods
appendItem, getIndexOfItem, getItemAtIndex, insertItemAt, removeItemAt

Example

  <menubar id="sample-menubar">
    <menu id="file-menu" label="File">
      <menupopup id="file-popup">
        <menuitem label="New"/>
        <menuitem label="Open"/>
        <menuitem label="Save"/>
        <menuseparator/>
        <menuitem label="Exit"/>
      </menupopup>
    </menu>
    <menu id="edit-menu" label="Edit">
      <menupopup id="edit-popup">
        <menuitem label="Undo"/>
        <menuitem label="Redo"/>
      </menupopup>
    </menu>
  </menubar>

Attributes

acceltext
Type: string
Text that appears beside beside the menu label to indicate the shortcut key (accelerator key) to use to invoke the command. If this value is set, it overrides an assigned key set in the key attribute. This attribute does not apply to menus directly on the menubar.

accesskey
类型: character【字符】
本属性允许为控件(元素)设定一个字符作为快捷键,这个字符应该是 label 属性文本中的一个字符。该字符将会被加下划线以重点强调,平台和主体的变换并不影响这一表现行为。 当用户点击 ALT (在其他平台上具有类似功能的键) 和这个字符对应的按键时, 控件(元素)将立刻被从窗口中的某处激活或/并且获得焦点 。虽说字符不分大小写,但是当label中存在大写字符和小写字符时,快捷键的字符将首先选择与之完全匹配的那一个,如果label中存在两个或更多的与accesskey字符相同的字符,其中的第一个字符将被加下划线。
      *(有些键在监听按键事件时,分别对应event.ctrlKey和event.metaKey。)

 

Example

Image:XUL_ref_accesskey_attr.png
<vbox>	
  <label value="Enter Name" accesskey="e" control="myName"/>
  <textbox id="myName"/>
  <button label="Cancel" accesskey="n"/>
  <button label="Ok" accesskey="O"/>
</vbox>

See also

label attribute, acceltext attribute

allowevents
Type: boolean
类型:boolean
If true, events are passed to children of the element. Otherwise, events are passed to the element only.
如果为真,事件向子元素传递。否则,事件只传递到当前元素。

crop
Type: one of the values below
If the label of the element is too big to fit in its given space, the text will be cropped on the side specified by the crop attribute. An ellipsis will be used in place of the cropped text. If the box direction is reversed, the cropping is reversed.
  • start: The text will be cropped on its left side.
  • end: The text will be cropped on its right side.
  • left: The text will be cropped on its left side.
  • right: The text will be cropped on its right side.
  • center: The text will be cropped in the middle, showing both the start and end of the text normally.
  • none: The text will be not be cropped using an ellipsis. However, the text will simply be cut off if it is too large. The side depends on the CSS text alignment.

disabled
 
类型:boolean
表示元素是被禁用的。

如果这个元素的disabled属性被设置为true,表示元素被禁用,被禁用的属性在页面上通常会显示灰色文本,它无法响应用户的操作,它也无法得到光标。

然而,这个元素仍然能够响应鼠标事件,如果要启用这个元素,把disabled设置为false

示例:

Image:XUL_ref_attr_disabled.png
// Disabling an element
document.getElementById('buttonRemove').setAttribute("disabled", "true");

// Enabling back an element by removing the "disabled" attribute
document.getElementById('buttonRemove').removeAttribute("disabled");

Firefox 3.5 note

For keyset elements, support for this attribute was added in Firefox 3.5.

label
Type: string
The label that will appear on the element. If this is left out, no text appears.
label 在元素上显示。如果左侧出界,则不显示任何文字。

menuactive
Type: boolean
This attribute is set on an item in a menu when it is being hovered over. Typcially, the theme will use this to highlight the item. A DOMMenuItemActive event will be sent to the item when the item is hovered over, and a DOMMenuItemInactive event will be sent to the item when the selection moves away.
open
Type: boolean
For the menu type buttons, the open attribute is set to true when the menu is open. The open attribute is not present if the menu is closed.

 

sizetopopup
Type: one of the values below
Indicates how the menu width and the menupopup width are determined. If the sizetopopup attribute is left out or set to none, the menu will be its preferred width and the popup may extend outside of this width, unaffected by the maximum width of the menu itself. Otherwise, the menu will size itself to at least the size of the popup. If the menu has a maximum width, the popup will also be this width.
none
The width of the popup will not be constrained to the size of the menu.
pref
The preferred width of the menu label or button will be the size needed for the popup contents. This is the default value for menulists.
always
Both the preferred and minimum width of the menu label or button will be the same as that necessary for the menupopup.
value
Type: string
The string attribute allows you to associate a data value with an element. It is not used for any specific purpose, but you can access it with a script for your own use.

Properties

accessibleType
Type: integer
A value indicating the type of accessibility object for the element.

control
Type: menu element
Returns the enclosing menu that the item is inside, if any, or null if there is no enclosing menu.

itemCount
Type: integer
Read only property holding the number of child items.
menupopup
Type: menupopup element
A reference to the menupopup used by the menu or menulist. This property is read-only.
open
Type: boolean
This property will be set to true when the menu is open. The menu may be opened by setting the open property to true and closed by setting it to false.
parentContainer
Type: menu element
Read only property that returns the containing menu element, or null if there isn't a containing menu.

value
Type: string
Gets and sets the value of the value attribute.

Methods

Inherited Methods
addEventListener(), appendChild(), blur, click, cloneNode(), compareDocumentPosition, dispatchEvent(), doCommand, focus, getAttribute(), getAttributeNode(), getAttributeNodeNS(), getAttributeNS(), getBoundingClientRect(), getClientRects(), getElementsByAttribute, getElementsByAttributeNS, getElementsByClassName(), getElementsByTagName(), getElementsByTagNameNS(), getFeature(), getUserData, hasAttribute(), hasAttributeNS(), hasAttributes(), hasChildNodes(), insertBefore(), isDefaultNamespace(), isEqualNode, isSameNode, isSupported(), lookupNamespaceURI, lookupPrefix, normalize(), querySelector(), querySelectorAll(), removeAttribute(), removeAttributeNode(), removeAttributeNS(), removeChild(), removeEventListener(), replaceChild(), setAttribute(), setAttributeNode(), setAttributeNodeNS(), setAttributeNS(), setUserData

appendItem( label, value )
Return type: element
Creates a new item and adds it to the end of the existing list of items. You may optionally set a value. The function returns the newly created element.
getIndexOfItem( item )
Return type: integer
Returns the zero-based position of the specified item. Items are numbered starting at the first item displayed in the list.
getItemAtIndex( index )
Return type: element
Returns the element that is at the specified index.
insertItemAt( index, label, value )
Return type: element
This method creates a new item and inserts it at the specified position. You may optionally set a value. The new item element is returned.
removeItemAt( index )
Return type: element
Removes the child item in the element at the specified index. The method returns the removed item.

Elements
menubar, menuitem, menulist, menupopup, menuseparator
Interfaces
nsIAccessibleProvider, nsIDOMXULContainerElement, nsIDOMXULContainerItemElement, nsIDOMXULSelectControlItemElement
 

文档标签和贡献者

此页面的贡献者: ziyunfei, Cuimingda
最后编辑者: ziyunfei,