practices/ui_guidelines/menu_design.jd

page.title=Menu Design Guidelines
parent.title=UI Guidelines
parent.link=index.html
@jd:body

<div id="qv-wrapper">
<div id="qv">

<h2>Quickview</h2>

<ul>
  <li>An Options menu is for any commands that are global to the current activity. </li>
  <li>A Context menu is for any commands that apply to the current selection. </li>
  <li>Place the most frequently used operations first. </li>
  <li>Put only the most important commands fixed on the screen. </li>
  <li>The commands on the Context menu that appears when you touch &amp; hold on an item should be duplicated on the activity you get to by a normal press on that item.
</ul>


<h2>In this document</h2>

<ol>
  <li><a href=#tour_of_the_menus>Tour of the Menus</a>
	<ol>
       <li style="padding-top: 4px;"><a href=#options_menu>Options Menu</a></li>
       <li style="padding-top: 4px;"><a href=#context_menu>Context Menu</a></li>
       <li style="padding-top: 4px;"><a href=#comparison_of_options_and_context_menus>Comparison of Options &amp; Context Menus</a></li>
       <li style="padding-top: 4px;"><a href=#commands_fixed>Commands Fixed in an Activity Screen</a></li>
	</ol>
  </li>
  <li><a href=#guidelines>Guidelines</a>
	<ol>
       <li style="padding-top: 4px;"><a href=#separate_commands>Separate specific from global commands</a></li>
       <li style="padding-top: 4px;"><a href=#most_frequently_used>Place most frequently used first</a></li>
       <li style="padding-top: 4px;"><a href=#dont_put_commands>Don't put commands <em>only</em> in a Context menu</li>
       <li style="padding-top: 4px;"><a href=#first_in_context_menu>First command in Context menu should be most intuitive</li>
       <li style="padding-top: 4px;"><a href=#selecting_content_item>Selecting an item should perform most intuitive operation</a></li>
       <li style="padding-top: 4px;"><a href=#context_menu_should_identify>A Context menu should identify the selected item</li>
       <li style="padding-top: 4px;"><a href=#most_important_commands>Put only most important commands fixed on the screen</a></li>
       <li style="padding-top: 4px;"><a href=#short_names>Use short names in Options icon menu</a></li>
       <li style="padding-top: 4px;"><a href=#a_dialog_should_not_have_an_options_menu>A dialog should not have Options menu</a></li>
       <li style="padding-top: 4px;"><a href=#do_not_substitute_message>If no Options menu, don't display message</a></li>
       <li style="padding-top: 4px;"><a href=#dim_hide_menu_items>Dim or hide menu items not available</a></li>
	</ol>
  </li>
</ol>

<h2>See also</h2>

<ol>
  <li><a href="http://android-developers.blogspot.com/2008/12/touch-mode.html">Touch mode</a></li>
  <li><a href="{@docRoot}guide/practices/ui_guidelines/activity_task_design.html">Activity and Task Design</a></li>
</ol>

</div>
</div>

<p>
  A menu holds a set of commands (user actions) that are normally hidden, and
  are accessible by a button, key, or gesture.  Menu commands provide a means
  for performing operations and for navigating to other parts of your
  application or other applications.  Menus are useful for freeing screen space,
  as an alternative to placing functionality and navigation, in buttons or other
  user controls in the content area of your application.
</p>

<p>
  The Android system provides two types of menus you can use to provide
  functionality or navigation. Between them, you should be able to organize
  the functionality and navigation for your application.  Briefly:
  <ul>
    <li>The <em>Options menu</em> contains primary functionality that applies
        globally to the current activity or starts a related activity.
        It is typically invoked by a user pressing a hard button, often labeled MENU.</li>
    <li>The <em>Context menu</em> contains secondary functionality for the currently
        selected item.  It is typically invoked by a user's touch &amp; hold
        on an item.  Like on the Options menu, the operation can run either
        in the current or another activity.</li>
  </ul>
</p>

<p>
  All but the simplest applications have menus.  The system automatically
  lays the menus out and provides standard ways for users to access them.
  In this sense, they are familiar and dependable ways for users to access
  functionality across all applications.  All menus are panels that "float"
  on top of the activity screen and are smaller than full screen, so that the
  application is still visible around its edges.  This is a visual reminder
  that a menu is an intermediary operation that disappears once it's used.
</p>

<p>
  Let's start out with a quick tour of the menus.
</p>

<h2 id="tour_of_the_menus">Tour of the Menus</h2>

<p class="note"><strong>Note:</strong> Your menus and screens might not look
like those shown in this document; they may vary from one version of Android
or device to another.
</p>

<h3 id="options_menu">Options Menu</h3>

<p>
  The Options menu contains commands that apply globally across the current
  activity, or can start another activity. They do not apply to a selected
  item in the content (a <a href="#context_menu">Context menu</a> does that).
</p>

<p>
  On most devices, a user presses the MENU button to access the Options menu,
  as shown in the screenshot below.  To close the menu, the user presses
  MENU again, or presses the BACK button.
  In fact, to cancel out of any menu, press the BACK button.  (Pressing the MENU
  button or touching outside the menu also works.)  Note that how to invoke this
  menu may be different on different devices.
</p>

<p>
  Each
  <a href="{@docRoot}guide/practices/ui_guidelines/activity_task_design.html#activities">activity</a>
  activity has its own set of operations and therefore its own Options menu.
  An application with multiple activities would have a different Options menu
  for each activity.
</p>

<p>
  For example, in the message list view of an email program, the Options menu
  might let you search the messages, compose a new message, refresh the list,
  or change the email settings.  The compose view of an email program would
  have a different Options menu, such as adding a CC field, attaching a file,
  or discarding the message.
</p>

<p id="options_icon_expanded_menus">
  In order to handle a large number of menu items, the Options menu
  progressively discloses them in two steps:
</p>

<ul>
  <li>
    <b>Options icon menu</b> - The first press of the MENU button displays a
    non-scrollable grid of icons at the bottom of the screen.  (On the G1
    phone, up to 6 buttons typically appear.)
  </li>
  <li>
    <b>Options expanded menu</b> - If the activity has more menu items than will
    fit on the icon menu, then the last icon is labeled "More" &mdash; selecting it
    displays a list that can contain any number of menu items and will scroll
    as necessary.
  </li>
</ul>

<img src={@docRoot}images/menu_design/MenuDiagram.png>

<p>
  On some versions of Android, the user can display keyboard shortcuts in the
  icon menu by long pressing the MENU button &mdash; the text in the icon menu
  alternates between the command names and their keyboard shortcuts (if any).
</p>

<h3 id="context_menu">Context Menu</h3>

<p>
  A Context menu is similar to a right-click context menu in a desktop
  operating system.  It is normally a shortcut that duplicates commands
  found elsewhere.
</p>

<p>
  A user can touch &amp; hold on content on the screen to
  access a Context menu (if one exists), as shown in the screenshot below.
  A Context menu is a list of menu items (commands) that can operate
  on the selected content.  The command can either be part of the current
  activity, or the system can pass the selected content along to
  an operation in another activity (by way of an
  <a href="{@docRoot}guide/practices/ui_guidelines/activity_task_design.html#intents">intent</a>).
</p>

<p>
  For example, in an email message list, a user can touch &amp; hold on
  an email message to open a Context menu containing commands to read,
  archive, or delete the message.
</p>

<p id="location">
  A user can also touch &amp; hold a <em>location</em> on the screen to
  access a Context menu.  An example is when the user does touch &amp; hold
  on a blank spot on the Home screen, a Context menu appears; selecting
  an item from that menu inserts an icon at that location.
</p>

<img src={@docRoot}images/menu_design/ContextMenuDiagram.png>

<h4 id="context_menu_shortcut">Context Menu is a Shortcut</h4>

<p>
  In the above example, if the user performs touch &amp; hold on the contact
  "Obi Wan Kenobi", a Context menu opens.  The commands provided in
  this Context menu are the complete set of actions that can be performed
  on this contact.
</p>

<p>
  A normal touch on an item in the content activates the most intuitive
  command for that selection &mdash; in this case, "View contact".
  We recommend that the most intuitive command also be listed as the
  first item in the Context menu.  In this example, selecting the contact
  "Obi Wan Kenobi" runs the same command "View contact" that is listed
  at the top of the Context menu.
</p>

<p>
  Also note, as shown in the following screenshot, the Context menu and the
  next screen both hold the same complete set of commands that can be performed
  on this contact.  The Context menu displays the commands in a list,
  while the "View contact" activity splits them into various items in the
  Options menu, icon buttons and list items.
</p>

<p>
  Because of this duplication, using the Context menu is considered a <em>shortcut</em>
  for going to the next screen and performing the operation there.  Context menus
  are less discoverable than either buttons fixed on-screen or the Options menu.
  Many users never discover or use Context menus.  It is for this reason that, for
  the most part, any command on a Context menu should also appear on the most
  intuitive operation's screen.  As the next section explains, text operations,
  such as "Select text" might appear only on a Context menu.  Also, rich
  applications, such as browsers, which themselves can contain web applications,
  may have commands on Context menus that are not available elsewhere.
</p>

<img src={@docRoot}images/menu_design/ContextMenuViewContactDiagram.png>

<h4>Text Commands in Context Menu</h4>

<p>
  Text links and text fields in the content both have system-provided operations
  that are common across all applications: operations such as "Select all", "Select text",
  "Copy all", and "Add to dictionary".  If the text field is editable, it also
  has  other operations, such as "Cut all" and "Input Method", and if text
  is also on the clipboard, it has "Paste".  The system automatically inserts
  the appropriate menu items into the Context menu of text links and text
  fields, as shown in the following screenshot.
</p>

<img src={@docRoot}images/menu_design/TextFieldContextMenuDiagram.png>


<h3 id="comparison_of_options_and_context_menus">Comparison of Options and Context Menus</h3>

<p>
	An Options menu holds commands that are global to the activity while a
	Context menu holds commands that apply only to an item in the content.
    As shown in these diagrams, the user navigates to the menu, then
    touches a menu item to perform an action or open a dialog.
</p>

<img src={@docRoot}images/menu_design/TaskFlowDiagram.png>

<p>
  For more technical information on menus, see the
  <a href="{@docRoot}guide/topics/ui/menus.html">Menus</a> developer guide.
</p>

<h3 id="commands_fixed">Commands Fixed in an Activity Screen</h4>

<p>
  Commands can also be fixed directly on screen, typically in
  text buttons, graphic buttons, or list items.  This placement is by far the most
  discoverable location for commands &mdash; a user can immediately see the command
  without having to first press a button.  This increased visibility needs to be
  weighed against the space such user controls take up, or the sense that they
  might clutter the visual design.
</p>

<h2 id="guidelines">Guidelines</h2>

<p>
  Selecting the right kind of menu to present, and using menus
  consistently, are critical factors in good application design. The following
  guidelines should assist user experience designers and application developers
  toward this end.
</p>

<h3 id="separate_commands">Separate selection-specific commands from global commands</h3>

<p>
  Put any commands that are global to the current activity in the Options menu
  or place them fixed in an activity screen; put commands that apply to the
  current selection in the Context menu.  (In any case, the command
  could either run as part of this activity or start another activity.)
</p>

<p>
  You can determine in which menu to place a command by what it operates on:
  If the command acts on selected content (or a particular
  <a href="#location">location</a>) on the screen, put the command in the
  Context menu for that content.  If the command acts on no specific content
  or location, put it in the Options menu.  This separation of commands
  is enforced by the system in the following way.  When you press the MENU
  button to display the Options menu, the selected content becomes unselected,
  and so cannot be operated on.  For an explanation
  of why the content becomes unselected, see the article on
  <a href="http://android-developers.blogspot.com/2008/12/touch-mode.html">Touch mode</a>.
</p>

<p>
  An example of a selection-specific Context menu is when a user performs a
  touch &amp; hold on a person's name in a list view of a contacts application.
  The Context menu would typically contain commands "View contact", "Call contact",
  and "Edit contact".
</p>

<h3 id="most_frequently_used">Place the most frequently used operations first</h3>

<p>
  Because of limited screen height, some menus may be scrollable, so it's
  important to place the most important commands so they can be viewed without
  scrolling.  In the case of the Options menu, place the most frequently used
  operation on its <a href="#options_icon_expanded_menus">icon menu</a>;
  the user will have to select "More" to see the rest.
  It's also useful to place similar commands in the same location &mdash;
  for example, the Search icon might always be the first icon in the Options
  menu across several activities that offer search.
</p>

<p>
  In a Context menu, the most intuitive command should be first, followed
  by commands in order of decreasing use, with the least used command at the bottom.
</p>

<h3 id="dont_put_commands">Don't put commands <em>only</em> in a Context menu</h3>
<p>
  If a user can fully access your application without using Context menus,
  then it's designed properly!  In general, if part of your application is inaccessible
  without using Context menus, then you need to duplicate those commands elsewhere.
</p>

<p>
  Before opening a Context menu, it has no visual representation that identifies
  its presence (whereas the Options menu has the MENU button), and so is not
  particularly discoverable.
  Therefore, in general, a Context menu should <em>duplicate</em> commands
  found in the corresponding activity screen.  For example, while it's useful to
  let the user call a phone number from a Context menu invoked by touch
  &amp; hold on a name in a list of contacts, that operation should <em>also</em>
  be available by the user touching the phone number itself when viewing contact details.
  See <a href="#context_menu_shortcut">shortcut</a> for an illustration of this example.
</p>

<h3 id="first_in_context_menu">The first command in a Context menu should be the selection's most intuitive command</h3>

<p>
  As described under <a href="#context_menu_shortcut">shortcut</a>,
  touching on an item in the content should activate the same command as touching
  the first item in the Context menu.  Both cases should be the most intuitive
  operation for that item.
</p>

<h3 id="selecting_content_item">Selecting an item in the content should perform the most intuitive operation</h3>

<p>
  In your application, when the user touches any actionable text (such as a link
  or list item) or image (such as a photo icon), execute the operation most
  likely to be desired by the user.
</p>

<p>
  Some examples of primary operations:
</p>

<ul>
    <li>Selecting an image executes "View image"</li>
    <li>Selecting a media icon or filename executes "Play"</li>
    <li>Selecting a URL link executes "Open link"</li>
    <li>Selecting an address executes "Go to address" (in a maps application)</li>
</ul>

<p>
  Note that selecting the same item in different contexts might invoke
  different operations:
</p>

<ul>
    <li>In a contact application, selecting a contact executes "View details"</li>
    <li>In an IM application, selecting a contact executes "Start chat"</li>
    <li>In an Email application, when adding a recipient to the "To" field
        through the contact book, selecting a contact executes "Add to recipient
        list"</li>
</ul>


<h3 id="context_menu_should_identify">A Context menu should identify the selected item</h3>

<p>
  When a user does touch &amp; hold on an item, the Context menu should
  contain the name of the selected item.  Therefore,
  when creating a Context menu, be sure to include a title and the name of the
  selected item so that it's clear to the user what the context is.
  For example, if a user selects a contact "Joan of Arc", put that name in the
  title of the Context menu (using
  {@link android.view.ContextMenu#setHeaderTitle(java.lang.CharSequence) setHeaderTitle}).
  Likewise, a command to edit the contact should be called "Edit contact",
  not just "Edit".
</p>


<h3 id="most_important_commands">Put only the most important commands fixed on the screen</h3>

<p>
  By putting commands in menus, you free up the screen to hold more content.
  On the other hand, fixing commands in the content area of an activity
  makes them more prominent and easy to use.
</p>

<p>
  Here are a number of important reasons to place commands fixed on the activity screen:
</p>

  <ul>
    <li>
      To give a command the highest prominence, ensuring the command is obvious and won't be overlooked.<br>
      Example: A "Buy" button in a store application.
    </li>
    <li>
      When quick access to the command is important and going to the menu would be
      tedious or slow.<br>
      Example: Next/Previous buttons or Zoom In/Out buttons in an image viewing application.
    </li>
    <li>
      When in the middle of an operation that needs to be completed.<br>
      Example: Save/Discard buttons in an image crop activity.
    </li>
    <li>
      Dialogs and wizards.<br>
      Example: OK/Cancel buttons
    </li>
    <li>
      For direct manipulation.<br>
      Example: Dragging an icon in the Home screen to the trash
    </li>
  </ul>

<h3 id="short_names">Use short names in the Options icon menu</h3>

<p>
  If a text label in the <a href="#options_icon_expanded_menus">Options icon menu</a>
  is too long, the system truncates it in the middle.  Thus, "Create Notification"
  is truncated to something like "Createication". You have no control over
  this truncation, so the best bet is to keep the text short.  In some versions of Android,
  when the icon is highlighted by a navigation key (such as a trackball), the
  entire descriptive text may be shown as a marquee, where the words are
  readable as they scroll by.  <!--For more information, see the Text Guidelines
  [update link].-->
</p>

<h3 id="a_dialog_should_not_have_an_options_menu">A dialog should not have an Options menu</h3>

<p>
  When a dialog is displayed, pressing the MENU button should do nothing.  This also holds true
  for activities that look like dialogs.  A dialog box is recognizable by being
  smaller than full-screen, having zero to three buttons, is non-scrollable, and
  possibly a list of selectable items that can include checkboxes or radio buttons.
  <!--For examples of dialogs, see Text Guidelines.-->
</p>

<p>
  The rationale behind not having a menu is that when a dialog is displayed, the user is in
  the middle of a procedure and should not be allowed to start a new global task
  (which is what the Option menu provides).
</p>

<h3 id="do_not_substitute_message">If an activity has no Options menu, do not display a message</h3>

<p>
  When the user presses the MENU button, if there is no Options menu, the system
  currently does nothing.  We recommend you do not perform any action (such as
  displaying a message).  It's a better user experience for this behavior to be
  consistent across applications.
</p>


<h3 id="dim_hide_menu_items">Dim or hide menu items that are not available in the current context</h3>

<p>
  Sometimes a menu item's action cannot be performed &mdash; for example,
  the "Forward" button in a browser cannot work until after the "Back"
  button has been pressed. We recommend:
</p>

<ul>
  <li>
    <b>In Options menu</b> - disable the menu item, which dims the text and icon,
    turning it gray.  This applies to menu items in both the icon menu and the
    "More" menu.  It would be disorienting for the icon menu to change from 6
    items to 5 items, and we treat the "More" menu the same way.
  </li>
  <li>
    <b>In Context menu</b> - hide the menu item.  This makes the menu shorter so the
    user sees only available choices (which also reduces any scrolling).
  </li>
</ul>

</body>
</html>