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- Q&A #9
- Keyboard Equivalents, Quit, Splash Screens, Buttons, and Embedded ScrollBar
-
- By the Apple Computer OpenDoc Human Interface Team
-
- As published in the December 1995 Apple Directions
-
- We frequently receive OpenDoc questions that we need to answer in a public
- forum to help our partners' OpenDoc development efforts. We think you'd like
- to know about the OpenDoc topics these questions address.
-
- Q: I received the Developer Release 3 CD and now I'm seriously writing some
- parts. Where do I find guidance on the human interface?
-
- A: There are a couple of places to look for human interface information.
- First, Part 3 of the OpenDoc Programmer's Guide (on the DR3 CD) contains
- human interface guidelines for OpenDoc.
-
- Finally, you can subscribe to the two-way OpenDoc-HI list server and send us
- your questions and comments. To subscribe, send a message to
- Listproc@cilabs.org and include "subscribe OpenDoc-HI <your name, not e-mail
- address>" in the body of the message.
-
- Q: What are the guidelines for the use of keyboard equivalents?
-
- A: Keyboard equivalents, or Command-key combinations, execute from the
- rightmost menu positions to the leftmost. Suppose you assign a new keyboard
- equivalent, and another command already has that same Command-key
- assignment. When the user invokes a keyboard equivalent that is assigned to
- more than one command, the command that will be invoked is the one that
- appears farthest to the right in the menu structure. The user should not
- have to think about which command will be invoked; duplicates make the
- effect of the command unpredictable and confusing to users. Users may also
- find it very confusing if one keyboard equivalent invokes one command in one
- part of the document but invokes a different command elsewhere.
-
- We've been careful to establish keyboard equivalents that represent the most
- effective use of a limited resource. To minimize the potential confusion, we
- recommend that you use only the reserved keyboard equivalents, defined in
- the Human Interface Guidelines (pages 128-29), plus the OpenDoc-specific
- reserved keyboard equivalents L (Info) and R (Redo). You should carefully
- consider the alternatives before adding a new keyboard equivalent to your
- editor.
-
- Q: Can we consider restoring the Quit command so that users won't be
- confused by today's model?
-
- A: There are two reasons why OpenDoc does not have a Quit command. First,
- Quit is an artifact of an application-centered model. Because we
- restructured the way applications (that is, editors) are started and stopped
- automatically, this command is no longer necessary.
-
- Second, we know that users often forget to use the Quit command, which can
- lead to disorientation. That is, when users close the last document in an
- application, they're left with the menu bar for that application, but they
- often believe they're in another domain--usually the Finder. This causes a
- lot of frustration for users.
-
- It's true that issuing a Quit command also means that all open windows of
- the application are closed. That's sometimes a very useful feature,
- particularly for experienced users. One option for closing all the windows
- of the current document is a Close All command--which is somewhat different
- from Quit, but is consistent with a document-centered model. However, the
- Document menu is already crowded. So instead of providing a Close All
- command, OpenDoc 1.0 allows you to perform the same action by using
- Option-click on the close box or pressing Command-Option-W. (One way that an
- OpenDoc document might have multiple windows open is if the user were
- viewing a contained part in its own window, using the "View in Window" menu
- item.)
-
- We know that some developers are interested in using OpenDoc technology, but
- aren't using the OpenDoc document model. If you are clearly working with an
- application model, it is appropriate to retain the Quit command. If you're
- considering doing this, please feel free to contact us for advice. Watch
- this space for further information on various content-model-specific
- guidelines and appropriate variations on OpenDoc guidelines.
-
- Q: When should I display my splash screen?
-
- A: The human interface guidelines covers this topic to some degree. While we
- can't give you any legal advice, we can tell you what we think is the best
- human interface for splash screens.
-
- Startup is a natural time to display your part editor's name and other
- information in a splash screen. However, OpenDoc may start up and shut down
- your part editor several times during the use of a document. Therefore,
- displaying your splash screen each time your part editor starts up can
- become overwhelming to users, especially when several part editors that are
- used in a single document try to display their splash screens.
-
- We prefer that splash screens appear either at the end of the installation
- of your editor, or upon first use. After that, the splash screen information
- should be made available through the "About [editor name]" command in the
- Apple menu.
-
- Here are some ways to make your splash screen pleasant and unobtrusive:
-
- • Display your splash screen in a modeless dialog box.
-
- • Make your splash screen as small as possible.
-
- • Display your splash screen for as short a time as possible; 5 seconds
- is appropriate.
-
- • Make your splash screen disappear automatically, without requiring user
- interaction.
-
- • Avoid the use of buttons on your splash screen.
-
- Q: How do I edit a button or similiar "hot" parts? Can I activate them?
-
- A: In OpenDoc, you cannot activate a hot part. (A hot part--a button part,
- for example--does not activate when you click it or drop an icon on it.
- Instead, it takes such user events and performs some action as a result.)
- You can select it using whatever mechanisms the container provides, such as
- Shift-click, but you can't activate it. Thus, if the user needs to set
- properties, we recommend that the user edit the hot part's properties by
- selecting the part, invoking the Part Info command from the Edit menu, and
- clicking the Settings button. This will open the properties for this part
- and allow the user to edit them. Remember that as the part developer, you
- are responsible for adding the Settings button to your part's Part Info
- dialog box.
-
- Q: The sample code I've looked at seems to finesse the whole issue of scroll
- bars in embedded parts by allowing scroll bars only in the root frame. (I
- presume there can be only one root frame per part.) Is this cheating, or is
- it an OpenDoc human interface guideline? When is it appropriate to use
- scroll bars in the frame?
-
- A: When your part is the root part in a document window, your part editor
- decides whether to display window scroll bars. In general, documents should
- have scroll bars when they can contain more information than is visible in
- the window. However, some documents are WYSIWYG, and some are not. If your
- part is WYSIWYG, then you should probably not display the scroll bars when
- it is embedded, since this can cause the layout of the document to change
- and create visual clutter.
-
- Some parts have a legitimate need to use scroll bars to navigate through
- content that is not visible in the frame. For example, a part that presents
- a dynamic list may need a scroll bar. On the other hand, a simple text part
- probably doesn't need one, since the frame could grow as a user adds more
- text. When you determine that it is beneficial to implement scroll bars in
- your embedded parts, observe the following guidelines:
-
- • Whenever the document window in which your part is displayed becomes
- active, enable scroll bars in all of your parts that have them--even if
- your part is not currently active. This allows the user immediate
- access to all such parts.
-
- • When the user clicks in an enabled scroll bar, immediately begin to
- scroll. In addition, the part containing the scroll bar should become
- the active part except when the clicked scroll bar belongs to the root
- part. This exception allows the user to scroll through the document to
- bring obscured portions of an active embedded part into view without
- losing the active state.
-
- • Provide a command that allows users to hide the scroll bars when they
- wish. Alternatively, you could provide an editor preference for this
- purpose.
-
- • Don't hide the scroll bars when your part becomes inactive. Rather,
- show the inactive appearance of scroll bars.
-
- • Scrolling keys (such as the page up and page down keys) scroll the root
- part. If the root part does not scroll, these keys apply to the active
- part.
-
- See the Macintosh Human Interface Guidelines for more complete information
- on scroll bars.
-
- __________________________________________________________
-
- Copyright (c) 1995 by Apple Computer, Inc. All Rights Reserved.