Wichert has been fiddling with a possible GUI design for APT, here it is.. Jason
Hi there! I just sat down and finished the last couple of sections. The only things that might still be added are details on the layout of some items. The new extensions with respect to multi-CD support might also warrant some changes, although they should be trivial. Comments are welcomed as usual, but I think we can send this off for a public review on debian-devel sometime this week.. Wichert.
Apt UI design
1. Introduction
---------------
This document describes the design of Apt (A Package Tool). It documents
what Apt is meant to do and describes the user interface. It does not
attempt to document how Apt internals will work.
2. Purpose
----------
The purpose of Apt is to be a replacement for dselect, the tool Debian
GNU/Linux has used for a long time to manage selecting, installing and
removing packages. Using Apt it should be possible to select packages
for multiple sources, manage the list of packages, navigate through
them and fetch them. Normal low-level tools (like dpkg) are used for the
actual installation, configuration and removing of packages.
3. User interface principles
----------------------------
3.1 goals
Apt should be usefull on all systems running Debian GNU/Linux (or any
other form of Linux). This means that it should be able to run on
text consoles. In modern times an X interface is also expected, so Apt
will provide that as well.
For simpler needs which don't need user interaction there is also a
command-line tool (apt-get) to do things like complete upgrades and
installation/removal of single packages.
3.2 Interface conformance
The best aspect of modern user interface is that they share a common
philosophy with respect to handling windows, the mouse and keyboard
commands. This assures that user do not need to learn a completely new
interface and that intuition will generaly give good results.
Apt will try to conform to established standard methods by using standard
keyboard shortcuts and mouse commands. A list of common keyboard shortcuts
that will be used are:
Space Toggle current entry or drop down list
Enter Execute/Enter current entry
Tab Jump to next pane/frame
Shift-Tab Jump to previous pane/frame
+ Expands the selected node in a tree
- Collapses the selected node in a tree
Up-arrow Move cursor up one entry
Down-arrow Move cursor down one entry
Left-arrow Move cursor left one control
Right-arrow Move cursor right one control
Page-Up Move cursor up one page of entries
Page-Down Move cursor down one page of entries
Alt-<key> Used to select a Menu directly (e.g. Alt-F opens the File Menu)
Ctrl-<key> Keyboard accelerators for Menu items
F10 (or right mouse button) - Popup menu (context sensitive)
Please note the popup-menu need not be available in all contexts.
Documenting standard mouse commands is out of scope for this document.
Any text on UI standards should suffice on this point.
3.3 Saving state
Apt will try to save the state when shutting down so that the user will
can continue where he/she left of before. Apt will save the following
information: user preferences, other options, position & sizes of
windows for the current interface method (ie X11 and console information
will be stored seperately) and package selection-states.
4. Using Apt
------------
4.1 First usage
The first time Apt is run the user should be presented with a number of
questions to determine the minimal configuration. At the moment this is
only the list of packages sources. After the user answers these he/she
will continue to the normal main screen.
4.2 The main screen
The main screen is the screen from which the user can select packages
to install/upgrade/remove. There are also option to manage the list of
packages displayed, search for packages and show extra information on
packages.
4.2.1 The package list
The number of Debian packages is currently at about 2200, and still growing.
This means the user can select from a bewildering number of packages.
Managing this list is not a simple task. Apt will not try to limit the user
in any way in selecting and viewing packages. Instead the user gets full
control over the list of displayed packages: he/she can select from which
sources packages, from which sections and for which priorities packages
are displayed. Only packages which meet these criteria are shown in the
main package list.
4.2.2 Searching packages
There are two methods to look for packages: the user can either narrow
down the list of packages by selection the source, section or priority
to manage the main package list. The other method is a seperate `search
package' option. With this command the user can select more criteria,
such are words to search for in the description, maintainer names, etc.
All packages which meet this criteria are then displayed in a window with
search results, ordered by likeliness. This search command will use the
same filtering as is used for the main package list. A package can be selected
from this list and the focus will jump to that package in the main package
list.
5. Package management
---------------------
Apt will not handle package mangement itself: it will call a low-level
tool (like dpkg) to handle the actual installation, configuration or
removal. Apt will try to make all options of the tool available via its
userinterface, but for some things manual interaction will still be
required.
5.1 Obsolete packages
dselect tries to handle obsolete packages by marking all installed
packages which are not in any source as obsolete. Unfortunately this
is not really correct behaviour: a source might become unavailable
temporarily for example. Apt will not try to detect obsolete packages.
Instead a special source called `unknown' is added to the list of sources
which contains all installed packages which have no known source.
5.2 Automatically installed packages
Occasionaly if the user selects a package other packages also have to be
installed to satisfy dependencies. Apt will remember which packages where
not manually selected but only installed to satisfy the dependency of
another package. Later when Apt is doing a complete run or only removing
packages it can detect which of these automatically installed packages
are no longer needed and remove them. This automatics removal can be toggled
on or off.
5.3 Multiple package version
It can happen that multiple version of the same package are available for
selection (for example of both the stable and unstable tree from Debian
are listed as sources). Apt can switch between two behaviours when
encountering this: it can either always select the newest version, or it
can use a preferred source. The preferred selection is the selection that
is first listed in the list of sources.
6. User interface
-----------------
6.1 Package-selection screen
The package-selection userinterface for Apt is very simple: there is one screen
in which a menu, a toolbar, the package list and package information is shown.
For frontends which support it the package list and package information panels
are seperate windows which can be resized and moved within the main window. For
other interfaces non-resizable panels will be used.
6.1.1 The menu
The menu contains all commands the user can perform. This includes
managing the package list, performing actions on packages, changing
options, etc. The complete menu is:
Actions:
Complete run
Install new packages
Remove packages
Upgrade packages
-------------------
Quit
Package:
Configure
Install
Reinstall (upgrade/downgrade)
Remove
Hold
Options:
List preferences (dialog to change columns shown and sort order)
System preferences (general Apt preferences)
Sources
Advanced:
Export packagelist
Import packagelist
Help:
Context
-------
About
6.1.2 The filterbar
To manage the list of packages there are three filters available through
the filterbar: selection by source, section, priority and status. This part of
the toolbar looks like this:
+--------------------------------------------------------------------------+
| | Sources V | | Sections V | | Priority V | | Status V | |
+--------------------------------------------------------------------------+
If you click on the `V' (downward pointing triangle) next to the
name of the filter or hit the right key-combination (Alt-S for sources
for example) a list drops down in which can you can select
the filter details. For example:
+--------------------------------------------------------------------------+
| | Sources V | | Sections V | | Priority V | | Status V | |
+--------------------------------------------------------------------------+
| [X] base |
| [ ] comm |
| [X] devel |
| [ ] doc |
....
6.1.3 The Package list
This is the largest part of the screen. It lists all package which pass
the current filter. For each package at least the package name is displayed,
and optionally more information. The list is displayed in a format very
much like the explorer Windows uses: there is a row for each package, and
one or more columns displaying information about the package. The user
can toggle which columns are displayed. The currently defined columns are:
* package name
* package status
* section
* priority
* status
* installed version
* available version
* source
6.1.3.1 Context-menu (popup)
The packagelist is one of the screen which has a context-menu. If the
users requests the context-menu Apt will offer the following items:
* Change columns shown (submenu)
+ show priority (toggle)
+ show status (toggle)
+ etc.
* Order by (submenu)
+ packagename (toggle, only 1 selected)
+ status (toggle, only 1 selected)
+ section (toggle, only 1 selected)
+ source (toggle, only 1 selected)
+ priority (toggle, only 1 selected)
* Panels (submenu)
+ package description (toggle)
+ package information (toggle)
----------------------- (seperator)
* Mark for hold (command)
* Mark for install (command)
* Marf for purge (command)
* Mark for removal (command)
* Show all information (command)
Please note the sorting algorithm used should be stable, so the user
can customize the sorting-method in any way he/she likes.
Some commands deserve a short explanation:
* Panels / package description: toggles if the package description panel
should be displayed or hidden
* Panels / package information: toggles if the package description panel
should be displayed or hidden (defaults to off)
* Show all information: popup a window with detailed information on the
package. See section 6.1.6 for details in this window.
6.1.4 Available shortcuts
All keyboard-shortcuts and mouse-commands listed in 3.2 will be available.
There is also an extra set of commands available which are specific for
this window:
= Mark package for hold
+ Mark package for installation
- Mark package for removal
_ (underscore) Mark package for purge
Enter Do nothing, move focus to next package
Shift-Enter Show all information on package
F3 Open the package-search dialog
6.1.5 Package information panels
Apt has two information panels: package information and packages description.
The description-panel shows the extended description as found in the control
file from the package. The informatino package shows all other information,
suchs as maintainer, dependencies, suggests, provides, etc.
6.1.6 Package information window
This window shows all information on the current package. Part of this
information is already shown in the two panels described above, but
since they need not be visible at all times this window also shows that
information. Besides the information there is also a button which can
take you directly to a webpage from the bugtracking-system which lists
all bugs for this package. The layout looks like this:
+======= Information on fubar ========+
| |
| +---------------------------------+ |
| | Version: 1:2.4-1 ^ |
| | Maintainer: John Doe <jdoe@debi # |
| | Depends: libc6 | |
| | Conflicts: fubar0 (<= 2.4) | |
| | Installed-size: 142Kb | |
| | . | |
| | . | |
| | . | |
| | . | |
| | . V |
| +-<# - - - - - - - - - - - - - ->-+ |
| |
| +------+ +------+ +------+ |
| | Back | | Bugs | | Help | |
| +------+ +------+ +------+ |
| |
+=====================================+
6.1.7 Handling special relations
Debian supports a number of relations between packages. These can require
extra input from the user to resolve problems. We'll discuss each relation
and how we handle it shortly. Apt will try to assemble the questions it
needs to ask the user so the number of prompts is reduced as much as
possible.
6.1.7.1 (Pre-)dependencies
If a package is (possibly automatically) marked for installed Apt will
check if that package (pre-)depends on other packages. If so these
packages should also be installed. Depending on how Apt is configured it
can do two things: it can either marks dependant packages for installtion
automatically, or it can ask the user if he/she agrees with installing
those packages. If the user disagrees the request for installation is
cancelled. Automatic installtion can be toggled seperately for packages
which should be upgraded or packages which should be newly installed.
6.1.7.2 Conflicts
Occasionally a package conflicts with a packages that is installed or
marked for installation. If Apt detects this it should ask the user
if he really wants to install the package, noting that other packages
must be removed to allow this.
6.1.7.3 Recommends
Some packages can be installed on their own, but need other packages
for some of their functionality. When the user selects a package
which recommends other packages Apt will ask the user if he/she wants
to install these packages as well.
6.1.7.4 Recommends
Some packages can be enhanced by installting other packages. When the
user selects a package which suggets other packages Apt will ask the
user if he/she wants to install these packages as well.
6.2 Download-screen
The download-screen is shown when Apt is downloading the packages to be
installed. The information shown is:
* progress total download
* progress current package
* size of remaining stuff to download
* expected time of download completion
* abort button
6.3 Installation screen
When all packages are downloaded Apt will start installing them. This is
down using dpkg. Currently this means that the installation-process has
to run in a window (or full-screen if the frontend does not supprt windows)
in which dpkg's input and output are shown, so the {pre,post}{inst,rm} scripts
are run correctly. In the future this screen can be replaced with another
frontend for a new package-configuration system.
7. Dialogs
----------
Apt has multiple dialogs This section describes each dialog. Please note
that all dialogs are application modal (ie while a dialog is displayed
all other parts of Apt are non-active, but the user may still switch
to different programs).
7.1 List options
Using this dialog the user can fine-tune the method in which the packagelist
is displayed. Currently defined options in this dialog are:
* Sort order. You can sort by multiple keys, so the order can be
fine-tuned. The user must be able to change the sort order. An
example:
Sort by:
[ 3 ] packagename ascending
[ 1 ] priority descending
[ 2 ] source ascending
This will sort first by priority, with the highest priority first. Packages
with equal priority are then sorted by archive source. Packages with
equal priority and source are then sorted by packagename. This can
easily be implemented by sorting first on packagename, then on source
and finally on priority using a stable sorting algorithm.
* Columns shown (can also be down using the pop-up menu)
Shows a list of all possible columns that can be shown in the packagelist.
The user can toggle for each column (except packagename) if it should be
shown or hidden.
* Toggle if Apt should automatically select the newest version of a package,
or the version from a preferred source. This is only relevant if multiple
versions of the same package are available.
7.2 System options
This dialog contains information about the Apt in general. The currently
defined options are:
* toggle if Apt will attempt to automatically remove no longer needed packages
* toggle if packages which are installed to meet dependencies may be
upgraded silently or if Apt should ask for confirmation
* toggle if packages which are newly installed to meet dependencies should be
installed silently or if Apt should ask for confirmation
7.3 Sources selection
In this dialog the user can select from which sources packages are
available. Please note that the user must also be able to change the
order of the source, since the order can be used to determine which
package should be instaled if multiple versions are available.
7.4 Package search
On occasion the user will want to search the packagelist for a specific
package. To make this possible Apt has a package search-dialog. In this
dialog the user can select a number of criteria for the wanted package.
After selecting this Apt will present the user with a list of packages
which meet the given criteria. The dialog will allow the user to select
the following criteria:
* packagename (substring match)
* (extended) description (subtring match)
* maintainer (substring match)
* source
* section
* priority
The resulting list of packages will be sorted by match-likelyhood.
When the user selects a list in the list of found packages Apt will
go back to the packagelist and will move the focus to the selected
package. Please note that the package search will honour the filter
that the user has given for the package list.
Attachment:
pgp2sm5UuU7tl.pgp
Description: PGP signature