4.4. User Interface¶
Alot sets up a widget tree and a mainloop
in the constructor of alot.ui.UI
. The visible area is
a urwid.Frame
, where the footer is used as a status line and the body part
displays the currently active alot.buffers.Buffer
.
To be able to bind keystrokes and translate them to Commands
, keypresses are not propagated down the widget tree as is
customary in urwid. Instead, the root widget given to urwids mainloop is a custom wrapper
(alot.ui.Inputwrap
) that interprets key presses. A dedicated
SendKeypressCommand
can be used to trigger
key presses to the wrapped root widget and thereby accessing standard urwid
behaviour.
In order to keep the interface non-blocking and react to events like terminal size changes, alot makes use of twisted’s deferred - a framework that makes it easy to deal with callbacks. Many commands in alot make use of inline callbacks, which allow you to treat deferred-returning functions almost like syncronous functions. Consider the following example of a function that prompts for some input and acts on it:
from twisted.internet import defer
@defer.inlineCallbacks
def greet(ui): # ui is instance of alot.ui.UI
name = yield ui.prompt('pls enter your name')
ui.notify('your name is: ' + name)
4.4.1. UI
- the main component¶
-
class
alot.ui.
UI
(dbman, initialcmdline)¶ This class integrates all components of alot and offers methods for user interaction like
prompt()
,notify()
etc. It handles the urwid widget tree and mainloop (we use twisted) and is responsible for opening, closing and focussing buffers.Parameters: - dbman –
DBManager
- initialcmdline (str) – commandline applied after setting up interface
- colourmode (int in [1,16,256]) – determines which theme to chose
-
apply_command
(cmd)¶ applies a command
This calls the pre and post hooks attached to the command, as well as
cmd.apply()
.Parameters: cmd ( Command
) – an applicable command
-
apply_commandline
(cmdline)¶ interprets a command line string
i.e., splits it into separate command strings, instanciates
Commands
accordingly and applies then in sequence.Parameters: cmdline (str) – command line to interpret
-
buffer_close
(buf, redraw=True)¶ closes given
Buffer
.This it removes it from the bufferlist and calls its cleanup() method.
-
build_statusbar
()¶ construct and return statusbar widget
-
choice
(message, choices={'y': 'yes', 'n': 'no'}, select=None, cancel=None, msg_position='above')¶ prompt user to make a choice.
Parameters: - message (unicode) – string to display before list of choices
- choices (dict: keymap->choice (both str)) – dict of possible choices
- select (str) – choice to return if enter/return is hit. Ignored if set to None.
- cancel (str) – choice to return if escape is hit. Ignored if set to None.
- msg_position (str) – determines if message is above or left of the prompt. Must be above or left.
Return type: twisted.defer.Deferred
-
clear_notify
(messages)¶ Clears notification popups. Call this to ged rid of messages that don’t time out.
Parameters: messages – The popups to remove. This should be exactly what notify()
returned when creating the popup
-
exit
()¶ shuts down user interface without cleaning up. Use a
alot.commands.globals.ExitCommand
for a clean shutdown.
-
get_buffers_of_type
(t)¶ returns currently open buffers for a given subclass of
Buffer
.Parameters: t (alot.buffers.Buffer) – Buffer class Return type: list
-
get_deep_focus
(startfrom=None)¶ return the bottom most focussed widget of the widget tree
-
notify
(message, priority='normal', timeout=0, block=False)¶ opens notification popup.
Parameters: - message (str) – message to print
- priority (str) – priority string, used to format the popup: currently, ‘normal’ and ‘error’ are defined. If you use ‘X’ here, the attribute ‘global_notify_X’ is used to format the popup.
- timeout (int) – seconds until message disappears. Defaults to the value of ‘notify_timeout’ in the general config section. A negative value means never time out.
- block (bool) – this notification blocks until a keypress is made
Returns: an urwid widget (this notification) that can be handed to
clear_notify()
for removal
-
prompt
(prefix, text=u'', completer=None, tab=0, history=[])¶ prompt for text input. This returns a
Deferred
that calls back with the input string.Parameters: - prefix (str) – text to print before the input field
- text (str) – initial content of the input field
- completer (
alot.completion.Completer()
) – completion object to use - tab (int) – number of tabs to press initially (to select completion results)
- history (list of str) – history to be used for up/down keys
Return type: twisted.defer.Deferred
-
show_as_root_until_keypress
(w, key, afterwards=None)¶ Replaces root widget by given
urwid.Widget
and makes the UI ignore all further commands apart from cursor movement. If later on key is pressed, the old root widget is reset, callable afterwards is called and normal behaviour is resumed.
-
update
(redraw=True)¶ redraw interface
-
buffers
= None¶ list of active buffers
-
commandprompthistory
= None¶ history of the command line prompt
-
db_was_locked
= None¶ flag used to prevent multiple ‘index locked’ notifications
-
input_queue
= None¶ stores partial keyboard input
-
last_commandline
= None¶ saves the last executed commandline
-
mode
= None¶ interface mode identifier - type of current buffer
- dbman –
4.4.2. Buffers¶
A buffer defines a view to your data. It knows how to render itself, to interpret keypresses and is visible in the “body” part of the widget frame. Different modes are defined by subclasses of the following base class.
-
class
alot.buffers.
Buffer
(ui, widget)¶ Abstract base class for buffers.
-
cleanup
()¶ called before buffer is closed
-
get_info
()¶ return dict of meta infos about this buffer. This can be requested to be displayed in the statusbar.
-
rebuild
()¶ tells the buffer to (re)construct its visible content.
-
Available modes are:
Mode | Buffer Subclass |
---|---|
search | SearchBuffer |
thread | ThreadBuffer |
bufferlist | BufferlistBuffer |
taglist | TagListBuffer |
envelope | EnvelopeBuffer |
-
class
alot.buffers.
BufferlistBuffer
(ui, filtfun=None)¶ lists all active buffers
-
class
alot.buffers.
EnvelopeBuffer
(ui, envelope)¶ message composition mode
-
toggle_all_headers
()¶ toggles visibility of all envelope headers
-
-
class
alot.buffers.
SearchBuffer
(ui, initialquery='', sort_order=None)¶ shows a result list of threads for a query
-
get_selected_threadline
()¶ returns curently focussed
alot.widgets.ThreadlineWidget
from the result list.
-
kill_filler_process
()¶ terminates the process that fills this buffers
PipeWalker
.
-
-
class
alot.buffers.
ThreadBuffer
(ui, thread)¶ displays a thread as a tree of messages
Parameters: -
collapse
(msgpos)¶ collapse message at given position
-
collapse_all
()¶ collapse all messages in thread
-
expand
(msgpos)¶ expand message at given position
-
expand_all
()¶ expand all messages in thread
-
focus_first
()¶ set focus to first message of thread
-
focus_first_reply
()¶ move focus to first reply to currently focussed message
-
focus_last_reply
()¶ move focus to last reply to currently focussed message
-
focus_next
()¶ focus next message in depth first order
-
focus_next_matching
(querystring)¶ focus next matching message in depth first order
-
focus_next_sibling
()¶ focus next sibling of currently focussed message in thread tree
-
focus_next_unfolded
()¶ focus next unfolded message in depth first order
-
focus_parent
()¶ move focus to parent of currently focussed message
-
focus_prev
()¶ focus previous message in depth first order
-
focus_prev_matching
(querystring)¶ focus previous matching message in depth first order
-
focus_prev_sibling
()¶ focus previous sibling of currently focussed message in thread tree
-
focus_prev_unfolded
()¶ focus previous unfolded message in depth first order
-
focus_property
(prop, direction)¶ does a walk in the given direction and focuses the first message tree that matches the given property
-
focus_selected_message
()¶ focus the summary line of currently focussed message
-
get_messagetree_positions
()¶ returns a Generator to walk through all positions of
MessageTree
in theThreadTree
of this buffer.
-
get_selected_message
()¶ returns focussed
Message
-
get_selected_message_position
()¶ returns position of focussed message in the thread tree
-
get_selected_messagetree
()¶ returns currently focussed
MessageTree
-
get_selected_mid
()¶ returns Message ID of focussed message
-
messagetree_at_position
(pos)¶ get
MessageTree
for given position
-
messagetrees
()¶ returns a Generator of all
MessageTree
in theThreadTree
of this buffer.
-
refresh
()¶ refresh and flushe caches of Thread tree
-
4.4.3. Widgets¶
What follows is a list of the non-standard urwid widgets used in alot. Some of them respect user settings, themes in particular.
4.4.3.1. utils¶
Utility Widgets not specific to alot
-
class
alot.widgets.utils.
AttrFlipWidget
(w, maps, init_map='normal')¶ An AttrMap that can remember attributes to set
4.4.3.2. globals¶
This contains alot-specific urwid.Widget
used in more than one mode.
-
class
alot.widgets.globals.
AttachmentWidget
(attachment, selectable=True)¶ one-line summary of an
Attachment
.
-
class
alot.widgets.globals.
CompleteEdit
(completer, on_exit, on_error=None, edit_text=u'', history=None, **kwargs)¶ This is a vamped-up
urwid.Edit
widget that allows for tab-completion usingCompleter
objectsThese widgets are meant to be used as user input prompts and hence react to ‘return’ key presses by calling a ‘on_exit’ callback that processes the current text value.
- The interpretation of some keypresses is hard-wired:
enter: calls ‘on_exit’ callback with current value esc: calls ‘on_exit’ with value None, which can be interpreted as cancelation tab: calls the completer and tabs forward in the result list shift tab: tabs backward in the result list up/down: move in the local input history ctrl f/b: moves curser one character to the right/left meta f/b shift right/left: moves the cursor one word to the right/left ctrl a/e: moves curser to the beginning/end of the input ctrl d: deletes the character under the cursor meta d: deletes everything from the cursor to the end of the next word meta delete/backspace ctrl w: deletes everything from the cursor to the beginning of the current word ctrl k: deletes everything from the cursor to the end of the input ctrl u: deletes everything from the cursor to the beginning of the input
Parameters: - completer (alot.completion.Completer) – completer to use
- on_exit (callable) – “enter”-callback that interprets the input (str)
- on_error (callback) – callback that handles
alot.errors.CompletionErrors
- edit_text (str) – initial text
- history (list or str) – initial command history
-
class
alot.widgets.globals.
HeadersList
(headerslist, key_attr, value_attr, gaps_attr=None)¶ renders a pile of header values as key/value list
Parameters: - headerslist (list of (str, str)) – list of key/value pairs to display
- key_attr (urwid.AttrSpec) – theming attribute to use for keys
- value_attr (urwid.AttrSpec) – theming attribute to use for values
- gaps_attr (urwid.AttrSpec) – theming attribute to wrap lines in
-
class
alot.widgets.globals.
TagWidget
(tag, fallback_normal=None, fallback_focus=None)¶ text widget that renders a tagstring.
It looks up the string it displays in the tags section of the config as well as custom theme settings for its tag.
4.4.3.3. bufferlist¶
Widgets specific to Bufferlist mode
-
class
alot.widgets.bufferlist.
BufferlineWidget
(buffer)¶ selectable text widget that represents a
Buffer
in theBufferlistBuffer
.
4.4.3.4. search¶
Widgets specific to search mode
-
class
alot.widgets.search.
ThreadlineWidget
(tid, dbman)¶ selectable line widget that represents a
Thread
in theSearchBuffer
.
4.4.3.5. thread¶
Widgets specific to thread mode
-
class
alot.widgets.thread.
DictList
(content, key_attr, value_attr, gaps_attr=None)¶ SimpleTree
that displays key-value pairs.The structure will obey the Tree API but will not actually be a tree but a flat list: It contains one top-level node (displaying the k/v pair in Columns) per pair. That is, the root will be the first pair, its sibblings will be the other pairs and first|last_child will always be None.
Parameters: - headerslist (list of (str, str)) – list of key/value pairs to display
- key_attr (urwid.AttrSpec) – theming attribute to use for keys
- value_attr (urwid.AttrSpec) – theming attribute to use for values
- gaps_attr (urwid.AttrSpec) – theming attribute to wrap lines in
-
class
alot.widgets.thread.
FocusableText
(txt, att, att_focus)¶ Selectable Text used for nodes in our example
-
class
alot.widgets.thread.
MessageSummaryWidget
(message, even=True)¶ one line summary of a
Message
.Parameters: - message (alot.db.Message) – a message
- even (bool) – even entry in a pile of messages? Used for theming.
-
class
alot.widgets.thread.
MessageTree
(message, odd=True)¶ Tree
that displays contents of a singlealot.db.Message
.Its root node is a
MessageSummaryWidget
, and its child nodes reflect the messages content (parts for headers/attachments etc).Collapsing this message corresponds to showing the summary only.
Parameters: - message (alot.db.Message) – Messag to display
- odd (bool) – theme summary widget as if this is an odd line (in the message-pile)
-
collapse_if_matches
(querystring)¶ collapse (and show summary only) if the
alot.db.Message
matches given querystring
-
replace_bodytext
(txt)¶ display txt instead of current msg ‘body’
-
class
alot.widgets.thread.
ThreadTree
(thread)¶ Tree
that parses a givenalot.db.Thread
into a tree ofMessageTrees
that display this threads individual messages. As MessageTreess are not urwid widgets themself this is to be used in combination withNestedTree
only.
4.4.4. Completion¶
alot.ui.UI.prompt()
allows tab completion using a Completer
object handed as ‘completer’ parameter. alot.completion
defines several
subclasses for different occasions like completing email addresses from an
AddressBook
, notmuch tagstrings. Some of these actually build on top
of each other; the QueryCompleter
for example uses a
TagsCompleter
internally to allow tagstring completion after
“is:” or “tag:” keywords when typing a notmuch querystring.
All these classes overide the method complete()
, which
for a given string and cursor position in that string returns
a list of tuples (completed_string, new_cursor_position) that are taken to be
the completed values. Note that completed_string does not need to have the original
string as prefix.
complete()
may rise alot.errors.CompletionError
exceptions.
-
class
alot.completion.
AbooksCompleter
(abooks, addressesonly=False)¶ completes a contact from given address books
Parameters: - abooks (list of
AddresBook
) – used to look up email addresses - addressesonly (bool) – only insert address, not the realname of the contact
- abooks (list of
-
class
alot.completion.
AccountCompleter
(**kwargs)¶ completes users’ own mailaddresses
-
class
alot.completion.
ArgparseOptionCompleter
(parser)¶ completes option parameters for a given argparse.Parser
Parameters: parser (argparse.ArgumentParser) – the option parser we look up parameter and choices from
-
class
alot.completion.
CommandCompleter
(dbman, mode, currentbuffer=None)¶ completes one command consisting of command name and parameters
Parameters:
-
class
alot.completion.
CommandLineCompleter
(dbman, mode, currentbuffer=None)¶ completes command lines: semicolon separated command strings
Parameters: -
get_context
(line, pos)¶ computes start and end position of substring of line that is the command string under given position
-
-
class
alot.completion.
CommandNameCompleter
(mode)¶ completes command names
Parameters: mode (str) – mode identifier
-
class
alot.completion.
Completer
¶ base class for completers
-
complete
(original, pos)¶ returns a list of completions and cursor positions for the string original from position pos on.
Parameters: Returns: pairs of completed string and cursor position in the new string
Return type: list of (str, int)
Raises: CompletionError
-
relevant_part
(original, pos, sep=' ')¶ calculates the subword in a sep-splitted list of substrings of original that pos is ia.n
-
-
class
alot.completion.
ContactsCompleter
(abooks, addressesonly=False)¶ completes contacts from given address books
Parameters: - abooks (list of
AddresBook
) – used to look up email addresses - addressesonly (bool) – only insert address, not the realname of the contact
- abooks (list of
-
class
alot.completion.
CryptoKeyCompleter
(private=False)¶ completion for gpg keys
Parameters: private (bool) – return private keys
-
class
alot.completion.
MultipleSelectionCompleter
(completer, separator=', ')¶ Meta-Completer that turns any Completer into one that deals with a list of completion strings using the wrapped Completer. This allows for example to easily construct a completer for comma separated recipient-lists using a
ContactsCompleter
.Parameters: -
relevant_part
(original, pos)¶ calculates the subword of original that pos is in
-
-
class
alot.completion.
PathCompleter
¶ completion for paths
-
class
alot.completion.
QueryCompleter
(dbman)¶ completion for a notmuch query string
Parameters: dbman ( DBManager
) – used to look up avaliable tagstrings
-
class
alot.completion.
StringlistCompleter
(resultlist, ignorecase=True, match_anywhere=False)¶ completer for a fixed list of strings
Parameters: - resultlist (list of str) – strings used for completion
- liberal (bool) – match case insensitive and not prefix-only
-
class
alot.completion.
TagCompleter
(dbman)¶ complete a tagstring
Parameters: dbman ( DBManager
) – used to look up avaliable tagstrings
-
class
alot.completion.
TagsCompleter
(dbman)¶ completion for a comma separated list of tagstrings
Parameters: dbman ( DBManager
) – used to look up avaliable tagstrings