4.3. User Interface¶
Alot sets up a widget tree and a
in the constructor of
alot.ui.UI. The visible area is
urwid.Frame, where the footer is used as a status line and the body part
displays the currently active
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
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)
UI - the main component¶
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.
Available modes are:
What follows is a list of the non-standard urwid widgets used in alot. Some of them respect user settings, themes in particular.
Utility Widgets not specific to alot
AttrFlipWidget(w, maps, init_map='normal')¶
An AttrMap that can remember attributes to set
Widgets specific to Bufferlist mode
selectable text widget that represents a
alot.ui.UI.prompt() allows tab completion using a
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
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