Make style and layout dynamic.

Recompute the lout of the application when the number of required line
for the completion change.

Use Prompt Toolkit to provide Dynamic colors when using the `config`
Magic.

IPython/terminal/ptshell.py

@@ -1,419 +1,451 b''
 """IPython terminal interface using prompt_toolkit in place of readline"""
 from __future__ import print_function
 
 import os
 import sys
 import signal
 import unicodedata
 from warnings import warn
 from wcwidth import wcwidth
 
 from IPython.core.error import TryNext
 from IPython.core.interactiveshell import InteractiveShell
 from IPython.utils.py3compat import PY3, cast_unicode_py2, input
 from IPython.utils.terminal import toggle_set_term_title, set_term_title
 from IPython.utils.process import abbrev_cwd
 from traitlets import Bool, CBool, Unicode, Dict, Integer
 
 from prompt_toolkit.completion import Completer, Completion
 from prompt_toolkit.enums import DEFAULT_BUFFER, SEARCH_BUFFER
 from prompt_toolkit.filters import HasFocus, HasSelection, Condition
 from prompt_toolkit.history import InMemoryHistory
-from prompt_toolkit.shortcuts import create_prompt_application, create_eventloop
+from prompt_toolkit.shortcuts import create_prompt_application, create_eventloop, create_prompt_layout
 from prompt_toolkit.interface import CommandLineInterface
 from prompt_toolkit.key_binding.manager import KeyBindingManager
 from prompt_toolkit.key_binding.vi_state import InputMode
 from prompt_toolkit.key_binding.bindings.vi import ViStateFilter
 from prompt_toolkit.keys import Keys
 from prompt_toolkit.layout.lexers import Lexer
 from prompt_toolkit.layout.lexers import PygmentsLexer
-from prompt_toolkit.styles import PygmentsStyle
+from prompt_toolkit.styles import PygmentsStyle, DynamicStyle
 
-from pygments.styles import get_style_by_name
+from pygments.styles import get_style_by_name, get_all_styles
 from pygments.lexers import Python3Lexer, BashLexer, PythonLexer
 from pygments.token import Token
 
 from .pt_inputhooks import get_inputhook_func
 from .interactiveshell import get_default_editor, TerminalMagics
 
 
 class IPythonPTCompleter(Completer):
     """Adaptor to provide IPython completions to prompt_toolkit"""
     def __init__(self, ipy_completer):
         self.ipy_completer = ipy_completer
 
     def get_completions(self, document, complete_event):
         if not document.current_line.strip():
             return
 
         used, matches = self.ipy_completer.complete(
                             line_buffer=document.current_line,
                             cursor_pos=document.cursor_position_col
         )
         start_pos = -len(used)
         for m in matches:
             m = unicodedata.normalize('NFC', m)
 
             # When the first character of the completion has a zero length,
             # then it's probably a decomposed unicode character. E.g. caused by
             # the "\dot" completion. Try to compose again with the previous
             # character.
             if wcwidth(m[0]) == 0:
                 if document.cursor_position + start_pos > 0:
                     char_before = document.text[document.cursor_position + start_pos - 1]
                     m = unicodedata.normalize('NFC', char_before + m)
 
                     # Yield the modified completion instead, if this worked.
                     if wcwidth(m[0:1]) == 1:
                         yield Completion(m, start_position=start_pos - 1)
                         continue
 
             yield Completion(m, start_position=start_pos)
 
 
 class IPythonPTLexer(Lexer):
     """
     Wrapper around PythonLexer and BashLexer.
     """
     def __init__(self):
         self.python_lexer = PygmentsLexer(Python3Lexer if PY3 else PythonLexer)
         self.shell_lexer = PygmentsLexer(BashLexer)
 
     def lex_document(self, cli, document):
         if document.text.startswith('!'):
             return self.shell_lexer.lex_document(cli, document)
         else:
             return self.python_lexer.lex_document(cli, document)
 
 
 class TerminalInteractiveShell(InteractiveShell):
     colors_force = True
 
     space_for_menu = Integer(6, config=True, help='space at the bottom of the screen to reserve for'
                                                   'the completion menu')
 
+    def _space_for_menu_changed(self, old, new):
+        self.relayout()
+
     pt_cli = None
 
     autoedit_syntax = CBool(False, config=True,
                             help="auto editing of files with syntax errors.")
 
     confirm_exit = CBool(True, config=True,
         help="""
         Set to confirm when you try to exit IPython with an EOF (Control-D
         in Unix, Control-Z/Enter in Windows). By typing 'exit' or 'quit',
         you can force a direct exit without any confirmation.""",
     )
     vi_mode = Bool(False, config=True,
         help="Use vi style keybindings at the prompt",
     )
 
     mouse_support = Bool(False, config=True,
         help="Enable mouse support in the prompt"
     )
 
-    highlighting_style = Unicode('', config=True,
-        help="The name of a Pygments style to use for syntax highlighting"
+    highlighting_style = Unicode('default', config=True,
+            help="The name of a Pygments style to use for syntax highlighting: \n %s" % ', '.join(get_all_styles())
     )
 
+    def _highlighting_style_changed(self, old, new):
+        self._style = self._make_style_from_name(self.highlighting_style)
+
     highlighting_style_overrides = Dict(config=True,
         help="Override highlighting format for specific tokens"
     )
 
     editor = Unicode(get_default_editor(), config=True,
         help="Set the editor used by IPython (default to $EDITOR/vi/notepad)."
     )
     
     term_title = Bool(True, config=True,
         help="Automatically set the terminal title"
     )
     def _term_title_changed(self, name, new_value):
         self.init_term_title()
     
     def init_term_title(self):
         # Enable or disable the terminal title.
         if self.term_title:
             toggle_set_term_title(True)
             set_term_title('IPython: ' + abbrev_cwd())
         else:
             toggle_set_term_title(False)
 
     def get_prompt_tokens(self, cli):
         return [
             (Token.Prompt, 'In ['),
             (Token.PromptNum, str(self.execution_count)),
             (Token.Prompt, ']: '),
         ]
 
     def get_continuation_tokens(self, cli, width):
         return [
             (Token.Prompt, (' ' * (width - 5)) + '...: '),
         ]
 
     def init_prompt_toolkit_cli(self):
         if ('IPY_TEST_SIMPLE_PROMPT' in os.environ) or not sys.stdin.isatty():
             # Fall back to plain non-interactive output for tests.
             # This is very limited, and only accepts a single line.
             def prompt():
                 return cast_unicode_py2(input('In [%d]: ' % self.execution_count))
             self.prompt_for_code = prompt
             return
 
         kbmanager = KeyBindingManager.for_prompt(enable_vi_mode=self.vi_mode)
         insert_mode = ViStateFilter(kbmanager.get_vi_state, InputMode.INSERT)
         # Ctrl+J == Enter, seemingly
         @kbmanager.registry.add_binding(Keys.ControlJ,
                             filter=(HasFocus(DEFAULT_BUFFER)
                                     & ~HasSelection()
                                     & insert_mode
                                    ))
         def _(event):
             b = event.current_buffer
             d = b.document
             if not (d.on_last_line or d.cursor_position_row >= d.line_count
                                            - d.empty_line_count_at_the_end()):
                 b.newline()
                 return
 
             status, indent = self.input_splitter.check_complete(d.text)
 
             if (status != 'incomplete') and b.accept_action.is_returnable:
                 b.accept_action.validate_and_handle(event.cli, b)
             else:
                 b.insert_text('\n' + (' ' * (indent or 0)))
 
         @kbmanager.registry.add_binding(Keys.ControlC, filter=HasFocus(DEFAULT_BUFFER))
         def _(event):
             event.current_buffer.reset()
 
         @kbmanager.registry.add_binding(Keys.ControlC, filter=HasFocus(SEARCH_BUFFER))
         def _(event):
             if event.current_buffer.document.text:
                 event.current_buffer.reset()
             else:
                 event.cli.push_focus(DEFAULT_BUFFER)
 
         supports_suspend = Condition(lambda cli: hasattr(signal, 'SIGTSTP'))
 
         @kbmanager.registry.add_binding(Keys.ControlZ, filter=supports_suspend)
         def _(event):
             event.cli.suspend_to_background()
 
         @Condition
         def cursor_in_leading_ws(cli):
             before = cli.application.buffer.document.current_line_before_cursor
             return (not before) or before.isspace()
 
         # Ctrl+I == Tab
         @kbmanager.registry.add_binding(Keys.ControlI,
                             filter=(HasFocus(DEFAULT_BUFFER)
                                     & ~HasSelection()
                                     & insert_mode
                                     & cursor_in_leading_ws
                                    ))
         def _(event):
             event.current_buffer.insert_text(' ' * 4)
 
         # Pre-populate history from IPython's history database
         history = InMemoryHistory()
         last_cell = u""
         for _, _, cell in self.history_manager.get_tail(self.history_load_length,
                                                         include_latest=True):
             # Ignore blank lines and consecutive duplicates
             cell = cell.rstrip()
             if cell and (cell != last_cell):
                 history.append(cell)
 
+        self._style = self._make_style_from_name(self.highlighting_style)
+        style = DynamicStyle(lambda: self._style)
+
+        self._app = create_prompt_application(
+                            key_bindings_registry=kbmanager.registry,
+                            history=history,
+                            completer=IPythonPTCompleter(self.Completer),
+                            enable_history_search=True,
+                            style=style,
+                            mouse_support=self.mouse_support,
+                            **self._layout_options()
+        )
+        self.pt_cli = CommandLineInterface(self._app,
+                           eventloop=create_eventloop(self.inputhook))
+
+    def _make_style_from_name(self, name):
+        """
+        Small wrapper that make an IPython compatible style from a style name
+
+        We need that to add style for prompt ... etc. 
+        """
+        style_cls = get_style_by_name(name)
         style_overrides = {
             Token.Prompt: '#009900',
             Token.PromptNum: '#00ff00 bold',
         }
-        if self.highlighting_style:
-            style_cls = get_style_by_name(self.highlighting_style)
-        else:
+        if name is 'default':
             style_cls = get_style_by_name('default')
             # The default theme needs to be visible on both a dark background
             # and a light background, because we can't tell what the terminal
             # looks like. These tweaks to the default theme help with that.
             style_overrides.update({
                 Token.Number: '#007700',
                 Token.Operator: 'noinherit',
                 Token.String: '#BB6622',
                 Token.Name.Function: '#2080D0',
                 Token.Name.Class: 'bold #2080D0',
                 Token.Name.Namespace: 'bold #2080D0',
             })
         style_overrides.update(self.highlighting_style_overrides)
         style = PygmentsStyle.from_defaults(pygments_style_cls=style_cls,
                                             style_dict=style_overrides)
 
-        app = create_prompt_application(multiline=True,
-                            lexer=IPythonPTLexer(),
-                            get_prompt_tokens=self.get_prompt_tokens,
-                            get_continuation_tokens=self.get_continuation_tokens,
-                            key_bindings_registry=kbmanager.registry,
-                            history=history,
-                            completer=IPythonPTCompleter(self.Completer),
-                            enable_history_search=True,
-                            style=style,
-                            mouse_support=self.mouse_support,
-                            reserve_space_for_menu=self.space_for_menu,
-        )
+        return style
 
-        self.pt_cli = CommandLineInterface(app,
-                           eventloop=create_eventloop(self.inputhook))
+    def _layout_options(self):
+        """
+        Return the current layout option for the current Terminal InteractiveShell
+        """
+        return {
+                'lexer':IPythonPTLexer(),
+                'reserve_space_for_menu':self.space_for_menu,
+                'get_prompt_tokens':self.get_prompt_tokens,
+                'get_continuation_tokens':self.get_continuation_tokens,
+                'multiline':False,
+                }
+
+
+    def _relayout(self):
+        """
+        Ask for a re computation of the application layout, if for example ,
+        some configuration options have changed.
+        """
+        self._app.layout = create_prompt_layout(**self._layout_options())
 
     def prompt_for_code(self):
         document = self.pt_cli.run(pre_run=self.pre_prompt)
         return document.text
 
     def init_io(self):
         if sys.platform not in {'win32', 'cli'}:
             return
 
         import colorama
         colorama.init()
 
         # For some reason we make these wrappers around stdout/stderr.
         # For now, we need to reset them so all output gets coloured.
         # https://github.com/ipython/ipython/issues/8669
         from IPython.utils import io
         io.stdout = io.IOStream(sys.stdout)
         io.stderr = io.IOStream(sys.stderr)
 
     def init_magics(self):
         super(TerminalInteractiveShell, self).init_magics()
         self.register_magics(TerminalMagics)
 
     def init_alias(self):
         # The parent class defines aliases that can be safely used with any
         # frontend.
         super(TerminalInteractiveShell, self).init_alias()
 
         # Now define aliases that only make sense on the terminal, because they
         # need direct access to the console in a way that we can't emulate in
         # GUI or web frontend
         if os.name == 'posix':
             for cmd in ['clear', 'more', 'less', 'man']:
                 self.alias_manager.soft_define_alias(cmd, cmd)
 
 
     def __init__(self, *args, **kwargs):
         super(TerminalInteractiveShell, self).__init__(*args, **kwargs)
         self.init_prompt_toolkit_cli()
         self.init_term_title()
         self.keep_running = True
 
     def ask_exit(self):
         self.keep_running = False
 
     rl_next_input = None
 
     def pre_prompt(self):
         if self.rl_next_input:
             self.pt_cli.application.buffer.text = cast_unicode_py2(self.rl_next_input)
             self.rl_next_input = None
 
     def interact(self):
         while self.keep_running:
             print(self.separate_in, end='')
 
             try:
                 code = self.prompt_for_code()
             except EOFError:
                 if (not self.confirm_exit) \
                         or self.ask_yes_no('Do you really want to exit ([y]/n)?','y','n'):
                     self.ask_exit()
 
             else:
                 if code:
                     self.run_cell(code, store_history=True)
                     if self.autoedit_syntax and self.SyntaxTB.last_syntax_error:
                         self.edit_syntax_error()
 
     def mainloop(self):
         # An extra layer of protection in case someone mashing Ctrl-C breaks
         # out of our internal code.
         while True:
             try:
                 self.interact()
                 break
             except KeyboardInterrupt:
                 print("\nKeyboardInterrupt escaped interact()\n")
 
     _inputhook = None
     def inputhook(self, context):
         if self._inputhook is not None:
             self._inputhook(context)
 
     def enable_gui(self, gui=None):
         if gui:
             self._inputhook = get_inputhook_func(gui)
         else:
             self._inputhook = None
 
     # Methods to support auto-editing of SyntaxErrors:
 
     def edit_syntax_error(self):
         """The bottom half of the syntax error handler called in the main loop.
 
         Loop until syntax error is fixed or user cancels.
         """
 
         while self.SyntaxTB.last_syntax_error:
             # copy and clear last_syntax_error
             err = self.SyntaxTB.clear_err_state()
             if not self._should_recompile(err):
                 return
             try:
                 # may set last_syntax_error again if a SyntaxError is raised
                 self.safe_execfile(err.filename, self.user_ns)
             except:
                 self.showtraceback()
             else:
                 try:
                     with open(err.filename) as f:
                         # This should be inside a display_trap block and I
                         # think it is.
                         sys.displayhook(f.read())
                 except:
                     self.showtraceback()
 
     def _should_recompile(self, e):
         """Utility routine for edit_syntax_error"""
 
         if e.filename in ('<ipython console>', '<input>', '<string>',
                           '<console>', '<BackgroundJob compilation>',
                           None):
             return False
         try:
             if (self.autoedit_syntax and
                     not self.ask_yes_no(
                         'Return to editor to correct syntax error? '
                         '[Y/n] ', 'y')):
                 return False
         except EOFError:
             return False
 
         def int0(x):
             try:
                 return int(x)
             except TypeError:
                 return 0
 
         # always pass integer line and offset values to editor hook
         try:
             self.hooks.fix_error_editor(e.filename,
                                         int0(e.lineno), int0(e.offset),
                                         e.msg)
         except TryNext:
             warn('Could not open editor')
             return False
         return True
 
     # Run !system commands directly, not through pipes, so terminal programs
     # work correctly.
     system = InteractiveShell.system_raw
 
 
 if __name__ == '__main__':
     TerminalInteractiveShell.instance().interact()