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* Moved AnsiCodeProcessor to separate file, refactored its API, and added unit tests....
* Moved AnsiCodeProcessor to separate file, refactored its API, and added unit tests. * Improved traceback display. * Modified FrontendWidget to use tabs instead of spaces for convenient deletion.

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console_widget.py
887 lines | 33.2 KiB | text/x-python | PythonLexer
# Standard library imports
import sys
# System library imports
from PyQt4 import QtCore, QtGui
# Local imports
from ansi_code_processor import QtAnsiCodeProcessor
from completion_widget import CompletionWidget
class ConsoleWidget(QtGui.QPlainTextEdit):
""" Base class for console-type widgets. This class is mainly concerned with
dealing with the prompt, keeping the cursor inside the editing line, and
handling ANSI escape sequences.
"""
# Whether to process ANSI escape codes.
ansi_codes = True
# The maximum number of lines of text before truncation.
buffer_size = 500
# Whether to use a CompletionWidget or plain text output for tab completion.
gui_completion = True
# Whether to override ShortcutEvents for the keybindings defined by this
# widget (Ctrl+n, Ctrl+a, etc). Enable this if you want this widget to take
# priority (when it has focus) over, e.g., window-level menu shortcuts.
override_shortcuts = False
# The number of spaces to show for a tab character.
tab_width = 4
# Protected class variables.
_ctrl_down_remap = { QtCore.Qt.Key_B : QtCore.Qt.Key_Left,
QtCore.Qt.Key_F : QtCore.Qt.Key_Right,
QtCore.Qt.Key_A : QtCore.Qt.Key_Home,
QtCore.Qt.Key_E : QtCore.Qt.Key_End,
QtCore.Qt.Key_P : QtCore.Qt.Key_Up,
QtCore.Qt.Key_N : QtCore.Qt.Key_Down,
QtCore.Qt.Key_D : QtCore.Qt.Key_Delete, }
_shortcuts = set(_ctrl_down_remap.keys() +
[ QtCore.Qt.Key_C, QtCore.Qt.Key_V ])
#---------------------------------------------------------------------------
# 'QObject' interface
#---------------------------------------------------------------------------
def __init__(self, parent=None):
QtGui.QPlainTextEdit.__init__(self, parent)
# Initialize protected variables. Some variables contain useful state
# information for subclasses; they should be considered read-only.
self._ansi_processor = QtAnsiCodeProcessor()
self._completion_widget = CompletionWidget(self)
self._continuation_prompt = '> '
self._continuation_prompt_html = None
self._executing = False
self._prompt = ''
self._prompt_html = None
self._prompt_pos = 0
self._reading = False
self._reading_callback = None
# Set a monospaced font.
self.reset_font()
# Define a custom context menu.
self._context_menu = QtGui.QMenu(self)
copy_action = QtGui.QAction('Copy', self)
copy_action.triggered.connect(self.copy)
self.copyAvailable.connect(copy_action.setEnabled)
self._context_menu.addAction(copy_action)
self._paste_action = QtGui.QAction('Paste', self)
self._paste_action.triggered.connect(self.paste)
self._context_menu.addAction(self._paste_action)
self._context_menu.addSeparator()
select_all_action = QtGui.QAction('Select All', self)
select_all_action.triggered.connect(self.selectAll)
self._context_menu.addAction(select_all_action)
def event(self, event):
""" Reimplemented to override shortcuts, if necessary.
"""
# On Mac OS, it is always unnecessary to override shortcuts, hence the
# check below. Users should just use the Control key instead of the
# Command key.
if self.override_shortcuts and \
sys.platform != 'darwin' and \
event.type() == QtCore.QEvent.ShortcutOverride and \
self._control_down(event.modifiers()) and \
event.key() in self._shortcuts:
event.accept()
return True
else:
return QtGui.QPlainTextEdit.event(self, event)
#---------------------------------------------------------------------------
# 'QWidget' interface
#---------------------------------------------------------------------------
def contextMenuEvent(self, event):
""" Reimplemented to create a menu without destructive actions like
'Cut' and 'Delete'.
"""
clipboard_empty = QtGui.QApplication.clipboard().text().isEmpty()
self._paste_action.setEnabled(not clipboard_empty)
self._context_menu.exec_(event.globalPos())
def dragMoveEvent(self, event):
""" Reimplemented to disable dropping text.
"""
event.ignore()
def keyPressEvent(self, event):
""" Reimplemented to create a console-like interface.
"""
intercepted = False
cursor = self.textCursor()
position = cursor.position()
key = event.key()
ctrl_down = self._control_down(event.modifiers())
alt_down = event.modifiers() & QtCore.Qt.AltModifier
shift_down = event.modifiers() & QtCore.Qt.ShiftModifier
# Even though we have reimplemented 'paste', the C++ level slot is still
# called by Qt. So we intercept the key press here.
if event.matches(QtGui.QKeySequence.Paste):
self.paste()
intercepted = True
elif ctrl_down:
if key in self._ctrl_down_remap:
ctrl_down = False
key = self._ctrl_down_remap[key]
event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress, key,
QtCore.Qt.NoModifier)
elif key == QtCore.Qt.Key_K:
if self._in_buffer(position):
cursor.movePosition(QtGui.QTextCursor.EndOfLine,
QtGui.QTextCursor.KeepAnchor)
cursor.removeSelectedText()
intercepted = True
elif key == QtCore.Qt.Key_X:
intercepted = True
elif key == QtCore.Qt.Key_Y:
self.paste()
intercepted = True
elif alt_down:
if key == QtCore.Qt.Key_B:
self.setTextCursor(self._get_word_start_cursor(position))
intercepted = True
elif key == QtCore.Qt.Key_F:
self.setTextCursor(self._get_word_end_cursor(position))
intercepted = True
elif key == QtCore.Qt.Key_Backspace:
cursor = self._get_word_start_cursor(position)
cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
cursor.removeSelectedText()
intercepted = True
elif key == QtCore.Qt.Key_D:
cursor = self._get_word_end_cursor(position)
cursor.setPosition(position, QtGui.QTextCursor.KeepAnchor)
cursor.removeSelectedText()
intercepted = True
if self._completion_widget.isVisible():
self._completion_widget.keyPressEvent(event)
intercepted = event.isAccepted()
else:
if key in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
if self._reading:
self.appendPlainText('\n')
self._reading = False
if self._reading_callback:
self._reading_callback()
elif not self._executing:
self.execute(interactive=True)
intercepted = True
elif key == QtCore.Qt.Key_Up:
if self._reading or not self._up_pressed():
intercepted = True
else:
prompt_line = self._get_prompt_cursor().blockNumber()
intercepted = cursor.blockNumber() <= prompt_line
elif key == QtCore.Qt.Key_Down:
if self._reading or not self._down_pressed():
intercepted = True
else:
end_line = self._get_end_cursor().blockNumber()
intercepted = cursor.blockNumber() == end_line
elif key == QtCore.Qt.Key_Tab:
if self._reading:
intercepted = False
else:
intercepted = not self._tab_pressed()
elif key == QtCore.Qt.Key_Left:
intercepted = not self._in_buffer(position - 1)
elif key == QtCore.Qt.Key_Home:
cursor.movePosition(QtGui.QTextCursor.StartOfLine)
start_pos = cursor.position()
start_line = cursor.blockNumber()
if start_line == self._get_prompt_cursor().blockNumber():
start_pos += len(self._prompt)
else:
start_pos += len(self._continuation_prompt)
if shift_down and self._in_buffer(position):
self._set_selection(position, start_pos)
else:
self._set_position(start_pos)
intercepted = True
elif key == QtCore.Qt.Key_Backspace and not alt_down:
# Line deletion (remove continuation prompt)
len_prompt = len(self._continuation_prompt)
if not self._reading and \
cursor.columnNumber() == len_prompt and \
position != self._prompt_pos:
cursor.setPosition(position - len_prompt,
QtGui.QTextCursor.KeepAnchor)
cursor.removeSelectedText()
# Regular backwards deletion
else:
anchor = cursor.anchor()
if anchor == position:
intercepted = not self._in_buffer(position - 1)
else:
intercepted = not self._in_buffer(min(anchor, position))
elif key == QtCore.Qt.Key_Delete:
anchor = cursor.anchor()
intercepted = not self._in_buffer(min(anchor, position))
# Don't move cursor if control is down to allow copy-paste using
# the keyboard in any part of the buffer.
if not ctrl_down:
self._keep_cursor_in_buffer()
if not intercepted:
QtGui.QPlainTextEdit.keyPressEvent(self, event)
#--------------------------------------------------------------------------
# 'QPlainTextEdit' interface
#--------------------------------------------------------------------------
def appendHtml(self, html):
""" Reimplemented to not append HTML as a new paragraph, which doesn't
make sense for a console widget.
"""
cursor = self._get_end_cursor()
cursor.insertHtml(html)
# After appending HTML, the text document "remembers" the current
# formatting, which means that subsequent calls to 'appendPlainText'
# will be formatted similarly, a behavior that we do not want. To
# prevent this, we make sure that the last character has no formatting.
cursor.movePosition(QtGui.QTextCursor.Left,
QtGui.QTextCursor.KeepAnchor)
if cursor.selection().toPlainText().trimmed().isEmpty():
# If the last character is whitespace, it doesn't matter how it's
# formatted, so just clear the formatting.
cursor.setCharFormat(QtGui.QTextCharFormat())
else:
# Otherwise, add an unformatted space.
cursor.movePosition(QtGui.QTextCursor.Right)
cursor.insertText(' ', QtGui.QTextCharFormat())
def appendPlainText(self, text):
""" Reimplemented to not append text as a new paragraph, which doesn't
make sense for a console widget. Also, if enabled, handle ANSI
codes.
"""
cursor = self._get_end_cursor()
if self.ansi_codes:
for substring in self._ansi_processor.split_string(text):
format = self._ansi_processor.get_format()
cursor.insertText(substring, format)
else:
cursor.insertText(text)
def clear(self, keep_input=False):
""" Reimplemented to write a new prompt. If 'keep_input' is set,
restores the old input buffer when the new prompt is written.
"""
QtGui.QPlainTextEdit.clear(self)
if keep_input:
input_buffer = self.input_buffer
self._show_prompt()
if keep_input:
self.input_buffer = input_buffer
def paste(self):
""" Reimplemented to ensure that text is pasted in the editing region.
"""
self._keep_cursor_in_buffer()
QtGui.QPlainTextEdit.paste(self)
def print_(self, printer):
""" Reimplemented to work around a bug in PyQt: the C++ level 'print_'
slot has the wrong signature.
"""
QtGui.QPlainTextEdit.print_(self, printer)
#---------------------------------------------------------------------------
# 'ConsoleWidget' public interface
#---------------------------------------------------------------------------
def execute(self, source=None, hidden=False, interactive=False):
""" Executes source or the input buffer, possibly prompting for more
input.
Parameters:
-----------
source : str, optional
The source to execute. If not specified, the input buffer will be
used. If specified and 'hidden' is False, the input buffer will be
replaced with the source before execution.
hidden : bool, optional (default False)
If set, no output will be shown and the prompt will not be modified.
In other words, it will be completely invisible to the user that
an execution has occurred.
interactive : bool, optional (default False)
Whether the console is to treat the source as having been manually
entered by the user. The effect of this parameter depends on the
subclass implementation.
Raises:
-------
RuntimeError
If incomplete input is given and 'hidden' is True. In this case,
it not possible to prompt for more input.
Returns:
--------
A boolean indicating whether the source was executed.
"""
if not hidden:
if source is not None:
self.input_buffer = source
self.appendPlainText('\n')
self._executing_input_buffer = self.input_buffer
self._executing = True
self._prompt_finished()
real_source = self.input_buffer if source is None else source
complete = self._is_complete(real_source, interactive)
if complete:
if not hidden:
# The maximum block count is only in effect during execution.
# This ensures that _prompt_pos does not become invalid due to
# text truncation.
self.setMaximumBlockCount(self.buffer_size)
self._execute(real_source, hidden)
elif hidden:
raise RuntimeError('Incomplete noninteractive input: "%s"' % source)
else:
self._show_continuation_prompt()
return complete
def _get_input_buffer(self):
""" The text that the user has entered entered at the current prompt.
"""
# If we're executing, the input buffer may not even exist anymore due to
# the limit imposed by 'buffer_size'. Therefore, we store it.
if self._executing:
return self._executing_input_buffer
cursor = self._get_end_cursor()
cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
input_buffer = str(cursor.selection().toPlainText())
# Strip out continuation prompts.
return input_buffer.replace('\n' + self._continuation_prompt, '\n')
def _set_input_buffer(self, string):
""" Replaces the text in the input buffer with 'string'.
"""
# Add continuation prompts where necessary.
lines = string.splitlines()
for i in xrange(1, len(lines)):
lines[i] = self._continuation_prompt + lines[i]
string = '\n'.join(lines)
# Replace buffer with new text.
cursor = self._get_end_cursor()
cursor.setPosition(self._prompt_pos, QtGui.QTextCursor.KeepAnchor)
cursor.insertText(string)
self.moveCursor(QtGui.QTextCursor.End)
input_buffer = property(_get_input_buffer, _set_input_buffer)
def _get_input_buffer_cursor_line(self):
""" The text in the line of the input buffer in which the user's cursor
rests. Returns a string if there is such a line; otherwise, None.
"""
if self._executing:
return None
cursor = self.textCursor()
if cursor.position() >= self._prompt_pos:
text = self._get_block_plain_text(cursor.block())
if cursor.blockNumber() == self._get_prompt_cursor().blockNumber():
return text[len(self._prompt):]
else:
return text[len(self._continuation_prompt):]
else:
return None
input_buffer_cursor_line = property(_get_input_buffer_cursor_line)
def _get_font(self):
""" The base font being used by the ConsoleWidget.
"""
return self.document().defaultFont()
def _set_font(self, font):
""" Sets the base font for the ConsoleWidget to the specified QFont.
"""
font_metrics = QtGui.QFontMetrics(font)
self.setTabStopWidth(self.tab_width * font_metrics.width(' '))
self._completion_widget.setFont(font)
self.document().setDefaultFont(font)
font = property(_get_font, _set_font)
def reset_font(self):
""" Sets the font to the default fixed-width font for this platform.
"""
if sys.platform == 'win32':
name = 'Courier'
elif sys.platform == 'darwin':
name = 'Monaco'
else:
name = 'Monospace'
font = QtGui.QFont(name, QtGui.qApp.font().pointSize())
font.setStyleHint(QtGui.QFont.TypeWriter)
self._set_font(font)
#---------------------------------------------------------------------------
# 'ConsoleWidget' abstract interface
#---------------------------------------------------------------------------
def _is_complete(self, source, interactive):
""" Returns whether 'source' can be executed. When triggered by an
Enter/Return key press, 'interactive' is True; otherwise, it is
False.
"""
raise NotImplementedError
def _execute(self, source, hidden):
""" Execute 'source'. If 'hidden', do not show any output.
"""
raise NotImplementedError
def _prompt_started_hook(self):
""" Called immediately after a new prompt is displayed.
"""
pass
def _prompt_finished_hook(self):
""" Called immediately after a prompt is finished, i.e. when some input
will be processed and a new prompt displayed.
"""
pass
def _up_pressed(self):
""" Called when the up key is pressed. Returns whether to continue
processing the event.
"""
return True
def _down_pressed(self):
""" Called when the down key is pressed. Returns whether to continue
processing the event.
"""
return True
def _tab_pressed(self):
""" Called when the tab key is pressed. Returns whether to continue
processing the event.
"""
return False
#--------------------------------------------------------------------------
# 'ConsoleWidget' protected interface
#--------------------------------------------------------------------------
def _append_html_fetching_plain_text(self, html):
""" Appends 'html', then returns the plain text version of it.
"""
anchor = self._get_end_cursor().position()
self.appendHtml(html)
cursor = self._get_end_cursor()
cursor.setPosition(anchor, QtGui.QTextCursor.KeepAnchor)
return str(cursor.selection().toPlainText())
def _append_plain_text_keeping_prompt(self, text):
""" Writes 'text' after the current prompt, then restores the old prompt
with its old input buffer.
"""
input_buffer = self.input_buffer
self.appendPlainText('\n')
self._prompt_finished()
self.appendPlainText(text)
self._show_prompt()
self.input_buffer = input_buffer
def _control_down(self, modifiers):
""" Given a KeyboardModifiers flags object, return whether the Control
key is down (on Mac OS, treat the Command key as a synonym for
Control).
"""
down = bool(modifiers & QtCore.Qt.ControlModifier)
# Note: on Mac OS, ControlModifier corresponds to the Command key while
# MetaModifier corresponds to the Control key.
if sys.platform == 'darwin':
down = down ^ bool(modifiers & QtCore.Qt.MetaModifier)
return down
def _complete_with_items(self, cursor, items):
""" Performs completion with 'items' at the specified cursor location.
"""
if len(items) == 1:
cursor.setPosition(self.textCursor().position(),
QtGui.QTextCursor.KeepAnchor)
cursor.insertText(items[0])
elif len(items) > 1:
if self.gui_completion:
self._completion_widget.show_items(cursor, items)
else:
text = '\n'.join(items) + '\n'
self._append_plain_text_keeping_prompt(text)
def _get_block_plain_text(self, block):
""" Given a QTextBlock, return its unformatted text.
"""
cursor = QtGui.QTextCursor(block)
cursor.movePosition(QtGui.QTextCursor.StartOfBlock)
cursor.movePosition(QtGui.QTextCursor.EndOfBlock,
QtGui.QTextCursor.KeepAnchor)
return str(cursor.selection().toPlainText())
def _get_end_cursor(self):
""" Convenience method that returns a cursor for the last character.
"""
cursor = self.textCursor()
cursor.movePosition(QtGui.QTextCursor.End)
return cursor
def _get_prompt_cursor(self):
""" Convenience method that returns a cursor for the prompt position.
"""
cursor = self.textCursor()
cursor.setPosition(self._prompt_pos)
return cursor
def _get_selection_cursor(self, start, end):
""" Convenience method that returns a cursor with text selected between
the positions 'start' and 'end'.
"""
cursor = self.textCursor()
cursor.setPosition(start)
cursor.setPosition(end, QtGui.QTextCursor.KeepAnchor)
return cursor
def _get_word_start_cursor(self, position):
""" Find the start of the word to the left the given position. If a
sequence of non-word characters precedes the first word, skip over
them. (This emulates the behavior of bash, emacs, etc.)
"""
document = self.document()
position -= 1
while self._in_buffer(position) and \
not document.characterAt(position).isLetterOrNumber():
position -= 1
while self._in_buffer(position) and \
document.characterAt(position).isLetterOrNumber():
position -= 1
cursor = self.textCursor()
cursor.setPosition(position + 1)
return cursor
def _get_word_end_cursor(self, position):
""" Find the end of the word to the right the given position. If a
sequence of non-word characters precedes the first word, skip over
them. (This emulates the behavior of bash, emacs, etc.)
"""
document = self.document()
end = self._get_end_cursor().position()
while position < end and \
not document.characterAt(position).isLetterOrNumber():
position += 1
while position < end and \
document.characterAt(position).isLetterOrNumber():
position += 1
cursor = self.textCursor()
cursor.setPosition(position)
return cursor
def _prompt_started(self):
""" Called immediately after a new prompt is displayed.
"""
# Temporarily disable the maximum block count to permit undo/redo and
# to ensure that the prompt position does not change due to truncation.
self.setMaximumBlockCount(0)
self.setUndoRedoEnabled(True)
self.setReadOnly(False)
self.moveCursor(QtGui.QTextCursor.End)
self.centerCursor()
self._executing = False
self._prompt_started_hook()
def _prompt_finished(self):
""" Called immediately after a prompt is finished, i.e. when some input
will be processed and a new prompt displayed.
"""
self.setUndoRedoEnabled(False)
self.setReadOnly(True)
self._prompt_finished_hook()
def _readline(self, prompt='', callback=None):
""" Reads one line of input from the user.
Parameters
----------
prompt : str, optional
The prompt to print before reading the line.
callback : callable, optional
A callback to execute with the read line. If not specified, input is
read *synchronously* and this method does not return until it has
been read.
Returns
-------
If a callback is specified, returns nothing. Otherwise, returns the
input string with the trailing newline stripped.
"""
if self._reading:
raise RuntimeError('Cannot read a line. Widget is already reading.')
if not callback and not self.isVisible():
# If the user cannot see the widget, this function cannot return.
raise RuntimeError('Cannot synchronously read a line if the widget'
'is not visible!')
self._reading = True
self._show_prompt(prompt, newline=False)
if callback is None:
self._reading_callback = None
while self._reading:
QtCore.QCoreApplication.processEvents()
return self.input_buffer.rstrip('\n')
else:
self._reading_callback = lambda: \
callback(self.input_buffer.rstrip('\n'))
def _reset(self):
""" Clears the console and resets internal state variables.
"""
QtGui.QPlainTextEdit.clear(self)
self._executing = self._reading = False
def _set_continuation_prompt(self, prompt, html=False):
""" Sets the continuation prompt.
Parameters
----------
prompt : str
The prompt to show when more input is needed.
html : bool, optional (default False)
If set, the prompt will be inserted as formatted HTML. Otherwise,
the prompt will be treated as plain text, though ANSI color codes
will be handled.
"""
if html:
self._continuation_prompt_html = prompt
else:
self._continuation_prompt = prompt
self._continuation_prompt_html = None
def _set_position(self, position):
""" Convenience method to set the position of the cursor.
"""
cursor = self.textCursor()
cursor.setPosition(position)
self.setTextCursor(cursor)
def _set_selection(self, start, end):
""" Convenience method to set the current selected text.
"""
self.setTextCursor(self._get_selection_cursor(start, end))
def _show_prompt(self, prompt=None, html=False, newline=True):
""" Writes a new prompt at the end of the buffer.
Parameters
----------
prompt : str, optional
The prompt to show. If not specified, the previous prompt is used.
html : bool, optional (default False)
Only relevant when a prompt is specified. If set, the prompt will
be inserted as formatted HTML. Otherwise, the prompt will be treated
as plain text, though ANSI color codes will be handled.
newline : bool, optional (default True)
If set, a new line will be written before showing the prompt if
there is not already a newline at the end of the buffer.
"""
# Insert a preliminary newline, if necessary.
if newline:
cursor = self._get_end_cursor()
if cursor.position() > 0:
cursor.movePosition(QtGui.QTextCursor.Left,
QtGui.QTextCursor.KeepAnchor)
if str(cursor.selection().toPlainText()) != '\n':
self.appendPlainText('\n')
# Write the prompt.
if prompt is None:
if self._prompt_html is None:
self.appendPlainText(self._prompt)
else:
self.appendHtml(self._prompt_html)
else:
if html:
self._prompt = self._append_html_fetching_plain_text(prompt)
self._prompt_html = prompt
else:
self.appendPlainText(prompt)
self._prompt = prompt
self._prompt_html = None
self._prompt_pos = self._get_end_cursor().position()
self._prompt_started()
def _show_continuation_prompt(self):
""" Writes a new continuation prompt at the end of the buffer.
"""
if self._continuation_prompt_html is None:
self.appendPlainText(self._continuation_prompt)
else:
self._continuation_prompt = self._append_html_fetching_plain_text(
self._continuation_prompt_html)
self._prompt_started()
def _in_buffer(self, position):
""" Returns whether the given position is inside the editing region.
"""
return position >= self._prompt_pos
def _keep_cursor_in_buffer(self):
""" Ensures that the cursor is inside the editing region. Returns
whether the cursor was moved.
"""
cursor = self.textCursor()
if cursor.position() < self._prompt_pos:
cursor.movePosition(QtGui.QTextCursor.End)
self.setTextCursor(cursor)
return True
else:
return False
class HistoryConsoleWidget(ConsoleWidget):
""" A ConsoleWidget that keeps a history of the commands that have been
executed.
"""
#---------------------------------------------------------------------------
# 'QObject' interface
#---------------------------------------------------------------------------
def __init__(self, parent=None):
super(HistoryConsoleWidget, self).__init__(parent)
self._history = []
self._history_index = 0
#---------------------------------------------------------------------------
# 'ConsoleWidget' public interface
#---------------------------------------------------------------------------
def execute(self, source=None, hidden=False, interactive=False):
""" Reimplemented to the store history.
"""
if not hidden:
history = self.input_buffer if source is None else source
executed = super(HistoryConsoleWidget, self).execute(
source, hidden, interactive)
if executed and not hidden:
self._history.append(history.rstrip())
self._history_index = len(self._history)
return executed
#---------------------------------------------------------------------------
# 'ConsoleWidget' abstract interface
#---------------------------------------------------------------------------
def _up_pressed(self):
""" Called when the up key is pressed. Returns whether to continue
processing the event.
"""
prompt_cursor = self._get_prompt_cursor()
if self.textCursor().blockNumber() == prompt_cursor.blockNumber():
self.history_previous()
# Go to the first line of prompt for seemless history scrolling.
cursor = self._get_prompt_cursor()
cursor.movePosition(QtGui.QTextCursor.EndOfLine)
self.setTextCursor(cursor)
return False
return True
def _down_pressed(self):
""" Called when the down key is pressed. Returns whether to continue
processing the event.
"""
end_cursor = self._get_end_cursor()
if self.textCursor().blockNumber() == end_cursor.blockNumber():
self.history_next()
return False
return True
#---------------------------------------------------------------------------
# 'HistoryConsoleWidget' interface
#---------------------------------------------------------------------------
def history_previous(self):
""" If possible, set the input buffer to the previous item in the
history.
"""
if self._history_index > 0:
self._history_index -= 1
self.input_buffer = self._history[self._history_index]
def history_next(self):
""" Set the input buffer to the next item in the history, or a blank
line if there is no subsequent item.
"""
if self._history_index < len(self._history):
self._history_index += 1
if self._history_index < len(self._history):
self.input_buffer = self._history[self._history_index]
else:
self.input_buffer = ''