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Backport PR #4118: ZMQ heartbeat channel: catch EINTR exceptions and continue....
Backport PR #4118: ZMQ heartbeat channel: catch EINTR exceptions and continue. The zmq heartbeat channel exits when it encounters an "Interrupted system call", thereby causing the qtconsole to report that it is not responding, despite the console working perfectly fine. Observed in a large Qt application embedding the ipython qtconsole in KDE desktop. Fixes #2310 Inspired by #501

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call_tip_widget.py
275 lines | 10.5 KiB | text/x-python | PythonLexer
# Standard library imports
import re
from unicodedata import category
# System library imports
from IPython.external.qt import QtCore, QtGui
class CallTipWidget(QtGui.QLabel):
""" Shows call tips by parsing the current text of Q[Plain]TextEdit.
"""
#--------------------------------------------------------------------------
# 'QObject' interface
#--------------------------------------------------------------------------
def __init__(self, text_edit):
""" Create a call tip manager that is attached to the specified Qt
text edit widget.
"""
assert isinstance(text_edit, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
super(CallTipWidget, self).__init__(None, QtCore.Qt.ToolTip)
self._hide_timer = QtCore.QBasicTimer()
self._text_edit = text_edit
self.setFont(text_edit.document().defaultFont())
self.setForegroundRole(QtGui.QPalette.ToolTipText)
self.setBackgroundRole(QtGui.QPalette.ToolTipBase)
self.setPalette(QtGui.QToolTip.palette())
self.setAlignment(QtCore.Qt.AlignLeft)
self.setIndent(1)
self.setFrameStyle(QtGui.QFrame.NoFrame)
self.setMargin(1 + self.style().pixelMetric(
QtGui.QStyle.PM_ToolTipLabelFrameWidth, None, self))
self.setWindowOpacity(self.style().styleHint(
QtGui.QStyle.SH_ToolTipLabel_Opacity, None, self, None) / 255.0)
def eventFilter(self, obj, event):
""" Reimplemented to hide on certain key presses and on text edit focus
changes.
"""
if obj == self._text_edit:
etype = event.type()
if etype == QtCore.QEvent.KeyPress:
key = event.key()
if key in (QtCore.Qt.Key_Enter, QtCore.Qt.Key_Return):
self.hide()
elif key == QtCore.Qt.Key_Escape:
self.hide()
return True
elif etype == QtCore.QEvent.FocusOut:
self.hide()
elif etype == QtCore.QEvent.Enter:
self._hide_timer.stop()
elif etype == QtCore.QEvent.Leave:
self._leave_event_hide()
return super(CallTipWidget, self).eventFilter(obj, event)
def timerEvent(self, event):
""" Reimplemented to hide the widget when the hide timer fires.
"""
if event.timerId() == self._hide_timer.timerId():
self._hide_timer.stop()
self.hide()
#--------------------------------------------------------------------------
# 'QWidget' interface
#--------------------------------------------------------------------------
def enterEvent(self, event):
""" Reimplemented to cancel the hide timer.
"""
super(CallTipWidget, self).enterEvent(event)
self._hide_timer.stop()
def hideEvent(self, event):
""" Reimplemented to disconnect signal handlers and event filter.
"""
super(CallTipWidget, self).hideEvent(event)
self._text_edit.cursorPositionChanged.disconnect(
self._cursor_position_changed)
self._text_edit.removeEventFilter(self)
def leaveEvent(self, event):
""" Reimplemented to start the hide timer.
"""
super(CallTipWidget, self).leaveEvent(event)
self._leave_event_hide()
def paintEvent(self, event):
""" Reimplemented to paint the background panel.
"""
painter = QtGui.QStylePainter(self)
option = QtGui.QStyleOptionFrame()
option.initFrom(self)
painter.drawPrimitive(QtGui.QStyle.PE_PanelTipLabel, option)
painter.end()
super(CallTipWidget, self).paintEvent(event)
def setFont(self, font):
""" Reimplemented to allow use of this method as a slot.
"""
super(CallTipWidget, self).setFont(font)
def showEvent(self, event):
""" Reimplemented to connect signal handlers and event filter.
"""
super(CallTipWidget, self).showEvent(event)
self._text_edit.cursorPositionChanged.connect(
self._cursor_position_changed)
self._text_edit.installEventFilter(self)
#--------------------------------------------------------------------------
# 'CallTipWidget' interface
#--------------------------------------------------------------------------
def show_call_info(self, call_line=None, doc=None, maxlines=20):
""" Attempts to show the specified call line and docstring at the
current cursor location. The docstring is possibly truncated for
length.
"""
if doc:
match = re.match("(?:[^\n]*\n){%i}" % maxlines, doc)
if match:
doc = doc[:match.end()] + '\n[Documentation continues...]'
else:
doc = ''
if call_line:
doc = '\n\n'.join([call_line, doc])
return self.show_tip(self._format_tooltip(doc))
def show_tip(self, tip):
""" Attempts to show the specified tip at the current cursor location.
"""
# Attempt to find the cursor position at which to show the call tip.
text_edit = self._text_edit
document = text_edit.document()
cursor = text_edit.textCursor()
search_pos = cursor.position() - 1
self._start_position, _ = self._find_parenthesis(search_pos,
forward=False)
if self._start_position == -1:
return False
# Set the text and resize the widget accordingly.
self.setText(tip)
self.resize(self.sizeHint())
# Locate and show the widget. Place the tip below the current line
# unless it would be off the screen. In that case, decide the best
# location based trying to minimize the area that goes off-screen.
padding = 3 # Distance in pixels between cursor bounds and tip box.
cursor_rect = text_edit.cursorRect(cursor)
screen_rect = QtGui.qApp.desktop().screenGeometry(text_edit)
point = text_edit.mapToGlobal(cursor_rect.bottomRight())
point.setY(point.y() + padding)
tip_height = self.size().height()
tip_width = self.size().width()
vertical = 'bottom'
horizontal = 'Right'
if point.y() + tip_height > screen_rect.height():
point_ = text_edit.mapToGlobal(cursor_rect.topRight())
# If tip is still off screen, check if point is in top or bottom
# half of screen.
if point_.y() - tip_height < padding:
# If point is in upper half of screen, show tip below it.
# otherwise above it.
if 2*point.y() < screen_rect.height():
vertical = 'bottom'
else:
vertical = 'top'
else:
vertical = 'top'
if point.x() + tip_width > screen_rect.width():
point_ = text_edit.mapToGlobal(cursor_rect.topRight())
# If tip is still off-screen, check if point is in the right or
# left half of the screen.
if point_.x() - tip_width < padding:
if 2*point.x() < screen_rect.width():
horizontal = 'Right'
else:
horizontal = 'Left'
else:
horizontal = 'Left'
pos = getattr(cursor_rect, '%s%s' %(vertical, horizontal))
point = text_edit.mapToGlobal(pos())
if vertical == 'top':
point.setY(point.y() - tip_height - padding)
if horizontal == 'Left':
point.setX(point.x() - tip_width - padding)
self.move(point)
self.show()
return True
#--------------------------------------------------------------------------
# Protected interface
#--------------------------------------------------------------------------
def _find_parenthesis(self, position, forward=True):
""" If 'forward' is True (resp. False), proceed forwards
(resp. backwards) through the line that contains 'position' until an
unmatched closing (resp. opening) parenthesis is found. Returns a
tuple containing the position of this parenthesis (or -1 if it is
not found) and the number commas (at depth 0) found along the way.
"""
commas = depth = 0
document = self._text_edit.document()
char = document.characterAt(position)
# Search until a match is found or a non-printable character is
# encountered.
while category(char) != 'Cc' and position > 0:
if char == ',' and depth == 0:
commas += 1
elif char == ')':
if forward and depth == 0:
break
depth += 1
elif char == '(':
if not forward and depth == 0:
break
depth -= 1
position += 1 if forward else -1
char = document.characterAt(position)
else:
position = -1
return position, commas
def _leave_event_hide(self):
""" Hides the tooltip after some time has passed (assuming the cursor is
not over the tooltip).
"""
if (not self._hide_timer.isActive() and
# If Enter events always came after Leave events, we wouldn't need
# this check. But on Mac OS, it sometimes happens the other way
# around when the tooltip is created.
QtGui.qApp.topLevelAt(QtGui.QCursor.pos()) != self):
self._hide_timer.start(300, self)
def _format_tooltip(self,doc):
import textwrap
# make sure a long argument list does not make
# the first row overflow the width of the actual tip body
rows = doc.split("\n")
# An object which is not a callable has '<no docstring>' as doc
if len(rows) == 1:
return doc
max_text_width = max(80, max([len(x) for x in rows[1:]]))
rows= textwrap.wrap(rows[0],max_text_width) + rows[1:]
doc = "\n".join(rows)
return doc
#------ Signal handlers ----------------------------------------------------
def _cursor_position_changed(self):
""" Updates the tip based on user cursor movement.
"""
cursor = self._text_edit.textCursor()
if cursor.position() <= self._start_position:
self.hide()
else:
position, commas = self._find_parenthesis(self._start_position + 1)
if position != -1:
self.hide()