The CallTipWidget is now smarter about automatically hiding itself.

IPython/frontend/qt/console/call_tip_widget.py

@@ -1,181 +1,214
 # Standard library imports
 import re
 from textwrap import dedent
 
 # System library imports
 from PyQt4 import QtCore, QtGui
 
 
 class CallTipWidget(QtGui.QLabel):
     """ Shows call tips by parsing the current text of Q[Plain]TextEdit.
     """
 
     #--------------------------------------------------------------------------
     # 'QObject' interface
     #--------------------------------------------------------------------------
 
     def __init__(self, parent):
         """ Create a call tip manager that is attached to the specified Qt
             text edit widget.
         """
         assert isinstance(parent, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
         QtGui.QLabel.__init__(self, parent, QtCore.Qt.ToolTip)
 
+        self._hide_timer = QtCore.QBasicTimer()
+
         self.setFont(parent.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) / 255.0)
 
     def eventFilter(self, obj, event):
         """ Reimplemented to hide on certain key presses and on parent focus
             changes.
         """
         if obj == self.parent():
             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._hide_later()
+
         return QtGui.QLabel.eventFilter(self, 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.
+        """
+        QtGui.QLabel.enterEvent(self, event)
+        self._hide_timer.stop()
+
     def hideEvent(self, event):
         """ Reimplemented to disconnect signal handlers and event filter.
         """
         QtGui.QLabel.hideEvent(self, event)
         parent = self.parent()
         parent.cursorPositionChanged.disconnect(self._cursor_position_changed)
         parent.removeEventFilter(self)
 
+    def leaveEvent(self, event):
+        """ Reimplemented to start the hide timer.
+        """
+        QtGui.QLabel.leaveEvent(self, event)
+        self._hide_later()
+
     def paintEvent(self, event):
         """ Reimplemented to paint the background panel.
         """
         painter = QtGui.QStylePainter(self)
         option = QtGui.QStyleOptionFrame()
         option.init(self)
         painter.drawPrimitive(QtGui.QStyle.PE_PanelTipLabel, option)
         painter.end()
 
         QtGui.QLabel.paintEvent(self, event)
 
     def showEvent(self, event):
         """ Reimplemented to connect signal handlers and event filter.
         """
         QtGui.QLabel.showEvent(self, event)
         parent = self.parent()
         parent.cursorPositionChanged.connect(self._cursor_position_changed)
         parent.installEventFilter(self)
 
     #--------------------------------------------------------------------------
     # 'CallTipWidget' interface
     #--------------------------------------------------------------------------
 
     def show_docstring(self, doc, maxlines=20):
         """ Attempts to show the specified docstring at the current cursor
             location. The docstring is dedented and possibly truncated for
             length.
         """
         doc = dedent(doc.rstrip()).lstrip()
         match = re.match("(?:[^\n]*\n){%i}" % maxlines, doc)
         if match:
             doc = doc[:match.end()] + '\n[Documentation continues...]'
         return self.show_tip(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.parent()
         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, place it above
         # the current line.
         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()
         if point.y() + tip_height > screen_rect.height():
             point = text_edit.mapToGlobal(cursor_rect.topRight())
             point.setY(point.y() - tip_height - 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.parent().document()
         qchar = document.characterAt(position)
         while (position > 0 and qchar.isPrint() and 
                # Need to check explicitly for line/paragraph separators:
                qchar.unicode() not in (0x2028, 0x2029)):
             char = qchar.toAscii()
             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
             qchar = document.characterAt(position)
         else:
             position = -1
         return position, commas
 
+    def _hide_later(self):
+        """ Hides the tooltip after some time has passed.
+        """
+        if not self._hide_timer.isActive():
+            self._hide_timer.start(300, self)
+
     #------ Signal handlers ----------------------------------------------------
 
     def _cursor_position_changed(self):
         """ Updates the tip based on user cursor movement.
         """
         cursor = self.parent().textCursor()
         if cursor.position() <= self._start_position:
             self.hide()
         else:
             position, commas = self._find_parenthesis(self._start_position + 1)
             if position != -1:
                 self.hide()