Polishing things up
[ejpi] / src / libraries / qtpie.py
index 7eef79c..884d5ce 100755 (executable)
@@ -1,10 +1,29 @@
 #!/usr/bin/env python
 
 import math
+import logging
 
 from PyQt4 import QtGui
 from PyQt4 import QtCore
 
+try:
+       from util import misc as misc_utils
+except ImportError:
+       class misc_utils(object):
+
+               @staticmethod
+               def log_exception(logger):
+
+                       def wrapper(func):
+                               return func
+                       return wrapper
+
+
+_moduleLogger = logging.getLogger(__name__)
+
+
+_TWOPI = 2 * math.pi
+
 
 def _radius_at(center, pos):
        delta = pos - center
@@ -23,7 +42,7 @@ def _angle_at(center, pos):
        radius = math.sqrt(xDelta ** 2 + yDelta ** 2)
        angle = math.acos(xDelta / radius)
        if 0 <= yDelta:
-               angle = 2*math.pi - angle
+               angle = _TWOPI - angle
 
        return angle
 
@@ -52,8 +71,8 @@ class QActionPieItem(object):
 
 class PieFiling(object):
 
-       INNER_RADIUS_DEFAULT = 32
-       OUTER_RADIUS_DEFAULT = 128
+       INNER_RADIUS_DEFAULT = 64
+       OUTER_RADIUS_DEFAULT = 192
 
        SELECTION_CENTER = -1
        SELECTION_NONE = -2
@@ -66,11 +85,16 @@ class PieFiling(object):
                self._children = []
                self._center = self.NULL_CENTER
 
+               self._cacheIndexToAngle = {}
+               self._cacheTotalWeight = 0
+
        def insertItem(self, item, index = -1):
                self._children.insert(index, item)
+               self._invalidate_cache()
 
        def removeItemAt(self, index):
                item = self._children.pop(index)
+               self._invalidate_cache()
 
        def set_center(self, item):
                if item is None:
@@ -82,6 +106,8 @@ class PieFiling(object):
 
        def clear(self):
                del self._children[:]
+               self._center = self.NULL_CENTER
+               self._invalidate_cache()
 
        def itemAt(self, index):
                return self._children[index]
@@ -110,13 +136,19 @@ class PieFiling(object):
        def __getitem__(self, index):
                return self._children[index]
 
+       def _invalidate_cache(self):
+               self._cacheIndexToAngle.clear()
+               self._cacheTotalWeight = sum(child.weight() for child in self._children)
+               if self._cacheTotalWeight == 0:
+                       self._cacheTotalWeight = 1
+
        def _index_to_angle(self, index, isShifted):
+               key = index, isShifted
+               if key in self._cacheIndexToAngle:
+                       return self._cacheIndexToAngle[key]
                index = index % len(self._children)
 
-               totalWeight = sum(child.weight() for child in self._children)
-               if totalWeight == 0:
-                       totalWeight = 1
-               baseAngle = (2 * math.pi) / totalWeight
+               baseAngle = _TWOPI / self._cacheTotalWeight
 
                angle = math.pi / 2
                if isShifted:
@@ -125,15 +157,16 @@ class PieFiling(object):
                        else:
                                angle -= baseAngle / 2
                while angle < 0:
-                       angle += 2*math.pi
+                       angle += _TWOPI
 
                for i, child in enumerate(self._children):
                        if index < i:
                                break
                        angle += child.weight() * baseAngle
-               while (2*math.pi) < angle:
-                       angle -= 2*math.pi
+               while _TWOPI < angle:
+                       angle -= _TWOPI
 
+               self._cacheIndexToAngle[key] = angle
                return angle
 
        def _angle_to_index(self, angle):
@@ -141,28 +174,29 @@ class PieFiling(object):
                if numChildren == 0:
                        return self.SELECTION_CENTER
 
-               totalWeight = sum(child.weight() for child in self._children)
-               if totalWeight == 0:
-                       totalWeight = 1
-               baseAngle = (2 * math.pi) / totalWeight
+               baseAngle = _TWOPI / self._cacheTotalWeight
 
                iterAngle = math.pi / 2 - (self.itemAt(0).weight() * baseAngle) / 2
                while iterAngle < 0:
-                       iterAngle += 2 * math.pi
+                       iterAngle += _TWOPI
 
                oldIterAngle = iterAngle
                for index, child in enumerate(self._children):
                        iterAngle += child.weight() * baseAngle
                        if oldIterAngle < angle and angle <= iterAngle:
                                return index - 1 if index != 0 else numChildren - 1
-                       elif oldIterAngle < (angle + 2*math.pi) and (angle + 2*math.pi <= iterAngle):
+                       elif oldIterAngle < (angle + _TWOPI) and (angle + _TWOPI <= iterAngle):
                                return index - 1 if index != 0 else numChildren - 1
                        oldIterAngle = iterAngle
 
 
 class PieArtist(object):
 
-       ICON_SIZE_DEFAULT = 32
+       ICON_SIZE_DEFAULT = 48
+
+       SHAPE_CIRCLE = "circle"
+       SHAPE_SQUARE = "square"
+       DEFAULT_SHAPE = SHAPE_SQUARE
 
        def __init__(self, filing):
                self._filing = filing
@@ -226,16 +260,17 @@ class PieArtist(object):
                        if selectionIndex == PieFiling.SELECTION_CENTER and self._filing.center().isEnabled():
                                painter.setBrush(self.palette.highlight())
                        else:
-                               painter.setBrush(self.palette.background())
+                               painter.setBrush(self.palette.window())
+                       painter.setPen(self.palette.mid().color())
 
-                       painter.fillRect(self._canvas.rect(), painter.brush())
+                       painter.drawRect(self._canvas.rect())
                        self._paint_center_foreground(painter, selectionIndex)
                        return self._canvas
                elif numChildren == 1:
                        if selectionIndex == 0 and self._filing[0].isEnabled():
                                painter.setBrush(self.palette.highlight())
                        else:
-                               painter.setBrush(self.palette.background())
+                               painter.setBrush(self.palette.window())
 
                        painter.fillRect(self._canvas.rect(), painter.brush())
                else:
@@ -257,25 +292,40 @@ class PieArtist(object):
                painter = QtGui.QPainter(mask)
                painter.setPen(QtCore.Qt.color1)
                painter.setBrush(QtCore.Qt.color1)
-               painter.drawEllipse(mask.rect().adjusted(0, 0, -1, -1))
+               if self.DEFAULT_SHAPE == self.SHAPE_SQUARE:
+                       painter.drawRect(mask.rect())
+               elif self.DEFAULT_SHAPE == self.SHAPE_CIRCLE:
+                       painter.drawEllipse(mask.rect().adjusted(0, 0, -1, -1))
+               else:
+                       raise NotImplementedError(self.DEFAULT_SHAPE)
 
        def _paint_slice_background(self, painter, adjustmentRect, i, selectionIndex):
+               if self.DEFAULT_SHAPE == self.SHAPE_SQUARE:
+                       currentWidth = adjustmentRect.width()
+                       newWidth = math.sqrt(2) * currentWidth
+                       dx = (newWidth - currentWidth) / 2
+                       adjustmentRect = adjustmentRect.adjusted(-dx, -dx, dx, dx)
+               elif self.DEFAULT_SHAPE == self.SHAPE_CIRCLE:
+                       pass
+               else:
+                       raise NotImplementedError(self.DEFAULT_SHAPE)
+
                if i == selectionIndex and self._filing[i].isEnabled():
                        painter.setBrush(self.palette.highlight())
                else:
-                       painter.setBrush(self.palette.background())
+                       painter.setBrush(self.palette.window())
                painter.setPen(self.palette.mid().color())
 
                a = self._filing._index_to_angle(i, True)
                b = self._filing._index_to_angle(i + 1, True)
                if b < a:
-                       b += 2*math.pi
+                       b += _TWOPI
                size = b - a
                if size < 0:
-                       size += 2*math.pi
+                       size += _TWOPI
 
-               startAngleInDeg = (a * 360 * 16) / (2*math.pi)
-               sizeInDeg = (size * 360 * 16) / (2*math.pi)
+               startAngleInDeg = (a * 360 * 16) / _TWOPI
+               sizeInDeg = (size * 360 * 16) / _TWOPI
                painter.drawPie(adjustmentRect, int(startAngleInDeg), int(sizeInDeg))
 
        def _paint_slice_foreground(self, painter, i, selectionIndex):
@@ -284,7 +334,7 @@ class PieArtist(object):
                a = self._filing._index_to_angle(i, True)
                b = self._filing._index_to_angle(i + 1, True)
                if b < a:
-                       b += 2*math.pi
+                       b += _TWOPI
                middleAngle = (a + b) / 2
                averageRadius = (self._cachedInnerRadius + self._cachedOuterRadius) / 2
 
@@ -333,13 +383,13 @@ class PieArtist(object):
                                        brush = self.palette.highlight()
                                else:
                                        pen = self.palette.mid()
-                                       brush = self.palette.background()
+                                       brush = self.palette.window()
                        else:
                                if action.isEnabled():
-                                       pen = self.palette.text()
+                                       pen = self.palette.windowText()
                                else:
                                        pen = self.palette.mid()
-                               brush = self.palette.background()
+                               brush = self.palette.window()
 
                        leftX = x - averageWidth + iconWidth
                        topY = y + textHeight/2
@@ -348,12 +398,12 @@ class PieArtist(object):
                        painter.drawText(leftX, topY, text)
 
        def _paint_center_background(self, painter, adjustmentRect, selectionIndex):
-               dark = self.palette.dark().color()
+               dark = self.palette.mid().color()
                light = self.palette.light().color()
                if selectionIndex == PieFiling.SELECTION_CENTER and self._filing.center().isEnabled():
                        background = self.palette.highlight().color()
                else:
-                       background = self.palette.background().color()
+                       background = self.palette.window().color()
 
                innerRadius = self._cachedInnerRadius
                adjustmentCenterPos = adjustmentRect.center()
@@ -372,16 +422,14 @@ class PieArtist(object):
                painter.setBrush(QtCore.Qt.NoBrush)
                painter.drawEllipse(innerRect)
 
-               painter.setPen(QtGui.QPen(dark, 1))
-               painter.setBrush(QtCore.Qt.NoBrush)
-               painter.drawEllipse(adjustmentRect)
-
-               r = QtCore.QRect(innerRect)
-               innerCenter = r.center()
-               innerRect.setLeft(innerCenter.x() + ((r.left() - innerCenter.x()) / 3) * 1)
-               innerRect.setRight(innerCenter.x() + ((r.right() - innerCenter.x()) / 3) * 1)
-               innerRect.setTop(innerCenter.y() + ((r.top() - innerCenter.y()) / 3) * 1)
-               innerRect.setBottom(innerCenter.y() + ((r.bottom() - innerCenter.y()) / 3) * 1)
+               if self.DEFAULT_SHAPE == self.SHAPE_SQUARE:
+                       pass
+               elif self.DEFAULT_SHAPE == self.SHAPE_CIRCLE:
+                       painter.setPen(QtGui.QPen(dark, 1))
+                       painter.setBrush(QtCore.Qt.NoBrush)
+                       painter.drawEllipse(adjustmentRect)
+               else:
+                       raise NotImplementedError(self.DEFAULT_SHAPE)
 
        def _paint_center_foreground(self, painter, selectionIndex):
                centerPos = self._canvas.rect().center()
@@ -414,17 +462,20 @@ class QPieDisplay(QtGui.QWidget):
        def sizeHint(self):
                return self._artist.pieSize()
 
+       @misc_utils.log_exception(_moduleLogger)
        def showEvent(self, showEvent):
                mask = self._artist.show(self.palette())
                self.setMask(mask)
 
                QtGui.QWidget.showEvent(self, showEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def hideEvent(self, hideEvent):
                self._artist.hide()
                self._selectionIndex = PieFiling.SELECTION_NONE
                QtGui.QWidget.hideEvent(self, hideEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def paintEvent(self, paintEvent):
                canvas = self._artist.paint(self._selectionIndex)
 
@@ -434,8 +485,10 @@ class QPieDisplay(QtGui.QWidget):
                QtGui.QWidget.paintEvent(self, paintEvent)
 
        def selectAt(self, index):
+               oldIndex = self._selectionIndex
                self._selectionIndex = index
-               self.update()
+               if self.isVisible():
+                       self.update()
 
 
 class QPieButton(QtGui.QWidget):
@@ -446,19 +499,31 @@ class QPieButton(QtGui.QWidget):
        aboutToShow = QtCore.pyqtSignal()
        aboutToHide = QtCore.pyqtSignal()
 
+       BUTTON_RADIUS = 24
+       DELAY = 250
+
        def __init__(self, buttonSlice, parent = None):
+               # @bug Artifacts on Maemo 5 due to window 3D effects, find way to disable them for just these?
+               # @bug The pie's are being pushed back on screen on Maemo, leading to coordinate issues
                QtGui.QWidget.__init__(self, parent)
+               self._cachedCenterPosition = self.rect().center()
+
                self._filing = PieFiling()
                self._display = QPieDisplay(self._filing, None, QtCore.Qt.SplashScreen)
                self._selectionIndex = PieFiling.SELECTION_NONE
 
                self._buttonFiling = PieFiling()
                self._buttonFiling.set_center(buttonSlice)
+               self._buttonFiling.setOuterRadius(self.BUTTON_RADIUS)
                self._buttonArtist = PieArtist(self._buttonFiling)
-               centerSize = self._buttonArtist.centerSize()
-               self._buttonFiling.setOuterRadius(max(centerSize.width(), centerSize.height()))
                self._poppedUp = False
 
+               self._delayPopupTimer = QtCore.QTimer()
+               self._delayPopupTimer.setInterval(self.DELAY)
+               self._delayPopupTimer.setSingleShot(True)
+               self._delayPopupTimer.timeout.connect(self._on_delayed_popup)
+               self._popupLocation = None
+
                self._mousePosition = None
                self.setFocusPolicy(QtCore.Qt.StrongFocus)
 
@@ -481,7 +546,7 @@ class QPieButton(QtGui.QWidget):
                return self._filing.itemAt(index)
 
        def indexAt(self, point):
-               return self._filing.indexAt(self.rect().center(), point)
+               return self._filing.indexAt(self._cachedCenterPosition, point)
 
        def innerRadius(self):
                return self._filing.innerRadius()
@@ -495,21 +560,36 @@ class QPieButton(QtGui.QWidget):
        def setOuterRadius(self, radius):
                self._filing.setOuterRadius(radius)
 
-       def sizeHint(self):
-               return self._buttonArtist.pieSize()
+       def buttonRadius(self):
+               return self._buttonFiling.outerRadius()
+
+       def setButtonRadius(self, radius):
+               self._buttonFiling.setOuterRadius(radius)
+               self._buttonArtist.show(self.palette())
 
+       def minimumSizeHint(self):
+               return self._buttonArtist.centerSize()
+
+       @misc_utils.log_exception(_moduleLogger)
        def mousePressEvent(self, mouseEvent):
-               self._popup_child(mouseEvent.globalPos())
                lastSelection = self._selectionIndex
 
                lastMousePos = mouseEvent.pos()
                self._mousePosition = lastMousePos
-               self._update_selection(self.rect().center())
+               self._update_selection(self._cachedCenterPosition)
 
-               if lastSelection != self._selectionIndex:
-                       self.highlighted.emit(self._selectionIndex)
-                       self._display.selectAt(self._selectionIndex)
+               self.highlighted.emit(self._selectionIndex)
 
+               self._display.selectAt(self._selectionIndex)
+               self._popupLocation = mouseEvent.globalPos()
+               self._delayPopupTimer.start()
+
+       @misc_utils.log_exception(_moduleLogger)
+       def _on_delayed_popup(self):
+               assert self._popupLocation is not None
+               self._popup_child(self._popupLocation)
+
+       @misc_utils.log_exception(_moduleLogger)
        def mouseMoveEvent(self, mouseEvent):
                lastSelection = self._selectionIndex
 
@@ -519,13 +599,23 @@ class QPieButton(QtGui.QWidget):
                        self._update_selection(lastMousePos)
                else:
                        # Relative
-                       self._update_selection(self.rect().center() + (lastMousePos - self._mousePosition))
+                       self._update_selection(
+                               self._cachedCenterPosition + (lastMousePos - self._mousePosition),
+                               ignoreOuter = True,
+                       )
 
                if lastSelection != self._selectionIndex:
                        self.highlighted.emit(self._selectionIndex)
                        self._display.selectAt(self._selectionIndex)
 
+               if self._selectionIndex != PieFiling.SELECTION_CENTER and self._delayPopupTimer.isActive():
+                       self._on_delayed_popup()
+
+       @misc_utils.log_exception(_moduleLogger)
        def mouseReleaseEvent(self, mouseEvent):
+               self._delayPopupTimer.stop()
+               self._popupLocation = None
+
                lastSelection = self._selectionIndex
 
                lastMousePos = mouseEvent.pos()
@@ -534,12 +624,16 @@ class QPieButton(QtGui.QWidget):
                        self._update_selection(lastMousePos)
                else:
                        # Relative
-                       self._update_selection(self.rect().center() + (lastMousePos - self._mousePosition))
+                       self._update_selection(
+                               self._cachedCenterPosition + (lastMousePos - self._mousePosition),
+                               ignoreOuter = True,
+                       )
                self._mousePosition = None
 
                self._activate_at(self._selectionIndex)
                self._hide_child()
 
+       @misc_utils.log_exception(_moduleLogger)
        def keyPressEvent(self, keyEvent):
                if keyEvent.key() in [QtCore.Qt.Key_Right, QtCore.Qt.Key_Down, QtCore.Qt.Key_Tab]:
                        self._popup_child(QtGui.QCursor.pos())
@@ -562,25 +656,39 @@ class QPieButton(QtGui.QWidget):
                        self._select_at(PieFiling.SELECTION_CENTER)
                        self._display.selectAt(self._selectionIndex)
                elif keyEvent.key() in [QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter, QtCore.Qt.Key_Space]:
+                       self._delayPopupTimer.stop()
+                       self._popupLocation = None
                        self._activate_at(self._selectionIndex)
                        self._hide_child()
                elif keyEvent.key() in [QtCore.Qt.Key_Escape, QtCore.Qt.Key_Backspace]:
+                       self._delayPopupTimer.stop()
+                       self._popupLocation = None
                        self._activate_at(PieFiling.SELECTION_NONE)
                        self._hide_child()
                else:
                        QtGui.QWidget.keyPressEvent(self, keyEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
+       def resizeEvent(self, resizeEvent):
+               self.setButtonRadius(min(resizeEvent.size().width(), resizeEvent.size().height()) / 2 - 1)
+               QtGui.QWidget.resizeEvent(self, resizeEvent)
+
+       @misc_utils.log_exception(_moduleLogger)
        def showEvent(self, showEvent):
                self._buttonArtist.show(self.palette())
+               self._cachedCenterPosition = self.rect().center()
 
                QtGui.QWidget.showEvent(self, showEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def hideEvent(self, hideEvent):
                self._display.hide()
                self._select_at(PieFiling.SELECTION_NONE)
                QtGui.QWidget.hideEvent(self, hideEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def paintEvent(self, paintEvent):
+               self.setButtonRadius(min(self.rect().width(), self.rect().height()) / 2 - 1)
                if self._poppedUp:
                        canvas = self._buttonArtist.paint(PieFiling.SELECTION_CENTER)
                else:
@@ -591,10 +699,19 @@ class QPieButton(QtGui.QWidget):
 
                QtGui.QWidget.paintEvent(self, paintEvent)
 
+       def __iter__(self):
+               return iter(self._filing)
+
+       def __len__(self):
+               return len(self._filing)
+
        def _popup_child(self, position):
                self._poppedUp = True
                self.aboutToShow.emit()
 
+               self._delayPopupTimer.stop()
+               self._popupLocation = None
+
                position = position - QtCore.QPoint(self._filing.outerRadius(), self._filing.outerRadius())
                self._display.move(position)
                self._display.show()
@@ -610,11 +727,11 @@ class QPieButton(QtGui.QWidget):
        def _select_at(self, index):
                self._selectionIndex = index
 
-       def _update_selection(self, lastMousePos):
-               radius = _radius_at(self.rect().center(), lastMousePos)
+       def _update_selection(self, lastMousePos, ignoreOuter = False):
+               radius = _radius_at(self._cachedCenterPosition, lastMousePos)
                if radius < self._filing.innerRadius():
                        self._select_at(PieFiling.SELECTION_CENTER)
-               elif radius <= self._filing.outerRadius():
+               elif radius <= self._filing.outerRadius() or ignoreOuter:
                        self._select_at(self.indexAt(lastMousePos))
                else:
                        self._select_at(PieFiling.SELECTION_NONE)
@@ -645,6 +762,8 @@ class QPieMenu(QtGui.QWidget):
 
        def __init__(self, parent = None):
                QtGui.QWidget.__init__(self, parent)
+               self._cachedCenterPosition = self.rect().center()
+
                self._filing = PieFiling()
                self._artist = PieArtist(self._filing)
                self._selectionIndex = PieFiling.SELECTION_NONE
@@ -676,7 +795,7 @@ class QPieMenu(QtGui.QWidget):
                return self._filing.itemAt(index)
 
        def indexAt(self, point):
-               return self._filing.indexAt(self.rect().center(), point)
+               return self._filing.indexAt(self._cachedCenterPosition, point)
 
        def innerRadius(self):
                return self._filing.innerRadius()
@@ -695,6 +814,7 @@ class QPieMenu(QtGui.QWidget):
        def sizeHint(self):
                return self._artist.pieSize()
 
+       @misc_utils.log_exception(_moduleLogger)
        def mousePressEvent(self, mouseEvent):
                lastSelection = self._selectionIndex
 
@@ -706,6 +826,7 @@ class QPieMenu(QtGui.QWidget):
                        self.highlighted.emit(self._selectionIndex)
                        self.update()
 
+       @misc_utils.log_exception(_moduleLogger)
        def mouseMoveEvent(self, mouseEvent):
                lastSelection = self._selectionIndex
 
@@ -716,6 +837,7 @@ class QPieMenu(QtGui.QWidget):
                        self.highlighted.emit(self._selectionIndex)
                        self.update()
 
+       @misc_utils.log_exception(_moduleLogger)
        def mouseReleaseEvent(self, mouseEvent):
                lastSelection = self._selectionIndex
 
@@ -726,12 +848,21 @@ class QPieMenu(QtGui.QWidget):
                self._activate_at(self._selectionIndex)
                self.update()
 
+       @misc_utils.log_exception(_moduleLogger)
        def keyPressEvent(self, keyEvent):
                if keyEvent.key() in [QtCore.Qt.Key_Right, QtCore.Qt.Key_Down, QtCore.Qt.Key_Tab]:
-                       self._select_at(self._selectionIndex + 1)
+                       if self._selectionIndex != len(self._filing) - 1:
+                               nextSelection = self._selectionIndex + 1
+                       else:
+                               nextSelection = 0
+                       self._select_at(nextSelection)
                        self.update()
                elif keyEvent.key() in [QtCore.Qt.Key_Left, QtCore.Qt.Key_Up, QtCore.Qt.Key_Backtab]:
-                       self._select_at(self._selectionIndex - 1)
+                       if 0 < self._selectionIndex:
+                               nextSelection = self._selectionIndex - 1
+                       else:
+                               nextSelection = len(self._filing) - 1
+                       self._select_at(nextSelection)
                        self.update()
                elif keyEvent.key() in [QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter, QtCore.Qt.Key_Space]:
                        self._activate_at(self._selectionIndex)
@@ -740,8 +871,10 @@ class QPieMenu(QtGui.QWidget):
                else:
                        QtGui.QWidget.keyPressEvent(self, keyEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def showEvent(self, showEvent):
                self.aboutToShow.emit()
+               self._cachedCenterPosition = self.rect().center()
 
                mask = self._artist.show(self.palette())
                self.setMask(mask)
@@ -751,11 +884,13 @@ class QPieMenu(QtGui.QWidget):
 
                QtGui.QWidget.showEvent(self, showEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def hideEvent(self, hideEvent):
                self._artist.hide()
                self._selectionIndex = PieFiling.SELECTION_NONE
                QtGui.QWidget.hideEvent(self, hideEvent)
 
+       @misc_utils.log_exception(_moduleLogger)
        def paintEvent(self, paintEvent):
                canvas = self._artist.paint(self._selectionIndex)
 
@@ -764,18 +899,17 @@ class QPieMenu(QtGui.QWidget):
 
                QtGui.QWidget.paintEvent(self, paintEvent)
 
+       def __iter__(self):
+               return iter(self._filing)
+
+       def __len__(self):
+               return len(self._filing)
+
        def _select_at(self, index):
                self._selectionIndex = index
 
-               numChildren = len(self._filing)
-               loopDelta = max(numChildren, 1)
-               while self._selectionIndex < 0:
-                       self._selectionIndex += loopDelta
-               while numChildren <= self._selectionIndex:
-                       self._selectionIndex -= loopDelta
-
        def _update_selection(self, lastMousePos):
-               radius = _radius_at(self.rect().center(), lastMousePos)
+               radius = _radius_at(self._cachedCenterPosition, lastMousePos)
                if radius < self._filing.innerRadius():
                        self._selectionIndex = PieFiling.SELECTION_CENTER
                elif radius <= self._filing.outerRadius():
@@ -803,6 +937,10 @@ class QPieMenu(QtGui.QWidget):
                self.hide()
 
 
+def init_pies():
+       PieFiling.NULL_CENTER.setEnabled(False)
+
+
 def _print(msg):
        print msg
 
@@ -813,7 +951,7 @@ def _on_about_to_hide(app):
 
 if __name__ == "__main__":
        app = QtGui.QApplication([])
-       PieFiling.NULL_CENTER.setEnabled(False)
+       init_pies()
 
        if False:
                pie = QPieMenu()
@@ -845,7 +983,7 @@ if __name__ == "__main__":
                mpie.insertItem(iconTextItem)
                mpie.show()
 
-       if False:
+       if True:
                oneAction = QtGui.QAction(None)
                oneAction.setText("Chew")
                oneAction.triggered.connect(lambda: _print("Chew"))
@@ -873,7 +1011,7 @@ if __name__ == "__main__":
                mpie.aboutToHide.connect(lambda: _on_about_to_hide(app))
                mpie.canceled.connect(lambda: _print("Canceled"))
 
-       if True:
+       if False:
                oneAction = QtGui.QAction(None)
                oneAction.setText("Chew")
                oneAction.triggered.connect(lambda: _print("Chew"))