class Callout(QGraphicsItem):
def __init__(self, chart):
QGraphicsItem.__init__(self, chart)
self._chart = chart
self._text = ""
self._textRect = QRectF()
self._anchor = QPointF()
self._font = QFont()
self._rect = QRectF()
def boundingRect(self):
anchor = self.mapFromParent(self._chart.mapToPosition(self._anchor))
rect = QRectF()
rect.setLeft(min(self._rect.left(), anchor.x()))
rect.setRight(max(self._rect.right(), anchor.x()))
rect.setTop(min(self._rect.top(), anchor.y()))
rect.setBottom(max(self._rect.bottom(), anchor.y()))
return rect
def paint(self, painter, option, widget):
path = QPainterPath()
path.addRoundedRect(self._rect, 5, 5)
anchor = self.mapFromParent(self._chart.mapToPosition(self._anchor))
if not self._rect.contains(anchor) and not self._anchor.isNull():
point1 = QPointF()
point2 = QPointF()
# establish the position of the anchor point in relation to _rect
above = anchor.y() <= self._rect.top()
aboveCenter = (anchor.y() > self._rect.top()
and anchor.y() <= self._rect.center().y())
belowCenter = (anchor.y() > self._rect.center().y()
and anchor.y() <= self._rect.bottom())
below = anchor.y() > self._rect.bottom()
onLeft = anchor.x() <= self._rect.left()
leftOfCenter = (anchor.x() > self._rect.left()
and anchor.x() <= self._rect.center().x())
rightOfCenter = (anchor.x() > self._rect.center().x()
and anchor.x() <= self._rect.right())
onRight = anchor.x() > self._rect.right()
# get the nearest _rect corner.
x = (onRight + rightOfCenter) * self._rect.width()
y = (below + belowCenter) * self._rect.height()
cornerCase = ((above and onLeft) or (above and onRight)
or (below and onLeft) or (below and onRight))
vertical = abs(anchor.x() - x) > abs(anchor.y() - y)
x1 = (x + leftOfCenter * 10 - rightOfCenter * 20 +
cornerCase * int(not vertical) *
(onLeft * 10 - onRight * 20))
y1 = (y + aboveCenter * 10 - belowCenter * 20 +
cornerCase * vertical * (above * 10 - below * 20))
point1.setX(x1)
point1.setY(y1)
x2 = (x + leftOfCenter * 20 - rightOfCenter * 10 +
cornerCase * int(not vertical) *
(onLeft * 20 - onRight * 10))
y2 = (y + aboveCenter * 20 - belowCenter * 10 +
cornerCase * vertical * (above * 20 - below * 10))
point2.setX(x2)
point2.setY(y2)
path.moveTo(point1)
path.lineTo(anchor)
path.lineTo(point2)
path = path.simplified()
painter.setBrush(QColor(255, 255, 255))
painter.drawPath(path)
painter.drawText(self._textRect, self._text)
def mousePressEvent(self, event):
event.setAccepted(True)
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
self.setPos(
mapToParent(event.pos() - event.buttonDownPos(Qt.LeftButton)))
event.setAccepted(True)
else:
event.setAccepted(False)
def setText(self, text):
self._text = text
metrics = QFontMetrics(self._font)
self._textRect = QRectF(
metrics.boundingRect(QRect(0.0, 0.0, 150.0, 150.0), Qt.AlignLeft,
self._text))
self._textRect.translate(5, 5)
self.prepareGeometryChange()
self._rect = self._textRect.adjusted(-5, -5, 5, 5)
def setAnchor(self, point):
self._anchor = QPointF(point)
def updateGeometry(self):
self.prepareGeometryChange()
self.setPos(self._chart.mapToPosition(self._anchor) + QPointF(10, -50))
class MandelbrotWidget(QWidget):
def __init__(self, parent=None):
super(MandelbrotWidget, self).__init__(parent)
self.thread = RenderThread()
self.pixmap = QPixmap()
self.pixmapOffset = QPointF()
self.lastDragPos = QPointF()
self.centerX = DefaultCenterX
self.centerY = DefaultCenterY
self.pixmapScale = DefaultScale
self.curScale = DefaultScale
self.thread.renderedImage.connect(self.updatePixmap)
self.setWindowTitle("Mandelbrot")
self.setCursor(Qt.CrossCursor)
self.resize(550, 400)
def paintEvent(self, event):
painter = QPainter(self)
painter.fillRect(self.rect(), Qt.black)
if self.pixmap.isNull():
painter.setPen(Qt.white)
painter.drawText(self.rect(), Qt.AlignCenter,
"Rendering initial image, please wait...")
return
if self.curScale == self.pixmapScale:
painter.drawPixmap(self.pixmapOffset, self.pixmap)
else:
scaleFactor = self.pixmapScale / self.curScale
newWidth = int(self.pixmap.width() * scaleFactor)
newHeight = int(self.pixmap.height() * scaleFactor)
newX = self.pixmapOffset.x() + (self.pixmap.width() - newWidth) / 2
newY = self.pixmapOffset.y() + (self.pixmap.height() - newHeight) / 2
painter.save()
painter.translate(newX, newY)
painter.scale(scaleFactor, scaleFactor)
exposed, _ = painter.transform().inverted()
exposed = exposed.mapRect(self.rect()).adjusted(-1, -1, 1, 1)
painter.drawPixmap(exposed, self.pixmap, exposed)
painter.restore()
text = "Use mouse wheel or the '+' and '-' keys to zoom. Press and " \
"hold left mouse button to scroll."
metrics = painter.fontMetrics()
textWidth = metrics.horizontalAdvance(text)
painter.setPen(Qt.NoPen)
painter.setBrush(QColor(0, 0, 0, 127))
painter.drawRect((self.width() - textWidth) / 2 - 5, 0, textWidth + 10,
metrics.lineSpacing() + 5)
painter.setPen(Qt.white)
painter.drawText((self.width() - textWidth) / 2,
metrics.leading() + metrics.ascent(), text)
def resizeEvent(self, event):
self.thread.render(self.centerX, self.centerY, self.curScale, self.size())
def keyPressEvent(self, event):
if event.key() == Qt.Key_Plus:
self.zoom(ZoomInFactor)
elif event.key() == Qt.Key_Minus:
self.zoom(ZoomOutFactor)
elif event.key() == Qt.Key_Left:
self.scroll(-ScrollStep, 0)
elif event.key() == Qt.Key_Right:
self.scroll(+ScrollStep, 0)
elif event.key() == Qt.Key_Down:
self.scroll(0, -ScrollStep)
elif event.key() == Qt.Key_Up:
self.scroll(0, +ScrollStep)
else:
super(MandelbrotWidget, self).keyPressEvent(event)
def wheelEvent(self, event):
numDegrees = event.angleDelta().y() / 8
numSteps = numDegrees / 15.0
self.zoom(pow(ZoomInFactor, numSteps))
def mousePressEvent(self, event):
if event.buttons() == Qt.LeftButton:
self.lastDragPos = event.position()
def mouseMoveEvent(self, event):
if event.buttons() & Qt.LeftButton:
pos = event.position()
self.pixmapOffset += pos - self.lastDragPos
self.lastDragPos = pos
self.update()
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton:
self.pixmapOffset += event.position() - self.lastDragPos
self.lastDragPos = QPointF()
deltaX = (self.width() - self.pixmap.width()) / 2 - self.pixmapOffset.x()
deltaY = (self.height() - self.pixmap.height()) / 2 - self.pixmapOffset.y()
self.scroll(deltaX, deltaY)
def updatePixmap(self, image, scaleFactor):
if not self.lastDragPos.isNull():
return
self.pixmap = QPixmap.fromImage(image)
self.pixmapOffset = QPointF()
self.lastDragPosition = QPointF()
self.pixmapScale = scaleFactor
self.update()
def zoom(self, zoomFactor):
self.curScale *= zoomFactor
self.update()
self.thread.render(self.centerX, self.centerY, self.curScale,
self.size())
def scroll(self, deltaX, deltaY):
self.centerX += deltaX * self.curScale
self.centerY += deltaY * self.curScale
self.update()
self.thread.render(self.centerX, self.centerY, self.curScale,
self.size())