# -*- coding: utf-8 -*-
#
# Licensed under the terms of the Qwt License
# Copyright (c) 2002 Uwe Rathmann, for the original C++ code
# Copyright (c) 2015 Pierre Raybaut, for the Python translation/optimization
# (see LICENSE file for more details)
"""
QwtPlotCanvas
-------------
.. autoclass:: QwtPlotCanvas
:members:
"""
from qwt.null_paintdevice import QwtNullPaintDevice
from qwt.painter import QwtPainter
from qwt.qt import PYQT5
from qwt.qt.QtGui import (QFrame, QPaintEngine, QPen, QBrush, QRegion, QImage,
QPainterPath, QPixmap, QGradient, QPainter, qAlpha,
QPolygonF, QStyleOption, QStyle, QStyleOptionFrame)
from qwt.qt.QtCore import Qt, QSizeF, QT_VERSION, QEvent, QPointF, QRectF
class Border(object):
def __init__(self):
self.pathlist = []
self.rectList = []
self.clipRegion = QRegion()
class Background(object):
def __init__(self):
self.path = QPainterPath()
self.brush = QBrush()
self.origin = QPointF()
class QwtStyleSheetRecorder(QwtNullPaintDevice):
def __init__(self, size):
super(QwtStyleSheetRecorder, self).__init__()
self.__size = size
self.__pen = QPen()
self.__brush = QBrush()
self.__origin = QPointF()
self.clipRects = []
self.border = Border()
self.background = Background()
def updateState(self, state):
if state.state() & QPaintEngine.DirtyPen:
self.__pen = state.pen()
if state.state() & QPaintEngine.DirtyBrush:
self.__brush = state.brush()
if state.state() & QPaintEngine.DirtyBrushOrigin:
self.__origin = state.brushOrigin()
def drawRects(self, rects, count):
for i in range(count):
self.border.rectList += rects[i]
def drawPath(self, path):
rect = QRectF(QPointF(0., 0.), self.__size)
if path.controlPointRect().contains(rect.center()):
self.setCornerRects(path)
self.alignCornerRects(rect)
self.background.path = path
self.background.brush = self.__brush
self.background.origin = self.__origin
else:
self.border.pathlist += [path]
def setCornerRects(self, path):
pos = QPointF(0., 0.)
for i in range(path.elementCount()):
el = path.elementAt(i)
if el.type in (QPainterPath.MoveToElement,
QPainterPath.LineToElement):
pos.setX(el.x)
pos.setY(el.y)
elif el.type == QPainterPath.CurveToElement:
r = QRectF(pos, QPointF(el.x, el.y))
self.clipRects += [r.normalized()]
pos.setX(el.x)
pos.setY(el.y)
elif el.type == QPainterPath.CurveToDataElement:
if self.clipRects:
r = self.clipRects[-1]
r.setCoords(min([r.left(), el.x]),
min([r.top(), el.y]),
max([r.right(), el.x]),
max([r.bottom(), el.y]))
self.clipRects[-1] = r.normalized()
def sizeMetrics(self):
return self.__size
def alignCornerRects(self, rect):
for r in self.clipRects:
if r.center().x() < rect.center().x():
r.setLeft(rect.left())
else:
r.setRight(rect.right())
if r.center().y() < rect.center().y():
r.setTop(rect.top())
else:
r.setBottom(rect.bottom())
def _rects_conv_PyQt5(rects):
# PyQt5 compatibility: the conversion from QRect to QRectF should not
# be necessary but it seems to be anyway... PyQt5 bug?
if PYQT5:
return [QRectF(rect) for rect in rects]
else:
return rects
def qwtDrawBackground(painter, canvas):
painter.save()
borderClip = canvas.borderPath(canvas.rect())
if not borderClip.isEmpty():
painter.setClipPath(borderClip, Qt.IntersectClip)
brush = canvas.palette().brush(canvas.backgroundRole())
if brush.style() == Qt.TexturePattern:
pm = QPixmap(canvas.size())
QwtPainter.fillPixmap(canvas, pm)
painter.drawPixmap(0, 0, pm)
elif brush.gradient():
rects = []
if brush.gradient().coordinateMode() == QGradient.ObjectBoundingMode:
rects += [canvas.rect()]
else:
rects += [painter.clipRegion().rects()]
useRaster = False
if painter.paintEngine().type() == QPaintEngine.X11:
useRaster = True
if useRaster:
format_ = QImage.Format_RGB32
stops = brush.gradient().stops()
for stop in stops:
if stop.second.alpha() != 255:
format_ = QImage.Format_ARGB32
break
image = QImage(canvas.size(), format_)
p = QPainter(image)
p.setPen(Qt.NoPen)
p.setBrush(brush)
p.drawRects(_rects_conv_PyQt5(rects))
p.end()
painter.drawImage(0, 0, image)
else:
painter.setPen(Qt.NoPen)
painter.setBrush(brush)
painter.drawRects(_rects_conv_PyQt5(rects))
else:
painter.setPen(Qt.NoPen)
painter.setBrush(brush)
painter.drawRects(_rects_conv_PyQt5(painter.clipRegion().rects()))
painter.restore()
def qwtRevertPath(path):
if path.elementCount() == 4:
el0 = path.elementAt(0)
el3 = path.elementAt(3)
path.setElementPositionAt(0, el3.x, el3.y)
path.setElementPositionAt(3, el0.x, el0.y)
def qwtCombinePathList(rect, pathList):
if not pathList:
return QPainterPath()
ordered = [None] * 8
for subPath in pathList:
index = -1
br = subPath.controlPointRect()
if br.center().x() < rect.center().x():
if br.center().y() < rect.center().y():
if abs(br.top()-rect.top()) < abs(br.left()-rect.left()):
index = 1
else:
index = 0
else:
if abs(br.bottom()-rect.bottom) < abs(br.left()-rect.left()):
index = 6
else:
index = 7
if subPath.currentPosition().y() > br.center().y():
qwtRevertPath(subPath)
else:
if br.center().y() < rect.center().y():
if abs(br.top()-rect.top()) < abs(br.right()-rect.right()):
index = 2
else:
index = 3
else:
if abs(br.bottom()-rect.bottom()) < abs(br.right()-rect.right()):
index = 5
else:
index = 4
if subPath.currentPosition().y() < br.center().y():
qwtRevertPath(subPath)
ordered[index] = subPath
for i in range(4):
if ordered[2*i].isEmpty() != ordered[2*i+1].isEmpty():
return QPainterPath()
corners = QPolygonF(rect)
path = QPainterPath()
for i in range(4):
if ordered[2*i].isEmpty():
path.lineTo(corners[i])
else:
path.connectPath(ordered[2*i])
path.connectPath(ordered[2*i+1])
path.closeSubpath()
return path
def qwtDrawStyledBackground(w, painter):
opt = QStyleOption()
opt.initFrom(w)
w.style().drawPrimitive(QStyle.PE_Widget, opt, painter, w)
def qwtBackgroundWidget(w):
if w.parentWidget() is None:
return w
if w.autoFillBackground():
brush = w.palette().brush(w.backgroundRole())
if brush.color().alpha() > 0:
return w
if w.testAttribute(Qt.WA_StyledBackground):
image = QImage(1, 1, QImage.Format_ARGB32)
image.fill(Qt.transparent)
painter = QPainter(image)
painter.translate(-w.rect().center())
qwtDrawStyledBackground(w, painter)
painter.end()
if qAlpha(image.pixel(0, 0)) != 0:
return w
return qwtBackgroundWidget(w.parentWidget())
def qwtFillBackground(*args):
if len(args) == 2:
painter, canvas = args
rects = []
if canvas.testAttribute(Qt.WA_StyledBackground):
recorder = QwtStyleSheetRecorder(canvas.size())
p = QPainter(recorder)
qwtDrawStyledBackground(canvas, p)
p.end()
if recorder.background.brush.isOpaque():
rects = recorder.clipRects
else:
rects += [canvas.rect()]
else:
r = canvas.rect()
radius = canvas.borderRadius()
if radius > 0.:
sz = QSizeF(radius, radius)
rects += [QRectF(r.topLeft(), sz),
QRectF(r.topRight()-QPointF(radius, 0), sz),
QRectF(r.bottomRight()-QPointF(radius, radius), sz),
QRectF(r.bottomLeft()-QPointF(0, radius), sz)]
qwtFillBackground(painter, canvas, rects)
elif len(args) == 3:
painter, widget, fillRects = args
if not fillRects:
return
if painter.hasClipping():
clipRegion = painter.transform().map(painter.clipRegion())
else:
clipRegion = widget.contentsRect()
bgWidget = qwtBackgroundWidget(widget.parentWidget())
for fillRect in fillRects:
rect = fillRect.toAlignedRect()
if clipRegion.intersects(rect):
pm = QPixmap(rect.size())
QwtPainter.fillPixmap(bgWidget, pm, widget.mapTo(bgWidget, rect.topLeft()))
painter.drawPixmap(rect, pm)
else:
raise TypeError("%s() takes 2 or 3 argument(s) (%s given)"\
% ("qwtFillBackground", len(args)))
class StyleSheetBackground(object):
def __init__(self):
self.brush = QBrush()
self.origin = QPointF()
class StyleSheet(object):
def __init__(self):
self.hasBorder = False
self.borderPath = QPainterPath()
self.cornerRects = []
self.background = StyleSheetBackground()
class QwtPlotCanvas_PrivateData(object):
def __init__(self):
self.focusIndicator = QwtPlotCanvas.NoFocusIndicator
self.borderRadius = 0
self.paintAttributes = 0
self.backingStore = None
self.styleSheet = StyleSheet()
self.styleSheet.hasBorder = False
[docs]class QwtPlotCanvas(QFrame):
"""
Canvas of a QwtPlot.
Canvas is the widget where all plot items are displayed
.. seealso::
:py:meth:`qwt.plot.QwtPlot.setCanvas()`
Paint attributes:
* `QwtPlotCanvas.BackingStore`:
Paint double buffered reusing the content of the pixmap buffer
when possible.
Using a backing store might improve the performance significantly,
when working with widget overlays (like rubber bands).
Disabling the cache might improve the performance for
incremental paints
(using :py:class:`qwt.plot_directpainter.QwtPlotDirectPainter`).
* `QwtPlotCanvas.Opaque`:
Try to fill the complete contents rectangle of the plot canvas
When using styled backgrounds Qt assumes, that the canvas doesn't
fill its area completely (f.e because of rounded borders) and
fills the area below the canvas. When this is done with gradients
it might result in a serious performance bottleneck - depending on
the size.
When the Opaque attribute is enabled the canvas tries to
identify the gaps with some heuristics and to fill those only.
.. warning::
Will not work for semitransparent backgrounds
* `QwtPlotCanvas.HackStyledBackground`:
Try to improve painting of styled backgrounds
`QwtPlotCanvas` supports the box model attributes for
customizing the layout with style sheets. Unfortunately
the design of Qt style sheets has no concept how to
handle backgrounds with rounded corners - beside of padding.
When HackStyledBackground is enabled the plot canvas tries
to separate the background from the background border
by reverse engineering to paint the background before and
the border after the plot items. In this order the border
gets perfectly antialiased and you can avoid some pixel
artifacts in the corners.
* `QwtPlotCanvas.ImmediatePaint`:
When ImmediatePaint is set replot() calls repaint()
instead of update().
.. seealso::
:py:meth:`replot()`, :py:meth:`QWidget.repaint()`,
:py:meth:`QWidget.update()`
Focus indicators:
* `QwtPlotCanvas.NoFocusIndicator`:
Don't paint a focus indicator
* `QwtPlotCanvas.CanvasFocusIndicator`:
The focus is related to the complete canvas.
Paint the focus indicator using paintFocus()
* `QwtPlotCanvas.ItemFocusIndicator`:
The focus is related to an item (curve, point, ...) on
the canvas. It is up to the application to display a
focus indication using f.e. highlighting.
.. py:class:: QwtPlotCanvas([plot=None])
Constructor
:param qwt.plot.QwtPlot plot: Parent plot widget
.. seealso::
:py:meth:`qwt.plot.QwtPlot.setCanvas()`
"""
# enum PaintAttribute
BackingStore = 1
Opaque = 2
HackStyledBackground = 4
ImmediatePaint = 8
# enum FocusIndicator
NoFocusIndicator, CanvasFocusIndicator, ItemFocusIndicator = list(range(3))
def __init__(self, plot=None):
super(QwtPlotCanvas, self).__init__(plot)
self.__plot = plot
self.setFrameStyle(QFrame.Panel|QFrame.Sunken)
self.setLineWidth(2)
self.__data = QwtPlotCanvas_PrivateData()
self.setCursor(Qt.CrossCursor)
self.setAutoFillBackground(True)
self.setPaintAttribute(QwtPlotCanvas.BackingStore, False)
self.setPaintAttribute(QwtPlotCanvas.Opaque, True)
self.setPaintAttribute(QwtPlotCanvas.HackStyledBackground, True)
[docs] def plot(self):
"""
:return: Parent plot widget
"""
return self.__plot
[docs] def setPaintAttribute(self, attribute, on=True):
"""
Changing the paint attributes
Paint attributes:
* `QwtPlotCanvas.BackingStore`
* `QwtPlotCanvas.Opaque`
* `QwtPlotCanvas.HackStyledBackground`
* `QwtPlotCanvas.ImmediatePaint`
:param int attribute: Paint attribute
:param bool on: On/Off
.. seealso::
:py:meth:`testPaintAttribute()`, :py:meth:`backingStore()`
"""
if bool(self.__data.paintAttributes & attribute) == on:
return
if on:
self.__data.paintAttributes |= attribute
else:
self.__data.paintAttributes &= ~attribute
if attribute == self.BackingStore:
if on:
if self.__data.backingStore is None:
self.__data.backingStore = QPixmap()
if self.isVisible():
if QT_VERSION >= 0x050000:
self.__data.backingStore = self.grab(self.rect())
else:
if PYQT5:
pm = QPixmap.grabWidget(self, self.rect())
else:
pm = self.grab(self.rect())
self.__data.backingStore = pm
else:
self.__data.backingStore = None
elif attribute == self.Opaque:
if on:
self.setAttribute(Qt.WA_OpaquePaintEvent, True)
elif attribute in (self.HackStyledBackground, self.ImmediatePaint):
pass
[docs] def testPaintAttribute(self, attribute):
"""
Test whether a paint attribute is enabled
:param int attribute: Paint attribute
:return: True, when attribute is enabled
.. seealso::
:py:meth:`setPaintAttribute()`
"""
return self.__data.paintAttributes & attribute
[docs] def backingStore(self):
"""
:return: Backing store, might be None
"""
return self.__data.backingStore
[docs] def invalidateBackingStore(self):
"""Invalidate the internal backing store"""
if self.__data.backingStore:
self.__data.backingStore = QPixmap()
[docs] def setFocusIndicator(self, focusIndicator):
"""
Set the focus indicator
Focus indicators:
* `QwtPlotCanvas.NoFocusIndicator`
* `QwtPlotCanvas.CanvasFocusIndicator`
* `QwtPlotCanvas.ItemFocusIndicator`
:param int focusIndicator: Focus indicator
.. seealso::
:py:meth:`focusIndicator()`
"""
self.__data.focusIndicator = focusIndicator
[docs] def focusIndicator(self):
"""
:return: Focus indicator
.. seealso::
:py:meth:`setFocusIndicator()`
"""
return self.__data.focusIndicator
[docs] def setBorderRadius(self, radius):
"""
Set the radius for the corners of the border frame
:param float radius: Radius of a rounded corner
.. seealso::
:py:meth:`borderRadius()`
"""
self.__data.borderRadius = max([0., radius])
[docs] def borderRadius(self):
"""
:return: Radius for the corners of the border frame
.. seealso::
:py:meth:`setBorderRadius()`
"""
return self.__data.borderRadius
def event(self, event):
if event.type() == QEvent.PolishRequest:
if self.testPaintAttribute(self.Opaque):
self.setAttribute(Qt.WA_OpaquePaintEvent, True)
if event.type() in (QEvent.PolishRequest, QEvent.StyleChange):
self.updateStyleSheetInfo()
return QFrame.event(self, event)
def paintEvent(self, event):
painter = QPainter(self)
painter.setClipRegion(event.region())
if self.testPaintAttribute(self.BackingStore) and\
self.__data.backingStore is not None:
bs = self.__data.backingStore
if bs.size() != self.size():
bs = QwtPainter.backingStore(self, self.size())
if self.testAttribute(Qt.WA_StyledBackground):
p = QPainter(bs)
qwtFillBackground(p, self)
self.drawCanvas(p, True)
else:
p = QPainter()
if self.__data.borderRadius <= 0.:
# print('**DEBUG: QwtPlotCanvas.paintEvent')
QwtPainter.fillPixmap(self, bs)
p.begin(bs)
self.drawCanvas(p, False)
else:
p.begin(bs)
qwtFillBackground(p, self)
self.drawCanvas(p, True)
if self.frameWidth() > 0:
self.drawBorder(p)
p.end()
painter.drawPixmap(0, 0, self.__data.backingStore)
else:
if self.testAttribute(Qt.WA_StyledBackground):
if self.testAttribute(Qt.WA_OpaquePaintEvent):
qwtFillBackground(painter, self)
self.drawCanvas(painter, True)
else:
self.drawCanvas(painter, False)
else:
if self.testAttribute(Qt.WA_OpaquePaintEvent):
if self.autoFillBackground():
qwtFillBackground(painter, self)
qwtDrawBackground(painter, self)
else:
if self.borderRadius() > 0.:
clipPath = QPainterPath()
clipPath.addRect(self.rect())
clipPath = clipPath.subtracted(self.borderPath(self.rect()))
painter.save()
painter.setClipPath(clipPath, Qt.IntersectClip)
qwtFillBackground(painter, self)
qwtDrawBackground(painter, self)
painter.restore()
self.drawCanvas(painter, False)
if self.frameWidth() > 0:
self.drawBorder(painter)
if self.hasFocus() and self.focusIndicator() == self.CanvasFocusIndicator:
self.drawFocusIndicator(painter)
def drawCanvas(self, painter, withBackground):
hackStyledBackground = False
if withBackground and self.testAttribute(Qt.WA_StyledBackground) and\
self.testPaintAttribute(self.HackStyledBackground):
# Antialiasing rounded borders is done by
# inserting pixels with colors between the
# border color and the color on the canvas,
# When the border is painted before the plot items
# these colors are interpolated for the canvas
# and the plot items need to be clipped excluding
# the anialiased pixels. In situations, where
# the plot items fill the area at the rounded
# borders this is noticeable.
# The only way to avoid these annoying "artefacts"
# is to paint the border on top of the plot items.
if self.__data.styleSheet.hasBorder and\
not self.__data.styleSheet.borderPath.isEmpty():
# We have a border with at least one rounded corner
hackStyledBackground = True
if withBackground:
painter.save()
if self.testAttribute(Qt.WA_StyledBackground):
if hackStyledBackground:
# paint background without border
painter.setPen(Qt.NoPen)
painter.setBrush(self.__data.styleSheet.background.brush)
painter.setBrushOrigin(self.__data.styleSheet.background.origin)
painter.setClipPath(self.__data.styleSheet.borderPath)
painter.drawRect(self.contentsRect())
else:
qwtDrawStyledBackground(self, painter)
elif self.autoFillBackground():
painter.setPen(Qt.NoPen)
painter.setBrush(self.palette().brush(self.backgroundRole()))
if self.__data.borderRadius > 0. and self.rect() == self.frameRect():
if self.frameWidth() > 0:
painter.setClipPath(self.borderPath(self.rect()))
painter.drawRect(self.rect())
else:
painter.setRenderHint(QPainter.Antialiasing, True)
painter.drawPath(self.borderPath(self.rect()))
else:
painter.drawRect(self.rect())
painter.restore()
painter.save()
if not self.__data.styleSheet.borderPath.isEmpty():
painter.setClipPath(self.__data.styleSheet.borderPath,
Qt.IntersectClip)
else:
if self.__data.borderRadius > 0.:
painter.setClipPath(self.borderPath(self.frameRect()),
Qt.IntersectClip)
else:
# print('**DEBUG: QwtPlotCanvas.drawCanvas')
painter.setClipRect(self.contentsRect(), Qt.IntersectClip)
self.plot().drawCanvas(painter)
painter.restore()
if withBackground and hackStyledBackground:
# Now paint the border on top
opt = QStyleOptionFrame()
opt.initFrom(self)
self.style().drawPrimitive(QStyle.PE_Frame, opt, painter, self)
[docs] def drawBorder(self, painter):
"""
Draw the border of the plot canvas
:param QPainter painter: Painter
.. seealso::
:py:meth:`setBorderRadius()`
"""
if self.__data.borderRadius > 0:
if self.frameWidth() > 0:
QwtPainter.drawRoundedFrame(painter, QRectF(self.frameRect()),
self.__data.borderRadius, self.__data.borderRadius,
self.palette(), self.frameWidth(), self.frameStyle())
else:
if QT_VERSION >= 0x040500:
if PYQT5:
from qwt.qt.QtGui import QStyleOptionFrame
else:
from qwt.qt.QtGui import QStyleOptionFrameV3 as\
QStyleOptionFrame
opt = QStyleOptionFrame()
opt.initFrom(self)
frameShape = self.frameStyle() & QFrame.Shape_Mask
frameShadow = self.frameStyle() & QFrame.Shadow_Mask
opt.frameShape = QFrame.Shape(int(opt.frameShape)|frameShape)
if frameShape in (QFrame.Box, QFrame.HLine, QFrame.VLine,
QFrame.StyledPanel, QFrame.Panel):
opt.lineWidth = self.lineWidth()
opt.midLineWidth = self.midLineWidth()
else:
opt.lineWidth = self.frameWidth()
if frameShadow == self.Sunken:
opt.state |= QStyle.State_Sunken
elif frameShadow == self.Raised:
opt.state |= QStyle.State_Raised
self.style().drawControl(QStyle.CE_ShapedFrame, opt, painter, self)
else:
self.drawFrame(painter)
def resizeEvent(self, event):
QFrame.resizeEvent(self, event)
self.updateStyleSheetInfo()
[docs] def drawFocusIndicator(self, painter):
"""
Draw the focus indication
:param QPainter painter: Painter
"""
margin = 1
focusRect = self.contentsRect()
focusRect.setRect(focusRect.x()+margin, focusRect.y()+margin,
focusRect.width()-2*margin, focusRect.height()-2*margin)
QwtPainter.drawFocusRect(painter, self, focusRect)
[docs] def replot(self):
"""
Invalidate the paint cache and repaint the canvas
"""
self.invalidateBackingStore()
if self.testPaintAttribute(self.ImmediatePaint):
self.repaint(self.contentsRect())
else:
self.update(self.contentsRect())
def invalidatePaintCache(self):
import warnings
warnings.warn("`invalidatePaintCache` has been removed: "\
"please use `replot` instead", RuntimeWarning)
self.replot()
[docs] def updateStyleSheetInfo(self):
"""
Update the cached information about the current style sheet
"""
if not self.testAttribute(Qt.WA_StyledBackground):
return
recorder = QwtStyleSheetRecorder(self.size())
painter = QPainter(recorder)
opt = QStyleOption()
opt.initFrom(self)
self.style().drawPrimitive(QStyle.PE_Widget, opt, painter, self)
painter.end()
self.__data.styleSheet.hasBorder = not recorder.border.rectList.isEmpty()
self.__data.styleSheet.cornerRects = recorder.clipRects
if recorder.background.path.isEmpty():
if not recorder.border.rectList.isEmpty():
self.__data.styleSheet.borderPath =\
qwtCombinePathList(self.rect(), recorder.border.pathlist)
else:
self.__data.styleSheet.borderPath = recorder.background.path
self.__data.styleSheet.background.brush = recorder.background.brush
self.__data.styleSheet.background.origin = recorder.background.origin
[docs] def borderPath(self, rect):
"""
Calculate the painter path for a styled or rounded border
When the canvas has no styled background or rounded borders
the painter path is empty.
:param QRect rect: Bounding rectangle of the canvas
:return: Painter path, that can be used for clipping
"""
if self.testAttribute(Qt.WA_StyledBackground):
recorder = QwtStyleSheetRecorder(rect.size())
painter = QPainter(recorder)
opt = QStyleOption()
opt.initFrom(self)
opt.rect = rect
self.style().drawPrimitive(QStyle.PE_Widget, opt, painter, self)
painter.end()
if not recorder.background.path.isEmpty():
return recorder.background.path
if not recorder.border.rectList.isEmpty():
return qwtCombinePathList(rect, recorder.border.pathlist)
elif self.__data.borderRadius > 0.:
fw2 = self.frameWidth()*.5
r = QRectF(rect).adjusted(fw2, fw2, -fw2, -fw2)
path = QPainterPath()
path.addRoundedRect(r, self.__data.borderRadius,
self.__data.borderRadius)
return path
return QPainterPath()