# -*- 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 collections.abc import Sequence from qtpy.QtCore import QEvent, QObject, QPoint, QPointF, QRect, QRectF, QSize, Qt from qtpy.QtGui import ( QBrush, QGradient, QImage, QPaintEngine, QPainter, QPainterPath, QPen, QPixmap, QPolygonF, QRegion, qAlpha, ) from qtpy.QtWidgets import QFrame, QStyle, QStyleOption, QStyleOptionFrame from qwt.null_paintdevice import QwtNullPaintDevice from qwt.painter import QwtPainter 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): if isinstance(rects, (QRect, QRectF)): self.border.rectList = [QRectF(rects)] elif isinstance(rects, Sequence): self.border.rectList.extend(QRectF(rects[i]) for i in range(count)) else: raise TypeError( "drawRects() expects a QRect, QRectF or a sequence of them, " f"but got {type(rects).__name__}" ) def drawPath(self, path): rect = QRectF(QPointF(0.0, 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, 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 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().boundingRect()] 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_) pntr = QPainter(image) pntr.setPen(Qt.NoPen) pntr.setBrush(brush) for rect in rects: pntr.drawRect(rect) pntr.end() painter.drawImage(0, 0, image) else: painter.setPen(Qt.NoPen) painter.setBrush(brush) for rect in rects: painter.drawRect(rect) else: painter.setPen(Qt.NoPen) painter.setBrush(brush) painter.drawRect(painter.clipRegion().boundingRect()) 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 > 0.0: sz = QSize(radius, radius) rects += [ QRect(r.topLeft(), sz), QRect(r.topRight() - QPoint(radius, 0), sz), QRect(r.bottomRight() - QPoint(radius, radius), sz), QRect(r.bottomLeft() - QPoint(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 rect in fillRects: 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(QObject): def __init__(self): QObject.__init__(self) self.focusIndicator = QwtPlotCanvas.NoFocusIndicator self.borderRadius = 0 self.paintAttributes = 0 self.backingStore = None self.styleSheet = StyleSheet() self.styleSheet.hasBorder = False 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) def plot(self): """ :return: Parent plot widget """ return self.__plot 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(): self.__data.backingStore = self.grab(self.rect()) 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 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 def backingStore(self): """ :return: Backing store, might be None """ return self.__data.backingStore def invalidateBackingStore(self): """Invalidate the internal backing store""" if self.__data.backingStore: self.__data.backingStore = QPixmap() 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 def focusIndicator(self): """ :return: Focus indicator .. seealso:: :py:meth:`setFocusIndicator()` """ return self.__data.focusIndicator 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([0.0, radius]) 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 and not self.__data.backingStore.isNull() ): bs = self.__data.backingStore pixelRatio = bs.devicePixelRatio() if bs.size() != self.size() * pixelRatio: 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 <= 0.0: # 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() > 0.0: 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 > 0.0 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 > 0.0: 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) 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: opt = QStyleOptionFrame() opt.initFrom(self) try: shape_mask = QFrame.Shape_Mask.value shadow_mask = QFrame.Shadow_Mask.value except AttributeError: shape_mask = QFrame.Shape_Mask shadow_mask = QFrame.Shadow_Mask frameShape = self.frameStyle() & shape_mask frameShadow = self.frameStyle() & 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 == QFrame.Sunken: opt.state |= QStyle.State_Sunken elif frameShadow == QFrame.Raised: opt.state |= QStyle.State_Raised self.style().drawControl(QStyle.CE_ShapedFrame, opt, painter, self) def resizeEvent(self, event): QFrame.resizeEvent(self, event) self.updateStyleSheetInfo() 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) 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() 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 = len(recorder.border.rectList) > 0 self.__data.styleSheet.cornerRects = recorder.clipRects if recorder.background.path.isEmpty(): if self.__data.styleSheet.hasBorder: 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 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 len(recorder.border.rectList) > 0: return qwtCombinePathList(rect, recorder.border.pathlist) elif self.__data.borderRadius > 0.0: fw2 = self.frameWidth() * 0.5 r = QRectF(rect).adjusted(fw2, fw2, -fw2, -fw2) path = QPainterPath() path.addRoundedRect(r, self.__data.borderRadius, self.__data.borderRadius) return path return QPainterPath()