# -*- 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) """ QwtAbstractScaleDraw -------------------- .. autoclass:: QwtAbstractScaleDraw :members: QwtScaleDraw ------------ .. autoclass:: QwtScaleDraw :members: """ import math from datetime import datetime from qtpy.QtCore import ( QLineF, QObject, QPoint, QPointF, QRect, QRectF, Qt, qFuzzyCompare, ) from qtpy.QtGui import QFontMetrics, QPalette, QTransform from qwt._math import qwtRadians from qwt.scale_div import QwtScaleDiv from qwt.scale_map import QwtScaleMap from qwt.text import QwtText class QwtAbstractScaleDraw_PrivateData(QObject): def __init__(self): QObject.__init__(self) self.spacing = 4 self.penWidth = 0 self.minExtent = 0.0 self.components = ( QwtAbstractScaleDraw.Backbone | QwtAbstractScaleDraw.Ticks | QwtAbstractScaleDraw.Labels ) self.tick_length = { QwtScaleDiv.MinorTick: 4.0, QwtScaleDiv.MediumTick: 6.0, QwtScaleDiv.MajorTick: 8.0, } self.tick_lighter_factor = { QwtScaleDiv.MinorTick: 100, QwtScaleDiv.MediumTick: 100, QwtScaleDiv.MajorTick: 100, } self.map = QwtScaleMap() self.scaleDiv = QwtScaleDiv() self.labelCache = {} class QwtAbstractScaleDraw(object): """ A abstract base class for drawing scales `QwtAbstractScaleDraw` can be used to draw linear or logarithmic scales. After a scale division has been specified as a `QwtScaleDiv` object using `setScaleDiv()`, the scale can be drawn with the `draw()` member. Scale components: * `QwtAbstractScaleDraw.Backbone`: Backbone = the line where the ticks are located * `QwtAbstractScaleDraw.Ticks`: Ticks * `QwtAbstractScaleDraw.Labels`: Labels .. py:class:: QwtAbstractScaleDraw() The range of the scale is initialized to [0, 100], The spacing (distance between ticks and labels) is set to 4, the tick lengths are set to 4,6 and 8 pixels """ # enum ScaleComponent Backbone = 0x01 Ticks = 0x02 Labels = 0x04 def __init__(self): self.__data = QwtAbstractScaleDraw_PrivateData() def extent(self, font): """ Calculate the extent The extent is the distance from the baseline to the outermost pixel of the scale draw in opposite to its orientation. It is at least minimumExtent() pixels. :param QFont font: Font used for drawing the tick labels :return: Number of pixels .. seealso:: :py:meth:`setMinimumExtent()`, :py:meth:`minimumExtent()` """ return 0.0 def drawTick(self, painter, value, len_): """ Draw a tick :param QPainter painter: Painter :param float value: Value of the tick :param float len: Length of the tick .. seealso:: :py:meth:`drawBackbone()`, :py:meth:`drawLabel()` """ pass def drawBackbone(self, painter): """ Draws the baseline of the scale :param QPainter painter: Painter .. seealso:: :py:meth:`drawTick()`, :py:meth:`drawLabel()` """ pass def drawLabel(self, painter, value): """ Draws the label for a major scale tick :param QPainter painter: Painter :param float value: Value .. seealso:: :py:meth:`drawTick()`, :py:meth:`drawBackbone()` """ pass def enableComponent(self, component, enable): """ En/Disable a component of the scale :param int component: Scale component :param bool enable: On/Off .. seealso:: :py:meth:`hasComponent()` """ if enable: self.__data.components |= component else: self.__data.components &= ~component def hasComponent(self, component): """ Check if a component is enabled :param int component: Component type :return: True, when component is enabled .. seealso:: :py:meth:`enableComponent()` """ return self.__data.components & component def setScaleDiv(self, scaleDiv): """ Change the scale division :param qwt.scale_div.QwtScaleDiv scaleDiv: New scale division """ self.__data.scaleDiv = scaleDiv self.__data.map.setScaleInterval(scaleDiv.lowerBound(), scaleDiv.upperBound()) self.invalidateCache() def setTransformation(self, transformation): """ Change the transformation of the scale :param qwt.transform.QwtTransform transformation: New scale transformation """ self.__data.map.setTransformation(transformation) def scaleMap(self): """ :return: Map how to translate between scale and pixel values """ return self.__data.map def scaleDiv(self): """ :return: scale division """ return self.__data.scaleDiv def setPenWidth(self, width): """ Specify the width of the scale pen :param int width: Pen width .. seealso:: :py:meth:`penWidth()` """ if width < 0: width = 0 if width != self.__data.penWidth: self.__data.penWidth = width def penWidth(self): """ :return: Scale pen width .. seealso:: :py:meth:`setPenWidth()` """ return self.__data.penWidth def draw(self, painter, palette): """ Draw the scale :param QPainter painter: The painter :param QPalette palette: Palette, text color is used for the labels, foreground color for ticks and backbone """ painter.save() pen = painter.pen() pen.setWidth(self.__data.penWidth) pen.setCosmetic(False) painter.setPen(pen) if self.hasComponent(QwtAbstractScaleDraw.Labels): painter.save() painter.setPen(palette.color(QPalette.Text)) majorTicks = self.__data.scaleDiv.ticks(QwtScaleDiv.MajorTick) for v in majorTicks: if self.__data.scaleDiv.contains(v): self.drawLabel(painter, v) painter.restore() if self.hasComponent(QwtAbstractScaleDraw.Ticks): painter.save() pen = painter.pen() pen.setCapStyle(Qt.FlatCap) default_color = palette.color(QPalette.WindowText) for tickType in range(QwtScaleDiv.NTickTypes): tickLen = self.__data.tick_length[tickType] if tickLen <= 0.0: continue factor = self.__data.tick_lighter_factor[tickType] pen.setColor(default_color.lighter(factor)) painter.setPen(pen) ticks = self.__data.scaleDiv.ticks(tickType) for v in ticks: if self.__data.scaleDiv.contains(v): self.drawTick(painter, v, tickLen) painter.restore() if self.hasComponent(QwtAbstractScaleDraw.Backbone): painter.save() pen = painter.pen() pen.setColor(palette.color(QPalette.WindowText)) pen.setCapStyle(Qt.FlatCap) painter.setPen(pen) self.drawBackbone(painter) painter.restore() painter.restore() def setSpacing(self, spacing): """ Set the spacing between tick and labels The spacing is the distance between ticks and labels. The default spacing is 4 pixels. :param float spacing: Spacing .. seealso:: :py:meth:`spacing()` """ if spacing < 0: spacing = 0 self.__data.spacing = spacing def spacing(self): """ Get the spacing The spacing is the distance between ticks and labels. The default spacing is 4 pixels. :return: Spacing .. seealso:: :py:meth:`setSpacing()` """ return self.__data.spacing def setMinimumExtent(self, minExtent): """ Set a minimum for the extent The extent is calculated from the components of the scale draw. In situations, where the labels are changing and the layout depends on the extent (f.e scrolling a scale), setting an upper limit as minimum extent will avoid jumps of the layout. :param float minExtent: Minimum extent .. seealso:: :py:meth:`extent()`, :py:meth:`minimumExtent()` """ if minExtent < 0.0: minExtent = 0.0 self.__data.minExtent = minExtent def minimumExtent(self): """ Get the minimum extent :return: Minimum extent .. seealso:: :py:meth:`extent()`, :py:meth:`setMinimumExtent()` """ return self.__data.minExtent def setTickLength(self, tick_type, length): """ Set the length of the ticks :param int tick_type: Tick type :param float length: New length .. warning:: the length is limited to [0..1000] """ if tick_type not in self.__data.tick_length: raise ValueError("Invalid tick type: %r" % tick_type) self.__data.tick_length[tick_type] = min([1000.0, max([0.0, length])]) def tickLength(self, tick_type): """ :param int tick_type: Tick type :return: Length of the ticks .. seealso:: :py:meth:`setTickLength()`, :py:meth:`maxTickLength()` """ if tick_type not in self.__data.tick_length: raise ValueError("Invalid tick type: %r" % tick_type) return self.__data.tick_length[tick_type] def maxTickLength(self): """ :return: Length of the longest tick Useful for layout calculations .. seealso:: :py:meth:`tickLength()`, :py:meth:`setTickLength()` """ return max([0.0] + list(self.__data.tick_length.values())) def setTickLighterFactor(self, tick_type, factor): """ Set the color lighter factor of the ticks :param int tick_type: Tick type :param int factor: New factor """ if tick_type not in self.__data.tick_length: raise ValueError("Invalid tick type: %r" % tick_type) self.__data.tick_lighter_factor[tick_type] = min([0, factor]) def tickLighterFactor(self, tick_type): """ :param int tick_type: Tick type :return: Color lighter factor of the ticks .. seealso:: :py:meth:`setTickLighterFactor()` """ if tick_type not in self.__data.tick_length: raise ValueError("Invalid tick type: %r" % tick_type) return self.__data.tick_lighter_factor[tick_type] def label(self, value): """ Convert a value into its representing label The value is converted to a plain text using `QLocale().toString(value)`. This method is often overloaded by applications to have individual labels. :param float value: Value :return: Label string """ # Adding a space before the value is a way to add a margin on the left # of the scale. This helps to avoid truncating the first digit of the # tick labels while keeping a tight layout. return " %g" % value def tickLabel(self, font, value): """ Convert a value into its representing label and cache it. The conversion between value and label is called very often in the layout and painting code. Unfortunately the calculation of the label sizes might be slow (really slow for rich text in Qt4), so it's necessary to cache the labels. :param QFont font: Font :param float value: Value :return: Tuple (tick label, text size) """ lbl = self.__data.labelCache.get(value) if lbl is None: lbl = QwtText(self.label(value)) lbl.setRenderFlags(0) lbl.setLayoutAttribute(QwtText.MinimumLayout) self.__data.labelCache[value] = lbl return lbl, lbl.textSize(font) def invalidateCache(self): """ Invalidate the cache used by `tickLabel()` The cache is invalidated, when a new `QwtScaleDiv` is set. If the labels need to be changed. while the same `QwtScaleDiv` is set, `invalidateCache()` needs to be called manually. """ self.__data.labelCache.clear() class QwtScaleDraw_PrivateData(QObject): def __init__(self): QObject.__init__(self) self.len = 0 self.alignment = QwtScaleDraw.BottomScale self.labelAlignment = 0 self.labelRotation = 0.0 self.labelAutoSize = True self.pos = QPointF() class QwtScaleDraw(QwtAbstractScaleDraw): """ A class for drawing scales QwtScaleDraw can be used to draw linear or logarithmic scales. A scale has a position, an alignment and a length, which can be specified . The labels can be rotated and aligned to the ticks using `setLabelRotation()` and `setLabelAlignment()`. After a scale division has been specified as a QwtScaleDiv object using `QwtAbstractScaleDraw.setScaleDiv(scaleDiv)`, the scale can be drawn with the `QwtAbstractScaleDraw.draw()` member. Alignment of the scale draw: * `QwtScaleDraw.BottomScale`: The scale is below * `QwtScaleDraw.TopScale`: The scale is above * `QwtScaleDraw.LeftScale`: The scale is left * `QwtScaleDraw.RightScale`: The scale is right .. py:class:: QwtScaleDraw() The range of the scale is initialized to [0, 100], The position is at (0, 0) with a length of 100. The orientation is `QwtAbstractScaleDraw.Bottom`. """ # enum Alignment BottomScale, TopScale, LeftScale, RightScale = list(range(4)) Flags = ( Qt.AlignHCenter | Qt.AlignBottom, # BottomScale Qt.AlignHCenter | Qt.AlignTop, # TopScale Qt.AlignLeft | Qt.AlignVCenter, # LeftScale Qt.AlignRight | Qt.AlignVCenter, # RightScale ) def __init__(self): QwtAbstractScaleDraw.__init__(self) self.__data = QwtScaleDraw_PrivateData() self.setLength(100) self._max_label_sizes = {} def alignment(self): """ :return: Alignment of the scale .. seealso:: :py:meth:`setAlignment()` """ return self.__data.alignment def setAlignment(self, align): """ Set the alignment of the scale :param int align: Alignment of the scale Alignment of the scale draw: * `QwtScaleDraw.BottomScale`: The scale is below * `QwtScaleDraw.TopScale`: The scale is above * `QwtScaleDraw.LeftScale`: The scale is left * `QwtScaleDraw.RightScale`: The scale is right The default alignment is `QwtScaleDraw.BottomScale` .. seealso:: :py:meth:`alignment()` """ self.__data.alignment = align def orientation(self): """ Return the orientation TopScale, BottomScale are horizontal (`Qt.Horizontal`) scales, LeftScale, RightScale are vertical (`Qt.Vertical`) scales. :return: Orientation of the scale .. seealso:: :py:meth:`alignment()` """ if self.__data.alignment in (self.TopScale, self.BottomScale): return Qt.Horizontal elif self.__data.alignment in (self.LeftScale, self.RightScale): return Qt.Vertical def getBorderDistHint(self, font): """ Determine the minimum border distance This member function returns the minimum space needed to draw the mark labels at the scale's endpoints. :param QFont font: Font :return: tuple `(start, end)` Returned tuple: * start: Start border distance * end: End border distance """ start, end = 0, 1.0 if not self.hasComponent(QwtAbstractScaleDraw.Labels): return start, end ticks = self.scaleDiv().ticks(QwtScaleDiv.MajorTick) if len(ticks) == 0: return start, end minTick = ticks[0] minPos = self.scaleMap().transform(minTick) maxTick = minTick maxPos = minPos for tick in ticks: tickPos = self.scaleMap().transform(tick) if tickPos < minPos: minTick = tick minPos = tickPos if tickPos > self.scaleMap().transform(maxTick): maxTick = tick maxPos = tickPos s = 0.0 e = 0.0 if self.orientation() == Qt.Vertical: s = -self.labelRect(font, minTick).top() s -= abs(minPos - round(self.scaleMap().p2())) e = self.labelRect(font, maxTick).bottom() e -= abs(maxPos - self.scaleMap().p1()) else: s = -self.labelRect(font, minTick).left() s -= abs(minPos - self.scaleMap().p1()) e = self.labelRect(font, maxTick).right() e -= abs(maxPos - self.scaleMap().p2()) return max(math.ceil(s), 0), max(math.ceil(e), 0) def minLabelDist(self, font): """ Determine the minimum distance between two labels, that is necessary that the texts don't overlap. :param QFont font: Font :return: The maximum width of a label .. seealso:: :py:meth:`getBorderDistHint()` """ if not self.hasComponent(QwtAbstractScaleDraw.Labels): return 0 ticks = self.scaleDiv().ticks(QwtScaleDiv.MajorTick) if not ticks: return 0 fm = QFontMetrics(font) vertical = self.orientation() == Qt.Vertical bRect1 = QRectF() bRect2 = self.labelRect(font, ticks[0]) if vertical: bRect2.setRect(-bRect2.bottom(), 0.0, bRect2.height(), bRect2.width()) maxDist = 0.0 for tick in ticks: bRect1 = bRect2 bRect2 = self.labelRect(font, tick) if vertical: bRect2.setRect(-bRect2.bottom(), 0.0, bRect2.height(), bRect2.width()) dist = fm.leading() if bRect1.right() > 0: dist += bRect1.right() if bRect2.left() < 0: dist += -bRect2.left() if dist > maxDist: maxDist = dist angle = qwtRadians(self.labelRotation()) if vertical: angle += math.pi / 2 sinA = math.sin(angle) if qFuzzyCompare(sinA + 1.0, 1.0): return math.ceil(maxDist) fmHeight = fm.ascent() - 2 labelDist = fmHeight / math.sin(angle) * math.cos(angle) if labelDist < 0: labelDist = -labelDist if labelDist > maxDist: labelDist = maxDist if labelDist < fmHeight: labelDist = fmHeight return math.ceil(labelDist) def extent(self, font): """ Calculate the width/height that is needed for a vertical/horizontal scale. The extent is calculated from the pen width of the backbone, the major tick length, the spacing and the maximum width/height of the labels. :param QFont font: Font used for painting the labels :return: Extent .. seealso:: :py:meth:`minLength()` """ d = 0.0 if self.hasComponent(QwtAbstractScaleDraw.Labels): if self.orientation() == Qt.Vertical: d = self.maxLabelWidth(font) else: d = self.maxLabelHeight(font) if d > 0: d += self.spacing() if self.hasComponent(QwtAbstractScaleDraw.Ticks): d += self.maxTickLength() if self.hasComponent(QwtAbstractScaleDraw.Backbone): pw = max([1, self.penWidth()]) d += pw return max([d, self.minimumExtent()]) def minLength(self, font): """ Calculate the minimum length that is needed to draw the scale :param QFont font: Font used for painting the labels :return: Minimum length that is needed to draw the scale .. seealso:: :py:meth:`extent()` """ startDist, endDist = self.getBorderDistHint(font) sd = self.scaleDiv() minorCount = len(sd.ticks(QwtScaleDiv.MinorTick)) + len( sd.ticks(QwtScaleDiv.MediumTick) ) majorCount = len(sd.ticks(QwtScaleDiv.MajorTick)) lengthForLabels = 0 if self.hasComponent(QwtAbstractScaleDraw.Labels): lengthForLabels = self.minLabelDist(font) * majorCount lengthForTicks = 0 if self.hasComponent(QwtAbstractScaleDraw.Ticks): pw = max([1, self.penWidth()]) lengthForTicks = math.ceil((majorCount + minorCount) * (pw + 1.0)) return startDist + endDist + max([lengthForLabels, lengthForTicks]) def labelPosition(self, value): """ Find the position, where to paint a label The position has a distance that depends on the length of the ticks in direction of the `alignment()`. :param float value: Value :return: Position, where to paint a label """ tval = self.scaleMap().transform(value) dist = self.spacing() if self.hasComponent(QwtAbstractScaleDraw.Backbone): dist += max([1, self.penWidth()]) if self.hasComponent(QwtAbstractScaleDraw.Ticks): dist += self.tickLength(QwtScaleDiv.MajorTick) px = 0 py = 0 if self.alignment() == self.RightScale: px = self.__data.pos.x() + dist py = tval elif self.alignment() == self.LeftScale: px = self.__data.pos.x() - dist py = tval elif self.alignment() == self.BottomScale: px = tval py = self.__data.pos.y() + dist elif self.alignment() == self.TopScale: px = tval py = self.__data.pos.y() - dist return QPointF(px, py) def drawTick(self, painter, value, len_): """ Draw a tick :param QPainter painter: Painter :param float value: Value of the tick :param float len: Length of the tick .. seealso:: :py:meth:`drawBackbone()`, :py:meth:`drawLabel()` """ if len_ <= 0: return pos = self.__data.pos tval = self.scaleMap().transform(value) pw = self.penWidth() a = 0 if self.alignment() == self.LeftScale: x1 = pos.x() + a x2 = pos.x() + a - pw - len_ painter.drawLine(QLineF(x1, tval, x2, tval)) elif self.alignment() == self.RightScale: x1 = pos.x() x2 = pos.x() + pw + len_ painter.drawLine(QLineF(x1, tval, x2, tval)) elif self.alignment() == self.BottomScale: y1 = pos.y() y2 = pos.y() + pw + len_ painter.drawLine(QLineF(tval, y1, tval, y2)) elif self.alignment() == self.TopScale: y1 = pos.y() + a y2 = pos.y() - pw - len_ + a painter.drawLine(QLineF(tval, y1, tval, y2)) def drawBackbone(self, painter): """ Draws the baseline of the scale :param QPainter painter: Painter .. seealso:: :py:meth:`drawTick()`, :py:meth:`drawLabel()` """ pos = self.__data.pos len_ = self.__data.len off = 0.5 * self.penWidth() if self.alignment() == self.LeftScale: x = pos.x() - off painter.drawLine(QLineF(x, pos.y(), x, pos.y() + len_)) elif self.alignment() == self.RightScale: x = pos.x() + off painter.drawLine(QLineF(x, pos.y(), x, pos.y() + len_)) elif self.alignment() == self.TopScale: y = pos.y() - off painter.drawLine(QLineF(pos.x(), y, pos.x() + len_, y)) elif self.alignment() == self.BottomScale: y = pos.y() + off painter.drawLine(QLineF(pos.x(), y, pos.x() + len_, y)) def move(self, *args): """ Move the position of the scale The meaning of the parameter pos depends on the alignment: * `QwtScaleDraw.LeftScale`: The origin is the topmost point of the backbone. The backbone is a vertical line. Scale marks and labels are drawn at the left of the backbone. * `QwtScaleDraw.RightScale`: The origin is the topmost point of the backbone. The backbone is a vertical line. Scale marks and labels are drawn at the right of the backbone. * `QwtScaleDraw.TopScale`: The origin is the leftmost point of the backbone. The backbone is a horizontal line. Scale marks and labels are drawn above the backbone. * `QwtScaleDraw.BottomScale`: The origin is the leftmost point of the backbone. The backbone is a horizontal line Scale marks and labels are drawn below the backbone. .. py:method:: move(x, y) :noindex: :param float x: X coordinate :param float y: Y coordinate .. py:method:: move(pos) :noindex: :param QPointF pos: position .. seealso:: :py:meth:`pos()`, :py:meth:`setLength()` """ if len(args) == 2: x, y = args self.move(QPointF(x, y)) elif len(args) == 1: (pos,) = args self.__data.pos = pos self.updateMap() else: raise TypeError( "%s().move() takes 1 or 2 argument(s) (%s given)" % (self.__class__.__name__, len(args)) ) def pos(self): """ :return: Origin of the scale .. seealso:: :py:meth:`pos()`, :py:meth:`setLength()` """ return self.__data.pos def setLength(self, length): """ Set the length of the backbone. The length doesn't include the space needed for overlapping labels. :param float length: Length of the backbone .. seealso:: :py:meth:`move()`, :py:meth:`minLabelDist()` """ if length >= 0 and length < 10: length = 10 if length < 0 and length > -10: length = -10 self.__data.len = length self.updateMap() def length(self): """ :return: the length of the backbone .. seealso:: :py:meth:`setLength()`, :py:meth:`pos()` """ return self.__data.len def drawLabel(self, painter, value): """ Draws the label for a major scale tick :param QPainter painter: Painter :param float value: Value .. seealso:: :py:meth:`drawTick()`, :py:meth:`drawBackbone()`, :py:meth:`boundingLabelRect()` """ lbl, labelSize = self.tickLabel(painter.font(), value) if lbl is None or lbl.isEmpty(): return pos = self.labelPosition(value) transform = self.labelTransformation(pos, labelSize) painter.save() painter.setWorldTransform(transform, True) lbl.draw(painter, QRect(QPoint(0, 0), labelSize.toSize())) painter.restore() def boundingLabelRect(self, font, value): """ Find the bounding rectangle for the label. The coordinates of the rectangle are absolute (calculated from `pos()`) in direction of the tick. :param QFont font: Font used for painting :param float value: Value :return: Bounding rectangle .. seealso:: :py:meth:`labelRect()` """ lbl, labelSize = self.tickLabel(font, value) if lbl.isEmpty(): return QRect() pos = self.labelPosition(value) transform = self.labelTransformation(pos, labelSize) return transform.mapRect(QRect(QPoint(0, 0), labelSize.toSize())) def labelTransformation(self, pos, size): """ Calculate the transformation that is needed to paint a label depending on its alignment and rotation. :param QPointF pos: Position where to paint the label :param QSizeF size: Size of the label :return: Transformation matrix .. seealso:: :py:meth:`setLabelAlignment()`, :py:meth:`setLabelRotation()` """ transform = QTransform() transform.translate(pos.x(), pos.y()) transform.rotate(self.labelRotation()) flags = self.labelAlignment() if flags == 0: flags = self.Flags[self.alignment()] if flags & Qt.AlignLeft: x = -size.width() elif flags & Qt.AlignRight: x = 0.0 else: x = -(0.5 * size.width()) if flags & Qt.AlignTop: y = -size.height() elif flags & Qt.AlignBottom: y = 0 else: y = -(0.5 * size.height()) transform.translate(x, y) return transform def labelRect(self, font, value): """ Find the bounding rectangle for the label. The coordinates of the rectangle are relative to spacing + tick length from the backbone in direction of the tick. :param QFont font: Font used for painting :param float value: Value :return: Bounding rectangle that is needed to draw a label """ lbl, labelSize = self.tickLabel(font, value) if not lbl or lbl.isEmpty(): return QRectF(0.0, 0.0, 0.0, 0.0) pos = self.labelPosition(value) transform = self.labelTransformation(pos, labelSize) br = transform.mapRect(QRectF(QPointF(0, 0), labelSize)) br.translate(-pos.x(), -pos.y()) return br def labelSize(self, font, value): """ Calculate the size that is needed to draw a label :param QFont font: Label font :param float value: Value :return: Size that is needed to draw a label """ return self.labelRect(font, value).size() def setLabelRotation(self, rotation): """ Rotate all labels. When changing the rotation, it might be necessary to adjust the label flags too. Finding a useful combination is often the result of try and error. :param float rotation: Angle in degrees. When changing the label rotation, the label flags often needs to be adjusted too. .. seealso:: :py:meth:`setLabelAlignment()`, :py:meth:`labelRotation()`, :py:meth:`labelAlignment()` """ self.__data.labelRotation = rotation def labelRotation(self): """ :return: the label rotation .. seealso:: :py:meth:`setLabelRotation()`, :py:meth:`labelAlignment()` """ return self.__data.labelRotation def setLabelAlignment(self, alignment): """ Change the label flags Labels are aligned to the point tick length + spacing away from the backbone. The alignment is relative to the orientation of the label text. In case of an flags of 0 the label will be aligned depending on the orientation of the scale: * `QwtScaleDraw.TopScale`: `Qt.AlignHCenter | Qt.AlignTop` * `QwtScaleDraw.BottomScale`: `Qt.AlignHCenter | Qt.AlignBottom` * `QwtScaleDraw.LeftScale`: `Qt.AlignLeft | Qt.AlignVCenter` * `QwtScaleDraw.RightScale`: `Qt.AlignRight | Qt.AlignVCenter` Changing the alignment is often necessary for rotated labels. :param Qt.Alignment alignment Or'd `Qt.AlignmentFlags` .. seealso:: :py:meth:`setLabelRotation()`, :py:meth:`labelRotation()`, :py:meth:`labelAlignment()` .. warning:: The various alignments might be confusing. The alignment of the label is not the alignment of the scale and is not the alignment of the flags (`QwtText.flags()`) returned from `QwtAbstractScaleDraw.label()`. """ self.__data.labelAlignment = alignment def labelAlignment(self): """ :return: the label flags .. seealso:: :py:meth:`setLabelAlignment()`, :py:meth:`labelRotation()` """ return self.__data.labelAlignment def setLabelAutoSize(self, state): """ Set label automatic size option state When drawing text labels, if automatic size mode is enabled (default behavior), the axes are drawn in order to optimize layout space and depends on text label individual sizes. Otherwise, width and height won't change when axis range is changing. This option is not implemented in Qwt C++ library: this may be used either as an optimization (updating plot layout is faster when this option is enabled) or as an appearance preference (with Qwt default behavior, the size of axes may change when zooming and/or panning plot canvas which in some cases may not be desired). :param bool state: On/off .. seealso:: :py:meth:`labelAutoSize()` """ self.__data.labelAutoSize = state def labelAutoSize(self): """ :return: True if automatic size option is enabled for labels .. seealso:: :py:meth:`setLabelAutoSize()` """ return self.__data.labelAutoSize def _get_max_label_size(self, font): key = (font.toString(), self.labelRotation()) size = self._max_label_sizes.get(key) if size is None: size = self.labelSize(font, -999999) # -999999 is the biggest label size.setWidth(math.ceil(size.width())) size.setHeight(math.ceil(size.height())) return self._max_label_sizes.setdefault(key, size) else: return size def maxLabelWidth(self, font): """ :param QFont font: Font :return: the maximum width of a label """ ticks = self.scaleDiv().ticks(QwtScaleDiv.MajorTick) if not ticks: return 0 if self.labelAutoSize(): vmax = sorted( [v for v in ticks if self.scaleDiv().contains(v)], key=lambda obj: len("%g" % obj), )[-1] return math.ceil(self.labelSize(font, vmax).width()) ## Original implementation (closer to Qwt's C++ code, but slower): # return math.ceil(max([self.labelSize(font, v).width() # for v in ticks if self.scaleDiv().contains(v)])) else: return self._get_max_label_size(font).width() def maxLabelHeight(self, font): """ :param QFont font: Font :return: the maximum height of a label """ ticks = self.scaleDiv().ticks(QwtScaleDiv.MajorTick) if not ticks: return 0 if self.labelAutoSize(): vmax = sorted( [v for v in ticks if self.scaleDiv().contains(v)], key=lambda obj: len("%g" % obj), )[-1] return math.ceil(self.labelSize(font, vmax).height()) ## Original implementation (closer to Qwt's C++ code, but slower): # return math.ceil(max([self.labelSize(font, v).height() # for v in ticks if self.scaleDiv().contains(v)])) else: return self._get_max_label_size(font).height() def updateMap(self): pos = self.__data.pos len_ = self.__data.len sm = self.scaleMap() if self.orientation() == Qt.Vertical: sm.setPaintInterval(pos.y() + len_, pos.y()) else: sm.setPaintInterval(pos.x(), pos.x() + len_) class QwtDateTimeScaleDraw(QwtScaleDraw): """Scale draw for datetime axis This class formats axis labels as date/time strings from Unix timestamps. Args: format: Format string for datetime display (default: "%Y-%m-%d %H:%M:%S"). Uses Python datetime.strftime() format codes. spacing: Spacing between labels (default: 4) Examples: >>> # Create a datetime scale with default format >>> scale = QwtDateTimeScaleDraw() >>> # Create a datetime scale with custom format (time only) >>> scale = QwtDateTimeScaleDraw(format="%H:%M:%S") >>> # Create a datetime scale with date only >>> scale = QwtDateTimeScaleDraw(format="%Y-%m-%d", spacing=4) """ def __init__(self, format: str = "%Y-%m-%d %H:%M:%S", spacing: int = 4) -> None: super().__init__() self._format = format self.setSpacing(spacing) def get_format(self) -> str: """Get the current datetime format string Returns: str: Format string """ return self._format def set_format(self, format: str) -> None: """Set the datetime format string Args: format: Format string for datetime display """ self._format = format def label(self, value: float) -> QwtText: """Convert a timestamp value to a formatted date/time label Args: value: Unix timestamp (seconds since epoch) Returns: QwtText: Formatted label """ try: dt = datetime.fromtimestamp(value) return QwtText(dt.strftime(self._format)) except (ValueError, OSError): # Handle invalid timestamps return QwtText("")