# -*- 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 qtpy.QtCore import QLineF, 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(object):
def __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 = {}
[docs]
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()
[docs]
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
[docs]
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
[docs]
def drawBackbone(self, painter):
"""
Draws the baseline of the scale
:param QPainter painter: Painter
.. seealso::
:py:meth:`drawTick()`, :py:meth:`drawLabel()`
"""
pass
[docs]
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
[docs]
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
[docs]
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
[docs]
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()
[docs]
def scaleMap(self):
"""
:return: Map how to translate between scale and pixel values
"""
return self.__data.map
[docs]
def scaleDiv(self):
"""
:return: scale division
"""
return self.__data.scaleDiv
[docs]
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
[docs]
def penWidth(self):
"""
:return: Scale pen width
.. seealso::
:py:meth:`setPenWidth()`
"""
return self.__data.penWidth
[docs]
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()
[docs]
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
[docs]
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
[docs]
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
[docs]
def minimumExtent(self):
"""
Get the minimum extent
:return: Minimum extent
.. seealso::
:py:meth:`extent()`, :py:meth:`setMinimumExtent()`
"""
return self.__data.minExtent
[docs]
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])])
[docs]
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]
[docs]
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()))
[docs]
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])
[docs]
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]
[docs]
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
[docs]
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, tsize = self.__data.labelCache.get(value, (None, None))
if lbl is None:
lbl = QwtText(self.label(value))
lbl.setRenderFlags(0)
lbl.setLayoutAttribute(QwtText.MinimumLayout)
tsize = lbl.textSize(font)
self.__data.labelCache[value] = lbl, tsize
return lbl, tsize
[docs]
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(object):
def __init__(self):
self.len = 0
self.alignment = QwtScaleDraw.BottomScale
self.labelAlignment = 0
self.labelRotation = 0.0
self.labelAutoSize = True
self.pos = QPointF()
[docs]
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 = {}
[docs]
def alignment(self):
"""
:return: Alignment of the scale
.. seealso::
:py:meth:`setAlignment()`
"""
return self.__data.alignment
[docs]
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
[docs]
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
[docs]
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)
[docs]
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)
[docs]
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()])
[docs]
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])
[docs]
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)
[docs]
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))
[docs]
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))
[docs]
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))
)
[docs]
def pos(self):
"""
:return: Origin of the scale
.. seealso::
:py:meth:`pos()`, :py:meth:`setLength()`
"""
return self.__data.pos
[docs]
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()
[docs]
def length(self):
"""
:return: the length of the backbone
.. seealso::
:py:meth:`setLength()`, :py:meth:`pos()`
"""
return self.__data.len
[docs]
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()
[docs]
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()))
[docs]
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
[docs]
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()
[docs]
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
[docs]
def labelRotation(self):
"""
:return: the label rotation
.. seealso::
:py:meth:`setLabelRotation()`, :py:meth:`labelAlignment()`
"""
return self.__data.labelRotation
[docs]
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
[docs]
def labelAlignment(self):
"""
:return: the label flags
.. seealso::
:py:meth:`setLabelAlignment()`, :py:meth:`labelRotation()`
"""
return self.__data.labelAlignment
[docs]
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
[docs]
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
[docs]
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()
[docs]
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_)
