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# Copyright(c) 2007-2009 by Lorenzo Gil Sanchez <lorenzo.gil.sanchez@gmail.com>
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# This file is part of PyCha.
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# PyCha is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# PyCha is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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# You should have received a copy of the GNU Lesser General Public License
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# along with PyCha. If not, see <http://www.gnu.org/licenses/>.
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from pycha.chart import Chart, uniqueIndices
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from pycha.color import hex2rgb
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class BarChart(Chart):
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def __init__(self, surface=None, options={}):
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super(BarChart, self).__init__(surface, options)
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self.barWidthForSet = 0.0
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super(BarChart, self)._updateXY()
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# each dataset is centered around a line segment. that's why we
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# need n + 1 divisions on the x axis
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self.xscale = 1 / (self.xrange + 1.0)
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def _updateChart(self):
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"""Evaluates measures for vertical bars"""
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stores = self._getDatasetsValues()
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uniqx = uniqueIndices(stores)
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barWidth = 1.0 * self.options.barWidthFillFraction
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self.barWidthForSet = barWidth / len(stores)
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self.barMargin = (1.0 - self.options.barWidthFillFraction) / 2
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xdelta = min([abs(uniqx[j] - uniqx[j-1])
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for j in range(1, len(uniqx))])
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barWidth = xdelta * self.xscale * self.options.barWidthFillFraction
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self.barWidthForSet = barWidth / len(stores)
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self.barMargin = (xdelta * self.xscale
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* (1.0 - self.options.barWidthFillFraction) / 2)
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self.minxdelta = xdelta
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def _renderChart(self, cx):
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"""Renders a horizontal/vertical bar chart"""
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stroke_width = self.options.stroke.width
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ux, uy = cx.device_to_user_distance(stroke_width, stroke_width)
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# gather bar proportions
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x = self.area.x + self.area.w * bar.x
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y = self.area.y + self.area.h * bar.y
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w = self.area.w * bar.w
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h = self.area.h * bar.h
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return # don't draw when the bar is too small
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if self.options.stroke.shadow:
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cx.set_source_rgba(0, 0, 0, 0.15)
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rectangle = self._getShadowRectangle(x, y, w, h)
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cx.rectangle(*rectangle)
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if self.options.shouldFill or (not self.options.stroke.hide):
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cx.rectangle(x, y, w, h)
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if self.options.shouldFill:
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cx.set_source_rgb(*self.options.colorScheme[bar.name])
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if not self.options.stroke.hide:
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cx.set_source_rgb(*hex2rgb(self.options.stroke.color))
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# render yvals above/beside bars
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if self.options.yvals.show:
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cx.set_font_size(self.options.yvals.fontSize)
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cx.set_source_rgb(*hex2rgb(self.options.yvals.fontColor))
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label = unicode(bar.yval)
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extents = cx.text_extents(label)
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self._renderYVal(cx, label, labelW, labelH, x, y, w, h)
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for bar in self.bars:
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def _renderYVal(self, cx, label, width, height, x, y, w, h):
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raise NotImplementedError
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class VerticalBarChart(BarChart):
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def _updateChart(self):
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"""Evaluates measures for vertical bars"""
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super(VerticalBarChart, self)._updateChart()
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for i, (name, store) in enumerate(self.datasets):
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x = (((xval - self.minxval) * self.xscale)
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+ self.barMargin + (i * self.barWidthForSet))
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w = self.barWidthForSet
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h = abs(yval) * self.yscale
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y = (1.0 - h) - self.area.origin
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y = 1 - self.area.origin
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rect = Rect(x, y, w, h, xval, yval, name)
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if (0.0 <= rect.x <= 1.0) and (0.0 <= rect.y <= 1.0):
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self.bars.append(rect)
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def _updateTicks(self):
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"""Evaluates bar ticks"""
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super(BarChart, self)._updateTicks()
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offset = (self.minxdelta * self.xscale) / 2
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self.xticks = [(tick[0] + offset, tick[1]) for tick in self.xticks]
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def _getShadowRectangle(self, x, y, w, h):
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return (x-2, y-2, w+4, h+2)
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def _renderYVal(self, cx, label, labelW, labelH, barX, barY, barW, barH):
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x = barX + (barW / 2.0) - (labelW / 2.0)
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if self.options.yvals.inside:
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y = barY + (1.5 * labelH)
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y = barY - 0.5 * labelH
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# if the label doesn't fit below the bar, put it above the bar
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if y > (barY + barH):
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y = barY - 0.5 * labelH
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class HorizontalBarChart(BarChart):
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def _updateChart(self):
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"""Evaluates measures for horizontal bars"""
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super(HorizontalBarChart, self)._updateChart()
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for i, (name, store) in enumerate(self.datasets):
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y = (((xval - self.minxval) * self.xscale)
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+ self.barMargin + (i * self.barWidthForSet))
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h = self.barWidthForSet
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w = abs(yval) * self.yscale
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x = self.area.origin - w
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rect = Rect(x, y, w, h, xval, yval, name)
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if (0.0 <= rect.x <= 1.0) and (0.0 <= rect.y <= 1.0):
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self.bars.append(rect)
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def _updateTicks(self):
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"""Evaluates bar ticks"""
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super(BarChart, self)._updateTicks()
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offset = (self.minxdelta * self.xscale) / 2
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self.xticks = [(1.0 - tick[0], tick[1]) for tick in self.yticks]
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self.yticks = [(tick[0] + offset, tick[1]) for tick in tmp]
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def _renderLines(self, cx):
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"""Aux function for _renderBackground"""
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self._renderLine(cx, tick, True)
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def _getShadowRectangle(self, x, y, w, h):
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return (x, y-2, w+2, h+4)
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def _renderXAxis(self, cx):
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"""Draws the horizontal line representing the X axis"""
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cx.move_to(self.area.x, self.area.y + self.area.h)
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cx.line_to(self.area.x + self.area.w, self.area.y + self.area.h)
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def _renderYAxis(self, cx):
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# draws the vertical line representing the Y axis
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cx.move_to(self.area.x + self.area.origin * self.area.w,
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cx.line_to(self.area.x + self.area.origin * self.area.w,
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self.area.y + self.area.h)
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def _renderYVal(self, cx, label, labelW, labelH, barX, barY, barW, barH):
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y = barY + (barH / 2.0) + (labelH / 2.0)
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if self.options.yvals.inside:
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x = barX + barW - (1.2 * labelW)
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x = barX + barW + 0.2 * labelW
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# if the label doesn't fit to the left of the bar, put it to the right
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x = barX + barW + 0.2 * labelW
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def __init__(self, x, y, w, h, xval, yval, name):
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self.x, self.y, self.w, self.h = x, y, w, h
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self.xval, self.yval = xval, yval
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return ("<pycha.bar.Rect@(%.2f, %.2f) %.2fx%.2f (%.2f, %.2f) %s>"
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% (self.x, self.y, self.w, self.h, self.xval, self.yval,
added
removed
pycha/bar.py
