tablib/tablib/packages/openpyxl/chart.py

'''
Copyright (c) 2010 openpyxl

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

@license: http://www.opensource.org/licenses/mit-license.php
@author: Eric Gazoni
'''

import math

from .style import NumberFormat
from .drawing import Drawing, Shape
from .shared.units import pixels_to_EMU, short_color
from .cell import get_column_letter

class Axis(object):

    POSITION_BOTTOM = 'b'
    POSITION_LEFT = 'l'

    ORIENTATION_MIN_MAX = "minMax"

    def __init__(self):

        self.orientation = self.ORIENTATION_MIN_MAX
        self.number_format = NumberFormat()
        for attr in ('position','tick_label_position','crosses',
            'auto','label_align','label_offset','cross_between'):
            setattr(self, attr, None)
        self.min = 0
        self.max = None
        self.unit = None

    @classmethod
    def default_category(cls):
        """ default values for category axes """

        ax = Axis()
        ax.id = 60871424
        ax.cross = 60873344
        ax.position = Axis.POSITION_BOTTOM
        ax.tick_label_position = 'nextTo'
        ax.crosses = "autoZero"
        ax.auto = True
        ax.label_align = 'ctr'
        ax.label_offset = 100
        return ax

    @classmethod
    def default_value(cls):
        """ default values for value axes """

        ax = Axis()
        ax.id = 60873344
        ax.cross = 60871424
        ax.position = Axis.POSITION_LEFT
        ax.major_gridlines = None
        ax.tick_label_position = 'nextTo'
        ax.crosses = 'autoZero'
        ax.auto = False
        ax.cross_between = 'between'
        return ax

class Reference(object):
    """ a simple wrapper around a serie of reference data """

    def __init__(self, sheet, pos1, pos2=None):

        self.sheet = sheet
        self.pos1 = pos1
        self.pos2 = pos2

    def get_type(self):

        if isinstance(self.cache[0], basestring):
            return 'str'
        else:
            return 'num'

    def _get_ref(self):
        """ format excel reference notation """

        if self.pos2:
            return '%s!$%s$%s:$%s$%s' % (self.sheet.title,
                get_column_letter(self.pos1[1]+1), self.pos1[0]+1,
                get_column_letter(self.pos2[1]+1), self.pos2[0]+1)
        else:
            return '%s!$%s$%s' % (self.sheet.title,
                get_column_letter(self.pos1[1]+1), self.pos1[0]+1)


    def _get_cache(self):
        """ read data in sheet - to be used at writing time """

        cache = []
        if self.pos2:
            for row in range(self.pos1[0], self.pos2[0]+1):
                for col in range(self.pos1[1], self.pos2[1]+1):
                    cache.append(self.sheet.cell(row=row, column=col).value)
        else:
            cell = self.sheet.cell(row=self.pos1[0], column=self.pos1[1])
            cache.append(cell.value)
        return cache


class Serie(object):
    """ a serie of data and possibly associated labels """

    MARKER_NONE = 'none'

    def __init__(self, values, labels=None, legend=None, color=None, xvalues=None):

        self.marker = Serie.MARKER_NONE
        self.values = values
        self.xvalues = xvalues
        self.labels = labels
        self.legend = legend
        self.error_bar = None
        self._color = color

    def _get_color(self):
        return self._color

    def _set_color(self, color):
        self._color = short_color(color)

    color = property(_get_color, _set_color)

    def get_min_max(self):

        if self.error_bar:
            err_cache = self.error_bar.values._get_cache()
            vals = [v + err_cache[i] \
                for i,v in enumerate(self.values._get_cache())]
        else:
            vals = self.values._get_cache()
        return min(vals), max(vals)

    def __len__(self):

        return len(self.values.cache)

class Legend(object):

    def __init__(self):

        self.position = 'r'
        self.layout = None

class ErrorBar(object):

    PLUS = 1
    MINUS = 2
    PLUS_MINUS = 3

    def __init__(self, _type, values):

        self.type = _type
        self.values = values

class Chart(object):
    """ raw chart class """

    GROUPING_CLUSTERED = 'clustered'
    GROUPING_STANDARD = 'standard'

    BAR_CHART = 1
    LINE_CHART = 2
    SCATTER_CHART = 3

    def __init__(self, _type, grouping):

        self._series = []

        # public api
        self.type = _type
        self.grouping = grouping
        self.x_axis = Axis.default_category()
        self.y_axis = Axis.default_value()
        self.legend = Legend()
        self.lang = 'fr-FR'
        self.title = ''
        self.print_margins = dict(b=.75, l=.7, r=.7, t=.75, header=0.3, footer=.3)

        # the containing drawing
        self.drawing = Drawing()

        # the offset for the plot part in percentage of the drawing size
        self.width = .6
        self.height = .6
        self.margin_top = self._get_max_margin_top()
        self.margin_left = 0

        # the user defined shapes
        self._shapes = []

    def add_serie(self, serie):

        serie.id = len(self._series)
        self._series.append(serie)
        self._compute_min_max()
        if not None in [s.xvalues for s in self._series]:
            self._compute_xmin_xmax()

    def add_shape(self, shape):

        shape._chart = self
        self._shapes.append(shape)

    def get_x_units(self):
        """ calculate one unit for x axis in EMU """

        return max([len(s.values._get_cache()) for s in self._series])

    def get_y_units(self):
        """ calculate one unit for y axis in EMU """

        dh = pixels_to_EMU(self.drawing.height)
        return (dh * self.height) / self.y_axis.max

    def get_y_chars(self):
        """ estimate nb of chars for y axis """

        _max = max([max(s.values._get_cache()) for s in self._series])
        return len(str(int(_max)))

    def _compute_min_max(self):
        """ compute y axis limits and units """

        maxi = max([max(s.values._get_cache()) for s in self._series])

        mul = None
        if maxi < 1:
            s = str(maxi).split('.')[1]
            mul = 10
            for x in s:
                if x == '0':
                    mul *= 10
                else:
                    break
            maxi = maxi * mul

        maxi = math.ceil(maxi * 1.1)
        sz =  len(str(int(maxi))) - 1
        unit = math.ceil(math.ceil(maxi / pow(10, sz)) * pow(10, sz-1))
        maxi = math.ceil(maxi/unit) * unit

        if mul is not None:
            maxi = maxi/mul
            unit = unit/mul

        if maxi / unit > 9:
            # no more that 10 ticks
            unit *= 2

        self.y_axis.max = maxi
        self.y_axis.unit = unit

    def _compute_xmin_xmax(self):
        """ compute x axis limits and units """

        maxi = max([max(s.xvalues._get_cache()) for s in self._series])

        mul = None
        if maxi < 1:
            s = str(maxi).split('.')[1]
            mul = 10
            for x in s:
                if x == '0':
                    mul *= 10
                else:
                    break
            maxi = maxi * mul

        maxi = math.ceil(maxi * 1.1)
        sz =  len(str(int(maxi))) - 1
        unit = math.ceil(math.ceil(maxi / pow(10, sz)) * pow(10, sz-1))
        maxi = math.ceil(maxi/unit) * unit

        if mul is not None:
            maxi = maxi/mul
            unit = unit/mul

        if maxi / unit > 9:
            # no more that 10 ticks
            unit *= 2

        self.x_axis.max = maxi
        self.x_axis.unit = unit

    def _get_max_margin_top(self):

        mb = Shape.FONT_HEIGHT + Shape.MARGIN_BOTTOM
        plot_height = self.drawing.height * self.height
        return float(self.drawing.height - plot_height - mb)/self.drawing.height

    def _get_min_margin_left(self):

        ml = (self.get_y_chars() * Shape.FONT_WIDTH) + Shape.MARGIN_LEFT
        return float(ml)/self.drawing.width

    def _get_margin_top(self):
        """ get margin in percent """

        return min(self.margin_top, self._get_max_margin_top())

    def _get_margin_left(self):

        return max(self._get_min_margin_left(), self.margin_left)

class BarChart(Chart):
    def __init__(self):
        super(BarChart, self).__init__(Chart.BAR_CHART, Chart.GROUPING_CLUSTERED)

class LineChart(Chart):
    def __init__(self):
        super(LineChart, self).__init__(Chart.LINE_CHART, Chart.GROUPING_STANDARD)

class ScatterChart(Chart):
    def __init__(self):
        super(ScatterChart, self).__init__(Chart.SCATTER_CHART, Chart.GROUPING_STANDARD)