From 6c0355d7194c60dcb778bb34a3df5a9bac511f37 Mon Sep 17 00:00:00 2001
From: Agustin Zubiaga <aguz@sugarlabs.org>
Date: Mon, 02 Jul 2012 00:48:34 +0000
Subject: Some charts.py fixes (sugarpycha)

---
(limited to 'sugarpycha/line.py')

diff --git a/sugarpycha/line.py b/sugarpycha/line.py
new file mode 100644
index 0000000..9b12152
--- /dev/null
+++ b/sugarpycha/line.py
@@ -0,0 +1,129 @@
+# Copyright(c) 2007-2010 by Lorenzo Gil Sanchez <lorenzo.gil.sanchez@gmail.com>
+#
+# This file is part of PyCha.
+#
+# PyCha is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# PyCha is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with PyCha.  If not, see <http://www.gnu.org/licenses/>.
+
+from pycha.chart import Chart
+from pycha.color import hex2rgb
+
+
+class LineChart(Chart):
+
+    def __init__(self, surface=None, options={}, debug=False):
+        super(LineChart, self).__init__(surface, options, debug)
+        self.points = []
+
+    def _updateChart(self):
+        """Evaluates measures for line charts"""
+        self.points = []
+
+        for i, (name, store) in enumerate(self.datasets):
+            for item in store:
+                xval, yval = item
+                x = (xval - self.minxval) * self.xscale
+                y = 1.0 - (yval - self.minyval) * self.yscale
+                point = Point(x, y, xval, yval, name)
+
+                if 0.0 <= point.x <= 1.0 and 0.0 <= point.y <= 1.0:
+                    self.points.append(point)
+
+    def _renderChart(self, cx):
+        """Renders a line chart"""
+
+        def preparePath(storeName):
+            cx.new_path()
+            firstPoint = True
+            lastX = None
+            if self.options.shouldFill:
+                # Go to the (0,0) coordinate to start drawing the area
+                #cx.move_to(self.layout.chart.x,
+                #           self.layout.chart.y + self.layout.chart.h)
+                offset = (1.0 - self.origin) * self.layout.chart.h
+                cx.move_to(self.layout.chart.x, self.layout.chart.y + offset)
+
+            for point in self.points:
+                if point.name == storeName:
+                    if not self.options.shouldFill and firstPoint:
+                        # starts the first point of the line
+                        cx.move_to(point.x * self.layout.chart.w
+                                   + self.layout.chart.x,
+                                   point.y * self.layout.chart.h
+                                   + self.layout.chart.y)
+                        firstPoint = False
+                        continue
+                    cx.line_to(point.x * self.layout.chart.w
+                               + self.layout.chart.x,
+                               point.y * self.layout.chart.h
+                               + self.layout.chart.y)
+                    # we remember the last X coordinate to close the area
+                    # properly. See bug #4
+                    lastX = point.x
+
+            if self.options.shouldFill:
+                # Close the path to the start point
+                y = ((1.0 - self.origin) * self.layout.chart.h
+                     + self.layout.chart.y)
+                cx.line_to(lastX * self.layout.chart.w
+                           + self.layout.chart.x, y)
+                cx.line_to(self.layout.chart.x, y)
+                cx.close_path()
+            else:
+                cx.set_source_rgb(*self.colorScheme[storeName])
+                cx.stroke()
+
+        cx.save()
+        cx.set_line_width(self.options.stroke.width)
+        if self.options.shouldFill:
+
+            def drawLine(storeName):
+                if self.options.stroke.shadow:
+                    # draw shadow
+                    cx.save()
+                    cx.set_source_rgba(0, 0, 0, 0.15)
+                    cx.translate(2, -2)
+                    preparePath(storeName)
+                    cx.fill()
+                    cx.restore()
+
+                # fill the line
+                cx.set_source_rgb(*self.colorScheme[storeName])
+                preparePath(storeName)
+                cx.fill()
+
+                if not self.options.stroke.hide:
+                    # draw stroke
+                    cx.set_source_rgb(*hex2rgb(self.options.stroke.color))
+                    preparePath(storeName)
+                    cx.stroke()
+
+            # draw the lines
+            for key in self._getDatasetsKeys():
+                drawLine(key)
+        else:
+            for key in self._getDatasetsKeys():
+                preparePath(key)
+
+        cx.restore()
+
+
+class Point(object):
+
+    def __init__(self, x, y, xval, yval, name):
+        self.x, self.y = x, y
+        self.xval, self.yval = xval, yval
+        self.name = name
+
+    def __str__(self):
+        return "<pycha.line.Point@(%.2f, %.2f)>" % (self.x, self.y)
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