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Diffstat (limited to 'pygtk_chart/chart_object.py')
| -rw-r--r-- | pygtk_chart/chart_object.py | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/pygtk_chart/chart_object.py b/pygtk_chart/chart_object.py new file mode 100644 index 0000000..8e4cd7e --- /dev/null +++ b/pygtk_chart/chart_object.py @@ -0,0 +1,155 @@ +#!/usr/bin/env python +# +# chart_object.py +# +# Copyright 2009 Sven Festersen <sven@sven-festersen.de> +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program 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 General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, +# MA 02110-1301, USA. +""" +This module contains the ChartObject class. + +Author: Sven Festersen (sven@sven-festersen.de) +""" +import cairo +import gobject + +class ChartObject(gobject.GObject): + """ + This is the base class for all things that can be drawn on a chart + widget. + It emits the signal 'appearance-changed' when it needs to be + redrawn. + + Properties + ========== + ChartObject inherits properties from gobject.GObject. + Additional properties: + - visible (sets whether the object should be visible, + type: boolean) + - antialias (sets whether the object should be antialiased, + type: boolean). + + Signals + ======= + ChartObject inherits signals from gobject.GObject, + Additional signals: + - appearance-changed (emitted if the object needs to be redrawn). + """ + + __gsignals__ = {"appearance-changed": (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE, [])} + + + __gproperties__ = {"visible": (gobject.TYPE_BOOLEAN, + "visibilty of the object", + "Set whether to draw the object or not.", + True, gobject.PARAM_READWRITE), + "antialias": (gobject.TYPE_BOOLEAN, + "use antialiasing", + "Set whether to use antialiasing when drawing the object.", + True, gobject.PARAM_READWRITE)} + + def __init__(self): + gobject.GObject.__init__(self) + self._show = True + self._antialias = True + + def do_get_property(self, property): + if property.name == "visible": + return self._show + elif property.name == "antialias": + return self._antialias + else: + raise AttributeError, "Property %s does not exist." % property.name + + def do_set_property(self, property, value): + if property.name == "visible": + self._show = value + elif property.name == "antialias": + self._antialias = value + else: + raise AttributeError, "Property %s does not exist." % property.name + + def _do_draw(self, context, rect): + """ + A derived class should override this method. The drawing stuff + should happen here. + + @type context: cairo.Context + @param context: The context to draw on. + @type rect: gtk.gdk.Rectangle + @param rect: A rectangle representing the charts area. + """ + pass + + def draw(self, context, rect, *args): + """ + This method is called by the parent Chart instance. It + calls _do_draw. + + @type context: cairo.Context + @param context: The context to draw on. + @type rect: gtk.gdk.Rectangle + @param rect: A rectangle representing the charts area. + """ + res = None + if self._show: + if not self._antialias: + context.set_antialias(cairo.ANTIALIAS_NONE) + res = self._do_draw(context, rect, *args) + context.set_antialias(cairo.ANTIALIAS_DEFAULT) + return res + + def set_antialias(self, antialias): + """ + This method sets the antialiasing mode of the ChartObject. Antialiasing + is enabled by default. + + @type antialias: boolean + @param antialias: If False, antialiasing is disabled for this + ChartObject. + """ + self.set_property("antialias", antialias) + self.emit("appearance_changed") + + def get_antialias(self): + """ + Returns True if antialiasing is enabled for the object. + + @return: boolean. + """ + return self.get_property("antialias") + + def set_visible(self, visible): + """ + Use this method to set whether the ChartObject should be visible or + not. + + @type visible: boolean + @param visible: If False, the PlotObject won't be drawn. + """ + self.set_property("visible", visible) + self.emit("appearance_changed") + + def get_visible(self): + """ + Returns True if the object is visble. + + @return: boolean. + """ + return self.get_property("visible") + + +gobject.type_register(ChartObject) |