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# -*- coding: UTF-8 -*-
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"""Cell renderer for directed graph.
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This module contains the implementation of a custom GtkCellRenderer that
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draws part of the directed graph based on the lines suggested by the code
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Because we're shiny, we use Cairo to do this, and because we're naughty
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we cheat and draw over the bits of the TreeViewColumn that are supposed to
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just be for the background.
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__copyright__ = "Copyright © 2005 Canonical Ltd."
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__author__ = "Scott James Remnant <scott@ubuntu.com>"
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class CellRendererGraph(gtk.GenericCellRenderer):
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"""Cell renderer for directed graph.
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node (column, colour) tuple to draw revision node,
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in_lines (start, end, colour) tuple list to draw inward lines,
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out_lines (start, end, colour) tuple list to draw outward lines.
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"node": ( gobject.TYPE_PYOBJECT, "node",
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"revision node instruction",
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gobject.PARAM_WRITABLE
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"in-lines": ( gobject.TYPE_PYOBJECT, "in-lines",
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"instructions to draw lines into the cell",
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gobject.PARAM_WRITABLE
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"out-lines": ( gobject.TYPE_PYOBJECT, "out-lines",
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"instructions to draw lines out of the cell",
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gobject.PARAM_WRITABLE
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def do_set_property(self, property, value):
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"""Set properties from GObject properties."""
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if property.name == "node":
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elif property.name == "in-lines":
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elif property.name == "out-lines":
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self.out_lines = value
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raise AttributeError, "no such property: '%s'" % property.name
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def box_size(self, widget):
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"""Calculate box size based on widget's font.
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Cache this as it's probably expensive to get. It ensures that we
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draw the graph at least as large as the text.
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except AttributeError:
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pango_ctx = widget.get_pango_context()
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font_desc = widget.get_style().font_desc
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metrics = pango_ctx.get_metrics(font_desc)
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ascent = pango.PIXELS(metrics.get_ascent())
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descent = pango.PIXELS(metrics.get_descent())
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self._box_size = ascent + descent + 6
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def set_colour(self, ctx, colour, bg, fg):
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"""Set the context source colour.
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Picks a distinct colour based on an internal wheel; the bg
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parameter provides the value that should be assigned to the 'zero'
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colours and the fg parameter provides the multiplier that should be
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applied to the foreground colours.
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colour %= len(colours)
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red = (colours[colour][0] * fg) or bg
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green = (colours[colour][1] * fg) or bg
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blue = (colours[colour][2] * fg) or bg
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ctx.set_source_rgb(red, green, blue)
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def on_get_size(self, widget, cell_area):
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"""Return the size we need for this cell.
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Each cell is drawn individually and is only as wide as it needs
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to be, we let the TreeViewColumn take care of making them all
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box_size = self.box_size(widget) + 1
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for start, end, colour in self.in_lines + self.out_lines:
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cols = max(cols, start, end)
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width = box_size * (cols + 1)
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# FIXME I have no idea how to use cell_area properly
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return (0, 0, width, height)
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def on_render(self, window, widget, bg_area, cell_area, exp_area, flags):
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"""Render an individual cell.
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Draws the cell contents using cairo, taking care to clip what we
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do to within the background area so we don't draw over other cells.
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Note that we're a bit naughty there and should really be drawing
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in the cell_area (or even the exposed area), but we explicitly don't
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We try and be a little clever, if the line we need to draw is going
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to cross other columns we actually draw it as in the .---' style
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instead of a pure diagonal ... this reduces confusion by an
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ctx = window.cairo_create()
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ctx.rectangle(bg_area.x, bg_area.y, bg_area.width, bg_area.height)
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box_size = self.box_size(widget)
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ctx.set_line_width(box_size / 8)
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ctx.set_line_cap(cairo.LINE_CAP_SQUARE)
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# Draw lines into the cell
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for start, end, colour in self.in_lines:
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ctx.move_to(cell_area.x + box_size * start + box_size / 2,
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bg_area.y - bg_area.height / 2)
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ctx.line_to(cell_area.x + box_size * start, bg_area.y)
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ctx.line_to(cell_area.x + box_size * end + box_size, bg_area.y)
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elif start - end < -1:
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ctx.line_to(cell_area.x + box_size * start + box_size,
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ctx.line_to(cell_area.x + box_size * end, bg_area.y)
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ctx.line_to(cell_area.x + box_size * end + box_size / 2,
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bg_area.y + bg_area.height / 2)
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self.set_colour(ctx, colour, 0.0, 0.65)
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# Draw lines out of the cell
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for start, end, colour in self.out_lines:
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ctx.move_to(cell_area.x + box_size * start + box_size / 2,
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bg_area.y + bg_area.height / 2)
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ctx.line_to(cell_area.x + box_size * start,
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bg_area.y + bg_area.height)
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ctx.line_to(cell_area.x + box_size * end + box_size,
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bg_area.y + bg_area.height)
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elif start - end < -1:
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ctx.line_to(cell_area.x + box_size * start + box_size,
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bg_area.y + bg_area.height)
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ctx.line_to(cell_area.x + box_size * end,
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bg_area.y + bg_area.height)
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ctx.line_to(cell_area.x + box_size * end + box_size / 2,
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bg_area.y + bg_area.height / 2 + bg_area.height)
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self.set_colour(ctx, colour, 0.0, 0.65)
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# Draw the revision node in the right column
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(column, colour) = self.node
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ctx.arc(cell_area.x + box_size * column + box_size / 2,
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cell_area.y + cell_area.height / 2,
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box_size / 4, 0, 2 * math.pi)
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self.set_colour(ctx, colour, 0.0, 0.5)
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ctx.stroke_preserve()
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self.set_colour(ctx, colour, 0.5, 1.0)
added
removed
viz/graphcell.py
