# -*- coding: UTF-8 -*- """Cell renderer for directed graph. This module contains the implementation of a custom GtkCellRenderer that draws part of the directed graph based on the lines suggested by the code in graph.py. Because we're shiny, we use Cairo to do this, and because we're naughty we cheat and draw over the bits of the TreeViewColumn that are supposed to just be for the background. """ __copyright__ = "Copyright © 2005-2011 Canonical Ltd." __author__ = "Scott James Remnant " import math from gi.repository import Gtk from gi.repository import GObject from gi.repository import Pango from gi.repository import PangoCairo # Cairo constants are not exported yet. These are taken from documentation. CAIRO_LINE_CAP_BUTT = 0 CAIRO_LINE_CAP_ROUND = 1 CAIRO_LINE_CAP_SQUARE = 2 CAIRO_FILL_RULE_WINDING = 0 CAIRO_FILL_RULE_EVEN_ODD = 1 # Macro from Pango header. def PANGO_PIXELS(d): return (d + 512) / 1000 class CellRendererGraph(Gtk.CellRendererPixbuf): """Cell renderer for directed graph. Properties: node (column, colour) tuple to draw revision node, in_lines (start, end, colour) tuple list to draw inward lines, out_lines (start, end, colour) tuple list to draw outward lines. """ columns_len = 0 __gproperties__ = { "node": ( GObject.TYPE_PYOBJECT, "node", "revision node instruction", GObject.PARAM_WRITABLE ), "tags": ( GObject.TYPE_PYOBJECT, "tags", "list of tags associated with the node", GObject.PARAM_WRITABLE ), "in-lines": ( GObject.TYPE_PYOBJECT, "in-lines", "instructions to draw lines into the cell", GObject.PARAM_WRITABLE ), "out-lines": ( GObject.TYPE_PYOBJECT, "out-lines", "instructions to draw lines out of the cell", GObject.PARAM_WRITABLE ), } def do_set_property(self, property, value): """Set properties from GObject properties.""" if property.name == "node": self.node = value elif property.name == "tags": self.tags = value elif property.name == "in-lines": self.in_lines = value elif property.name == "out-lines": self.out_lines = value else: raise AttributeError, "no such property: '%s'" % property.name def box_size(self, widget): """Calculate box size based on widget's font. Cache this as it's probably expensive to get. It ensures that we draw the graph at least as large as the text. """ try: return self._box_size except AttributeError: pango_ctx = widget.get_pango_context() font_desc = widget.get_style_context().get_font( Gtk.StateType.NORMAL) metrics = pango_ctx.get_metrics(font_desc, None) ascent = PANGO_PIXELS(metrics.get_ascent()) descent = PANGO_PIXELS(metrics.get_descent()) self._box_size = ascent + descent + 6 return self._box_size def set_colour(self, ctx, colour, bg, fg): """Set the context source colour. Picks a distinct colour based on an internal wheel; the bg parameter provides the value that should be assigned to the 'zero' colours and the fg parameter provides the multiplier that should be applied to the foreground colours. """ mainline_color = ( 0.0, 0.0, 0.0 ) colours = [ ( 1.0, 0.0, 0.0 ), ( 1.0, 1.0, 0.0 ), ( 0.0, 1.0, 0.0 ), ( 0.0, 1.0, 1.0 ), ( 0.0, 0.0, 1.0 ), ( 1.0, 0.0, 1.0 ), ] if colour == 0: colour_rgb = mainline_color else: colour_rgb = colours[colour % len(colours)] red = (colour_rgb[0] * fg) or bg green = (colour_rgb[1] * fg) or bg blue = (colour_rgb[2] * fg) or bg ctx.set_source_rgb(red, green, blue) def do_activate(event, widget, path, bg_area, cell_area, flags): """Renderers cannot be activated; always return True.""" return True def do_editing_started(event, widget, path, fb_area, cell_area, flags): """Renderers cannot be edited; always return None.""" return None def do_get_size(self, widget, cell_area): """Return the size we need for this cell. Each cell is drawn individually and is only as wide as it needs to be, we let the TreeViewColumn take care of making them all line up. """ box_size = self.box_size(widget) + 1 width = box_size * (self.columns_len + 1) height = box_size # FIXME I have no idea how to use cell_area properly return (0, 0, width, height) def do_render(self, ctx, widget, bg_area, cell_area, flags): """Render an individual cell. Draws the cell contents using cairo, taking care to clip what we do to within the background area so we don't draw over other cells. Note that we're a bit naughty there and should really be drawing in the cell_area (or even the exposed area), but we explicitly don't want any gutter. We try and be a little clever, if the line we need to draw is going to cross other columns we actually draw it as in the .---' style instead of a pure diagonal ... this reduces confusion by an incredible amount. """ ctx.rectangle(bg_area.x, bg_area.y, bg_area.width, bg_area.height) ctx.clip() box_size = self.box_size(widget) ctx.set_line_width(box_size / 8) # Draw lines into the cell for start, end, colour in self.in_lines: self.render_line (ctx, cell_area, box_size, bg_area.y, bg_area.height, start, end, colour, flags) # Draw lines out of the cell for start, end, colour in self.out_lines: self.render_line (ctx, cell_area, box_size, bg_area.y + bg_area.height, bg_area.height, start, end, colour, flags) # Draw the revision node in the right column (column, colour) = self.node ctx.arc(cell_area.x + box_size * column + box_size / 2, cell_area.y + cell_area.height / 2, box_size / 4, 0, 2 * math.pi) if flags & Gtk.CellRendererState.SELECTED: ctx.set_source_rgb(1.0, 1.0, 1.0) ctx.set_line_width(box_size / 4) ctx.stroke_preserve() ctx.set_line_width(box_size / 8) self.set_colour(ctx, colour, 0.0, 0.5) ctx.stroke_preserve() self.set_colour(ctx, colour, 0.5, 1.0) ctx.fill() self.render_tags(ctx, widget.create_pango_context(), cell_area, box_size) def render_line(self, ctx, cell_area, box_size, mid, height, start, end, colour, flags): if start is None: ctx.set_line_cap(CAIRO_LINE_CAP_ROUND) x = cell_area.x + box_size * end + box_size / 2 ctx.move_to(x, mid + height / 3) ctx.line_to(x, mid + height / 3) ctx.move_to(x, mid + height / 6) ctx.line_to(x, mid + height / 6) elif end is None: ctx.set_line_cap(CAIRO_LINE_CAP_ROUND) x = cell_area.x + box_size * start + box_size / 2 ctx.move_to(x, mid - height / 3) ctx.line_to(x, mid - height / 3) ctx.move_to(x, mid - height / 6) ctx.line_to(x, mid - height / 6) else: ctx.set_line_cap(CAIRO_LINE_CAP_BUTT) startx = cell_area.x + box_size * start + box_size / 2 endx = cell_area.x + box_size * end + box_size / 2 ctx.move_to(startx, mid - height / 2) if start - end == 0 : ctx.line_to(endx, mid + height / 2 + 1) else: ctx.curve_to(startx, mid - height / 5, startx, mid - height / 5, startx + (endx - startx) / 2, mid) ctx.curve_to(endx, mid + height / 5, endx, mid + height / 5 , endx, mid + height / 2 + 1) if flags & Gtk.CellRendererState.SELECTED: ctx.set_source_rgb(1.0, 1.0, 1.0) ctx.set_line_width(box_size / 5) ctx.stroke_preserve() ctx.set_line_width(box_size / 8) self.set_colour(ctx, colour, 0.0, 0.65) ctx.stroke() def render_tags(self, ctx, pango_ctx, cell_area, box_size): # colour ID used in self.set_colour on the tags TAG_COLOUR_ID = 1 (column, colour) = self.node font_desc = Pango.FontDescription() font_desc.set_size(Pango.SCALE * 7) tag_layout = Pango.Layout(pango_ctx) tag_layout.set_font_description(font_desc) # The width of the tag label stack width = 0 for tag_idx, tag in enumerate(self.tags): tag_layout.set_text(" " + tag + " ", -1) text_width, text_height = tag_layout.get_pixel_size() x0 = cell_area.x + \ box_size * (column + 1.3) + width y0 = cell_area.y + \ cell_area.height / 2 - \ text_height / 2 width += text_width + 5 # Draw the tag border ctx.move_to(x0 - box_size / 3, y0 + text_height / 2) ctx.line_to(x0, y0) ctx.line_to(x0 + text_width, y0) ctx.line_to(x0 + text_width, y0 + text_height) ctx.line_to(x0, y0 + text_height) ctx.line_to(x0 - box_size / 3, y0 + text_height / 2) ctx.new_sub_path() ctx.arc(x0 - box_size / 12, y0 + text_height / 2, box_size / 7, 0, 2 * math.pi); self.set_colour(ctx, TAG_COLOUR_ID, 0.0, 0.5) ctx.stroke_preserve() ctx.set_fill_rule (CAIRO_FILL_RULE_EVEN_ODD) self.set_colour(ctx, TAG_COLOUR_ID, 0.5, 1.0) ctx.fill() # Draw the tag text self.set_colour(ctx, 0, 0.0, 0.0) ctx.move_to(x0, y0) PangoCairo.show_layout(ctx, tag_layout)