1
2NOTE: I am no longer actively developing GooCanvas, so no major new
3features will be added (unless a new maintainer takes over). I'll still
4try to fix any bugs that appear though, and may accept minor patches.
5
6
7Bugs:
8
9 o I need to check the bounds are being calculated correctly so that they
10   are correct for all zoom settings. Since cairo uses fixed point maths
11   and I think only calculates up to a certain tolerance there might be
12   slight errors in our gdouble results. So as the canvas is scaled this
13   could eventually lead to the bounds being a pixel out, leading to painting
14   errors. Maybe we should extend any bounds returned from cairo slightly to
15   cover the maximum possible errors.
16
17
18Features definitely needed:
19
20 o API for modifying GooCanvasPath data.
21 o Editable text item - a port of GtkTextView.
22
23 o Need a function to setup a given cairo context with the defaults settings
24   of a GooCanvas, e.g. default line width.
25
26 o Check canvas and all items can be completely configured with properties
27   so that GtkBuilder can be used to load hierarchies of items/models.
28   Add "root-item" and "root-item-model" properties? Will GtkBuilder be able
29   to handle the tree of items/models like that? What about GUI builders?
30   How can gradients be specified by object properties?
31
32
33Possible additional features:
34
35 o Need a way to efficiently notify items about changes in canvas scale, if
36   they request it. Could use something similar to the update flags.
37
38 o Change GooCanvasStyle so it doesn't expose GValues in the API.
39   Use get/set_boolean/int/double/boxed() instead.
40
41 o Drag-and-Drop - probably copy all the GTK+ widget signals so items can
42   implement their own behavior.
43
44 o Caching of rendered items to improve performance. Items would have a cache
45   option with choices like Never, Always and WhenVisible.
46   But don't use caches when printing.
47 o Filters like in SVG, to add graphical effects.
48 o Support using the same item in different places, like SVG 'use'.
49 o Support using system color names, like SVG, e.g. "ActiveBorder".
50   This helps you write widget-like items that fit in with the rest of GTK+.
51 o "scale-line-width" boolean property to specify if the line width scales
52   with the canvas? The item bounds will change at different scale settings.
53 o Arrows on path items, just like on polyline.
54
55
56Requests from GTK+ people:
57
58 o Use separate GooCanvasContainer[Model] interfaces? May help bindings.
59 o GooCanvasWidget width & height are redundant - use widget's requested size.
60 o Make PathCommand and LineDash structs opaque.
61 o Use floating flag and sink() for objects.
62 o Use 1-byte integer percentage for xalign/yalign instead of doubles?
63 o Make it easy to add a border and background to items. "border-width",
64   "border-color" and "background-color" properties? Might also need "x-pad",
65   "y-pad", "x-radius", "y-radius" etc. Maybe have a related border item.
66   Note that we only have the bounds in device coords, so drawing a border of
67   a rotated item would be awkward. (Maybe we store the user bounds somewhere.)
68 o Link/URL item, or enable URLs in the markup of text items.
69 o A button item, with different children displayed for different states,
70   maybe with optional automatic prelighting.
71
72