Situation @ pcb-rnd
v1.2.1
The HIDs are plug-ins, sitting in src_plugins/hid_*
; GTK2 one is called hid_gtk
.
First, get an instance of the main HID structure pcb_hid_t
.
This structure is general enough. Nothing too entangled to GTK2 nor GTK3 there.
pcb_hid_t pcb_gui = pcb_hid_find_gui ()
Q: How GTK HID is initialized ?
A: hid_hid_gtk_init ()
in <hid_gtk/gtkhid-main.c>
The GUI seems to start building from ghid_do_export ()
There are 2 big structures for GTK2 GUI:
GhidGui _ghidgui, *ghidgui = &_ghidgui;
GHidPort ghid_port, *gport;
GTK3 compatibility within these 2 structures:
Type | GTK3 compatible | GTK3 replacement | GTK2 compatible ? |
---|---|---|---|
GtkWidget |
|||
GtkObject |
GObject |
could be |
|
GdkPixmap |
GdkPixbuf |
could be |
|
GtkAction |
deprecated |
GAction (gio) |
could be (not desired) |
GtkActionGroup |
GActionGroup |
(not desired) |
|
GtkEntry |
|||
GTimeVal |
(glib) |
Type | GTK+3 compatible | GTK+3 replacement | GTK+2 compatible ? |
---|---|---|---|
GtkWidget |
|||
GdkPixmap |
GdkPixbuf |
could be |
|
GdkDrawable |
Cairo surface |
(not desired) |
|
GdkColor |
GdkRGBA |
1 |
|
GdkColormap |
GdkVisual |
1 |
1 An abstracted structure was envisioned, but abandoned due to scarce use of color objects.
Drawing primitives using GDKx
GDK2
pcb-rnd
v1.2.1 is using gdk_draw…
functions, on an already abstracted
pcb_hid_t
intance of hid_gc_s
structure.
Type | GTK+3 compatible | GTK+3 replacement | GTK+2 compatible ? |
---|---|---|---|
GdkGC |
Cairo context |
could be (not desired) |
Indirectly, a GdkGC
needs a GdkDrawable
which is also deprecated in GTK3.
A good replacement is a GdkWindow
. Unfortunately pcb-rnd
is making more use
of deprecated GdkPixmap
objects than GdkWindow
.
gdk_draw_line
has been deprecated since GTK+ 2.22. Use cairo_line_to
and cairo_stroke
instead. gdk_gc_new
has been deprecated since GTK+ 2.22.
Use Cairo for rendering.
Cairo API needs a context:
cairo_line_to (cairo_t *cr,
double x,
double y);
cairo_t *
cairo_create (cairo_surface_t *target);
and then pops-up the Cairo Surface !
A cairo_surface_t
represents an image, either as the destination of a
drawing operation or as source when drawing onto another surface.
GDK does not wrap the cairo API, instead it allows to create cairo contexts
which can be used to draw on GdkWindow
. Additional functions allow use
GdkRectangles
with cairo and to use GdkColors
, GdkRGBAs
, GdkPixbufs
and GdkWindows
as sources for drawing operations.
GDK3
Cairo Interaction
Cairo is a graphics library that supports vector graphics and image compositing that can be used with GDK. GTK+ does all of its drawing using cairo. But I guess, it is also the case with late GDK2 !
Open GL
GdkGLContext
is an object representing the platform-specific OpenGL drawing context.
Very modern GDK3
GdkDrawingContext
is an object that represents the current drawing state of a GdkWindow
.
It’s possible to use a GdkDrawingContext
to draw on a GdkWindow
via
rendering API like Cairo or OpenGL.
Since: 3.22
Plans for pcb-rnd
v1.2.2 ?
-
What we must have:
-
the old gtk2 HID, with pixmaps and all the existing obsolete code - for existing/old systems. We won’t remove or change this, there’s absolutely no reason to risk running on older systems. We probably won’t remove it in any time soon, because some people love to run real OLD systems.
-
whichever gtk HID with gl rendering; let’s say gtk2+gl, because gtk2 is what we have working today. This seems to be real appealing for many users.
-
-
What extras we could have and totally makes sense:
-
the new, gtk3 HID, with Cairo for sw rendering, because as far as I understand there’s no other option for sw rendering in gtk3
-
the new, gtk3 HID with gl rendering
-
-
What we could temporarily have, if it helped us on our way to previous:
-
a temporary, hidden, development gtk2+cairo implementation so that cairo can be done in something that’s already there before gtk3 happens. This must not interfere with the gdk/pixmap implementation. This must not remain for long in the repo, and must be converted into the gtk3+cairo hid ASAP.
-
-
What we shouldn’t have because it doesn’t make much sense but increases the confusion and development/maintainance costs:
-
a permanent, advertised gtk2+cairo HID. gtk2 works perfectly fine with existing installation and the existing code. Cairo can only add slowdown to this and introduces new build risks. Old systems don’t need cairo to work. New systems will have gtk3 sooner or layer anyway. Other than a few "obsolete" marks in the manual, there’s absolutely no issue with a gtk2+pixmap.
-
Roadmap (short term)
-
keep pushing the
lib_gtk_common
split, trying to isolate general concepts from low-level GDK2 / GDK3 details. -
Name policy on object / functions in
lib_gtk_common
? -
Agree on names for "top" level objects / structures, and start implementation in
hid_gtk3
for those high level structures. -
Open thinking about infrastructure for menus and actions, but don’t change a thing yet.
Names proposal
Before | After |
---|---|
GhidGui |
pcb_gtk_gui_t |
extern GhidGui _ghidgui, *ghidgui; |
pcb_gtk_gui_t _pcb_gtk_gui, *pcb_gtk_gui; |
GHidPort |
pcb_gtk_viewport_t |
extern GHidPort ghid_port, *gport; |
pcb_gtk_viewport_t _pcb_gtk_viewport *pcb_gtk_viewport |
Situation svn r7460
├── hid_gtk
│ ├── actions.c
│ ├── colors.c
│ ├── common.c
│ ├── glue_common.c
│ ├── glue_conf.c
│ ├── glue_event.c
│ ├── glue_hid.c
│ ├── glue_win32.c
│ ├── gtkhid-gdk.c
│ ├── gtkhid-gl.c
│ └── gtkhid-main.c
├── hid_gtk3
│ └── colors.c
├── lib_gtk_common
│ ├── act_fileio.c
│ ├── act_print.c
│ ├── bu_*.c
│ ├── dlg_*.c
│ ├── dlg_topwin.c
│ ├── in_keyboard.c
│ ├── in_mouse.c
│ ├── lib_gtk_common.c
│ ├── ui_crosshair.c
│ ├── ui_zoompan.c
│ ├── util_block_hook.c
│ ├── util_ext_chg.c
│ ├── util_listener.c
│ ├── util_str.c
│ ├── util_timer.c
│ ├── util_watch.c
│ ├── win_place.c
│ └── wt_*.c
├── lib_gtk_config
│ ├── gtk_conf_list.c
│ ├── gui-config.c
│ └── lib_gtk_config.c
box
check_button
cursor_pos
dwg_tooltip
entry
icons
info_bar
layer_selector
menu
mode_btn
notebook
spin_button
status_line
text_view
about
attribute
command
confirm
drc
drc_cr
export
file_chooser
fontsel
input
library
library_param
log
message
netlist
pinout
print
progress
propedit
report
route_style
search
accel_label.c
coord_entry.c
layer_selector.c
layer_selector_cr.c
preview.c
route_style.c
GUI creation Timeline
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glue.h
FIXME: draw relationships between "top level" structures, and common, config
Detail common GTK2/GTK3 features ; distinguish between low level GTK2/3 ones.
Road blocks ahead
Thinking about:
-
Menus : Split Application menus and per topic contextual menus.
-
Actions : use
GAction
if needed -
Short cut, multi-key shortcuts :
-
Suggests more use of GIO : https://developer.gnome.org/gio/stable/ch01.html