Bill, Thank you for these explanations - it is very helpful. I have been
reading more on J and GTK (and C) lately and now have a little better
understanding of those and the addons/gui/gtk.ijs file.
I have figured out how to add the following to gtk.ijs:
- how to translate gtk enums (those with bitmasks as well)
- what the function parameters n x *x *c f, i etc. mean (and that the first
parameter is the return value) so can add the function declarations
But I don't know how to 'add'(use) structs like GtkTargetEntry here.
I saw that there are some structs in the file like GdkEventKey but I dont
understand how these are used:
sizeofGdkEventKey =: 56
GdkEventKey =: 24
and then
getGdkEventKey =: 3 : '_2 ic memr y, GdkEventKey, 8, JCHAR' (what is happening
here ?)
or
GdkEventButton_state =: 48 (in the gtk reference for struct GdkEventButton
both state and button are guint yet here they have different values...)
GdkEventButton_button =: 52
How are the above mentioned specific values 56, 24 and 48, 52 determined or for
eg. there is also sizeofGdkEventMotion =: 80 ?
(how are the appropriate values found in J for gdouble, gint, etc. to get to
that number for the size of the struct)
And also a question that leads me to the basics of how the gtk addon works:
The thing about gtk_target_entry_new is that it is not in the .h files in
addons/api/gtkinclude/gtk-2.0/gtk
So would it work if I added its declaration to the addons/gui/gtk.ijs file ?
(Is this a problem - because the truth is I don't understand which gtk files
the gtk.ijs is reading and translating to Jgtk. Does it read directly from the
gtk files installed on my pc(by this I mean the bare gtk install unrelated to
J) or does gtk(the actual pure gtk files) come with the J package in some
folder from where the addon gtk.ijs is reading and translating this to Jgtk ?
[I have selected and installed everything from the package manager but don't
have a good overview how the addon for gtk basically works]
Random remarks for random questions would again be very helpful :)
Thanks,
Emir
Message: 2
Date: Sat, 19 Nov 2011 23:38:58 +0800
From: bill lam <bbill....@gmail.com>
Subject: Re: [Jprogramming] Questions on Drag and Drop in J GTK
To: jprogramming <programming@jsoftware.com>
Message-ID: <20111119153858.GA2892@debian.b2j>
Content-Type: text/plain; charset=us-ascii
To be honest, I've never tried gtk dnd so I can just make some random
remarks,
1.consig, consig3, ... consig7
the suffix indicate the number of parameter of the callback handler,
consig is acutally consig2.
2.signal names accept both hyphen and underscore.
3.callback handler
the parameters are always 32 or 64-bit intergers depending on J32/J64.
the first parameter is the widget that received the signal., the last
parameter is user-data that is already used by JGTK, do not use it in
your code. eg.
for consig
'widget data'=. y
for consig3
'widget event data'=. y
for consig4
'widget foo bar data'=. y
the actual number of parameter depends on signals. You can get this
information from gtk api reference, and then use the appropiate
consig[n] as needed.
drag_begin_handl (GtkWidget *widget, GdkDragContext *context, gpointer
user_data){
const gchar *name = gtk_widget_get_name (widget);
g_print("%s: drag_begin_handl\n", name);
}
should be something like
(should use consig3 to connect signal)
drag_begin_handl=: 3 : 0
'widget context data'=. y
name=. memr 0 _1,~ gtk_widget_get_name widget
smoutput name, ': drag_begin_handl'
)
4. gtk datatypes are list in api reference,
in particular I can see there is gtk_target_entry_new
which may be useful.
5. The "drag-data-received" signal
void user_function (GtkWidget *widget,
GdkDragContext *drag_context,
gint x,
gint y,
GtkSelectionData *data,
guint info,
guint time,
gpointer user_data)
there are 8 parameters in its handler, thus consig8 is needed. However
the biggest is consig7 in jgtk, I have just added consig8 to Public repo,
please add it yourself and also add other dnd related api to run your
codes.
--
regards,
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