Re: Sending GdkEvents to Gtk Widget

[Andy Stewart]

Hi Bharathwaaj,

Bharathwaaj Srinivasan bharathwaa...@gmail.com writes:

 Hi Andy,

 I couldn't understand the meaning of serializeEvent.
Because it's Haskell. :)

I will explain at below.

 But still I simply tried the following in the socket source callback from 
 GLib.

             GdkEvent event;
     memset(event, 0, sizeof(GdkEvent));
     event.key.type = GDK_KEY_PRESS;
     event.key.keyval = GDK_Tab;
     event.key.send_event = TRUE;
This is wrong, 
you should get field value from event that return by signal key_press_event,
and not build those filed by yourself.
Then you can send *all* GdkEvent to another process, and not just Tab key.

Here is C structure of GdkEventKey:

typedef struct {
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 time;
  guint state;
  guint keyval;
  gint length;
  gchar *string;
  guint16 hardware_keycode;
  guint8 group;
  guint is_modifier : 1;
} GdkEventKey;

On *server* process, you should hang some function on singal
key_press_event, then you can get keyPress event when you typing
something at server side.

Then you need pick-up public field from keyPress event.
Example:

... singalEvent is get in key_press_event signal ...

...
serialize_event_type = signalEvent.key.type
serialize_event_keyval = signalEvent.key.keyval
serialize_event_send_event = signalEvent.key.send_event
...

Note, you need serialize *all* public field in GdkEventKey except
*GdkWindow* field.

Because, when you send event to *client* process, you want propagate
event in *client* process, so you need *client* process widget GdkWindow
and not *server* one.

After you serialize event value, you need send to network, below i
explain how to handle at client side.

     gdk_threads_enter();
     printf(Sending Tab event to gtk_idle_add_full\n);
     gtk_idle_add_full(G_PRIORITY_DEFAULT, 
 (GSourceFunc)gtk_main_do_event, NULL, event,
 NULL);
     gdk_threads_leave();

 This also lead to the same behaviour. The WebKit Gtk main window freezed from 
 responding for further
 events.
Because you haven't set field GdkWindow of GdkEventKey, it's 0 by your
memset.

When you call gtk_main_do_event, gtk_main_do_event will
lookup GdkWindow field to decide which widget need receive event, since
GdkWindow field is 0, your *client* process will freezed.

So client should do like this.

1) When your *client* receive serialize event from network, then use
below code to fill all flied except *GdkWindow* field:

GdkEvent event;
memset(event, 0, sizeof(GdkEvent));
...
event.key.type = serialize_event_type
event.key.keyval = serialize_event_keyval
event.key.send_event = serialize_event_send_event
...

2) Then fill *GdkWindow* field with client widget.

You need get GdkWindow pointer from WebKit widget.

widget_window_ptr = webkitWidget.window

Then fill event GdkWindow field with webkit GdkWindow pointer.

event.key.window = widget_window_ptr

That's all.

Cheers,

  -- Andy


 I also tried replacing gtk_idle_add_full with g_idle_add_full. Still same 
 behaviour.

 Please help me if i'm missing something.

 Kind regards,
 Bharath

 On Mon, Jul 12, 2010 at 12:33 PM, Andy Stewart lazycat.mana...@gmail.com 
 wrote:

 Hi Bharathwaaj,

 I'm a developer of gtk2hs (Haskell binding to gtk+).

 I have fix same problem (WebKit widget and GdkEvent) at Haskell side.
 
 (https://patch-tag.com/r/AndyStewart/gtk-serialized-event/snapshot/current/content/pretty/Graphics/UI/Gtk/Gdk/
 SerializedEvent.hsc)
 This is screenshot : 
 http://farm5.static.flickr.com/4080/4758242386_5230d3d54d_b.jpg

 Though i use Haskell, but i can explain how to pass GdkEvent from one
 process to another.

 Below are step:

 1) Serialize GdkEvent at *server* process.
 2) Then send SerializeEvent over the network
 3) When *client* process receive SerializeEvent from network, re-build
 GdkEvent.
 4) Then you can use gtk_main_do_event propagate same event on current
 focus widget, or use gtk_widget_event propagate event on specify widget.

 Only trick is you need use idle_add_full wrap gtk_main_do_event to make
 sure gtk_main_do_event running in *main thread* and not *listen event
 thread*.

 Hope above will help you. :)

 Cheers,

  -- Andy

 Bharathwaaj Srinivasan bharathwaa...@gmail.com writes:

  Hi,
 
  Is it possible to send GdkEvents to a GtkWidget from the application?
 
  Currently I've a GIOChannel which is listening to a socket and the 
 GSource is attached to the
 Glib
  main loop.
 
      g_type_init();
      g_thread_init(NULL);
      gdk_threads_init();
      gdk_threads_enter();
      gtk_init(NULL, NULL);
 
      channel = g_io_channel_unix_new (fd);
      g_io_channel_set_encoding 

Sending GdkEvents to Gtk Widget

[Bharathwaaj Srinivasan]

Hi,

Is it possible to send GdkEvents to a GtkWidget from the application?

Currently I've a GIOChannel which is listening to a socket and the GSource
is attached to the Glib main loop.

g_type_init();
g_thread_init(NULL);
gdk_threads_init();
gdk_threads_enter();
gtk_init(NULL, NULL);

channel = g_io_channel_unix_new (fd);
g_io_channel_set_encoding (channel, NULL, NULL);
g_io_channel_set_buffered (channel, FALSE);

source = g_io_create_watch (channel, G_IO_IN);
g_source_set_priority (source, G_PRIORITY_DEFAULT);
g_source_set_can_recurse (source, TRUE);
g_source_set_callback (source, (GSourceFunc) event_handler, NULL, NULL);
g_source_attach (source, NULL);

g_source_unref (source);
g_io_channel_unref(channel);

gtk_main();
gdk_threads_leave();

GdkEvents (Keyboard events) are passed from say another process by writing
to the socket fd.

Glib calls the callback event_handler for data available to read. The
event_handler callback reads the GdkEvent passed by another process and
calls gtk_main_do_event to pass the event to the widget.

But this doesn't work and the application freezes.

I use gdk_threads_enter and gdk_threads_leave in the callback and before
gtk_main for making gtk thread aware as the callback comes from Glib.

Kindly help me in providing a mechanism to pass GdkEvents from the top. If
this is not possible, please explain why.

The main purpose for which I need this is I'm using GtkWebKit and I send Tab
key event to make the focus move to the next element in the Webview.

Events are being fed from another process.

Kind regards,
Bharath
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Re: Sending GdkEvents to Gtk Widget

[Andy Stewart]

Hi Bharathwaaj,

I'm a developer of gtk2hs (Haskell binding to gtk+).

I have fix same problem (WebKit widget and GdkEvent) at Haskell side.
(https://patch-tag.com/r/AndyStewart/gtk-serialized-event/snapshot/current/content/pretty/Graphics/UI/Gtk/Gdk/SerializedEvent.hsc)
This is screenshot : 
http://farm5.static.flickr.com/4080/4758242386_5230d3d54d_b.jpg

Though i use Haskell, but i can explain how to pass GdkEvent from one
process to another.

Below are step:

1) Serialize GdkEvent at *server* process.
2) Then send SerializeEvent over the network
3) When *client* process receive SerializeEvent from network, re-build
GdkEvent.
4) Then you can use gtk_main_do_event propagate same event on current
focus widget, or use gtk_widget_event propagate event on specify widget.

Only trick is you need use idle_add_full wrap gtk_main_do_event to make
sure gtk_main_do_event running in *main thread* and not *listen event
thread*.

Hope above will help you. :)

Cheers,

  -- Andy

Bharathwaaj Srinivasan bharathwaa...@gmail.com writes:

 Hi,

 Is it possible to send GdkEvents to a GtkWidget from the application?

 Currently I've a GIOChannel which is listening to a socket and the GSource is 
 attached to the Glib
 main loop.

     g_type_init();
     g_thread_init(NULL);
     gdk_threads_init();
     gdk_threads_enter();
     gtk_init(NULL, NULL);

     channel = g_io_channel_unix_new (fd);
     g_io_channel_set_encoding (channel, NULL, NULL);
     g_io_channel_set_buffered (channel, FALSE);

     source = g_io_create_watch (channel, G_IO_IN);
     g_source_set_priority (source, G_PRIORITY_DEFAULT);
     g_source_set_can_recurse (source, TRUE);
     g_source_set_callback (source, (GSourceFunc) event_handler, NULL, NULL);
     g_source_attach (source, NULL);

     g_source_unref (source);
     g_io_channel_unref(channel);

     gtk_main();
     gdk_threads_leave();

 GdkEvents (Keyboard events) are passed from say another process by writing to 
 the socket fd.

 Glib calls the callback event_handler for data available to read. The 
 event_handler callback reads
 the GdkEvent passed by
 another process and calls gtk_main_do_event to pass the event to the widget.

 But this doesn't work and the application freezes.

 I use gdk_threads_enter and gdk_threads_leave in the callback and before 
 gtk_main for making gtk
 thread aware as the
 callback comes from Glib.

 Kindly help me in providing a mechanism to pass GdkEvents from the top. If 
 this is not possible,
 please explain why.

 The main purpose for which I need this is I'm using GtkWebKit and I send Tab 
 key event to make the
 focus move to the next
 element in the Webview.

 Events are being fed from another process.

 Kind regards,
 Bharath

 ___
 gtk-list mailing list
 gtk-list@gnome.org
 http://mail.gnome.org/mailman/listinfo/gtk-list

___
gtk-list mailing list
gtk-list@gnome.org
http://mail.gnome.org/mailman/listinfo/gtk-list

Re: Sending GdkEvents to Gtk Widget

[Bharathwaaj Srinivasan]

Hi Andy,

I couldn't understand the meaning of serializeEvent.

But still I simply tried the following in the socket source callback from
GLib.

GdkEvent event;
memset(event, 0, sizeof(GdkEvent));
event.key.type = GDK_KEY_PRESS;
event.key.keyval = GDK_Tab;
event.key.send_event = TRUE;
gdk_threads_enter();
printf(Sending Tab event to gtk_idle_add_full\n);
gtk_idle_add_full(G_PRIORITY_DEFAULT,
(GSourceFunc)gtk_main_do_event, NULL, event, NULL);
gdk_threads_leave();

This also lead to the same behaviour. The WebKit Gtk main window freezed
from responding for further events.

I also tried replacing gtk_idle_add_full with g_idle_add_full. Still same
behaviour.

Please help me if i'm missing something.

Kind regards,
Bharath


On Mon, Jul 12, 2010 at 12:33 PM, Andy Stewart lazycat.mana...@gmail.comwrote:

 Hi Bharathwaaj,

 I'm a developer of gtk2hs (Haskell binding to gtk+).

 I have fix same problem (WebKit widget and GdkEvent) at Haskell side.
 (
 https://patch-tag.com/r/AndyStewart/gtk-serialized-event/snapshot/current/content/pretty/Graphics/UI/Gtk/Gdk/SerializedEvent.hsc
 )
 This is screenshot :
 http://farm5.static.flickr.com/4080/4758242386_5230d3d54d_b.jpg

 Though i use Haskell, but i can explain how to pass GdkEvent from one
 process to another.

 Below are step:

 1) Serialize GdkEvent at *server* process.
 2) Then send SerializeEvent over the network
 3) When *client* process receive SerializeEvent from network, re-build
 GdkEvent.
 4) Then you can use gtk_main_do_event propagate same event on current
 focus widget, or use gtk_widget_event propagate event on specify widget.

 Only trick is you need use idle_add_full wrap gtk_main_do_event to make
 sure gtk_main_do_event running in *main thread* and not *listen event
 thread*.

 Hope above will help you. :)

 Cheers,

  -- Andy

 Bharathwaaj Srinivasan bharathwaa...@gmail.com writes:

  Hi,
 
  Is it possible to send GdkEvents to a GtkWidget from the application?
 
  Currently I've a GIOChannel which is listening to a socket and the
 GSource is attached to the Glib
  main loop.
 
  g_type_init();
  g_thread_init(NULL);
  gdk_threads_init();
  gdk_threads_enter();
  gtk_init(NULL, NULL);
 
  channel = g_io_channel_unix_new (fd);
  g_io_channel_set_encoding (channel, NULL, NULL);
  g_io_channel_set_buffered (channel, FALSE);
 
  source = g_io_create_watch (channel, G_IO_IN);
  g_source_set_priority (source, G_PRIORITY_DEFAULT);
  g_source_set_can_recurse (source, TRUE);
  g_source_set_callback (source, (GSourceFunc) event_handler, NULL,
 NULL);
  g_source_attach (source, NULL);
 
  g_source_unref (source);
  g_io_channel_unref(channel);
 
  gtk_main();
  gdk_threads_leave();
 
  GdkEvents (Keyboard events) are passed from say another process by
 writing to the socket fd.
 
  Glib calls the callback event_handler for data available to read. The
 event_handler callback reads
  the GdkEvent passed by
  another process and calls gtk_main_do_event to pass the event to the
 widget.
 
  But this doesn't work and the application freezes.
 
  I use gdk_threads_enter and gdk_threads_leave in the callback and before
 gtk_main for making gtk
  thread aware as the
  callback comes from Glib.
 
  Kindly help me in providing a mechanism to pass GdkEvents from the top.
 If this is not possible,
  please explain why.
 
  The main purpose for which I need this is I'm using GtkWebKit and I send
 Tab key event to make the
  focus move to the next
  element in the Webview.
 
  Events are being fed from another process.
 
  Kind regards,
  Bharath
 
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 http://mail.gnome.org/mailman/listinfo/gtk-list

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Re: Sending GdkEvents to Gtk Widget

[Bharathwaaj Srinivasan]

Hi Andy,

Thank you very much for your patient reply.

I had actually filled the GdkWindow field. But while copy pasting line by
line, it somehow got missed. :P

Now it is solved. The problem was, I was blocking the callback function
without returning it to GLib!

Since mine was kinda minimal test program, I had written an infinite while
loop in the GSource callback function to call gtk_main_do_event without
returning the GLib callback. How silly! :(

Also i didn't add idle_add_full. But directly called gtk_main_do_event and
it worked, because the callback comes from the same g main loop which gtk is
running. I just added the gdk_threads_enter/leave calls before calling
gtk_main_do_event.

Actually, in my case there is no gtk involved in the server. I get a
platform specific event which I've to remap to GdkEvent to be passed to the
browser.

Thank you once again!

Cheers,
Bharath

On Mon, Jul 12, 2010 at 9:49 PM, Andy Stewart lazycat.mana...@gmail.comwrote:

 Hi Bharathwaaj,

 Bharathwaaj Srinivasan bharathwaa...@gmail.com writes:

  Hi Andy,
 
  I couldn't understand the meaning of serializeEvent.
 Because it's Haskell. :)

 I will explain at below.
 
  But still I simply tried the following in the socket source callback from
 GLib.
 
  GdkEvent event;
  memset(event, 0, sizeof(GdkEvent));
  event.key.type = GDK_KEY_PRESS;
  event.key.keyval = GDK_Tab;
  event.key.send_event = TRUE;
 This is wrong,
 you should get field value from event that return by signal
 key_press_event,
 and not build those filed by yourself.
 Then you can send *all* GdkEvent to another process, and not just Tab key.

 Here is C structure of GdkEventKey:

 typedef struct {
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 time;
  guint state;
  guint keyval;
  gint length;
  gchar *string;
  guint16 hardware_keycode;
  guint8 group;
  guint is_modifier : 1;
 } GdkEventKey;

 On *server* process, you should hang some function on singal
 key_press_event, then you can get keyPress event when you typing
 something at server side.

 Then you need pick-up public field from keyPress event.
 Example:

... singalEvent is get in key_press_event signal ...

...
serialize_event_type = signalEvent.key.type
serialize_event_keyval = signalEvent.key.keyval
serialize_event_send_event = signalEvent.key.send_event
...

 Note, you need serialize *all* public field in GdkEventKey except
 *GdkWindow* field.

 Because, when you send event to *client* process, you want propagate
 event in *client* process, so you need *client* process widget GdkWindow
 and not *server* one.

 After you serialize event value, you need send to network, below i
 explain how to handle at client side.

  gdk_threads_enter();
  printf(Sending Tab event to gtk_idle_add_full\n);
  gtk_idle_add_full(G_PRIORITY_DEFAULT,
 (GSourceFunc)gtk_main_do_event, NULL, event,
  NULL);
  gdk_threads_leave();
 
  This also lead to the same behaviour. The WebKit Gtk main window freezed
 from responding for further
  events.
 Because you haven't set field GdkWindow of GdkEventKey, it's 0 by your
 memset.

 When you call gtk_main_do_event, gtk_main_do_event will
 lookup GdkWindow field to decide which widget need receive event, since
 GdkWindow field is 0, your *client* process will freezed.

 So client should do like this.

 1) When your *client* receive serialize event from network, then use
 below code to fill all flied except *GdkWindow* field:

GdkEvent event;
memset(event, 0, sizeof(GdkEvent));
...
 event.key.type = serialize_event_type
event.key.keyval = serialize_event_keyval
event.key.send_event = serialize_event_send_event
...

 2) Then fill *GdkWindow* field with client widget.

You need get GdkWindow pointer from WebKit widget.

widget_window_ptr = webkitWidget.window

Then fill event GdkWindow field with webkit GdkWindow pointer.

event.key.window = widget_window_ptr

 That's all.

 Cheers,

  -- Andy

 
  I also tried replacing gtk_idle_add_full with g_idle_add_full. Still same
 behaviour.
 
  Please help me if i'm missing something.
 
  Kind regards,
  Bharath
 
  On Mon, Jul 12, 2010 at 12:33 PM, Andy Stewart 
 lazycat.mana...@gmail.com wrote:
 
  Hi Bharathwaaj,
 
  I'm a developer of gtk2hs (Haskell binding to gtk+).
 
  I have fix same problem (WebKit widget and GdkEvent) at Haskell side.
  (
 https://patch-tag.com/r/AndyStewart/gtk-serialized-event/snapshot/current/content/pretty/Graphics/UI/Gtk/Gdk/
  SerializedEvent.hsc)
  This is screenshot :
 http://farm5.static.flickr.com/4080/4758242386_5230d3d54d_b.jpg
 
  Though i use Haskell, but i can explain how to pass GdkEvent from one
  process to another.
 
  Below are step:
 
  1) Serialize GdkEvent at *server* process.
  2) Then send SerializeEvent over the network
  3) When *client*