Re: Questions on Key-Press Event

[Bob Caryl <bob fis-cal com>]

Once again, I apologize for how Thunderbird managles links.

Bob

Bob Caryl wrote:

> Hello,
>
> I have several applications that use more than one window.  I 
> implemented context sensitive help by using the following in the 
> constructor for the main application window:
>
> // code snippet
> Gtk::Main::signal_key_snooper().connect(sigc::mem_fun(*this,&<your 
> window class name::your callback slot>));
> ///////////////////////
>
> where "your window class name" is what it describes, as well as "your 
> callback slot."  In the callback slot connected to this signal, you 
> can intercept any keystroke you like, then return 1 so the regular 
> keystroke handlers will ignore the keystroke, or 0 to allow this event 
> to be passed along to them.
>
> The callback syntax is like this:
>
> // code snippet
> sigc::slot< int, Widget *, GdkEventKey * >
> /////////////////////////////////////////////
>
> or:
>
> // code snippet
> int <your widget class name>::<your callback slot name>(Gtk::Widget 
> *,GdkEventKey *)
> {
>    ... your code goes here
> }
> ///////////////////////////////////////////
>
> The widget pointer passed to your function points to the widget that 
> had focus when the key was pressed.
> GdkEventKey is as follows:
>
> // code snippet
> typedef struct {
>  GdkEventType type;
>  GdkWindow *window;
>  gint8 send_event;
>  guint32 time;
>  guint state;
>  guint keyval;
>  gint length;
>  gchar *string;
>  guint16 hardware_keycode;
>  guint8 group;
> } GdkEventKey;
> ///////////////////////////////////////////
>
> Describes a key press or key release event.
>
> GdkEventType <cid:part1.01000202.04020205@fis-cal.com> /type/;     the 
> type of the event (GDK_KEY_PRESS or GDK_KEY_RELEASE).
> GdkWindow <cid:part2.04000809.05080203@fis-cal.com> */window/;     the 
> window which received the event.
> gint8 <cid:part3.09050804.02010101@fis-cal.com> /send_event/;     TRUE 
> if the event was sent explicitly (e.g. using XSendEvent).
> guint32 <cid:part4.04020206.09030901@fis-cal.com> /time/;     the time 
> of the event in milliseconds.
> guint <cid:part5.06070804.09090804@fis-cal.com> /state/;     a 
> bit-mask representing the state of the modifier keys (e.g. Control, 
> Shift and Alt) and the pointer buttons. See GdkModifierType 
> <cid:part6.01030209.08030201@fis-cal.com>.
> guint <cid:part5.06070804.09090804@fis-cal.com> /keyval/;     the key 
> that was pressed or released. See the <gdk/gdkkeysyms.h> header file 
> for a complete list of GDK key codes.
> gint <cid:part8.05050907.05060706@fis-cal.com> /length/;     the 
> length of /string/.
> gchar <cid:part9.07020608.06070005@fis-cal.com> */string/;     a 
> string containing the an approximation of the text that would result 
> from this keypress. The only correct way to handle text input of text 
> is using input methods (see GtkIMContext 
> <cid:part10.05080800.07080200@fis-cal.com>), so this field is 
> deprecated and should never be used. (gdk_unicode_to_keyval() 
> <cid:part11.08050709.03050102@fis-cal.com> provides a non-deprecated 
> way of getting an approximate translation for a key.) The string is 
> encoded in the encoding of the current locale (Note: this for 
> backwards compatibility: strings in GTK+ and GDK are typically in 
> UTF-8.) and NUL-terminated. In some cases, the translation of the key 
> code will be a single NUL byte, in which case looking at /length/ is 
> necessary to distinguish it from the an empty translation.
> guint16 <cid:part12.00000809.07050707@fis-cal.com> /hardware_keycode/; 
> the raw code of the key that was pressed or released.
> guint8 <cid:part13.01050009.09090503@fis-cal.com> /group/;     the 
> keyboard group.
>
>
> I use the "keyval" field of this structure in my application.  The 
> above information tells you which include file has all the key values 
> defined.
>
> I hope this helps a little bit.
>
> Bob
>
> Efrat Regev wrote:
>
> >  Hello,
> >
> >  I'm having some difficulty with key-press events,
> > and haven't been able to find answers in the mailing
> > list, docs, faqs, etc. I'd very much appreciate any
> > help.
> >
> >  My main window has a menu-bar, tool-bar, and other
> > widget children. I'm trying to capture the events of
> > the keyboard's arrows being pressed (since the
> > application is a simple game). My main window
> > overrides
> > virtual bool
> > my_main_wnd::on_key_press_event(GdkEventKey *p_event).
> > This doesn't work (for me), due to two reasons:
> > A. When my main window overrides on_key_press_event, I
> > get notified of these events, but the keyboard has no
> > effect on the window's menu. When I erase the
> > override, however, the menu works fine with the
> > keyboard. Is there a way to both get the key-press
> > event and have the menu working properly?
> > B. In on_key_press_event, I switch(){} on
> > p_event->keyval. I'm checking for cases such as case
> > GDK_leftarrow:, but when I press the left key I get a
> > different value (65361), not the one I expect
> > (GDK_leftarrow). What should I write in the case _:,
> > therefore?
> >
> >  Again, many thanks for you time. Additionally,
> > thanks to all those who contributed to this awesome
> > ass-kicking library!
> >
> >  
> >
> >
> >
> >
> >        
> > __________________________________ Yahoo! Music Unlimited Access over 
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> >
> >  
>
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