Hi,
You need to step back a second and think about some redesign
following some simple guidelines. If, after you've redesigned, your
problem doesn't go away, it will, at the very least certainly change
its nature.
Basically, you are mixing graphical and event-based programming
domains (I think, a little hard to know since it's not obvious if
your code follows your specifications precisely or not). For
example, do you require a new widget every time to display a new
incoming value? In the first instance, I will assume that you
require a single widget to display all incoming values. If this is
the case, you should try to redesign your program flow thus:
main()
{
// make ALL widgets necessary for program
// enter while loop to read all values from stdin
// for each value, update the entry widget to display accordingly
gtk_main();
}
In other words, take all your widget creation out of the while loop,
leaving only the reading from stdin and update of your display widget.
That said, as an example, this program will demonstrate output of
text to a widget. In the real world of event-driven programs,
however, it won't do much, since your mainloop will sit and wait for
user events which will never arrive, since there's nothing to do
except screen refreshes. Though I can't see the deleted code, so
this may not be relevant.
Does/Will your program require reading from standard input for the
entirety of its existence? Or will these data be delivered to your
program periodically from somewhere else (e.g., a program which has
read the voltage from the battery)? Whatever the case, the proper
way to deal with this is to create your widgets, enter the main loop,
and then wait for events to arrive which require processing. You
will need to define the method by which your external program will
deliver its information to your display program and accommodate
accordingly.
If, on the other hand, your requirements are that each data point
instantiates a separate widget for display (as your program currently
implies), then try the following:
1) inside your while loop, remove all gtk_widget_show() calls
(typically, a call to gtk_widget_show() after each widget is created
is unnecessary).
2) at the end of the while loop, make a single call to
gtk_widget_show_all(), specifying the top-most widget in the
hierarchy created within the while loop.
cheers,
richard
On Nov 13, 2006, at 6:41 AM, ybisou wrote:
>
>
>> Why do you put gtk_widget_show_all and gtk_main calls in the loop?
>> You
>> should move at least the gtk_main call outside of the loop.
>
> I made some changes but I still can't have the widget to output all
> the
> integers coming from the STDIN. Only the first one is on the
> screen ! I will
> appreciate if you could help me, thanks !
> Here is a snipet of the code...
>
> // GTK initializations
>
> int main( int argc, char *argv[] )
> {
>
> /* GTK widget setup */
>
> unsigned int val;
> char buf[5];
>
> while(read(STDIN_FILENO, &val, sizeof(int))) // here is my
> problem, I'm not
> able to actually go through this while loop more than once or is
> there a way
> to refresh the windows so their contents could also be refreshed
> (variables)?
> {
> char temp[5];
> //read(STDIN_FILENO, &val, sizeof(int));
> buf[0]=ita(val/100);
> buf[1]=ita((val-((val/100)*100))/10);
> buf[2]='.';
> buf[3]=ita(val-((val/10)*10));
>
> printf(" reading %d",val); //just making sure i'm reading val
>
>
> //
> --------------------------------------------------------------------
> // Create text entry widget and modify.
> //
> --------------------------------------------------------------------
>
> text_entry_Widget = gtk_entry_new();
>
> gtk_widget_modify_text(text_entry_Widget, GTK_STATE_NORMAL,
> &colorGreen);
> gtk_widget_modify_base(text_entry_Widget, GTK_STATE_NORMAL,
> &colorBlack);
>
> GtkStyle *style = gtk_widget_get_style(text_entry_Widget);
> pango_font_description_set_weight(style->font_desc,
> PANGO_WEIGHT_BOLD);
>
> gtk_widget_modify_font(text_entry_Widget, style->font_desc);
>
> int text_width = 5; // Width of field in
> characters
> gtk_entry_set_width_chars(GTK_ENTRY(text_entry_Widget),
> text_width);
>
> gtk_editable_set_editable(GTK_EDITABLE(text_entry_Widget), FALSE);
> GTK_WIDGET_UNSET_FLAGS(text_entry_Widget, GTK_CAN_FOCUS);
>
>
> strcat(buf," V"); // V for volts after the int
> gtk_entry_set_text(GTK_ENTRY(text_entry_Widget), buf); //
> output the int
> value
>
> PangoFontDescription *font_desc =
> pango_font_description_from_string
> ("PANGO_STYLE_OBLIQUE,Monospace 30");
> gtk_widget_modify_font (text_entry_Widget, font_desc);
> pango_font_description_free (font_desc);
>
>
> //
> --------------------------------------------------------------------
>
>
> vbox = gtk_vbox_new (FALSE, 5);
> gtk_box_pack_start (GTK_BOX (vBox_Widget), vbox, FALSE, FALSE, 0);
>
> frame = gtk_frame_new ("DC Voltages");
>
>
> label = gtk_label_new ("\nThis voltage comes from 12 V battery \n"\
> "It's value should be stable.\n"\
> "When undervoltage, a signal is generated");
>
> PangoFontDescription *font_desc2 =
> pango_font_description_from_string
> ("PANGO_STYLE_OBLIQUE,Monospace 10");
> //PangoFontDescription *font_desc2 =
> pango_font_description_from_string
> ("PANGO_STYLE_OBLIQUE,PANGO_VARIANT_NORMAL,PANGO_WEIGHT_BOLD,PANGO_STR
> ETCH_EXPANDED
> ,Monospace 30");
> gtk_widget_modify_font (label, font_desc2);
> pango_font_description_free (font_desc2);
>
> gtk_widget_show (label);
>
>
> gtk_label_set_line_wrap (GTK_LABEL (label), TRUE);
> gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_LEFT);
> gtk_container_add (GTK_CONTAINER (frame), label);
> gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
>
>
> gtk_box_pack_start (GTK_BOX (vbox), text_entry_Widget, NULL,
> NULL, 0);
> gtk_widget_show (text_entry_Widget); // show the int value
>
> gtk_container_add (GTK_CONTAINER (hbox), vBox_Widget);
>
> text=gtk_text_new(NULL, NULL);
> gtk_widget_show(text);
> gtk_container_add(GTK_CONTAINER(vbox), text);
> gtk_text_insert(GTK_TEXT(text), NULL, NULL, NULL, buffer, strlen
> (buffer));
>
> //Text motif
>
> fnt=gdk_font_load("-unknown-Arial-normal-r-normal-*-*-650-96-96-p-0-
> iso8859-1");
>
> gtk_text_insert (GTK_TEXT (text), fnt, &text->style->black, NULL,
> "\nSupports ", -1);
>
> //creating a seperator
> separator = gtk_hseparator_new ();
> gtk_box_pack_start (GTK_BOX (vbox), separator, FALSE, TRUE, 5);
> gtk_widget_show (separator);
>
> // some other stuff here
>
> }
> gtk_widget_show_all (window);
> gtk_main ();
>
>
> close(fd);
> return 0;
> }
>
> --
> View this message in context: http://www.nabble.com/help-with-
> window-widgets-tf2615494.html#a7311745
> Sent from the Gtk+ - General mailing list archive at Nabble.com.
>
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