sec-spinbuttons.html

gtk 开发手册和参考文档。 包括gtk glib gdk等

><P
><TT
CLASS="LITERAL"
>GTK_SPIN_PAGE_FORWARD</TT
> and <TT
CLASS="LITERAL"
>GTK_SPIN_PAGE_BACKWARD</TT
> simply
alter the value of the Spin Button by <TT
CLASS="LITERAL"
>increment</TT
>.</P
><P
><TT
CLASS="LITERAL"
>GTK_SPIN_HOME</TT
> sets the value of the Spin Button to the bottom of
the Adjustments range.</P
><P
><TT
CLASS="LITERAL"
>GTK_SPIN_END</TT
> sets the value of the Spin Button to the top of the
Adjustments range.</P
><P
><TT
CLASS="LITERAL"
>GTK_SPIN_USER_DEFINED</TT
> simply alters the value of the Spin Button
by the specified amount.</P
><P
>We move away from functions for setting and retreving the range attributes
of the Spin Button now, and move onto functions that effect the
appearance and behaviour of the Spin Button widget itself.</P
><P
>The first of these functions is used to constrain the text box of the
Spin Button such that it may only contain a numeric value. This
prevents a user from typing anything other than numeric values into
the text box of a Spin Button:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_numeric( GtkSpinButton *spin_button,
                                  gboolean       numeric );</PRE
></TD
></TR
></TABLE
><P
>You can set whether a Spin Button will wrap around between the upper
and lower range values with the following function:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_wrap( GtkSpinButton *spin_button,
                               gboolean       wrap );</PRE
></TD
></TR
></TABLE
><P
>You can set a Spin Button to round the value to the nearest
<TT
CLASS="LITERAL"
>step_increment</TT
>, which is set within the Adjustment object used
with the Spin Button. This is accomplished with the following
function:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_snap_to_ticks( GtkSpinButton  *spin_button,
                                        gboolean        snap_to_ticks );</PRE
></TD
></TR
></TABLE
><P
>The update policy of a Spin Button can be changed with the following
function:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_update_policy( GtkSpinButton  *spin_button,
                                    GtkSpinButtonUpdatePolicy policy );</PRE
></TD
></TR
></TABLE
><P
></P
><P
>The possible values of <TT
CLASS="LITERAL"
>policy</TT
> are either <TT
CLASS="LITERAL"
>GTK_UPDATE_ALWAYS</TT
> or
<TT
CLASS="LITERAL"
>GTK_UPDATE_IF_VALID</TT
>.</P
><P
>These policies affect the behavior of a Spin Button when parsing
inserted text and syncing its value with the values of the
Adjustment.</P
><P
>In the case of <TT
CLASS="LITERAL"
>GTK_UPDATE_IF_VALID</TT
> the Spin Button only value
gets changed if the text input is a numeric value that is within the
range specified by the Adjustment. Otherwise the text is reset to the
current value.</P
><P
>In case of <TT
CLASS="LITERAL"
>GTK_UPDATE_ALWAYS</TT
> we ignore errors while converting
text into a numeric value.</P
><P
>The appearance of the buttons used in a Spin Button can be changed
using the following function:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_shadow_type( GtkSpinButton *spin_button,
                                      GtkShadowType  shadow_type );</PRE
></TD
></TR
></TABLE
><P
>As usual, the <TT
CLASS="LITERAL"
>shadow_type</TT
> can be one of:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>  GTK_SHADOW_IN
  GTK_SHADOW_OUT
  GTK_SHADOW_ETCHED_IN
  GTK_SHADOW_ETCHED_OUT</PRE
></TD
></TR
></TABLE
><P
>Finally, you can explicitly request that a Spin Button update itself:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_update( GtkSpinButton  *spin_button );</PRE
></TD
></TR
></TABLE
><P
>It's example time again.</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/* example-start spinbutton spinbutton.c */

#include &#60;stdio.h&#62;
#include &#60;gtk/gtk.h&#62;

static GtkWidget *spinner1;

void toggle_snap( GtkWidget     *widget,
		  GtkSpinButton *spin )
{
  gtk_spin_button_set_snap_to_ticks (spin, GTK_TOGGLE_BUTTON (widget)-&#62;active);
}

void toggle_numeric( GtkWidget *widget,
		     GtkSpinButton *spin )
{
  gtk_spin_button_set_numeric (spin, GTK_TOGGLE_BUTTON (widget)-&#62;active);
}

void change_digits( GtkWidget *widget,
	            GtkSpinButton *spin )
{
  gtk_spin_button_set_digits (GTK_SPIN_BUTTON (spinner1),
                              gtk_spin_button_get_value_as_int (spin));
}

void get_value( GtkWidget *widget,
		gpointer data )
{
  gchar buf[32];
  GtkLabel *label;
  GtkSpinButton *spin;

  spin = GTK_SPIN_BUTTON (spinner1);
  label = GTK_LABEL (gtk_object_get_user_data (GTK_OBJECT (widget)));
  if (GPOINTER_TO_INT (data) == 1)
    sprintf (buf, "%d", gtk_spin_button_get_value_as_int (spin));
  else
    sprintf (buf, "%0.*f", spin-&#62;digits,
             gtk_spin_button_get_value_as_float (spin));
  gtk_label_set_text (label, buf);
}


int main( int   argc,
          char *argv[] )
{
  GtkWidget *window;
  GtkWidget *frame;
  GtkWidget *hbox;
  GtkWidget *main_vbox;
  GtkWidget *vbox;
  GtkWidget *vbox2;
  GtkWidget *spinner2;
  GtkWidget *spinner;
  GtkWidget *button;
  GtkWidget *label;
  GtkWidget *val_label;
  GtkAdjustment *adj;

  /* Initialise GTK */
  gtk_init(&#38;argc, &#38;argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  gtk_signal_connect (GTK_OBJECT (window), "destroy",
		      GTK_SIGNAL_FUNC (gtk_main_quit),
		      NULL);

  gtk_window_set_title (GTK_WINDOW (window), "Spin Button");

  main_vbox = gtk_vbox_new (FALSE, 5);
  gtk_container_set_border_width (GTK_CONTAINER (main_vbox), 10);
  gtk_container_add (GTK_CONTAINER (window), main_vbox);
  
  frame = gtk_frame_new ("Not accelerated");
  gtk_box_pack_start (GTK_BOX (main_vbox), frame, TRUE, TRUE, 0);
  
  vbox = gtk_vbox_new (FALSE, 0);
  gtk_container_set_border_width (GTK_CONTAINER (vbox), 5);
  gtk_container_add (GTK_CONTAINER (frame), vbox);
  
  /* Day, month, year spinners */
  
  hbox = gtk_hbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (vbox), hbox, TRUE, TRUE, 5);
  
  vbox2 = gtk_vbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (hbox), vbox2, TRUE, TRUE, 5);
  
  label = gtk_label_new ("Day :");
  gtk_misc_set_alignment (GTK_MISC (label), 0, 0.5);
  gtk_box_pack_start (GTK_BOX (vbox2), label, FALSE, TRUE, 0);
  
  adj = (GtkAdjustment *) gtk_adjustment_new (1.0, 1.0, 31.0, 1.0,
					      5.0, 0.0);
  spinner = gtk_spin_button_new (adj, 0, 0);
  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner), TRUE);
  gtk_spin_button_set_shadow_type (GTK_SPIN_BUTTON (spinner),
				   GTK_SHADOW_OUT);
  gtk_box_pack_start (GTK_BOX (vbox2), spinner, FALSE, TRUE, 0);
  
  vbox2 = gtk_vbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (hbox), vbox2, TRUE, TRUE, 5);
  
  label = gtk_label_new ("Month :");
  gtk_misc_set_alignment (GTK_MISC (label), 0, 0.5);
  gtk_box_pack_start (GTK_BOX (vbox2), label, FALSE, TRUE, 0);
  
  adj = (GtkAdjustment *) gtk_adjustment_new (1.0, 1.0, 12.0, 1.0,
					      5.0, 0.0);
  spinner = gtk_spin_button_new (adj, 0, 0);
  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner), TRUE);
  gtk_spin_button_set_shadow_type (GTK_SPIN_BUTTON (spinner),
				   GTK_SHADOW_ETCHED_IN);
  gtk_box_pack_start (GTK_BOX (vbox2), spinner, FALSE, TRUE, 0);
  
  vbox2 = gtk_vbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (hbox), vbox2, TRUE, TRUE, 5);
  
  label = gtk_label_new ("Year :");
  gtk_misc_set_alignment (GTK_MISC (label), 0, 0.5);
  gtk_box_pack_start (GTK_BOX (vbox2), label, FALSE, TRUE, 0);
  
  adj = (GtkAdjustment *) gtk_adjustment_new (1998.0, 0.0, 2100.0,
					      1.0, 100.0, 0.0);
  spinner = gtk_spin_button_new (adj, 0, 0);
  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner), FALSE);
  gtk_spin_button_set_shadow_type (GTK_SPIN_BUTTON (spinner),
				   GTK_SHADOW_IN);
  gtk_widget_set_usize (spinner, 55, 0);
  gtk_box_pack_start (GTK_BOX (vbox2), spinner, FALSE, TRUE, 0);
  
  frame = gtk_frame_new ("Accelerated");
  gtk_box_pack_start (GTK_BOX (main_vbox), frame, TRUE, TRUE, 0);
  
  vbox = gtk_vbox_new (FALSE, 0);
  gtk_container_set_border_width (GTK_CONTAINER (vbox), 5);
  gtk_container_add (GTK_CONTAINER (frame), vbox);
  
  hbox = gtk_hbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, TRUE, 5);
  
  vbox2 = gtk_vbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (hbox), vbox2, TRUE, TRUE, 5);
  
  label = gtk_label_new ("Value :");
  gtk_misc_set_alignment (GTK_MISC (label), 0, 0.5);
  gtk_box_pack_start (GTK_BOX (vbox2), label, FALSE, TRUE, 0);
  
  adj = (GtkAdjustment *) gtk_adjustment_new (0.0, -10000.0, 10000.0,
					      0.5, 100.0, 0.0);
  spinner1 = gtk_spin_button_new (adj, 1.0, 2);
  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner1), TRUE);
  gtk_widget_set_usize (spinner1, 100, 0);
  gtk_box_pack_start (GTK_BOX (vbox2), spinner1, FALSE, TRUE, 0);
  
  vbox2 = gtk_vbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (hbox), vbox2, TRUE, TRUE, 5);
  
  label = gtk_label_new ("Digits :");
  gtk_misc_set_alignment (GTK_MISC (label), 0, 0.5);
  gtk_box_pack_start (GTK_BOX (vbox2), label, FALSE, TRUE, 0);
  
  adj = (GtkAdjustment *) gtk_adjustment_new (2, 1, 5, 1, 1, 0);
  spinner2 = gtk_spin_button_new (adj, 0.0, 0);
  gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner2), TRUE);
  gtk_signal_connect (GTK_OBJECT (adj), "value_changed",
		      GTK_SIGNAL_FUNC (change_digits),
		      (gpointer) spinner2);
  gtk_box_pack_start (GTK_BOX (vbox2), spinner2, FALSE, TRUE, 0);
  
  hbox = gtk_hbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, TRUE, 5);
  
  button = gtk_check_button_new_with_label ("Snap to 0.5-ticks");
  gtk_signal_connect (GTK_OBJECT (button), "clicked",
		      GTK_SIGNAL_FUNC (toggle_snap),
		      spinner1);
  gtk_box_pack_start (GTK_BOX (vbox), button, TRUE, TRUE, 0);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
  
  button = gtk_check_button_new_with_label ("Numeric only input mode");
  gtk_signal_connect (GTK_OBJECT (button), "clicked",
		      GTK_SIGNAL_FUNC (toggle_numeric),
		      spinner1);
  gtk_box_pack_start (GTK_BOX (vbox), button, TRUE, TRUE, 0);
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
  
  val_label = gtk_label_new ("");
  
  hbox = gtk_hbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, TRUE, 5);
  button = gtk_button_new_with_label ("Value as Int");
  gtk_object_set_user_data (GTK_OBJECT (button), val_label);
  gtk_signal_connect (GTK_OBJECT (button), "clicked",
		      GTK_SIGNAL_FUNC (get_value),
		      GINT_TO_POINTER (1));
  gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 5);
  
  button = gtk_button_new_with_label ("Value as Float");
  gtk_object_set_user_data (GTK_OBJECT (button), val_label);
  gtk_signal_connect (GTK_OBJECT (button), "clicked",
		      GTK_SIGNAL_FUNC (get_value),
		      GINT_TO_POINTER (2));
  gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 5);
  
  gtk_box_pack_start (GTK_BOX (vbox), val_label, TRUE, TRUE, 0);
  gtk_label_set_text (GTK_LABEL (val_label), "0");
  
  hbox = gtk_hbox_new (FALSE, 0);
  gtk_box_pack_start (GTK_BOX (main_vbox), hbox, FALSE, TRUE, 0);
  
  button = gtk_button_new_with_label ("Close");
  gtk_signal_connect_object (GTK_OBJECT (button), "clicked",
			     GTK_SIGNAL_FUNC (gtk_widget_destroy),
			     GTK_OBJECT (window));
  gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 5);

  gtk_widget_show_all (window);

  /* Enter the event loop */
  gtk_main ();
    
  return(0);
}
/* example-end */</PRE
></TD
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