x1030.html

GTK编程

>void gtk_spin_button_set_wrap( GtkSpinButton *spin_button,
                               gboolean       wrap );</PRE
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>可以设置让微调按钮构件将其值圆整到最接近<TT
CLASS="LITERAL"
>step_increment</TT
>的值(在该微调按钮构件使用的调整对象中设置的)。用下面的函数实现：</P
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CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_snap_to_ticks( GtkSpinButton  *spin_button,
                                        gboolean        snap_to_ticks );</PRE
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><P
>微调按钮构件的更新方式可以用下面的函数改变：</P
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CLASS="PROGRAMLISTING"
>void gtk_spin_button_set_update_policy( GtkSpinButton  *spin_button,
                                    GtkSpinButtonUpdatePolicy policy );</PRE
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><P
>其中<TT
CLASS="LITERAL"
>policy</TT
>参数可以取<TT
CLASS="LITERAL"
>GTK_UPDATE_ALWAYS</TT
>或<TT
CLASS="LITERAL"
>GTK_UPDATE_IF_VALID</TT
>。</P
><P
>这些更新方式影响微调按钮构件在解析插入文本并将其值与调整对象的值同步时的行为。</P
><P
>在<TT
CLASS="LITERAL"
>GTK_UPDATE_IF_VALID</TT
>方式下，微调按钮构件只有在输入文本是其调整对象指定范围你合法的值时才进行更新，否则文本会被重置为当前的值。</P
><P
>在<TT
CLASS="LITERAL"
>GTK_UPDATE_ALWAYS</TT
>方式下，我们将忽略在文本转换为数值时的错误。</P
><P
>最后，可以强行要求微调按钮构件更新自己：</P
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><PRE
CLASS="PROGRAMLISTING"
>void gtk_spin_button_update( GtkSpinButton  *spin_button );</PRE
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><P
>下面是一个使用微调按钮构件的示例。</P
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CLASS="INLINEMEDIAOBJECT"
><IMG
SRC="images/spinbutton.png"></SPAN
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CLASS="PROGRAMLISTING"
>&#13;#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 (g_object_get_data (G_OBJECT (widget), "user_data"));
  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 (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;

  /* 初始化 */
  gtk_init (&#38;argc, &#38;argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  g_signal_connect (G_OBJECT (window), "destroy",
		    G_CALLBACK (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);
  
  /* 日、月、年微调器 */
  
  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_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_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_widget_set_size_request (spinner, 55, -1);
  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_size_request (spinner1, 100, -1);
  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);
  g_signal_connect (G_OBJECT (adj), "value_changed",
		    G_CALLBACK (change_digits),
		    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");
  g_signal_connect (G_OBJECT (button), "clicked",
		    G_CALLBACK (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");
  g_signal_connect (G_OBJECT (button), "clicked",
		    G_CALLBACK (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");
  g_object_set_data (G_OBJECT (button), "user_data", val_label);
  g_signal_connect (G_OBJECT (button), "clicked",
		    G_CALLBACK (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");
  g_object_set_data (G_OBJECT (button), "user_data", val_label);
  g_signal_connect (G_OBJECT (button), "clicked",
		    G_CALLBACK (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");
  g_signal_connect_swapped (G_OBJECT (button), "clicked",
                            G_CALLBACK (gtk_widget_destroy),
			    window);
  gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 5);

  gtk_widget_show_all (window);

  /* 进入事件循环 */
  gtk_main ();
    
  return 0;
}&#13;</PRE
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