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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"><HTML><HEAD><TITLE>示例</TITLE><METANAME="GENERATOR"CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+"><LINKREL="HOME"TITLE="GTK+ 2.0 教程"HREF="book1.html"><LINKREL="UP"TITLE="范围构件 Range Widgets"HREF="c696.html"><LINKREL="PREVIOUS"TITLE="键盘和鼠标绑定"HREF="x788.html"><LINKREL="NEXT"TITLE="杂项构件"HREF="c816.html"></HEAD><BODYCLASS="SECT1"BGCOLOR="#FFFFFF"TEXT="#000000"LINK="#0000FF"VLINK="#840084"ALINK="#0000FF"><DIVCLASS="NAVHEADER"><TABLESUMMARY="Header navigation table"WIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><THCOLSPAN="3"ALIGN="center">GTK+ 2.0 教程</TH></TR><TR><TDWIDTH="10%"ALIGN="left"VALIGN="bottom"><AHREF="x788.html"ACCESSKEY="P"><<< Previous</A></TD><TDWIDTH="80%"ALIGN="center"VALIGN="bottom">范围构件 Range Widgets</TD><TDWIDTH="10%"ALIGN="right"VALIGN="bottom"><AHREF="c816.html"ACCESSKEY="N">Next >>></A></TD></TR></TABLE><HRALIGN="LEFT"WIDTH="100%"></DIV><DIVCLASS="SECT1"><H1CLASS="SECT1"><ANAME="SEC-RANGEWIDGETSEXAMPLE">示例</H1><P>这个示例可以说是<TTCLASS="FILENAME">testgtk.c</TT>里的"范围控制"测试部分的修改版。它主要是在一个窗口上放置了三个范围构件，都连接到同一个调整对象，并使用上面以及调整对象部分提到的一些调整参数的控制方法，这样你可以看到它们怎样影响这些构件的使用效果。</P><P><SPANCLASS="INLINEMEDIAOBJECT"><IMGSRC="images/rangewidgets.png"></SPAN></P><TABLEBORDER="0"BGCOLOR="#E0E0E0"WIDTH="100%"><TR><TD><PRECLASS="PROGRAMLISTING"> #include <gtk/gtk.h>GtkWidget *hscale, *vscale;void cb_pos_menu_select( GtkWidget *item, GtkPositionType pos ){ /* 设置两个比例构件的比例值的显示位置 */ gtk_scale_set_value_pos (GTK_SCALE (hscale), pos); gtk_scale_set_value_pos (GTK_SCALE (vscale), pos);}void cb_update_menu_select( GtkWidget *item, GtkUpdateType policy ){ /* 设置两个比例构件的更新方式 */ gtk_range_set_update_policy (GTK_RANGE (hscale), policy); gtk_range_set_update_policy (GTK_RANGE (vscale), policy);}void cb_digits_scale( GtkAdjustment *adj ){ /* 设置adj->value圆整的小数位数 */ gtk_scale_set_digits (GTK_SCALE (hscale), (gint) adj->value); gtk_scale_set_digits (GTK_SCALE (vscale), (gint) adj->value);}void cb_page_size( GtkAdjustment *get, GtkAdjustment *set ){ /* 将示例调整对象的page size和page increment size设置 * 为"Page Size"比例构件指定的值 */ set->page_size = get->value; set->page_increment = get->value; /* 设置调整对象的值并使它引发一个 "changed" 信号，以重新配置所有 * 已经连接到这个调整对象的构件。 */ gtk_adjustment_set_value (set, CLAMP (set->value, set->lower, (set->upper - set->page_size)));}void cb_draw_value( GtkToggleButton *button ){ /* 根据复选按钮的状态设置在比例构件上是否显示比例值 */ gtk_scale_set_draw_value (GTK_SCALE (hscale), button->active); gtk_scale_set_draw_value (GTK_SCALE (vscale), button->active); }/* 方便的函数 */GtkWidget *make_menu_item (gchar *name, GCallback callback, gpointer data){ GtkWidget *item; item = gtk_menu_item_new_with_label (name); g_signal_connect (G_OBJECT (item), "activate", callback, data); gtk_widget_show (item); return item;}void scale_set_default_values( GtkScale *scale ){ gtk_range_set_update_policy (GTK_RANGE (scale), GTK_UPDATE_CONTINUOUS); gtk_scale_set_digits (scale, 1); gtk_scale_set_value_pos (scale, GTK_POS_TOP); gtk_scale_set_draw_value (scale, TRUE);}/* 创建示例窗口 */void create_range_controls( void ){ GtkWidget *window; GtkWidget *box1, *box2, *box3; GtkWidget *button; GtkWidget *scrollbar; GtkWidget *separator; GtkWidget *opt, *menu, *item; GtkWidget *label; GtkWidget *scale; GtkObject *adj1, *adj2; /* 标准的创建窗口代码 */ 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), "range controls"); box1 = gtk_vbox_new (FALSE, 0); gtk_container_add (GTK_CONTAINER (window), box1); gtk_widget_show (box1); box2 = gtk_hbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0); gtk_widget_show (box2); /* value, lower, upper, step_increment, page_increment, page_size */ /* 注意，page_size值只对滚动条构件有区别，并且，你实际上能取得的最高值 * 是(upper - page_size)。 */ adj1 = gtk_adjustment_new (0.0, 0.0, 101.0, 0.1, 1.0, 1.0); vscale = gtk_vscale_new (GTK_ADJUSTMENT (adj1)); scale_set_default_values (GTK_SCALE (vscale)); gtk_box_pack_start (GTK_BOX (box2), vscale, TRUE, TRUE, 0); gtk_widget_show (vscale); box3 = gtk_vbox_new (FALSE, 10); gtk_box_pack_start (GTK_BOX (box2), box3, TRUE, TRUE, 0); gtk_widget_show (box3); /* 重新使用同一个调整对象 */ hscale = gtk_hscale_new (GTK_ADJUSTMENT (adj1)); gtk_widget_set_size_request (GTK_WIDGET (hscale), 200, -1); scale_set_default_values (GTK_SCALE (hscale)); gtk_box_pack_start (GTK_BOX (box3), hscale, TRUE, TRUE, 0); gtk_widget_show (hscale); /* 再次重用同一个调整对象 */ scrollbar = gtk_hscrollbar_new (GTK_ADJUSTMENT (adj1)); /* 注意，这导致当滚动条移动时，比例构件总是连续更新 */ gtk_range_set_update_policy (GTK_RANGE (scrollbar), GTK_UPDATE_CONTINUOUS); gtk_box_pack_start (GTK_BOX (box3), scrollbar, TRUE, TRUE, 0); gtk_widget_show (scrollbar); box2 = gtk_hbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0); gtk_widget_show (box2); /* 用一个复选按钮控制是否显示比例构件的值 */ button = gtk_check_button_new_with_label("Display value on scale widgets"); gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE); g_signal_connect (G_OBJECT (button), "toggled", G_CALLBACK (cb_draw_value), NULL); gtk_box_pack_start (GTK_BOX (box2), button, TRUE, TRUE, 0); gtk_widget_show (button); box2 = gtk_hbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); /* 用一个选项菜单以改变显示值的位置 */ label = gtk_label_new ("Scale Value Position:"); gtk_box_pack_start (GTK_BOX (box2), label, FALSE, FALSE, 0); gtk_widget_show (label); opt = gtk_option_menu_new (); menu = gtk_menu_new (); item = make_menu_item ("Top", G_CALLBACK (cb_pos_menu_select), GINT_TO_POINTER (GTK_POS_TOP)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); item = make_menu_item ("Bottom", G_CALLBACK (cb_pos_menu_select), GINT_TO_POINTER (GTK_POS_BOTTOM)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); item = make_menu_item ("Left", G_CALLBACK (cb_pos_menu_select), GINT_TO_POINTER (GTK_POS_LEFT)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); item = make_menu_item ("Right", G_CALLBACK (cb_pos_menu_select), GINT_TO_POINTER (GTK_POS_RIGHT)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); gtk_option_menu_set_menu (GTK_OPTION_MENU (opt), menu); gtk_box_pack_start (GTK_BOX (box2), opt, TRUE, TRUE, 0); gtk_widget_show (opt); gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0); gtk_widget_show (box2); box2 = gtk_hbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); /* 另一个选项菜单，这里是用于设置比例构件的更新方式 */ label = gtk_label_new ("Scale Update Policy:"); gtk_box_pack_start (GTK_BOX (box2), label, FALSE, FALSE, 0); gtk_widget_show (label); opt = gtk_option_menu_new (); menu = gtk_menu_new (); item = make_menu_item ("Continuous", G_CALLBACK (cb_update_menu_select), GINT_TO_POINTER (GTK_UPDATE_CONTINUOUS)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); item = make_menu_item ("Discontinuous", G_CALLBACK (cb_update_menu_select), GINT_TO_POINTER (GTK_UPDATE_DISCONTINUOUS)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); item = make_menu_item ("Delayed", G_CALLBACK (cb_update_menu_select), GINT_TO_POINTER (GTK_UPDATE_DELAYED)); gtk_menu_shell_append (GTK_MENU_SHELL (menu), item); gtk_option_menu_set_menu (GTK_OPTION_MENU (opt), menu); gtk_box_pack_start (GTK_BOX (box2), opt, TRUE, TRUE, 0); gtk_widget_show (opt); gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0); gtk_widget_show (box2); box2 = gtk_hbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); /* 一个水平比例构件，用于调整示例比例构件的显示小数位数。 */ label = gtk_label_new ("Scale Digits:"); gtk_box_pack_start (GTK_BOX (box2), label, FALSE, FALSE, 0); gtk_widget_show (label); adj2 = gtk_adjustment_new (1.0, 0.0, 5.0, 1.0, 1.0, 0.0); g_signal_connect (G_OBJECT (adj2), "value_changed", G_CALLBACK (cb_digits_scale), NULL); scale = gtk_hscale_new (GTK_ADJUSTMENT (adj2)); gtk_scale_set_digits (GTK_SCALE (scale), 0); gtk_box_pack_start (GTK_BOX (box2), scale, TRUE, TRUE, 0); gtk_widget_show (scale); gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0); gtk_widget_show (box2); box2 = gtk_hbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); /* 以及，最后一个水平比例构件用于调整滚动条的page size。 */ label = gtk_label_new ("Scrollbar Page Size:"); gtk_box_pack_start (GTK_BOX (box2), label, FALSE, FALSE, 0); gtk_widget_show (label); adj2 = gtk_adjustment_new (1.0, 1.0, 101.0, 1.0, 1.0, 0.0); g_signal_connect (G_OBJECT (adj2), "value_changed", G_CALLBACK (cb_page_size), adj1); scale = gtk_hscale_new (GTK_ADJUSTMENT (adj2)); gtk_scale_set_digits (GTK_SCALE (scale), 0); gtk_box_pack_start (GTK_BOX (box2), scale, TRUE, TRUE, 0); gtk_widget_show (scale); gtk_box_pack_start (GTK_BOX (box1), box2, TRUE, TRUE, 0); gtk_widget_show (box2); separator = gtk_hseparator_new (); gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 0); gtk_widget_show (separator); box2 = gtk_vbox_new (FALSE, 10); gtk_container_set_border_width (GTK_CONTAINER (box2), 10); gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, TRUE, 0); gtk_widget_show (box2); button = gtk_button_new_with_label ("Quit"); g_signal_connect_swapped (G_OBJECT (button), "clicked", G_CALLBACK (gtk_main_quit), NULL); gtk_box_pack_start (GTK_BOX (box2), button, TRUE, TRUE, 0); GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT); gtk_widget_grab_default (button); gtk_widget_show (button); gtk_widget_show (window);}int main( int argc, char *argv[] ){ gtk_init (&argc, &argv); create_range_controls (); gtk_main (); return 0;} </PRE></TD></TR></TABLE><P>可以注意到程序没有对 "delete_event" 事件调用 g_signal_connect()，仅仅对 "destroy" 信号调用了该函数。但是 "destroy" 函数一样会执行，因为未经处理的 "delete_event" 事件会引发一个 "destroy" 信号给窗口。</P></DIV><DIVCLASS="NAVFOOTER"><HRALIGN="LEFT"WIDTH="100%"><TABLESUMMARY="Footer navigation table"WIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top"><AHREF="x788.html"ACCESSKEY="P"><<< Previous</A></TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="book1.html"ACCESSKEY="H">Home</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top"><AHREF="c816.html"ACCESSKEY="N">Next >>></A></TD></TR><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top">键盘和鼠标绑定</TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="c696.html"ACCESSKEY="U">Up</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top">杂项构件</TD></TR></TABLE></DIV></BODY></HTML>⌨️ 快捷键说明
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