GTK 如何用鼠标拖动event窗口

Question

建立了一个Even窗口，用来接收事件信息。但是为什么不能用鼠标进行拖动和改变大小？

是不是还有什么事件需要添加上？

另外，想知道如何完成刚才提出的用鼠标拖拽与改变大小的动作。
谢谢!

Answer 1

回复 1# fengtom_lcdtv

    看你的另一篇帖子，你要的就是下面的功能吧：

1. #include <gtk/gtk.h>
3. gboolean progress_button_release (GtkWidget *progress, GdkEvent *event, gpointer data);
4. gboolean progress_button_press (GtkWidget *progress, GdkEvent *event, gpointer data);
5. gboolean progress_motion_notify (GtkWidget *progress, GdkEvent *event, gpointer data);
7. int main (int argc, char* argv[])
8. {
9.   GtkWidget *window;
10.   GtkWidget *label;
11.   GtkWidget *progress;
12.   GtkWidget *vbox;
14.   gtk_init (&argc, &argv);
16.   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
17.   gtk_widget_set_size_request (window, 400, 300);
19.   label = gtk_label_new ("mouse progress bar");
20.   gtk_widget_show (label);
22.   progress = gtk_progress_bar_new ();
23.   gtk_widget_show (progress);
24.   gtk_widget_set_size_request (progress, -1, 30);
25.   gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR(progress), 0.2);
27.   gtk_widget_add_events (progress, GDK_BUTTON_RELEASE_MASK |
28.                                    GDK_BUTTON_PRESS_MASK   |
29.                                                                    GDK_POINTER_MOTION_MASK );
30.   g_signal_connect (progress, "button-release-event",
31.                     G_CALLBACK (progress_button_release), NULL);
32.   g_signal_connect (progress, "button-press-event",
33.                     G_CALLBACK (progress_button_press), NULL);
34.   g_signal_connect (progress, "motion-notify-event",
35.                     G_CALLBACK (progress_motion_notify), NULL);
38.   vbox = gtk_vbox_new (FALSE, 5);
39.   gtk_widget_show (vbox);
41.   gtk_box_pack_start (GTK_BOX(vbox), label, FALSE, FALSE, 5);
42.   gtk_box_pack_start (GTK_BOX(vbox), progress, TRUE, FALSE, 5);
44.   gtk_container_add (GTK_CONTAINER(window), vbox);
46.   gtk_widget_show (window);
48.   gtk_main ();
50.   return 0;
51. }
53. gboolean
54. progress_button_release (GtkWidget *progress, GdkEvent *event, gpointer data)
55. {
56.   GdkEventButton *eb = (GdkEventButton *)event;
57.   GtkAllocation allocation;
58.   gint pressed;
60.   pressed = (gint)g_object_get_data (G_OBJECT(progress), "pressed");
61. #if GTK_MINOR_VERSION >= 18
62.   gtk_widget_get_allocation (progress, &allocation);
63. #else
64.   allocation = progress->allocation;
65. #endif
66.   if (pressed)
67.     gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR(progress), eb->x / (allocation.width * 1.0));
69.   g_object_set_data (G_OBJECT(progress), "pressed", (gpointer)0);
70.   return FALSE;
71. }
73. gboolean
74. progress_button_press (GtkWidget *progress, GdkEvent *event, gpointer data)
75. {
76.   g_object_set_data (G_OBJECT(progress), "pressed", (gpointer)1);
77.   return FALSE;
78. }
80. gboolean
81. progress_motion_notify (GtkWidget *progress, GdkEvent *event, gpointer data)
82. {
83.   GdkEventMotion *em = (GdkEventMotion *)event;
84.   gint pressed;
85.   GtkAllocation allocation;
87.   pressed = (gint)g_object_get_data (G_OBJECT(progress), "pressed");
88. #if GTK_MINOR_VERSION >= 18
89.   gtk_widget_get_allocation (progress, &allocation);
90. #else
91.   allocation = progress->allocation;
92. #endif
93.   if (pressed)
94.   {
95.     gdouble fraction = em->x / (allocation.width * 1.0);
96.         if (fraction > 1.0)
97.           fraction = 1.0;
98.         if (fraction < 0.0)
99.           fraction = 0.0;
100.     gtk_progress_bar_set_fraction (GTK_PROGRESS_BAR(progress), fraction);
101.   }
103.   return FALSE;
104. }

复制代码注意 gtk_widget_add_events

Answer 2

本帖最后由 nketc 于 2011-03-24 21:33 编辑

录了个动画

Answer 3

谢谢nketc ：
虽然我想问的是：如何通过鼠标拖拽使fixed中的一个Label控件自由移动，和用鼠标改变这个Label控件的大小。
但是你的示例却让我对于事件和信号之间的联系有了一定的认识。
谢谢。

另外我想问一下：Label需要添加在一个Eventbox内才可以接收信号。你的这个示例我想解决Label移动应该够了，但是改变大小的话，如何确定鼠标已经在Label的边缘了呢？