如何在自定义中添加 GtkWidget？

问题描述

我制作了一个自定义 GTK 小部件，我需要向其中添加一个 GTK 按钮，以便在自定义小部件中继承其信号。自定义小部件是一个时间线，所以我想使用 GTK 按钮来避免弄乱鼠标坐标。当用户想要移动按钮所代表的图片或只是在时间轴上延长其延迟时，按钮小部件会发出信号，我的生活会轻松得多。

按钮当然不会显示在时间线上。那是我的问题。我知道我必须将按钮放在容器内，但如何在绘图功能中做到这一点？有没有人知道如何做到这一点？我用谷歌搜索并查看了这里，但没有运气。

这是自定义小部件绘制功能：

static gboolean img_timeline_draw(GtkWidget *da,cairo_t *cr)
{
  GtkWidget *button; 
  ImgTimelinePrivate *priv = img_timeline_get_instance_private((ImgTimeline*)da);
  gint width = gtk_widget_get_allocated_width(da);
  
  cairo_translate (cr,12);

  img_timeline_draw_time_ticks(da,cr,width);
  
  //Video timeline
  cairo_translate (cr,20);
  cairo_set_source_rgba(cr,priv->video_background[0],priv->video_background[1],priv->video_background[2],priv->video_background[3]);
  cairo_set_line_width(cr,1);
  cairo_rectangle(cr,10,width - 2,59);
  cairo_fill(cr);
  //separator
  cairo_set_source_rgb(cr,1,69,3);
  cairo_fill(cr);
  //Audio timeline
  cairo_set_source_rgba(cr,priv->audio_background[0],priv->audio_background[1],priv->audio_background[2],priv->audio_background[3]);
  cairo_rectangle(cr,72,59);
  cairo_fill(cr);

  button = gtk_button_new_with_label("I'm invisible...");
  gtk_widget_set_realized(button,TRUE);
  gtk_widget_show(button);
  return FALSE;
}

这是主要的：

int main(int argc,char *argv[])
{
  gtk_init(&argc,&argv);

  GtkWidget *window=gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title(GTK_WINDOW(window),"Imagination timeline widget");
  gtk_window_set_position(GTK_WINDOW(window),GTK_WIN_POS_CENTER);
  gtk_window_set_default_size(GTK_WINDOW(window),800,200);
  g_signal_connect(window,"destroy",G_CALLBACK(gtk_main_quit),NULL);

  GtkWidget *timeline = img_timeline_new();
  g_object_set(timeline,"total_time",300,NULL);
  g_object_set(timeline,"video_background","#0084ff","audio_background",NULL);

  gtk_widget_add_events( timeline,GDK_BUTTON1_MOTION_MASK
                         | GDK_POINTER_MOTION_HINT_MASK
                         | GDK_BUTTON_PRESS_MASK
                         | GDK_BUTTON_RELEASE_MASK
                         | GDK_SCROLL_MASK
                         | GDK_KEY_PRESS_MASK );

  GtkWidget *scrolledwindow1 = gtk_scrolled_window_new(NULL,NULL);
  GtkWidget *viewport = gtk_viewport_new(NULL,NULL);
  g_signal_connect( G_OBJECT(timeline),"scroll-event",G_CALLBACK(img_timeline_scroll),scrolledwindow1);

  gtk_widget_set_hexpand(viewport,TRUE);
  gtk_widget_set_vexpand(viewport,TRUE);
  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolledwindow1),GTK_POLICY_AUTOMATIC,GTK_POLICY_NEVER);
  
  gtk_container_add (GTK_CONTAINER(viewport),timeline);
  gtk_container_add (GTK_CONTAINER(scrolledwindow1),viewport);
  gtk_container_add (GTK_CONTAINER (window),scrolledwindow1);
  gtk_widget_show_all(window);

  gtk_main();
  return 0;
}

解决方法

好的，解决方案是继承 GtkLayout 而不是 GtkDrawingArea 并在自定义小部件绘制函数中使用 gtk_container_propagate_draw() ！

c custom-widgets gtk gtk3