Tech insights

  You can also embed gVim in GNU Emacs (GTK build with X11 backend). There are two things to take care of in this case - moving focus to the embedded widget and redirecting keyboard input to the widget. A GTK widget can only have focus if it's set that way (remember there are multiple widgets in a window): // Allow to receive keyboard input gtk_widget_set_can_focus (widget, TRUE); // Receive keyboard input gtk_widget_grab_focus (widget);   Emacs filters keyboard events (KeyPress) before passing it to GTK. That's how C-g always works in Emacs. When Emacs receives XEMBED_REQUEST_FOCUS (event->type == ClientMessage && event->xclient.message_type == dpyinfo->Xatom_XEMBED && event->xclient.data.l[1] == XEMBED_REQUEST_FOCUS) , we need to set input focus to the widget using XSetInputFocus() using the handle event->xclient.window . Additionally, we set a flag that a widget is active. Whenever this flag is active, we stop filtering keyboard events. T...

In previous post , we learnt the basics of embedding a GTK application in another application. This works fine when the embedded application supports client server architecture like gVim. Note that in this case the client mode invocations are short lived processes while server process runs throughout the lifetime of the application. In contrast, an application like VLC provides a remote control interface to run  multiple operations in the same process. In this case, we need to obtain an input channel of the process and write our commands to the same. Here's an updated version of the code. Remember to update the two bold paths with appropriate video locations. The application starts with one video and then switches to the next one when the button is clicked. embed.c #include <gtk/gtkx.h> gchar *string; GMutex mutex; void send_hello(GtkButton *btn) {   /* Note the \n at the end */   string = g_strdup_printf("add /home/anand/Downloads/test.mp4 \n"); } static vo...