Make the menu items of menu created, functionable using GTK+ - c

Question

Here in this code I have created a menu bar and added menus and menu items to it...
But i dont know how to make the created menu items functionable... for eg: I want the 'Open' menu item of 'File' in the menu bar, open a file and display it...
I'm making a project on a Text Editor using GTK+ 3
#include <gtk/gtk.h>
GtkWidget *window;
GdkPixbuf *icon;
GtkWidget *vbox;
GtkWidget *menubar;
GtkWidget *fileMenu;
GtkWidget *fileMi;
GtkWidget *editMenu;
GtkWidget *editMi;
GtkWidget *searchMenu;
GtkWidget *searchMi;
GtkWidget *newMi;
GtkWidget *openMi;
GtkWidget *saveMi;
GtkWidget *saveasMi;
GtkWidget *quitMi;
GtkWidget *undoMi;
GtkWidget *redoMi;
GtkWidget *cutMi;
GtkWidget *copyMi;
GtkWidget *pasteMi;
GtkWidget *fontMi;
GtkWidget *findMi;
GtkWidget *replaceMi;
GtkWidget *text_view;
GtkTextBuffer *buffer;
void txt(){
text_view = gtk_text_view_new ();
gtk_box_pack_start (GTK_BOX (vbox), text_view, TRUE, TRUE, 0);
}
GdkPixbuf *create_pixbuf (const gchar *filename)
{
GdkPixbuf *pixbuf;
GError *error = NULL;
pixbuf = gdk_pixbuf_new_from_file (filename, &error);
if (!pixbuf)
{
fprintf (stderr, "%s\n", error->message);
g_error_free (error);
}
return pixbuf;
}
static void fileOpen(GtkWidget *load, gpointer window)
{
GtkWidget *choose;
GtkFileChooserAction action= GTK_FILE_CHOOSER_ACTION_OPEN;
choose = gtk_file_chooser_dialog_new("Choose a file to open", GTK_WINDOW(window), GTK_FILE_CHOOSER_ACTION_OPEN, GTK_STOCK_OK, GTK_RESPONSE_OK, GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL, NULL);
if (gtk_dialog_run(GTK_DIALOG(choose)) == GTK_RESPONSE_ACCEPT)
{
char *path = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(choose));
gtk_text_buffer_set_text(buffer, path, -1);
}
gtk_widget_destroy(choose);
}
static void fileSave(GtkWidget *save, gpointer window)
{
GtkWidget *saved;
saved = gtk_file_chooser_dialog_new("Choose a file to open", GTK_WINDOW(window), GTK_FILE_CHOOSER_ACTION_SAVE, GTK_STOCK_OK, GTK_RESPONSE_OK, GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL, NULL);
gtk_widget_show_all(saved);
gint resp = gtk_dialog_run(GTK_DIALOG(saved));
gtk_widget_destroy(saved);
}
int main (int argc, char *argv[])
{
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
icon = create_pixbuf ("Web.png");
gtk_window_set_title (GTK_WINDOW (window), "Write Pad");
gtk_window_set_default_size (GTK_WINDOW (window), 500, 400);
gtk_window_set_position (GTK_WINDOW (window), GTK_WIN_POS_CENTER);
gtk_window_set_icon (GTK_WINDOW (window), icon);
vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
gtk_container_add (GTK_CONTAINER (window), vbox);
menubar = gtk_menu_bar_new ();
fileMenu = gtk_menu_new ();
fileMi = gtk_menu_item_new_with_label ("File");
newMi = gtk_menu_item_new_with_label ("New");
openMi = gtk_menu_item_new_with_label ("Open");
saveMi = gtk_menu_item_new_with_label ("Save");
saveasMi = gtk_menu_item_new_with_label ("Save As");
quitMi = gtk_menu_item_new_with_label ("Quit");
menubar = gtk_menu_bar_new ();
editMenu = gtk_menu_new ();
editMi = gtk_menu_item_new_with_label ("Edit");
undoMi = gtk_menu_item_new_with_label ("Undo");
redoMi = gtk_menu_item_new_with_label ("Redo");
cutMi = gtk_menu_item_new_with_label ("Cut");
copyMi = gtk_menu_item_new_with_label ("Copy");
pasteMi = gtk_menu_item_new_with_label ("Paste");
fontMi = gtk_menu_item_new_with_label ("Font");
menubar = gtk_menu_bar_new ();
searchMenu = gtk_menu_new ();
searchMi = gtk_menu_item_new_with_label ("Search");
findMi = gtk_menu_item_new_with_label ("Find");
replaceMi = gtk_menu_item_new_with_label ("Replace");
gtk_menu_item_set_submenu (GTK_MENU_ITEM (fileMi), fileMenu);
gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), newMi);
gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), openMi);
gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), saveMi);
gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), saveasMi);
gtk_menu_shell_append (GTK_MENU_SHELL (fileMenu), quitMi);
gtk_menu_shell_append (GTK_MENU_SHELL (menubar), fileMi);
gtk_menu_item_set_submenu (GTK_MENU_ITEM (editMi), editMenu);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), undoMi);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), redoMi);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), cutMi);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), copyMi);
gtk_menu_shell_append (GTK_MENU_SHELL (editMenu), pasteMi);
gtk_menu_shell_append (GTK_MENU_SHELL (editMenu), fontMi);
gtk_menu_shell_append (GTK_MENU_SHELL (menubar), editMi);
gtk_menu_item_set_submenu (GTK_MENU_ITEM (searchMi), searchMenu);
gtk_menu_shell_append(GTK_MENU_SHELL(searchMenu), findMi);
gtk_menu_shell_append(GTK_MENU_SHELL(searchMenu), replaceMi);
gtk_box_pack_start (GTK_BOX (vbox), menubar, FALSE, FALSE, 0);
txt();
buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));
g_signal_connect (G_OBJECT (window), "destroy", G_CALLBACK (gtk_main_quit), NULL);
g_signal_connect (G_OBJECT (quitMi), "activate", G_CALLBACK (gtk_main_quit), NULL);
g_signal_connect (G_OBJECT (newMi), "activate", G_CALLBACK (main), NULL);
g_signal_connect(G_OBJECT (openMi), "activate", G_CALLBACK(fileOpen), NULL);
g_signal_connect(G_OBJECT (saveMi), "activate", G_CALLBACK(fileSave), NULL);
gtk_widget_show_all (window);
gtk_main ();
return 0;
}

Answer 1

Basically, the problem you have is caused by the fact that all of your widgets are global variables, but your fileOpen function takes a gpointer window argument:
//global
GtkWidget *window;
//gpointer window argument -> local variable, not global
static void fileOpen(GtkWidget *load, gpointer window)
{
GtkWidget *choose;
GtkFileChooserAction action= GTK_FILE_CHOOSER_ACTION_OPEN;
choose = gtk_file_chooser_dialog_new(
"Choose a file to open",
GTK_WINDOW(window),//window is not global, but function argument here !
GTK_FILE_CHOOSER_ACTION_OPEN, GTK_STOCK_OK, GTK_RESPONSE_OK, GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL, NULL
);
if (gtk_dialog_run(GTK_DIALOG(choose)) == GTK_RESPONSE_ACCEPT)
{
char *path = gtk_file_chooser_get_filename(
GTK_FILE_CHOOSER(choose)
);
gtk_text_buffer_set_text(buffer, path, -1);
}
gtk_widget_destroy(choose);
}
A quick fix would be to rename the argument to something like gp_data or something. A better fix would be to not use a global variable, and instead rely on the gpointer to pass on the objects you need:
g_signal_connect(
G_OBJECT (openMi),
"activate",
G_CALLBACK(fileOpen),
(gpointer)text_view // text_view and buffer needn't be global now
);
And then use the gpointer argument to get the window and anything else you might need. You could also use a custom struct or array of widgets to pass to the callback in case you need more stuff to work with, but in this case, you should be OK with just passing the text_view widget, and changing the callback to something like this:
static void fileOpen(GtkWidget *load, gpointer widget)
{
//get the buffer
GtkTextBuffer *buffer = gtk_text_view_get_buffer(
GTK_TEXT_VIEW (widget)
);
//get window from text_View widget passed to callback
//so window doesn't have to be global either...
GtkWidget *window = gtk_widget_get_toplevel(
widget
), *choose;
GtkFileChooserAction action= GTK_FILE_CHOOSER_ACTION_OPEN;
choose = gtk_file_chooser_dialog_new(
"Choose a file to open",
GTK_WINDOW(window),
GTK_FILE_CHOOSER_ACTION_OPEN, GTK_STOCK_OK, GTK_RESPONSE_OK, GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL, NULL
);
if (gtk_dialog_run(GTK_DIALOG(choose)) == GTK_RESPONSE_ACCEPT)
{
char *path = gtk_file_chooser_get_filename(
GTK_FILE_CHOOSER(choose)
);
gtk_text_buffer_set_text(buffer, path, -1);
}
gtk_widget_destroy(choose);
}
Note that I haven't tested this code, but this should be enough to get you started. You'll have to change the code you have a bit, but you should be able to get rid of all of those global variables simply by passing the right widget to the callbacks.
As always: Read the documentation, just adding the link to the answer for future reference