Functions with GtkNotebook

GtkNotebook is a very important object in the text file editor tfe. It connects the application and TfeTextView objects. tfenotebook.h and tfenotebook.c have a set of functions related to GtkTextbook.

 1 void
 2 notebook_page_save(GtkNotebook *nb);
 3 
 4 void
 5 notebook_page_open (GtkNotebook *nb);
 6 
 7 void
 8 notebook_page_new_with_file (GtkNotebook *nb, GFile *file);
 9 
10 void
11 notebook_page_new (GtkNotebook *nb);
12

This header file shows the public functions in tfenotebook.c.

10-11: notebook_page_new generates a new GtkNotebookPage and adds GtkScrolledWindow and TfeTextView on the page.
7-8: notebook_page_new_with_file generates a new GtkNotebookPage and adds GtkScrolledWindow and TfeTextView on the page. The file is read and set into GtkTextBuffer. The GFile file is copied and set in the TfeTextView object.
4-5: notebook_page_open shows a file chooser dialog. Then, user chooses a file and the file is set into GtkTextBuffer.
1-2: notebook_page_save saves the contents in GtkTextBuffer into the file, which has been set in the TfeTextView.

You probably find that the functions above are higher level functions of

tfe_text_view_new
tfe_text_view_new_with_file
tef_text_view_open
tfe_text_view_save

respectively.

There are two layers. One of them is tfe_text_view ..., which is the lower level layer. The other is note_book ..., which is the higher level layer.

Now let's look at each program of the functions.

notebook_page_new

 1 static gchar*
 2 get_untitled () {
 3   static int c = -1;
 4   if (++c == 0) 
 5     return g_strdup_printf("Untitled");
 6   else
 7     return g_strdup_printf ("Untitled%u", c);
 8 }
 9 
10 static void
11 notebook_page_build (GtkNotebook *nb, GtkWidget *tv, char *filename) {
12   GtkWidget *scr;
13   GtkNotebookPage *nbp;
14   GtkWidget *lab;
15   gint i;
16   scr = gtk_scrolled_window_new ();
17 
18   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scr), tv);
19   lab = gtk_label_new (filename);
20   i = gtk_notebook_append_page (nb, scr, lab);
21   nbp = gtk_notebook_get_page (nb, scr);
22   g_object_set (nbp, "tab-expand", TRUE, NULL);
23   gtk_notebook_set_current_page (nb, i);
24   g_signal_connect (GTK_TEXT_VIEW (tv), "change-file", G_CALLBACK (file_changed), nb);
25 }
26 
27 void
28 notebook_page_new (GtkNotebook *nb) {
29   g_return_if_fail(GTK_IS_NOTEBOOK (nb));
30 
31   GtkWidget *tv;
32   char *filename;
33 
34   tv = tfe_text_view_new ();
35   filename = get_untitled ();
36   notebook_page_build (nb, tv, filename);
37 }

27-37: notebook_page_new function.
29: g_return_if_fail is used to check the argument.
34: Generate TfeTextView object.
35: Generate filename, which is "Untitled", "Untitled2", ... .
1-8: get_untitled function.
3: Static variable c is initialized at the first call of this function. After that c keeps its value except it is changed explicitly.
4-7: Increase c by one and if it is zero then the name is "Untitled". If it is a positive integer then the name is "Untitled<the integer>", for example, "Untitled1", "Untitled2", and so on. It returns the name. g_strdup_printf generates a string and it should be freed by g_free function. The caller of get_untitled is in charge of freeing the memories of the string.
36: call notebook_page_build to build the contents of the page.
10- 25: notebook_page_build function.
17-18: Generate GtkScrolledWindow and set tv to its child.
19-20: Generate GtkLabel, then append it to GtkNotebookPage.
21-22: Set "tab-expand" property to TRUE.
23: Set the page to the current page.
24: Connect "change-file" signal and file_changed handler.

notebook_page_new_with_file

 1 void
 2 notebook_page_new_with_file (GtkNotebook *nb, GFile *file) {
 3   g_return_if_fail(GTK_IS_NOTEBOOK (nb));
 4   g_return_if_fail(G_IS_FILE (file));
 5 
 6   GtkWidget *tv;
 7   char *filename;
 8 
 9   if ((tv = tfe_text_view_new_with_file (file)) == NULL)
10     return; /* read error */
11   filename = g_file_get_basename (file);
12   notebook_page_build (nb, tv, filename);
13 }

9-10: Call tfe_text_view_new_with_file. If it returns NULL, then do nothing and return because of an error. -11-13: Get the filename , build the contents of the page.

notebook_page_open

 1 static void
 2 open_response (TfeTextView *tv, gint response, GtkNotebook *nb) {
 3   GFile *file;
 4   char *filename;
 5 
 6   if (response != TFE_OPEN_RESPONSE_SUCCESS) {
 7     g_object_ref_sink (tv);
 8     g_object_unref (tv);
 9   }else if (! G_IS_FILE (file = tfe_text_view_get_file (tv))) {
10     g_object_ref_sink (tv);
11     g_object_unref (tv);
12   }else {
13     filename = g_file_get_basename (file);
14     g_object_unref (file);
15     notebook_page_build (nb, GTK_WIDGET (tv), filename);
16   }
17 }
18 
19 void
20 notebook_page_open (GtkNotebook *nb) {
21   g_return_if_fail(GTK_IS_NOTEBOOK (nb));
22 
23   GtkWidget *tv;
24 
25   tv = tfe_text_view_new ();
26   g_signal_connect (TFE_TEXT_VIEW (tv), "open-response", G_CALLBACK (open_response), nb);
27   tfe_text_view_open (TFE_TEXT_VIEW (tv), gtk_widget_get_ancestor (GTK_WIDGET (nb), GTK_TYPE_WINDOW));
28 }

19-28: notebook_page_open function.
25: Generate TfeTextView object.
26: Connect the signal "open-response" and the handler open_response.
27: Call tfe_text_view_open. It emits "open-response" signal to inform the status after the series of functions run.
1-17: open_response handler. This is the post-function of notebook_page_open.
6-8: If the status is NOT TFE_OPEN_RESPONSE_SUCCESS, cancel what we did in notebook_page_open. The object tv hasn't been a child widget of some other widget yet. Such object has floating reference. It needs to do g_object_ref_sink and clear the floating reference before g_object_unref.
9-11: If tfe_text_view_get_file returns a pointer not to point GFile, then something bad happens. Cancel what we did. Sink and unref tv.
12-16: Otherwise, everything is okay. Get the filename, build the contents of the page.

notebook_page_save

 1 void
 2 notebook_page_save(GtkNotebook *nb) {
 3   gint i;
 4   GtkWidget *scr;
 5   GtkWidget *tv;
 6 
 7   i = gtk_notebook_get_current_page (nb);
 8   scr = gtk_notebook_get_nth_page (nb, i);
 9   tv = gtk_scrolled_window_get_child (GTK_SCROLLED_WINDOW (scr));
10   tfe_text_view_save (TFE_TEXT_VIEW (tv));
11 }

7-9: Get TfeTextView belongs to the current notebook page.
10: Call tfe_text_view_save.

file_changed handler

The function file_changed is a handler connected to "change-file" signal. If tv->file is changed, TfeTextView emits this signal. This handler changes the label of GtkNotebookPage.

 1 static void
 2 file_changed (TfeTextView *tv, GtkNotebook *nb) {
 3   GFile *file;
 4   char *filename;
 5   GtkWidget *scr;
 6   GtkWidget *label;
 7 
 8   file = tfe_text_view_get_file (tv);
 9   scr = gtk_widget_get_parent (GTK_WIDGET (tv));
10   if (G_IS_FILE (file))
11     filename = g_file_get_basename (file);
12   else
13     filename = get_untitled ();
14   label = gtk_label_new (filename);
15   gtk_notebook_set_tab_label (nb, scr, label);
16   g_object_unref (file);
17   g_free (filename);
18 }

8: Get GFile from TfeTextView.
9: Get GkScrolledWindow which is the parent widget of tv.
10-13: If file points GFile, then assign the filename of the GFile into filename. Otherwise (file is NULL), assign untitled string to filename.
14-15: Generate a label with the filename and set it into GtkNotebookPage.
16-17: Free filename and unref file.

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