Fix pager bug #25!

Finally fixed! An extra check to see whether the pager is at the
bottom. Apparently if you click to put the cursor somewhere that's
not the end of the text buffer, then scroll up with your scroll
wheel, then _sometimes_ the pager wouldn't stop paging when you
paged down to the end again, because the GtkAdjustment's "changed"
signal didn't fire. But now that's fixed.

diff --git a/libchimara/pager.c b/libchimara/pager.c
index d54c777501107d459ceca7aac2e9d147f5b39fff..456bcd1477908133da7fd7769302500d5b83d85e 100644 (file)
--- a/libchimara/pager.c
+++ b/libchimara/pager.c
@@ -2,6 +2,10 @@
 
 #include "pager.h"
 
+/* Not sure if necessary, but this is the margin within which the pager will
+stop paging if it's close to the end of the text buffer */
+#define PAGER_FUZZINESS 1.0
+
 /* Helper function: move the pager to the last visible position in the buffer,
  and return the distance between the pager and the end of the buffer in buffer
  coordinates */
@@ -32,11 +36,6 @@ move_pager_and_get_scroll_distance(GtkTextView *textview, gint *view_height, gin
        gtk_text_view_get_iter_location(textview, &newpager, &pagerpos);
        gtk_text_view_get_iter_location(textview, &end, &endpos);
 
-       /*
-       g_printerr("View height = %d\n", visiblerect.height);
-       g_printerr("End - Pager = %d - %d = %d\n", endpos.y, pagerpos.y, endpos.y - pagerpos.y);
-       */
-       
        *view_height = visiblerect.height;
        *scroll_distance = endpos.y - pagerpos.y;
 }
@@ -59,12 +58,27 @@ stop_paging(winid_t win)
        g_signal_handler_block(win->widget, win->pager_keypress_handler);
 }
 
+/* Helper function: If the adjustment is at its maximum value, stop paging */
+static void
+check_paging(GtkAdjustment *adj, winid_t win)
+{
+       double page_size, upper, value;
+       g_object_get(adj,
+               "page-size", &page_size,
+               "upper", &upper,
+               "value", &value,
+               NULL);
+       if(value + PAGER_FUZZINESS >= upper - page_size && win->currently_paging)
+               stop_paging(win);
+}
+
 void
 pager_on_clicked(GtkButton *pager, winid_t win)
 {
        GtkAdjustment *adj = gtk_scrolled_window_get_vadjustment( GTK_SCROLLED_WINDOW(win->scrolledwindow) );
        double upper = gtk_adjustment_get_upper(adj);
        gtk_adjustment_set_value(adj, upper);
+       check_paging(adj, win);
 }
 
 /* When the user scrolls up in a textbuffer, start paging. */
@@ -76,9 +90,17 @@ pager_after_adjustment_changed(GtkAdjustment *adj, winid_t win)
        move_pager_and_get_scroll_distance( GTK_TEXT_VIEW(win->widget), &view_height, &scroll_distance, TRUE );
 
        if(scroll_distance > 0 && !win->currently_paging)
+       {
                start_paging(win);
+               return;
+       }
        else if(scroll_distance == 0 && win->currently_paging)
+       {
                stop_paging(win);
+               return;
+       }
+
+       check_paging(adj, win);
 }
 
 /* Handle key press events in the textview while paging is active */
@@ -99,12 +121,15 @@ pager_on_key_press_event(GtkTextView *textview, GdkEventKey *event, winid_t win)
                case GDK_KEY_Page_Down: case GDK_KEY_KP_Page_Down:
                case GDK_KEY_Return: case GDK_KEY_KP_Enter:
                        gtk_adjustment_set_value(adj, CLAMP(value + page_size, lower, upper - page_size));
+                       check_paging(adj, win);
                        return TRUE;
                case GDK_KEY_Page_Up: case GDK_KEY_KP_Page_Up:
                        gtk_adjustment_set_value(adj, CLAMP(value - page_size, lower, upper - page_size));
+                       check_paging(adj, win);
                        return TRUE;
                case GDK_KEY_End: case GDK_KEY_KP_End:
-                       gtk_adjustment_set_value(adj, upper);
+                       gtk_adjustment_set_value(adj, upper - page_size);
+                       check_paging(adj, win);
                        return TRUE;
                        /* don't handle "up" and "down", they're used for input history */
        }