LinGui: make activity log window scrolling work better

scroll on update only when the scrollbar is at the bottom

git-svn-id: svn://localhost/HandBrake/trunk@1611 b64f7644-9d1e-0410-96f1-a4d463321fa5

diff --git a/gtk/src/callbacks.c b/gtk/src/callbacks.c
index 9b5b4c6..78196b2 100644 (file)
--- a/gtk/src/callbacks.c
+++ b/gtk/src/callbacks.c
@@ -2814,7 +2814,7 @@ ghb_log_cb(GIOChannel *source, GIOCondition cond, gpointer data)
        GtkTextView *textview;
        GtkTextBuffer *buffer;
        GtkTextIter iter;
-       //GtkTextMark *mark;
+       GtkTextMark *mark;
        GError *gerror = NULL;
        GIOStatus status;
        
@@ -2823,15 +2823,42 @@ ghb_log_cb(GIOChannel *source, GIOCondition cond, gpointer data)
        status = g_io_channel_read_line (source, &text, &length, NULL, &gerror);
        if (text != NULL)
        {
+               GdkWindow *window;
+               gint width, height;
+               gint x, y;
+               gboolean bottom = FALSE;
+
                textview = GTK_TEXT_VIEW(GHB_WIDGET (ud->builder, "activity_view"));
                buffer = gtk_text_view_get_buffer (textview);
                // I would like to auto-scroll the window when the scrollbar
-               // is at the bottom, but I'm having difficulty finding a way
-               // to reliably detect that the scrollbar is at the bottom
-               //mark = gtk_text_buffer_get_insert (buffer);
-               //gtk_text_view_scroll_mark_onscreen(textview, mark);
+               // is at the bottom, 
+               // must determining whether the insert point is at
+               // the bottom of the window 
+               window = gtk_text_view_get_window(textview, GTK_TEXT_WINDOW_TEXT);
+               if (window != NULL)
+               {
+                       gdk_drawable_get_size(GDK_DRAWABLE(window), &width, &height);
+                       gtk_text_view_window_to_buffer_coords(textview, 
+                               GTK_TEXT_WINDOW_TEXT, width, height, &x, &y);
+                       gtk_text_view_get_iter_at_location(textview, &iter, x, y);
+                       if (gtk_text_iter_is_end(&iter))
+                       {
+                               bottom = TRUE;
+                       }
+               }
+               else
+               {
+                       // If the window isn't available, assume bottom
+                       bottom = TRUE;
+               }
                gtk_text_buffer_get_end_iter(buffer, &iter);
                gtk_text_buffer_insert(buffer, &iter, text, -1);
+               if (bottom)
+               {
+                       //gtk_text_view_scroll_to_iter(textview, &iter, 0, FALSE, 0, 0);
+                       mark = gtk_text_buffer_get_insert (buffer);
+                       gtk_text_view_scroll_mark_onscreen(textview, mark);
+               }
                g_io_channel_write_chars (ud->activity_log, text, length, &length, NULL);
                g_free(text);
        }