[ghex: 1/2] findreplace: watch/busy feedback and cancellable

[Logan Rathbone <larathbone src gnome org>]

commit c8cbc6f1c899e5947e692fe14d177b06ea46f626
Author: Logan Rathbone <poprocks gmail com>
Date:   Tue Dec 21 01:40:38 2021 -0500

    findreplace: watch/busy feedback and cancellable
    
    nb: This doesn't work 100% perfectly at this stage. If you cancel, the
    worker thread operation will continue in the background and then be
    silently discarded. Thus CPU usage can continue to be high while a large
    cancelled find/replace task completes in the background.

 src/findreplace.c  | 133 +++++++++++++++++++++++++++++++++++------------------
 src/hex-document.c |   4 +-
 2 files changed, 90 insertions(+), 47 deletions(-)
---
diff --git a/src/findreplace.c b/src/findreplace.c
index bfc4867..b0c346e 100644
--- a/src/findreplace.c
+++ b/src/findreplace.c
@@ -70,6 +70,7 @@ typedef struct {
        GtkWidget *f_next, *f_prev, *f_clear;
        GtkWidget *close;
        gboolean found;
+       GCancellable *cancellable;
 
 } FindDialogPrivate;
 
@@ -111,7 +112,8 @@ static void replace_all_cb (GtkButton *button, gpointer user_data);
 static void replace_clear_cb (GtkButton *button, gpointer user_data);
 static void goto_byte_cb (GtkButton *button, gpointer user_data);
 static gint64 get_search_string (HexDocument *doc, gchar **str);
-
+static void pane_dialog_update_busy_state (PaneDialog *self);
+static void mark_gh_busy (GtkHex *gh, gboolean busy);
 
 static GtkWidget *
 create_hex_view (HexDocument *doc)
@@ -156,6 +158,15 @@ pane_dialog_real_close (PaneDialog *self)
        gtk_widget_hide (GTK_WIDGET(self));
 }
 
+static void
+find_cancel_cb (GtkButton *button, gpointer user_data)
+{
+       FindDialog *self = FIND_DIALOG(user_data);
+       FindDialogPrivate *f_priv = find_dialog_get_instance_private (self);
+
+       g_cancellable_cancel (f_priv->cancellable);
+}
+
 static void
 common_cancel_cb (GtkButton *button, gpointer user_data)
 {
@@ -177,6 +188,37 @@ no_string_dialog (GtkWindow *parent)
                        _("No string provided."));
 }
 
+static void
+set_watch_cursor (GtkWidget *widget, gboolean enabled)
+{
+  if (enabled)
+  {
+    gtk_widget_set_cursor_from_name (widget, "watch");
+  }
+  else
+  {
+    gtk_widget_set_cursor (widget, NULL);
+  }
+}
+
+static void
+mark_gh_busy (GtkHex *gh, gboolean busy)
+{
+       set_watch_cursor (GTK_WIDGET(gh), busy);
+       g_object_set_data (G_OBJECT(gh), "busy", GINT_TO_POINTER(busy));
+}
+
+static gboolean
+gh_is_busy (GtkHex *gh)
+{
+       gpointer data = g_object_get_data (G_OBJECT(gh), "busy");
+
+       if (data)
+               return GPOINTER_TO_INT (data);
+       else
+               return FALSE;
+}
+
 static void
 find_ready_cb (GObject *source_object,
                         GAsyncResult *res,
@@ -191,6 +233,14 @@ find_ready_cb (GObject *source_object,
 
        find_data = hex_document_find_finish (doc, res);
 
+       /* Typically this will be due to a cancellation - could theoretically be
+        * an error, but not much we can do to report a search error anyway.
+        */
+       if (! find_data)
+               goto out;
+
+       g_object_unref (res);
+
        if (find_data->found)
        {
                f_priv->found = TRUE;
@@ -214,6 +264,10 @@ find_ready_cb (GObject *source_object,
 
                f_priv->found = FALSE;
        }
+
+out:
+       mark_gh_busy (priv->gh, FALSE);
+       pane_dialog_update_busy_state (PANE_DIALOG(self));
 }
 
 static void
@@ -253,6 +307,7 @@ find_common (FindDialog *self, enum FindDirection direction,
        
        if (direction == FIND_FORWARD)
        {
+               g_cancellable_reset (f_priv->cancellable);
                hex_document_find_forward_async (doc,
                                f_priv->found == FALSE ? cursor_pos : cursor_pos + 1,
                                str,
@@ -260,7 +315,7 @@ find_common (FindDialog *self, enum FindDirection direction,
                                &offset,
                                found_msg,
                                not_found_msg,
-                               NULL,   /* cancellable */
+                               f_priv->cancellable,
                                find_ready_cb,
                                self);
        }
@@ -278,43 +333,8 @@ find_common (FindDialog *self, enum FindDirection direction,
                                self);
        }
 
-
-#if 0
-       if (direction == FIND_FORWARD 
-               ?
-                       hex_document_find_forward (doc,
-                               found == FALSE ? cursor_pos : cursor_pos + 1,
-                               str, str_len, &offset)
-                       
-               :
-                       hex_document_find_backward (doc,
-                               cursor_pos, str, str_len, &offset)
-                       )
-#endif
-
-#if 0
-       {
-               found = TRUE;
-               gtk_hex_set_cursor (priv->gh, offset);
-
-               /* If string found, insert auto-highlights of search string */
-
-               if (priv->auto_highlight)
-                       gtk_hex_delete_autohighlight (priv->gh, priv->auto_highlight);
-
-               priv->auto_highlight = NULL;
-               priv->auto_highlight = gtk_hex_insert_autohighlight (priv->gh,
-                               str, str_len);
-
-               gtk_widget_grab_focus (GTK_WIDGET(priv->gh));
-       }
-       else
-       {
-               display_info_dialog (parent, found ? found_msg : not_found_msg);
-
-               found = FALSE;
-       }
-#endif
+       mark_gh_busy (priv->gh, TRUE);
+       pane_dialog_update_busy_state (PANE_DIALOG(self));
 }
 
 static void
@@ -718,13 +738,31 @@ pane_dialog_class_init (PaneDialogClass *klass)
                                          G_TYPE_NONE, 0);
 }
 
+/* Helper */
+static void
+pane_dialog_update_busy_state (PaneDialog *self)
+{
+       PaneDialogPrivate *priv = pane_dialog_get_instance_private (self);
+
+       if (FIND_IS_DIALOG (self))
+       {
+               FindDialogPrivate *f_priv;
+               gboolean busy;
+
+               f_priv = find_dialog_get_instance_private (FIND_DIALOG(self));
+               busy = gh_is_busy (priv->gh);
+               gtk_widget_set_sensitive (f_priv->f_next, !busy);
+               gtk_widget_set_sensitive (f_priv->f_prev, !busy);
+       }
+}
+
 void
 pane_dialog_set_hex (PaneDialog *self, GtkHex *gh)
 {
        PaneDialogPrivate *priv;
 
-       g_return_if_fail (PANE_IS_DIALOG(self));
-       g_return_if_fail (GTK_IS_HEX(gh));
+       g_return_if_fail (PANE_IS_DIALOG (self));
+       g_return_if_fail (GTK_IS_HEX (gh));
 
        priv = pane_dialog_get_instance_private (PANE_DIALOG(self));
 
@@ -735,6 +773,8 @@ pane_dialog_set_hex (PaneDialog *self, GtkHex *gh)
        priv->auto_highlight = NULL;
 
        priv->gh = gh;
+
+       pane_dialog_update_busy_state (self);
 }
 
 void
@@ -742,9 +782,7 @@ pane_dialog_close (PaneDialog *self)
 {
        g_return_if_fail (PANE_IS_DIALOG (self));
 
-       g_signal_emit(self,
-                       signals[CLOSED],
-                       0);     /* GQuark detail (just set to 0 if unknown) */
+       g_signal_emit(self, signals[CLOSED], 0);
 }
 
 /* FindDialog */
@@ -754,6 +792,8 @@ find_dialog_init (FindDialog *self)
 {
        FindDialogPrivate *f_priv = find_dialog_get_instance_private (self);
 
+       f_priv->cancellable = g_cancellable_new ();
+
        /* Setup our root container. */
        f_priv->vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
        gtk_widget_set_parent (f_priv->vbox, GTK_WIDGET(self));
@@ -805,6 +845,8 @@ find_dialog_init (FindDialog *self)
        gtk_widget_set_halign (f_priv->close, GTK_ALIGN_END);
        g_signal_connect (G_OBJECT (f_priv->close), "clicked",
                        G_CALLBACK(common_cancel_cb), self);
+       g_signal_connect (G_OBJECT (f_priv->close), "clicked",
+                       G_CALLBACK(find_cancel_cb), self);
        gtk_box_append (GTK_BOX(f_priv->hbox), f_priv->close);
        gtk_accessible_update_property (GTK_ACCESSIBLE(f_priv->close),
                        GTK_ACCESSIBLE_PROPERTY_LABEL,
@@ -829,11 +871,12 @@ find_dialog_grab_focus (GtkWidget *widget)
 }
 
 static void
-find_dialog_dispose(GObject *object)
+find_dialog_dispose (GObject *object)
 {
        FindDialog *self = FIND_DIALOG(object);
        FindDialogPrivate *f_priv = find_dialog_get_instance_private (self);
 
+       g_clear_object (&f_priv->cancellable);
        g_clear_pointer (&f_priv->vbox, gtk_widget_unparent);
 
        /* Boilerplate: chain up
diff --git a/src/hex-document.c b/src/hex-document.c
index 16d0c18..1b8e42a 100644
--- a/src/hex-document.c
+++ b/src/hex-document.c
@@ -842,9 +842,9 @@ hex_document_find_forward_async (HexDocument *doc,
        find_data->not_found_msg = not_found_msg;
 
        task = g_task_new (doc, cancellable, callback, user_data);
+       g_task_set_return_on_cancel (task, TRUE);
        g_task_set_task_data (task, find_data, g_free);
        g_task_run_in_thread (task, hex_document_find_forward_thread);
-       g_object_unref (task);  /* _run_in_thread takes a ref */
 }
 
 gboolean
@@ -905,9 +905,9 @@ hex_document_find_backward_async (HexDocument *doc,
        find_data->not_found_msg = not_found_msg;
 
        task = g_task_new (doc, cancellable, callback, user_data);
+       g_task_set_return_on_cancel (task, TRUE);
        g_task_set_task_data (task, find_data, g_free);
        g_task_run_in_thread (task, hex_document_find_backward_thread);
-       g_object_unref (task);  /* _run_in_thread takes a ref */
 }
 
 gboolean