Stop relying on gtk to track which dives are selected

We spend way too much effort trying to get gtk to manage the dives that
are selected. The straw that broke the camel's back is that gtk forces us
to expand any nodes that we want to select - so selecting a summary entry
for a dive trip forced us to expand all the dives in the dive trip. Which
as Linus pointed out really sucked from a user experience.

So instead we now completeley ignore gtk's weird idea of what is selected
and what isn't and simply track things ourselves. We still need to play
some games with gtk to make sure that the correct rows are SHOWN as
selected, but still, the overall code seems much cleaner.

This commit contains a bunch of debugging code that is ifdef'ed out -
this is extremely useful to make sure I didn't mess anything up, but
eventually I'll want to remove that again as it just looks ugly in the
code.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 101 insertions, 47 deletions

diff --git a/divelist.c b/divelist.c
index 5b4ef0a10..19ab600e8 100644
--- a/divelist.c
+++ b/divelist.c
@@ -78,6 +78,78 @@ static void dump_model(GtkListStore *store)
 
 static GList *selected_dives;
 static int *selectiontracker;
+static int st_size = 0;
+
+gboolean is_in_st(int idx, int *atpos)
+{
+	int i;
+
+	for (i = 0; i < amount_selected; i++)
+		if (selectiontracker[i] == idx) {
+			if (atpos)
+				*atpos = i;
+			return TRUE;
+		}
+	return FALSE;
+}
+
+#if DEBUG_SELECTION_TRACKING
+void dump_selection(void)
+{
+	int i;
+
+	printf("currently selected are ");
+	for (i = 0; i < amount_selected; i++)
+		printf("%d ", selectiontracker[i]);
+	printf("\n");
+}
+#endif
+
+void track_select(int idx)
+{
+	if (idx < 0)
+		return;
+
+#if DEBUG_SELECTION_TRACKING
+	printf("add %d to selection of %d entries\n", idx, amount_selected);
+#endif
+	if (is_in_st(idx, NULL))
+		return;
+	if (amount_selected >= st_size) {
+		selectiontracker = realloc(selectiontracker, dive_table.nr * sizeof(int));
+		st_size = dive_table.nr;
+	}
+	selectiontracker[amount_selected] = idx;
+	amount_selected++;
+	if (amount_selected == 1)
+		selected_dive = idx;
+#if DEBUG_SELECTION_TRACKING
+	printf("increased amount_selected to %d\n", amount_selected);
+	dump_selection();
+#endif
+}
+
+void track_unselect(int idx)
+{
+	if (idx < 0)
+		return;
+
+#if DEBUG_SELECTION_TRACKING
+	printf("remove %d from selection of %d entries\n", idx, amount_selected);
+#endif
+	int atpos;
+
+	if (! is_in_st(idx, &atpos))
+		return;
+	memmove(selectiontracker + atpos,
+		selectiontracker + atpos + 1,
+		(amount_selected - atpos - 1) * sizeof(int));
+	amount_selected--;
+#if DEBUG_SELECTION_TRACKING
+	printf("removed %d at pos %d and decreased amount_selected to %d\n", idx, atpos, amount_selected);
+	dump_selection();
+#endif
+}
 
 /* when subsurface starts we want to have the last dive selected. So we simply
    walk to the first leaf (and skip the summary entries - which have negative
@@ -96,6 +168,7 @@ static void first_leaf(GtkTreeModel *model, GtkTreeIter *iter, int *diveidx)
 		if(!gtk_tree_view_row_expanded(GTK_TREE_VIEW(dive_list.tree_view), tpath))
 			gtk_tree_view_expand_row(GTK_TREE_VIEW(dive_list.tree_view), tpath, FALSE);
 		gtk_tree_model_get(GTK_TREE_MODEL(model), iter, DIVE_INDEX, diveidx, -1);
+		track_select(*diveidx);
 	}
 }
 
@@ -105,15 +178,21 @@ static void select_children(GtkTreeModel *model, GtkTreeSelection * selection,
 			GtkTreeIter *iter, gboolean was_selected)
 {
 	int i, nr_children;
+	gboolean unexpand = FALSE;
 	GtkTreeIter parent;
 	GtkTreePath *tpath;
 
 	memcpy(&parent, iter, sizeof(parent));
 
 	tpath = gtk_tree_model_get_path(model, &parent);
-	if(!gtk_tree_view_row_expanded(GTK_TREE_VIEW(dive_list.tree_view), tpath))
-		gtk_tree_view_expand_row(GTK_TREE_VIEW(dive_list.tree_view), tpath, FALSE);
 
+	/* stupid gtk doesn't allow us to select rows that are invisible; so if the
+	   user clicks on a row that isn't expanded, we briefly expand it, select the
+	   children, and then unexpand it again */
+	if(!gtk_tree_view_row_expanded(GTK_TREE_VIEW(dive_list.tree_view), tpath)) {
+		unexpand = TRUE;
+		gtk_tree_view_expand_row(GTK_TREE_VIEW(dive_list.tree_view), tpath, FALSE);
+	}
 	nr_children = gtk_tree_model_iter_n_children(model, &parent);
 	for (i = 0; i < nr_children; i++) {
 		gtk_tree_model_iter_nth_child(model, iter, &parent, i);
@@ -122,6 +201,18 @@ static void select_children(GtkTreeModel *model, GtkTreeSelection * selection,
 		else
 			gtk_tree_selection_select_iter(selection, iter);
 	}
+	if (unexpand)
+		gtk_tree_view_collapse_row(GTK_TREE_VIEW(dive_list.tree_view), tpath);
+}
+
+/* make sure that if we expand a summary row that is selected, the children show
+   up as selected, too */
+void row_expanded_cb(GtkTreeView *tree_view, GtkTreeIter *iter, GtkTreePath *path, gpointer data)
+{
+	GtkTreeSelection *selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(dive_list.tree_view));
+
+	if (gtk_tree_selection_path_is_selected(selection, path))
+		select_children(GTK_TREE_MODEL(dive_list.model), selection, iter, FALSE);
 }
 
 /* this is called _before_ the selection is changed, for every single entry;
@@ -135,6 +226,11 @@ gboolean modify_selection_cb(GtkTreeSelection *selection, GtkTreeModel *model,
 
 	if (gtk_tree_model_get_iter(model, &iter, path)) {
 		gtk_tree_model_get(model, &iter, DIVE_INDEX, &dive_idx, -1);
+		/* turns out we need to move the selectiontracker here */
+		if (was_selected)
+			track_unselect(dive_idx);
+		else
+			track_select(dive_idx);
 		if (dive_idx < 0) {
 			select_children(model, selection, &iter, was_selected);
 		}
@@ -146,49 +242,8 @@ gboolean modify_selection_cb(GtkTreeSelection *selection, GtkTreeModel *model,
 /* this is called when gtk thinks that the selection has changed */
 static void selection_cb(GtkTreeSelection *selection, gpointer userdata)
 {
-	GtkTreeIter iter;
-	GtkTreePath *path;
-
-	int nr_selected = gtk_tree_selection_count_selected_rows(selection);
-
-	if (selected_dives) {
-		g_list_foreach (selected_dives, (GFunc) gtk_tree_path_free, NULL);
-		g_list_free (selected_dives);
-	}
-	selected_dives = gtk_tree_selection_get_selected_rows(selection, NULL);
-	selectiontracker = realloc(selectiontracker, nr_selected * sizeof(int));
-
-	switch (nr_selected) {
-	case 0: /* there is no clear way to figure out which dive to show */
-		amount_selected = 0;
-		selected_dive = -1;
-		return;
-	case 1:	
-		/* just pick that dive as selected */
-		amount_selected = 1;
-		path = g_list_nth_data(selected_dives, 0);
-		if (gtk_tree_model_get_iter(GTK_TREE_MODEL(dive_list.model), &iter, path)) {
-			gtk_tree_model_get(GTK_TREE_MODEL(dive_list.model), &iter, DIVE_INDEX, &selected_dive, -1);
-			/* due to the way this callback gets invoked it is possible that
-			   in the process of unselecting a summary dive we get here with
-			   just one summary dive selected - ignore that case */
-			if (selected_dive < 0) {
-				amount_selected = 0;
-				return;
-			}
-			selectiontracker[0] = selected_dive;
-			repaint_dive();
-		}
-		return;
-	default: /* multiple selections - what now?
-		  * We don't change the selected dive unless there is exactly one dive selected; not sure this
-		  * is the most intuitive solution.
-		  * The dives that have been selected are processed */
-		amount_selected = g_list_length(selected_dives);
-		process_selected_dives(selected_dives, selectiontracker, GTK_TREE_MODEL(dive_list.model));
-		repaint_dive();
-		return;
-	}
+	process_selected_dives(selected_dives, selectiontracker, GTK_TREE_MODEL(dive_list.model));
+	repaint_dive();
 }
 
 const char *star_strings[] = {
@@ -834,8 +889,6 @@ static void fill_dive_list(void)
 		first_leaf(GTK_TREE_MODEL(dive_list.model), &iter, &selected_dive);
 		selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(dive_list.tree_view));
 		gtk_tree_selection_select_iter(selection, &iter);
-		selectiontracker = realloc(selectiontracker, sizeof(int));
-		*selectiontracker = selected_dive;
 	}
 }
 
@@ -1137,6 +1190,7 @@ GtkWidget *dive_list_create(void)
 
 	g_signal_connect_after(dive_list.tree_view, "realize", G_CALLBACK(realize_cb), NULL);
 	g_signal_connect(dive_list.tree_view, "row-activated", G_CALLBACK(row_activated_cb), NULL);
+	g_signal_connect(dive_list.tree_view, "row-expanded", G_CALLBACK(row_expanded_cb), NULL);
 	g_signal_connect(dive_list.tree_view, "button-press-event", G_CALLBACK(button_press_cb), NULL);
 	g_signal_connect(dive_list.tree_view, "popup-menu", G_CALLBACK(popup_menu_cb), NULL);
 	g_signal_connect(selection, "changed", G_CALLBACK(selection_cb), NULL);