Allow multiple selections in the dive list

At this point we don't do anything with this - the commit just provides
the infrastructure changes so that this becomes possible. Subsurface
behaves the same if exactly one dive is selected and simply keeps the last
selected dive if zero or more than one dives are selected.

The goal is to be able to select multiple dives and then do actions on
them. For example pick a tank used for all of them. Or edit the location
or (yet to be implemented) other equipment data like weight carried.
And also to be able to merge multiple dives.

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

1 files changed, 31 insertions, 6 deletions

diff --git a/divelist.c b/divelist.c
index 1cc76b38a..5f2063e9f 100644
--- a/divelist.c
+++ b/divelist.c
@@ -50,17 +50,42 @@ enum {
 	DIVELIST_COLUMNS
 };
 
+static GList *selected_dives;
+
 static void selection_cb(GtkTreeSelection *selection, GtkTreeModel *model)
 {
 	GtkTreeIter iter;
 	GValue value = {0, };
+	GtkTreePath *path;
 
-	if (!gtk_tree_selection_get_selected(selection, NULL, &iter))
-		return;
+	int nr_selected = gtk_tree_selection_count_selected_rows(selection);
 
-	gtk_tree_model_get_value(model, &iter, DIVE_INDEX, &value);
-	selected_dive = g_value_get_int(&value);
-	repaint_dive();
+	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);
+
+	switch (nr_selected) {
+	case 0: /* keep showing the last selected dive */
+		return;
+	case 1:	
+		/* just pick that dive as selected */
+		path = g_list_nth_data(selected_dives, 0);
+		if (gtk_tree_model_get_iter(model, &iter, path)) {
+			gtk_tree_model_get_value(model, &iter, DIVE_INDEX, &value);
+			selected_dive = g_value_get_int(&value);
+			repaint_dive();
+		}
+		return;
+	default: /* multiple selections - what now? At this point I
+		  * don't want to change the selected dive unless
+		  * there is exactly one dive selected; not sure this
+		  * is the most intuitive solution.
+		  * I do however want to keep around which dives have
+		  * been selected */
+		return;
+	}
 }
 
 static void date_data_func(GtkTreeViewColumn *col,
@@ -505,7 +530,7 @@ GtkWidget *dive_list_create(void)
 
 	selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(dive_list.tree_view));
 
-	gtk_tree_selection_set_mode(GTK_TREE_SELECTION(selection), GTK_SELECTION_BROWSE);
+	gtk_tree_selection_set_mode(GTK_TREE_SELECTION(selection), GTK_SELECTION_MULTIPLE);
 	gtk_widget_set_size_request(dive_list.tree_view, 200, 200);
 
 	dive_list.date = divelist_column(&dive_list, DIVE_DATE, "Date", date_data_func, PANGO_ALIGN_LEFT, TRUE);