Add better support for default ListColumn values

lethosor · lethosor · commit 97fb50c28f8a · 2016-01-06T17:30:07.000-05:00
This is only necessary for multiple-selection columns, and there aren't any
with non-pointer entry types currently, but casting nullptr to non-pointer types
isn't a great idea.
diff --git a/plugins/listcolumn.h b/plugins/listcolumn.h
@@ -35,8 +35,9 @@ class ListColumn
     bool allow_search;
     bool feed_mouse_set_highlight;
     bool feed_changed_highlight;
+    T default_value;
 
-    ListColumn()
+    ListColumn(const T default_value_ = T())
     {
         bottom_margin = 3;
         clear();
@@ -50,6 +51,7 @@ class ListColumn
         allow_search = true;
         feed_mouse_set_highlight = false;
         feed_changed_highlight = false;
+        default_value = default_value_;
     }
 
     void clear()
@@ -310,7 +312,7 @@ class ListColumn
     {
         vector<T> results = getSelectedElems(true);
         if (results.size() == 0)
-            return (T)nullptr;
+            return default_value;
         else
             return results[0];
     }

Original file line number	Diff line number	Diff line change
`@@ -35,8 +35,9 @@ class ListColumn`
`35`	`35`	`bool allow_search;`
`36`	`36`	`bool feed_mouse_set_highlight;`
`37`	`37`	`bool feed_changed_highlight;`
	`38`	`+ T default_value;`
`38`	`39`
`39`		`- ListColumn()`
	`40`	`+ ListColumn(const T default_value_ = T())`
`40`	`41`	`{`
`41`	`42`	`bottom_margin = 3;`
`42`	`43`	`clear();`
`@@ -50,6 +51,7 @@ class ListColumn`
`50`	`51`	`allow_search = true;`
`51`	`52`	`feed_mouse_set_highlight = false;`
`52`	`53`	`feed_changed_highlight = false;`
	`54`	`+ default_value = default_value_;`
`53`	`55`	`}`
`54`	`56`
`55`	`57`	`void clear()`
`@@ -310,7 +312,7 @@ class ListColumn`
`310`	`312`	`{`
`311`	`313`	`vector<T> results = getSelectedElems(true);`
`312`	`314`	`if (results.size() == 0)`
`313`		`- return (T)nullptr;`
	`315`	`+ return default_value;`
`314`	`316`	`else`
`315`	`317`	`return results[0];`
`316`	`318`	`}`