Reduce number of allocations for menu creation

Every time either the Slit menu or the Toolbar menu were added to the
root menu, the whole root menu was (re)created from scratch. Now we
create and remove only the menus needed.

Side effect: the position of these menus is now at the end of the root
menu and not somewhere in between. If users complaint, I' ll think about
it.

2 files changed, 29 insertions, 7 deletions

diff --git a/src/FbTk/Menu.cc b/src/FbTk/Menu.cc
index 4dbb48c..8dddc16 100644
--- a/src/FbTk/Menu.cc
+++ b/src/FbTk/Menu.cc
@@ -91,6 +91,12 @@ Menu* s_focused = 0; // holds currently focused menu
 Menu* Menu::shownMenu() { return s_shown; }
 Menu* Menu::focused() { return s_focused; }
 
+void Menu::hideShownMenu() {
+    if (s_shown)
+        s_shown->hide();
+}
+
+
 Menu::Menu(FbTk::ThemeProxy<MenuTheme> &tm, ImageControl &imgctrl):
     m_theme(tm),
     m_parent(0),
@@ -240,6 +246,18 @@ int Menu::insertItem(MenuItem *item, int pos) {
     return m_items.size();
 }
 
+
+int Menu::findSubmenuIndex(const FbTk::Menu* submenu) const {
+    size_t i;
+    for (i = 0; i < m_items.size(); i++) {
+        if (m_items[i]->submenu() == submenu) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+
 void Menu::fixMenuItemIndices() {
     for (size_t i = 0; i < m_items.size(); i++)
         m_items[i]->setIndex(i);
@@ -1391,9 +1409,5 @@ void Menu::drawLine(int index, int size){
     item->drawLine(m_frame, theme(), size, item_x, item_y, m_item_w);
 }
 
-void Menu::hideShownMenu() {
-    if (s_shown)
-        s_shown->hide();
-}
 
 } // end namespace FbTk
diff --git a/src/FbTk/Menu.hh b/src/FbTk/Menu.hh
index 49893c1..27d5b12 100644
--- a/src/FbTk/Menu.hh
+++ b/src/FbTk/Menu.hh
@@ -45,6 +45,12 @@ template <typename T> class RefCount;
 ///   Base class for menus
 class Menu: public FbTk::EventHandler, FbTk::FbWindowRenderer {
 public:
+
+    static Menu* shownMenu();
+    static Menu* focused();
+    static void hideShownMenu();
+
+
     enum Alignment{ ALIGNDONTCARE = 1, ALIGNTOP, ALIGNBOTTOM };
     enum { RIGHT = 1, LEFT };
 
@@ -134,11 +140,13 @@ public:
     FbTk::ThemeProxy<MenuTheme> &theme() { return m_theme; }
     const FbTk::ThemeProxy<MenuTheme> &theme() const { return m_theme; }
     unsigned char alpha() const { return theme()->alpha(); }
-    static Menu* shownMenu();
-    static Menu* focused();
-    static void hideShownMenu();
     const MenuItem *find(size_t i) const { return m_items[i]; }
     MenuItem *find(size_t i) { return m_items[i]; }
+
+    // returns index of 'submenu', it it is in the top most list of
+    // menu items. -1 if no match is found
+    int findSubmenuIndex(const Menu* submenu) const;
+
     //@}
     /// @return true if index is valid
     bool validIndex(int index) const { return (index < static_cast<int>(numberOfItems()) && index >= 0); }