bugfix: consistent use of 'int' for alpha values (#3187373)

WindowMenuAccessor returned strange alpha values if compiled
with 'g++ -Os'; unholy black magic happens if template<int> faces
functions returning only 'usigned char'.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/FbTk/Container.cc b/src/FbTk/Container.cc
index e1d2e07..b944c98 100644
--- a/src/FbTk/Container.cc
+++ b/src/FbTk/Container.cc
@@ -440,7 +440,7 @@ void Container::for_each(std::mem_fun_t<void, FbWindow> function) {
     std::for_each(begin(), end(), function);
 }
 
-void Container::setAlpha(unsigned char alpha) {
+void Container::setAlpha(int alpha) {
     FbWindow::setAlpha(alpha);
     STLUtil::forAll(m_item_list, std::bind2nd(std::mem_fun(&Button::setAlpha), alpha));
 }