Many changes for wxInputHandler creation mainly related to:

1. Allow the theme to create only the input handlers it customizes instead
   of forcing it to always create a handler even if the standard one is used:
   wxTheme::GetInputHandler() now takes wxInputConsumer to make this possible

2. Prefer delegation to inheritance when creating customized input handlers,
   almost all (except for wxStdScrollbarInputHandler) standard handler classes
   are now private, use wxClassName::GetStdInputHandler() to retrieve the
   standard handler for any class or polymorphic DoGetStdInputHandler()


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41227 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/univ/scrolbar.cpp

@@ -589,6 +589,15 @@ bool wxScrollBar::ScrollPages(int nPages)
     return true;
 }
 
+/* static */
+wxInputHandler *wxScrollBar::GetStdInputHandler(wxInputHandler *handlerDef)
+{
+    static wxStdScrollBarInputHandler
+        s_handler(wxTheme::Get()->GetRenderer(), handlerDef);
+
+    return &s_handler;
+}
+
 // ============================================================================
 // scroll bar input handler
 // ============================================================================
@@ -737,7 +746,7 @@ bool wxStdScrollBarInputHandler::HandleMouse(wxInputConsumer *consumer,
 {
     // is this a click event from an acceptable button?
     int btn = event.GetButton();
-    if ( (btn != -1) && IsAllowedButton(btn) )
+    if ( btn == wxMOUSE_BTN_LEFT )
     {
         // determine which part of the window mouse is in
         wxScrollBar *scrollbar = wxStaticCast(consumer->GetInputWindow(), wxScrollBar);