From 57f20fcbb78c23ec9833e18efb524b5239db7c98 Mon Sep 17 00:00:00 2001
From: Stefan Seyfried <seife@tuxbox-git.slipkontur.de>
Date: Sat, 16 Jan 2016 17:48:30 +0100
Subject: [PATCH] CListHelpers: allow UpDownKey with int type, too

---
 src/gui/widget/listhelpers.cpp | 25 ++++++++++++++++++-------
 src/gui/widget/listhelpers.h   | 10 +++++++++-
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/gui/widget/listhelpers.cpp b/src/gui/widget/listhelpers.cpp
index 7ad2e1cec..c06c3504f 100644
--- a/src/gui/widget/listhelpers.cpp
+++ b/src/gui/widget/listhelpers.cpp
@@ -24,10 +24,10 @@
 #include <global.h>
 #include <gui/bouquetlist.h>
 
-template <class T> int CListHelpers::UpDownKey(T list, neutrino_msg_t msg, int lines, int sel)
+static int upDownKey(int size, neutrino_msg_t msg, int lines, int sel)
 {
 	int step;
-	if (list.empty())
+	if (size <= 0) /* list.empty() or similar... */
 		return -1;
 
 	if (msg >= CRCInput::RC_MaxRC) {
@@ -47,7 +47,6 @@ template <class T> int CListHelpers::UpDownKey(T list, neutrino_msg_t msg, int l
 		printf("CListHelpers:%s: invalid key? 0x%lx\n", __func__, msg);
 		return -1;
 	}
-	int size = (int)list.size(); /* bigger than 0, because we checked for empty() before */
 	// printf("CListHelpers:%s: key 0x%04lx lines %d size %d sel %d\n", __func__, msg, lines, size, sel);
 	int new_sel = sel + step;
 	if (new_sel < 0) {
@@ -65,8 +64,20 @@ template <class T> int CListHelpers::UpDownKey(T list, neutrino_msg_t msg, int l
 	return new_sel;
 }
 
+int CListHelpers::_UpDownKey(int size, neutrino_msg_t msg, int lines, int sel, _id<int>)
+{
+	return upDownKey(size, msg, lines, sel);
+}
+
+template <typename T> int CListHelpers::_UpDownKey(T list, neutrino_msg_t msg, int lines, int sel, _id<T>)
+{
+	return upDownKey(list.size(), msg, lines, sel);
+}
+
 /* all used versions need to be prototyped here, to avoid linker errors */
-template int CListHelpers::UpDownKey<std::vector<CBouquet*> >(std::vector<CBouquet*>, neutrino_msg_t, int, int);
-template int CListHelpers::UpDownKey<std::vector<CZapitBouquet*> >(std::vector<CZapitBouquet*>, neutrino_msg_t, int, int);
-template int CListHelpers::UpDownKey<std::vector<CZapitChannel*> >(std::vector<CZapitChannel*>, neutrino_msg_t, int, int);
-template int CListHelpers::UpDownKey<std::vector<CChannelEvent> >(std::vector<CChannelEvent>, neutrino_msg_t, int, int);
+/* helper macro for the prototypes */
+#define updown_t(x) template int CListHelpers::_UpDownKey<x >(x, neutrino_msg_t, int, int, _id<x >)
+updown_t(std::vector<CBouquet*>);
+updown_t(std::vector<CZapitBouquet*>);
+updown_t(std::vector<CZapitChannel*>);
+updown_t(std::vector<CChannelEvent>);
diff --git a/src/gui/widget/listhelpers.h b/src/gui/widget/listhelpers.h
index 4ac2274cc..228bd88d7 100644
--- a/src/gui/widget/listhelpers.h
+++ b/src/gui/widget/listhelpers.h
@@ -21,10 +21,18 @@
 
 #ifndef __LISTHELPERS__
 #define __LISTHELPERS__
+/* allow to trick the compiler into overriding template definitions */
+template<typename T> struct _id { typedef T type; };
 
 class CListHelpers
 {
 	public:
-		template <class T> int UpDownKey(T list, neutrino_msg_t k, int lines, int sel);
+		template <typename T> int UpDownKey(T list, neutrino_msg_t k, int lines, int sel) {
+			return _UpDownKey(list, k, lines, sel, _id<T>());
+		}
+	private:
+		/* stackoverflow.com/questions/3052579 */
+		template <typename T> int _UpDownKey(T list, neutrino_msg_t k, int lines, int sel, _id<T>);
+		int _UpDownKey(int list, neutrino_msg_t k, int lines, int sel, _id<int>);
 };
 #endif