add CListHelpers class

this can be used to factor out duplicate code implementations
from all the various channel-, bouquet-, eventlists etc...

src/gui/widget/Makefile.am

@@ -25,6 +25,7 @@ libneutrino_gui_widget_a_SOURCES = \
 	keyboard_input.cpp \
 	listbox.cpp \
 	listframe.cpp \
+	listhelpers.cpp \
 	menue.cpp \
 	messagebox.cpp \
 	mountchooser.cpp \

src/gui/widget/listhelpers.cpp

@@ -0,0 +1,71 @@
+/*
+	Helper functions for various list implementations in neutrino
+	Copyright (C) 2016 Stefan Seyfried
+
+	License: GPL
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, see http://www.gnu.org/licenses/
+*/
+
+#include <driver/rcinput.h>
+#include "listhelpers.h"
+
+#include <global.h>
+#include <gui/bouquetlist.h>
+
+template <class T> int CListHelpers::UpDownKey(T list, neutrino_msg_t msg, int lines, int sel)
+{
+	int step;
+	if (list.empty())
+		return -1;
+
+	if (msg >= CRCInput::RC_MaxRC) {
+		printf("CListHelpers:%s: invalid key? 0x%lx\n", __func__, msg);
+		return -1;
+	}
+	int key = (int)msg;
+	if (key == g_settings.key_pageup)
+		step = -lines;
+	else if (key == g_settings.key_pagedown)
+		step = lines;
+	else if (msg == CRCInput::RC_up)
+		step = -1;
+	else if (msg == CRCInput::RC_down)
+		step = 1;
+	else {
+		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) {
+		if (sel != 0 && step != 1)
+			new_sel = 0;
+		else
+			new_sel = size - 1;
+	}
+	else if (new_sel > size - 1) {
+		if (sel != size - 1)
+			new_sel = size - 1;
+		else
+			new_sel = 0;
+	}
+	return new_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);

src/gui/widget/listhelpers.h

@@ -0,0 +1,30 @@
+/*
+	Helper functions for various list implementations in neutrino
+	Copyright (C) 2016 Stefan Seyfried
+
+	License: GPL
+
+	This program is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, see http://www.gnu.org/licenses/
+*/
+
+
+#ifndef __LISTHELPERS__
+#define __LISTHELPERS__
+
+class CListHelpers
+{
+	public:
+		template <class T> int UpDownKey(T list, neutrino_msg_t k, int lines, int sel);
+};
+#endif