[PATCH] wpa_gui-qt4: improve scan results signal display

[Kel Modderman]

Display signal strength in dBm with visual indicator in the form
of a bar for scan results displayed by wpa_gui-qt4. Any signal > -35dBm is
treated as full signal bar, signals between range of -95<->-35dBm are
displayed linearly. Convert WEXT signal level value to scale that nl80211
typically reports in dBm. The condition which differentiates 8-bit WEXT dBm
and regular dBm is probably fragile, but there is currently no way to know
what the driver is going to report for signal strength.

This patch is tested with 0.7.3 and also applies to hostapd.git

See also:
 http://mail.gnome.org/archives/networkmanager-list/2009-November/msg00003.html
 http://lists.shmoo.com/pipermail/hostap/2009-April/019682.html

Signed-off-by: Kel Modderman <kel at otaku42.de>
---
--- a/wpa_supplicant/wpa_gui-qt4/scanresults.cpp
+++ b/wpa_supplicant/wpa_gui-qt4/scanresults.cpp
@@ -15,6 +15,7 @@
 #include <cstdio>
 
 #include "scanresults.h"
+#include "signalbar.h"
 #include "wpagui.h"
 #include "networkconfig.h"
 
@@ -33,6 +34,7 @@ ScanResults::ScanResults(QWidget *parent
 	wpagui = NULL;
 	scanResultsWidget->setItemsExpandable(FALSE);
 	scanResultsWidget->setRootIsDecorated(FALSE);
+	scanResultsWidget->setItemDelegate(new SignalBar(scanResultsWidget));
 }
 
 
@@ -91,7 +93,7 @@ void ScanResults::updateResults()
 				bssid = (*it).mid(pos);
 			else if ((*it).startsWith("freq="))
 				freq = (*it).mid(pos);
-			else if ((*it).startsWith("qual="))
+			else if ((*it).startsWith("level="))
 				signal = (*it).mid(pos);
 			else if ((*it).startsWith("flags="))
 				flags = (*it).mid(pos);
--- /dev/null
+++ b/wpa_supplicant/wpa_gui-qt4/signalbar.h
@@ -0,0 +1,34 @@
+/*
+ * wpa_gui - SignalBar class
+ * Copyright (c) 2011, Kel Modderman <kel at otaku42.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#ifndef SIGNALBAR_H
+#define SIGNALBAR_H
+
+#include <QObject>
+#include <QStyledItemDelegate>
+
+class SignalBar : public QStyledItemDelegate
+{
+	Q_OBJECT
+
+public:
+	SignalBar(QObject *parent = 0);
+	~SignalBar();
+
+	virtual void paint(QPainter *painter,
+			   const QStyleOptionViewItem &option,
+			   const QModelIndex &index) const ;
+};
+
+#endif /* SIGNALBAR_H */
--- /dev/null
+++ b/wpa_supplicant/wpa_gui-qt4/signalbar.cpp
@@ -0,0 +1,64 @@
+/*
+ * wpa_gui - SignalBar class
+ * Copyright (c) 2011, Kel Modderman <kel at otaku42.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include <cstdio>
+#include <qapplication.h>
+
+#include "signalbar.h"
+
+
+SignalBar::SignalBar(QObject *parent)
+	: QStyledItemDelegate(parent)
+{
+}
+
+
+SignalBar::~SignalBar()
+{
+}
+
+
+void SignalBar::paint(QPainter *painter,
+		      const QStyleOptionViewItem &option,
+		      const QModelIndex &index) const
+{
+	QStyleOptionProgressBar opts;
+	int signal;
+
+	if (index.column() != 3) {
+		QStyledItemDelegate::paint(painter, option, index);
+		return;
+	}
+
+	if (index.data().toInt() > 0)
+		signal = 0 - (256 - index.data().toInt());
+	else
+		signal = index.data().toInt();
+
+	opts.minimum = -95;
+	opts.maximum = -35;
+	if (signal < opts.minimum)
+		opts.progress = opts.minimum;
+	else if (signal > opts.maximum)
+		opts.progress = opts.maximum;
+	else
+		opts.progress = signal;
+
+	opts.text = QString::number(signal) + " dBm";
+	opts.textVisible = true;
+	opts.rect = option.rect;
+
+	QApplication::style()->drawControl(QStyle::CE_ProgressBar,
+					   &opts, painter);
+}
--- a/wpa_supplicant/wpa_gui-qt4/wpa_gui.pro
+++ b/wpa_supplicant/wpa_gui-qt4/wpa_gui.pro
@@ -34,6 +34,7 @@ HEADERS	+= wpamsg.h \
 	wpagui.h \
 	eventhistory.h \
 	scanresults.h \
+	signalbar.h \
 	userdatarequest.h \
 	networkconfig.h \
 	addinterface.h \
@@ -44,6 +45,7 @@ SOURCES	+= main.cpp \
 	wpagui.cpp \
 	eventhistory.cpp \
 	scanresults.cpp \
+	signalbar.cpp \
 	userdatarequest.cpp \
 	networkconfig.cpp \
 	addinterface.cpp \