From: Drew Fisher <drew.m.fisher@gmail.com>
Date: Thu, 7 Oct 2010 20:28:50 +0000 (-0700)
Subject: Implement base64 encoding and decoding, so we can serialize images.
X-Git-Url: http://git.zarvox.org/shortlog/static/%7B%7B%20url_for%28%27main.signup_page%27%29%20%7D%7D?a=commitdiff_plain;h=65963cf96b801fc8d4322de69d142ca03d16b712;p=shareboard.git

Implement base64 encoding and decoding, so we can serialize images.
---

diff --git a/base64.cpp b/base64.cpp
new file mode 100644
index 0000000..a4fa948
--- /dev/null
+++ b/base64.cpp
@@ -0,0 +1,74 @@
+
+#include <QString>
+#include <QByteArray>
+#include <QDebug>
+#include <Qt>
+
+static QString keystring = QString("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");
+
+QString toBase64(QByteArray binary) {
+	QString retval;
+	int i;
+	int pad = binary.size() % 3;
+	for(i = 0; i < binary.size(); i+=3) {
+		quint8 a = 0;
+		quint8 b = 0;
+		quint8 c = 0;
+		a = binary[i];
+		retval.append(keystring[(a & 0xfc) >> 2 ]);
+		if( i+1 < binary.size()) {
+			b = binary[i+1];
+			quint8 idex = ((a & 0x03) << 4) |  ((b & 0xf0) >> 4);
+			retval.append(keystring[idex]);
+			if (i+2 == binary.size()) {
+				retval.append(keystring[(b & 0x0f) << 2]);
+			}
+		} else {
+			retval.append(keystring[(a & 0x03) << 4]);
+			break;
+		}
+		if( i+2 < binary.size()) {
+			c = binary[i+2];
+			quint8 idex = ((b & 0x0f) << 2) | ((c & 0xc0) >> 6);
+			retval.append(keystring[idex]);
+			retval.append(keystring[c & 0x3f]);
+		}
+	}
+	if(pad == 1)
+		retval.append("==");
+	if(pad == 2)
+		retval.append("=");
+	return retval;
+}
+
+QByteArray fromBase64(QString text) {
+	QByteArray retval;
+	if( text.size() % 4 != 0)
+		return retval;
+	for(int i = 0; i < text.size(); i+=4) {
+		quint8 idex1 = static_cast<quint8>(keystring.indexOf(text[i])); // Something between 0 and 63
+		quint8 idex2 = static_cast<quint8>(keystring.indexOf(text[i+1]));
+		quint8 idex3 = static_cast<quint8>(keystring.indexOf(text[i+2]));
+		quint8 idex4 = static_cast<quint8>(keystring.indexOf(text[i+3]));
+		retval.append( ((idex1 << 2) | ((idex2 & 0x30) >> 4))) ;
+		if(text[i+2] == '=')
+			return retval;
+		retval.append( ((idex2 & 0x0f) << 4) | ((idex3 & 0x3c) >> 2)  ) ;
+		if(text[i+3] == '=')
+			return retval;
+		retval.append( ((idex3 & 0x03) << 6) | (idex4)  ) ;
+
+	}
+	return retval;
+}
+
+/*
+ * Yay, unit tests.
+int main(void) {
+	QByteArray test = QByteArray("Texas!");
+	qDebug() << test;
+	qDebug() << toBase64(test);
+	qDebug() << fromBase64(toBase64(test));
+	return 0;
+}
+*/
diff --git a/base64.h b/base64.h
new file mode 100644
index 0000000..b57ddb6
--- /dev/null
+++ b/base64.h
@@ -0,0 +1,9 @@
+#ifndef __BASE64_H__
+#define __BASE64_H__
+#include <QString>
+#include <QByteArray>
+
+QString toBase64(QByteArray binary);
+QByteArray fromBase64(QString text);
+
+#endif // __BASE64_H__
diff --git a/shareboard.pro b/shareboard.pro
index 7a3909b..8ffb581 100644
--- a/shareboard.pro
+++ b/shareboard.pro
@@ -10,5 +10,5 @@ DEPENDPATH += .
 INCLUDEPATH += .
 
 # Input
-HEADERS += mainwindow.h action.h connectwidget.h connectionmanager.h shareboard.h shareboardcanvas.h
-SOURCES += main.cpp mainwindow.cpp action.cpp connectwidget.cpp connectionmanager.cpp shareboard.cpp shareboardcanvas.cpp
+HEADERS += mainwindow.h action.h connectwidget.h connectionmanager.h shareboard.h shareboardcanvas.h base64.h
+SOURCES += main.cpp mainwindow.cpp action.cpp connectwidget.cpp connectionmanager.cpp shareboard.cpp shareboardcanvas.cpp base64.cpp