refs #452, misc. functions for pixmap and hex value handling

src/blackmisc/blackmiscfreefunctions.cpp

@@ -357,3 +357,86 @@ bool BlackMisc::stringToBool(const QString &string)
     if (c == '0' || c == 'f' || c == 'n' || c == ' ') { return false; }
     return false;
 }
+
+QString BlackMisc::intToHex(int value, int digits)
+{
+    QString hex(QString::number(value, 16).toUpper());
+    int l = hex.length();
+    if (l >= digits) { return hex.right(digits); }
+    int d = digits - l;
+    return QString(d, '0') + hex;
+}
+
+bool BlackMisc::pixmapToPngByteArray(const QPixmap &pixmap, QByteArray &array)
+{
+    QBuffer buffer(&array);
+    buffer.open(QIODevice::WriteOnly);
+    bool s = pixmap.save(&buffer, "PNG");
+    buffer.close();
+    return s;
+}
+
+QString BlackMisc::bytesToHexString(const QByteArray &bytes)
+{
+    QString h;
+    for (int i = 0; i < bytes.size(); i++)
+    {
+        h.append(static_cast<int>(bytes.at(i)));
+    }
+    return h;
+}
+
+QByteArray BlackMisc::byteArrayFromHexString(const QString &hexString)
+{
+    QByteArray ba;
+    int pos = 0;
+    while (pos + 1 < hexString.length())
+    {
+        bool ok;
+        QString h = hexString.mid(pos, 2);
+        int hex = h.toInt(&ok, 16);
+        Q_ASSERT_X(ok, Q_FUNC_INFO, "Invalid hex");
+        if (!ok) { return QByteArray(); }
+        ba.push_back(static_cast<char>(hex));
+        pos += 2;
+    }
+    return ba;
+}
+
+QPixmap BlackMisc::pngByteArrayToPixmap(const QByteArray &array)
+{
+    if (array.isEmpty()) { return QPixmap(); }
+    QPixmap p;
+    bool s = p.loadFromData(array, "PNG");
+    return s ? p : QPixmap();
+}
+
+bool BlackMisc::pngByteArrayToPixmapRef(const QByteArray &array, QPixmap &pixmap)
+{
+    if (array.isEmpty()) { return false; }
+    bool s = pixmap.loadFromData(array, "PNG");
+    return s;
+}
+
+
+QString BlackMisc::pixmapToPngHexString(const QPixmap &pixmap)
+{
+    QByteArray ba;
+    bool s = pixmapToPngByteArray(pixmap, ba);
+    if (!s) { return QString(); }
+    return bytesToHexString(ba);
+}
+
+QPixmap BlackMisc::pngHexStringToPixmap(const QString &hexString)
+{
+    if (hexString.isEmpty()) { return QPixmap(); }
+    QByteArray ba(byteArrayFromHexString(hexString));
+    return pngByteArrayToPixmap(ba);
+}
+
+bool BlackMisc::pngHexStringToPixmapRef(const QString &hexString, QPixmap &pixmap)
+{
+    if (hexString.isEmpty()) { return false; }
+    QByteArray ba(byteArrayFromHexString(hexString));
+    return pngByteArrayToPixmapRef(ba, pixmap);
+}

src/blackmisc/blackmiscfreefunctions.h

@@ -35,6 +35,11 @@ inline void initBlackMiscResources()
     // cannot be declared within namespace, see docu
     // hence BlackMisc::initResources() calls this inline function
     Q_INIT_RESOURCE(blackmisc);
+
+    // set seed for random number if ever used
+    // that is needed only once on application startup
+    QTime time = QTime::currentTime();
+    qsrand((uint)time.msec());
 }
 
 //! Free functions in BlackMisc
@@ -328,6 +333,33 @@ namespace BlackMisc
     //! Merges an incremental json object into an existing one
     BLACKMISC_EXPORT QJsonObject applyIncrementalObject(const QJsonObject &previousObject, const QJsonObject &incrementalObject);
 
+    //! Int to hex value
+    BLACKMISC_EXPORT QString intToHex(int value, int digits = 2);
+
+    //! Int to hex value (per byte, 2 digits)
+    BLACKMISC_EXPORT QString bytesToHexString(const QByteArray &bytes);
+
+    //! Byte array from hex value string per byte, 2 digits
+    BLACKMISC_EXPORT QByteArray byteArrayFromHexString(const QString &hexString);
+
+    //! Pixmap to PNG byte array
+    BLACKMISC_EXPORT bool pixmapToPngByteArray(const QPixmap &pixmap, QByteArray &array);
+
+    //! Pixmap from PNG byte array
+    BLACKMISC_EXPORT QPixmap pngByteArrayToPixmap(const QByteArray &array);
+
+    //! Pixmap from PNG byte array
+    BLACKMISC_EXPORT bool pngByteArrayToPixmapRef(const QByteArray &array, QPixmap &pixmap);
+
+    //! Pixmap as HEX string (for PNG image)
+    BLACKMISC_EXPORT QString pixmapToPngHexString(const QPixmap &pixmap);
+
+    //! Hex encoded pixmap string to Pixmap
+    BLACKMISC_EXPORT QPixmap pngHexStringToPixmap(const QString &hexString);
+
+    //! Hex encoded pixmap string to Pixmap
+    BLACKMISC_EXPORT bool pngHexStringToPixmapRef(const QString &hexString, QPixmap &pixmap);
+
 } // BlackMisc
 
 #endif // guard