a bit better drawing of a key fingerprint

ui/widgets/vcard/omemo/keydelegate.cpp

@@ -22,10 +22,15 @@
 
 constexpr int minHeight = 50;
 constexpr int minWidth = 400;
+constexpr uint8_t margin = 10;
+constexpr uint8_t partSize = 8;
+constexpr uint8_t maxSingleLineParts = 3;
 
 UI::KeyDelegate::KeyDelegate(QObject* parent):
     QStyledItemDelegate(parent),
-    fingerPrintFont(QFontDatabase::systemFont(QFontDatabase::FixedFont))
+    fingerPrintFont(QFontDatabase::systemFont(QFontDatabase::FixedFont)),
+    fingerPrintMetrics(fingerPrintFont),
+    spaceWidth(fingerPrintMetrics.horizontalAdvance(" "))
 {
 }
 
@@ -46,14 +51,31 @@ void UI::KeyDelegate::paint(QPainter* painter, const QStyleOptionViewItem& optio
     QVariant fingerPrintV = index.data(UI::KeysModel::FingerPrint);
     if (fingerPrintV.isValid()) {
         painter->save();
-        QByteArray fingerPrint = fingerPrintV.toByteArray();
-
         painter->setFont(fingerPrintFont);
-        painter->drawText(option.rect, option.displayAlignment | Qt::AlignTop, fingerPrint.toHex());
+        QByteArray fingerPrint = fingerPrintV.toByteArray();
+        std::vector<QString> parts = getParts(fingerPrint);
+        uint8_t partsLength = parts.size();
+        QRect rect = option.rect;
+        rect.adjust(margin, margin, 0, 0);
+        QRect r;
+        uint8_t firstLine;
+        if (partsLength > maxSingleLineParts)
+            firstLine = partsLength / 2 + partsLength % 2;
+        else
+            firstLine = partsLength;
+
+        for (uint8_t i = 0; i < partsLength; ++i) {
+            if (i == firstLine) {
+                rect.setLeft(option.rect.left() + margin);
+                rect.adjust(0, r.height() + fingerPrintMetrics.leading(), 0, 0);
+            }
+            painter->drawText(rect, Qt::AlignLeft | Qt::AlignTop, parts[i], &r);
+            rect.adjust(r.width() + spaceWidth ,0, 0, 0);
+        }
 
         painter->restore();
     }
-    painter->drawText(option.rect, option.displayAlignment, index.data().toString());
+    //painter->drawText(option.rect, option.displayAlignment, index.data().toString());
 
     painter->restore();
 }
@@ -61,11 +83,50 @@ void UI::KeyDelegate::paint(QPainter* painter, const QStyleOptionViewItem& optio
 QSize UI::KeyDelegate::sizeHint(const QStyleOptionViewItem& option, const QModelIndex& index) const {
     QSize size = QStyledItemDelegate::sizeHint(option, index);
 
-    if (size.width() < minWidth)
+    int mh = margin * 2;
-        size.setWidth(minWidth);
+    int mw = margin * 2;
+    QVariant fingerPrintV = index.data(UI::KeysModel::FingerPrint);
+    if (fingerPrintV.isValid()) {
+        QString hex = fingerPrintV.toByteArray().toHex();
+        uint8_t parts = hex.size() / partSize;
 
-    if (size.height() < minHeight)
+        mh += fingerPrintMetrics.height();
-        size.setHeight(minHeight);
+        if (parts > maxSingleLineParts) {
+            mh += fingerPrintMetrics.height() + fingerPrintMetrics.leading();
+        }
+
+        uint8_t firstLine;
+        if (parts > maxSingleLineParts)
+            firstLine = parts / 2 + parts % 2;
+        else
+            firstLine = parts;
+
+        mw += firstLine * partSize * spaceWidth + (firstLine - 1) * spaceWidth;
+    }
+
+
+    if (size.width() < mw)
+        size.setWidth(mw);
+
+    if (size.height() < mh)
+        size.setHeight(mh);
 
     return size;
 }
+
+std::vector<QString> UI::KeyDelegate::getParts(const QByteArray& data) {
+    QString hex = data.toHex();
+    uint8_t parts = hex.size() / partSize;
+    std::vector<QString> result(parts);
+    for (uint8_t i = 0; i < parts; ++i) {
+        uint16_t index = i * partSize;
+        uint8_t length = partSize;
+        if (index + length > hex.size())
+            length = hex.size() - index;
+        QStringRef part(&hex, index, length);
+        result[i] = part.toString();
+    }
+
+    return result;
+}
+

ui/widgets/vcard/omemo/keydelegate.h

@@ -18,6 +18,8 @@
 #define UI_KEYDELEGATE_H
 
 #include <QStyledItemDelegate>
+#include <QString>
+#include <vector>
 
 namespace UI {
 
@@ -32,6 +34,11 @@ public:
 
 private:
     QFont fingerPrintFont;
+    QFontMetrics fingerPrintMetrics;
+    int spaceWidth;
+
+private:
+    static std::vector<QString> getParts(const QByteArray& data);
 };
 
 }