Qt: Allow Drag-and-drop on info and protocol

Allow for drag-and-drop on info and protocol columns. Protocol columns
may also be dragged to the display filter, everything else is dragged
as plain-text and can just be used as text

Change-Id: I0fff390580c22175efe50037b18d7199949fd8eb
Reviewed-on: https://code.wireshark.org/review/33621
Petri-Dish: Roland Knall <rknall@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Roland Knall <rknall@gmail.com>

ui/qt/packet_list.cpp

@@ -658,24 +658,53 @@ void PacketList::mouseMoveEvent (QMouseEvent *event)
     if ( event->buttons() & Qt::LeftButton )
     {
         QModelIndex curIndex = indexAt(event->pos());
+
         ctx_column_ = curIndex.column();
+        QMimeData * mimeData = nullptr;
+        QWidget * content = nullptr;
+
         QString filter = getFilterFromRowAndColumn();
-        if ( ! filter.isEmpty() )
+        if ( ! filter.isEmpty() || get_column_format(curIndex.column()) == COL_PROTOCOL)
         {
-            QString abbrev = filter.left(filter.indexOf(' '));
+            QString abbrev;
             QString name = model()->headerData(ctx_column_, header()->orientation()).toString();
 
-            DisplayFilterMimeData * dfmd =
-                    new DisplayFilterMimeData(name, abbrev, filter);
-            QDrag * drag = new QDrag(this);
-            drag->setMimeData(dfmd);
+            if ( ! filter.isEmpty() )
+            {
+                abbrev = filter.left(filter.indexOf(' '));
+            }
+            else
+            {
+                filter = model()->data(curIndex).toString().toLower();
+                abbrev = filter;
+            }
 
-            DragLabel * content = new DragLabel(dfmd->labelText(), this);
-            qreal dpr = window()->windowHandle()->devicePixelRatio();
-            QPixmap pixmap(content->size() * dpr);
-            pixmap.setDevicePixelRatio(dpr);
-            content->render(&pixmap);
-            drag->setPixmap(pixmap);
+            mimeData = new DisplayFilterMimeData(name, abbrev, filter);
+            ((DisplayFilterMimeData *)mimeData)->allowPlainText();
+            content = new DragLabel(((DisplayFilterMimeData *)mimeData)->labelText(), this);
+        }
+        else
+        {
+            QString text = model()->data(curIndex).toString();
+            if ( ! text.isEmpty() )
+            {
+                mimeData = new QMimeData();
+                mimeData->setText(text);
+            }
+        }
+
+        if ( mimeData )
+        {
+            QDrag * drag = new QDrag(this);
+            drag->setMimeData(mimeData);
+            if ( content )
+            {
+                qreal dpr = window()->windowHandle()->devicePixelRatio();
+                QPixmap pixmap= QPixmap(content->size() * dpr);
+                pixmap.setDevicePixelRatio(dpr);
+                content->render(&pixmap);
+                drag->setPixmap(pixmap);
+            }
 
             drag->exec(Qt::CopyAction);
         }

ui/qt/utils/wireshark_mime_data.cpp

@@ -9,15 +9,18 @@
 
 #include <utils/wireshark_mime_data.h>
 
-DisplayFilterMimeData::DisplayFilterMimeData(QString description, QString field, QString filter) :
-QMimeData(),
-description_(description),
-filter_(filter),
-field_(field)
+void WiresharkMimeData::allowPlainText()
 {
-    setText(filter);
+    setText(labelText());
 }
 
+DisplayFilterMimeData::DisplayFilterMimeData(QString description, QString field, QString filter) :
+    WiresharkMimeData(),
+    description_(description),
+    filter_(filter),
+    field_(field)
+{}
+
 QString DisplayFilterMimeData::description() const
 {
     return description_;
@@ -38,8 +41,13 @@ QString DisplayFilterMimeData::labelText() const
     return QString("%1\n%2").arg(description_, filter_);
 }
 
+void DisplayFilterMimeData::allowPlainText()
+{
+    setText(filter_);
+}
+
 ToolbarEntryMimeData::ToolbarEntryMimeData(QString element, int pos) :
-    QMimeData(),
+    WiresharkMimeData(),
     element_(element),
     pos_(pos)
 {}

ui/qt/utils/wireshark_mime_data.h

@@ -12,7 +12,13 @@
 
 #include <QMimeData>
 
-class DisplayFilterMimeData: public QMimeData {
+class WiresharkMimeData: public QMimeData {
+public:
+    virtual QString labelText() const = 0;
+    virtual void allowPlainText();
+};
+
+class DisplayFilterMimeData: public WiresharkMimeData {
     Q_OBJECT
 public:
 
@@ -22,7 +28,8 @@ public:
     QString field() const;
     QString filter() const;
 
-    QString labelText() const;
+    QString labelText() const override;
+    void allowPlainText() override;
 
 private:
 
@@ -32,7 +39,7 @@ private:
 
 };
 
-class ToolbarEntryMimeData: public QMimeData {
+class ToolbarEntryMimeData: public WiresharkMimeData {
     Q_OBJECT
 public:
 
@@ -41,7 +48,7 @@ public:
     int position() const;
     QString element() const;
 
-    QString labelText() const;
+    QString labelText() const override;
 
 private: