Fix datainput metadata API

Add QHash map for metadata and implement UI in datainput management dialog
for specifying metadata table. Metadata keys and values are stored in
UIA file under "metadata" tag, delimiter-separated by '$' chars. Requires
corresponding changes on Runtime side.

Change-Id: I335ed893984208dcad3171357feb2e485bafea3b
Task-id: QT3DS-3046
Reviewed-by: Antti Määttä <antti.maatta@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

7 files changed, 281 insertions, 176 deletions

diff --git a/src/Authoring/Client/Code/Core/Doc/Doc.h b/src/Authoring/Client/Code/Core/Doc/Doc.h
index c18b85fb..60f0c3e6 100644
--- a/src/Authoring/Client/Code/Core/Doc/Doc.h
+++ b/src/Authoring/Client/Code/Core/Doc/Doc.h
@@ -51,6 +51,7 @@
 
 #include <QtCore/quuid.h>
 #include <QtCore/qsize.h>
+#include <QtCore/qhash.h>
 
 //==============================================================================
 //	Forwards
@@ -184,11 +185,10 @@ public:
     QString name;
     int type;
     QVector<ControlledItem> ctrldElems;
-    // As per QT3DS-2992 we currently need only a single key-value pair per datainput.
-    // For efficiency we use separate QStrings for both, as there is no need for more
-    // elaborate containers.
-    QString metaDataKey;
-    QString metaData;
+
+    // On editor side we use just QStrings as metadata will be squashed into strings
+    // anyway when storing into UIA file. (Runtime uses QVariants.)
+    QHash<QString, QString> metadata;
 
     // Bindings in other subpresentations, of QMap format
     // QMultiMap<subpresentation_id, QPair<datatype, strict>>.
diff --git a/src/Authoring/Studio/Application/DataInputDlg.cpp b/src/Authoring/Studio/Application/DataInputDlg.cpp
index 9bfec2a0..53b07d26 100644
--- a/src/Authoring/Studio/Application/DataInputDlg.cpp
+++ b/src/Authoring/Studio/Application/DataInputDlg.cpp
@@ -44,8 +44,7 @@ CDataInputDlg::CDataInputDlg(CDataInputDialogItem **datainput, QStandardItemMode
     , m_type(0)
     , m_min(0.0)
     , m_max(10.0)
-    , m_metadataKey(m_dataInput->metaDataKey)
-    , m_metadata(m_dataInput->metaData)
+    , m_metadata(m_dataInput->metadata)
     , m_acceptedTypes(acceptedTypes)
 {
     m_ui->setupUi(this);
@@ -89,11 +88,15 @@ CDataInputDlg::CDataInputDlg(CDataInputDialogItem **datainput, QStandardItemMode
             static_cast<void(QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged),
             this, &CDataInputDlg::onMaxChanged);
     connect(m_ui->lineEditInputName, &QLineEdit::textChanged, this, &CDataInputDlg::onNameChanged);
-    connect(m_ui->lineEditEvaluation, &QLineEdit::textChanged, this, &CDataInputDlg::onTextChanged);
-    connect(m_ui->lineEditMetadata, &QLineEdit::textChanged, this,
-            &CDataInputDlg::onMetadataChanged);
-    connect(m_ui->lineEditMetadataKey, &QLineEdit::textChanged, this,
-            &CDataInputDlg::onMetadataKeyChanged);
+    connect(m_ui->pushButtonAddMeta, &QPushButton::clicked, this, &CDataInputDlg::onMetadataAdded);
+    connect(m_ui->tableEditMetadata, &QTableWidget::itemDoubleClicked, this,
+            [this](QTableWidgetItem *item) {
+        m_ui->lineEditMetadataKey->setText(m_ui->tableEditMetadata->item(item->row(), 0)->text());
+        m_ui->lineEditMetadata->setText(m_ui->tableEditMetadata->item(item->row(), 1)->text());
+        m_metadataEdit = true;
+        m_editMetadataKey = m_ui->tableEditMetadata->item(item->row(), 0)->text();
+        m_ui->lineEditMetadataKey->setFocus();
+    });
 }
 
 CDataInputDlg::~CDataInputDlg()
@@ -105,7 +108,10 @@ void CDataInputDlg::initDialog()
 {
     // Disallow special characters and whitespaces
     QRegExpValidator *rxp = new QRegExpValidator(QRegExp("[A-Za-z0-9_]+"), this);
+    QRegExpValidator *rxpWsOk = new QRegExpValidator(QRegExp("[A-Za-z0-9_ ]+"), this);
     m_ui->lineEditInputName->setValidator(rxp);
+    m_ui->lineEditMetadataKey->setValidator(rxp);
+    m_ui->lineEditMetadata->setValidator(rxpWsOk);
 
     if (!m_dataInput->name.isEmpty()) {
         m_name = m_dataInput->name;
@@ -134,20 +140,23 @@ void CDataInputDlg::initDialog()
         m_ui->doubleSpinBoxMax->setValue(m_dataInput->maxValue);
     }
 
-    m_metadata = m_dataInput->metaData;
-    m_metadataKey = m_dataInput->metaDataKey;
-    m_ui->lineEditMetadata->setText(m_metadata);
-    m_ui->lineEditMetadataKey->setText(m_metadataKey);
+    m_metadata = m_dataInput->metadata;
+    // Removes focus dotted border, does not disable double-click
+    // to start editing an entry.
+    m_ui->tableEditMetadata->setFocusPolicy(Qt::NoFocus);
+    m_ui->tableEditMetadata->setRowCount(m_metadata.size());
+    m_ui->tableEditMetadata->setColumnCount(3);
+    m_ui->tableEditMetadata->setColumnWidth(0, 150);
+    m_ui->tableEditMetadata->setColumnWidth(1, 280);
+    m_ui->tableEditMetadata->setColumnWidth(2, 30);
+    m_ui->tableEditMetadata->setEditTriggers(QAbstractItemView::NoEditTriggers);
+
+    populateMetadata();
     updateVisibility(m_dataInput->type);
 }
 
 void CDataInputDlg::accept()
 {
-    if (m_metadataKey.isEmpty() && !m_metadata.isEmpty()) {
-        Qt3DSMessageBox::Show(tr("Metadata Error"), tr("Metadata key cannot be empty."),
-                              Qt3DSMessageBox::ICON_WARNING, false, this);
-        return;
-    }
     if (m_dataInput->name != m_name)
         m_dataInput->name = getUniqueId(m_name);
 
@@ -161,8 +170,8 @@ void CDataInputDlg::accept()
         m_dataInput->valueString = m_text;
     }
 #endif
-    m_dataInput->metaData = m_metadata;
-    m_dataInput->metaDataKey = m_metadataKey;
+    m_dataInput->metadata = m_metadata;
+
     QDialog::accept();
 }
 
@@ -194,25 +203,33 @@ void CDataInputDlg::onNameChanged(const QString &name)
     m_ui->lineEditInputName->setCursorPosition(cursorPos);
 }
 
-void CDataInputDlg::onTextChanged(const QString &text)
+void CDataInputDlg::onMetadataAdded()
 {
-    m_text = text;
-}
+    auto key = m_ui->lineEditMetadataKey->text();
+    auto metadata = m_ui->lineEditMetadata->text();
+    // Let's allow empty metadata because it might have significance to
+    // metadata user
+    if (key.isEmpty()) {
+        Qt3DSMessageBox::Show(tr("Metadata Error"), tr("Metadata key cannot be empty."),
+                              Qt3DSMessageBox::ICON_WARNING, false, this);
+        return;
+    }
 
-void CDataInputDlg::onMetadataChanged(const QString &metadata)
-{
-    int cursorPos = m_ui->lineEditMetadata->cursorPosition();
-    m_metadata = metadata;
-    m_ui->lineEditMetadata->setText(metadata);
-    m_ui->lineEditMetadata->setCursorPosition(cursorPos);
-}
+    // We are editing an existing key - value, remove old entry
+    if (m_metadataEdit) {
+        m_metadata.remove(m_editMetadataKey);
+        m_metadataEdit = false;
+        m_editMetadataKey.clear();
+    }
 
-void CDataInputDlg::onMetadataKeyChanged(const QString &metadataKey)
-{
-    int cursorPos = m_ui->lineEditMetadataKey->cursorPosition();
-    m_metadataKey = metadataKey;
-    m_ui->lineEditMetadataKey->setText(metadataKey);
-    m_ui->lineEditMetadataKey->setCursorPosition(cursorPos);
+    m_metadata.insert(key, metadata);
+    m_ui->tableEditMetadata->setRowCount(m_metadata.size());
+    m_ui->lineEditMetadata->clear();
+    m_ui->lineEditMetadataKey->clear();
+
+    // Let's update all entries since we do not know if QHash::insert() replaced an existing
+    // entry of just appended a new one.
+    populateMetadata();
 }
 
 QString CDataInputDlg::getUniqueId(const QString &id)
@@ -247,9 +264,6 @@ void CDataInputDlg::updateVisibility(int type)
         m_ui->lineEditEvaluation->setVisible(false);
         m_ui->labelEvaluation->setVisible(false);
     }
-#else
-    m_ui->lineEditEvaluation->setVisible(false);
-    m_ui->labelEvaluation->setVisible(false);
 #endif
     // Adjust text label positioning according to the
     // visibility of info text warning about allowed datatypes.
@@ -262,6 +276,23 @@ void CDataInputDlg::updateVisibility(int type)
     }
 }
 
+void CDataInputDlg::keyPressEvent(QKeyEvent *e)
+{
+    // If we are editing metadata entry, grab ESC event and clear text fields.
+    // Also get out of editing existing metadata entry -mode without saving changes.
+    if (e->key() == Qt::Key_Escape) {
+        if (m_ui->lineEditMetadata->hasFocus() || m_ui->lineEditMetadataKey->hasFocus()) {
+            m_ui->lineEditMetadata->clear();
+            m_ui->lineEditMetadataKey->clear();
+            m_metadataEdit = false;
+            // Return focus to main dialog to allow it to receive ESC events.
+            this->setFocus();
+            return;
+        }
+    }
+    QDialog::keyPressEvent(e);
+}
+
 const bool CDataInputDlg::isEquivalentDataType(int dlgType,
                                                qt3dsdm::DataModelDataType::Value dmType,
                                                bool strict)
@@ -305,3 +336,26 @@ QVector<EDataType> CDataInputDlg::getAcceptedTypes(qt3dsdm::DataModelDataType::V
     }
     return acceptedTypes;
 }
+
+void CDataInputDlg::populateMetadata()
+{
+    static const QIcon trashIcon = QIcon(":/images/Action-Trash-Normal.png");
+    m_ui->tableEditMetadata->clearContents();
+    QHashIterator<QString, QString> i(m_metadata);
+    int currRow = 0;
+    while (i.hasNext()) {
+        i.next();
+        QTableWidgetItem *key = new QTableWidgetItem(i.key());
+        QTableWidgetItem *metadata = new QTableWidgetItem(i.value());
+        m_ui->tableEditMetadata->setItem(currRow, 0, key);
+        m_ui->tableEditMetadata->setItem(currRow, 1, metadata);
+        QPushButton *delButton = new QPushButton(trashIcon, {}, nullptr);
+
+        m_ui->tableEditMetadata->setCellWidget(currRow, 2, delButton);
+        connect(delButton, &QPushButton::clicked, this, [this, i]{
+            m_metadata.remove(i.key());
+            populateMetadata();
+        });
+        ++currRow;
+    }
+}
diff --git a/src/Authoring/Studio/Application/DataInputDlg.h b/src/Authoring/Studio/Application/DataInputDlg.h
index 49593cd4..d9fb0fcf 100644
--- a/src/Authoring/Studio/Application/DataInputDlg.h
+++ b/src/Authoring/Studio/Application/DataInputDlg.h
@@ -30,6 +30,10 @@
 #define DATAINPUTDLG_H
 
 #include <QtWidgets/qdialog.h>
+#include <QtWidgets/QTableWidgetItem>
+#include <QtWidgets/QTableWidget>
+#include <QtCore/qhash.h>
+#include <QKeyEvent>
 
 #include "Doc.h"
 #include "Qt3DSDMDataTypes.h"
@@ -91,6 +95,7 @@ protected:
     void initDialog();
     QString getUniqueId(const QString &id);
     void updateVisibility(int type);
+    void keyPressEvent(QKeyEvent *e) override;
 
 private Q_SLOTS:
     void accept() override;
@@ -98,11 +103,11 @@ private Q_SLOTS:
     void onMinChanged(float min);
     void onMaxChanged(float max);
     void onNameChanged(const QString &name);
-    void onTextChanged(const QString &text);
-    void onMetadataChanged(const QString &metadata);
-    void onMetadataKeyChanged(const QString &metadataKey);
+    void onMetadataAdded();
 
 private:
+    void populateMetadata();
+
     Ui::DataInputDlg *m_ui;
     CDataInputDialogItem *m_dataInput;
     QStandardItemModel *m_data;
@@ -110,10 +115,10 @@ private:
     float m_max;
     float m_min;
     int m_type;
-    QString m_text;
-    QString m_metadataKey;
-    QString m_metadata;
+    QHash<QString, QString> m_metadata;
     QVector<EDataType> m_acceptedTypes;
+    bool m_metadataEdit = false; // are we editing existing metadata?
+    QString m_editMetadataKey; // original metadata key now being edited
 };
 
 #endif
diff --git a/src/Authoring/Studio/Application/DataInputDlg.ui b/src/Authoring/Studio/Application/DataInputDlg.ui
index 982e2d4f..d75db475 100644
--- a/src/Authoring/Studio/Application/DataInputDlg.ui
+++ b/src/Authoring/Studio/Application/DataInputDlg.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>533</width>
-    <height>300</height>
+    <height>307</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -71,7 +71,7 @@
             <item>
              <widget class="QLabel" name="labelNodeName">
               <property name="sizePolicy">
-               <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+               <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
                 <horstretch>0</horstretch>
                 <verstretch>0</verstretch>
                </sizepolicy>
@@ -85,6 +85,9 @@
               <property name="text">
                <string>Name</string>
               </property>
+              <property name="alignment">
+               <set>Qt::AlignLeading|Qt::AlignLeft|Qt::AlignVCenter</set>
+              </property>
              </widget>
             </item>
             <item>
@@ -93,22 +96,28 @@
                <enum>Qt::Vertical</enum>
               </property>
               <property name="sizeType">
-               <enum>QSizePolicy::Preferred</enum>
+               <enum>QSizePolicy::Expanding</enum>
               </property>
               <property name="sizeHint" stdset="0">
                <size>
                 <width>20</width>
-                <height>18</height>
+                <height>9</height>
                </size>
               </property>
              </spacer>
             </item>
             <item>
              <widget class="QLabel" name="labelNodeType">
+              <property name="sizePolicy">
+               <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+                <horstretch>0</horstretch>
+                <verstretch>0</verstretch>
+               </sizepolicy>
+              </property>
               <property name="minimumSize">
                <size>
                 <width>90</width>
-                <height>24</height>
+                <height>20</height>
                </size>
               </property>
               <property name="text">
@@ -117,61 +126,6 @@
              </widget>
             </item>
             <item>
-             <spacer name="verticalSpacer_2">
-              <property name="orientation">
-               <enum>Qt::Vertical</enum>
-              </property>
-              <property name="sizeType">
-               <enum>QSizePolicy::Expanding</enum>
-              </property>
-              <property name="sizeHint" stdset="0">
-               <size>
-                <width>20</width>
-                <height>14</height>
-               </size>
-              </property>
-             </spacer>
-            </item>
-            <item>
-             <widget class="QLabel" name="labelMetadataKey">
-              <property name="minimumSize">
-               <size>
-                <width>0</width>
-                <height>24</height>
-               </size>
-              </property>
-              <property name="text">
-               <string>Metadata Key</string>
-              </property>
-             </widget>
-            </item>
-            <item>
-             <widget class="QLabel" name="labelMetadata">
-              <property name="minimumSize">
-               <size>
-                <width>0</width>
-                <height>24</height>
-               </size>
-              </property>
-              <property name="text">
-               <string>Metadata</string>
-              </property>
-             </widget>
-            </item>
-            <item>
-             <widget class="QLabel" name="labelEvaluation">
-              <property name="minimumSize">
-               <size>
-                <width>0</width>
-                <height>24</height>
-               </size>
-              </property>
-              <property name="text">
-               <string>Evaluation</string>
-              </property>
-             </widget>
-            </item>
-            <item>
              <widget class="QLabel" name="labelMin">
               <property name="minimumSize">
                <size>
@@ -206,19 +160,6 @@
               </property>
              </widget>
             </item>
-            <item>
-             <spacer name="verticalSpacer_4">
-              <property name="orientation">
-               <enum>Qt::Vertical</enum>
-              </property>
-              <property name="sizeHint" stdset="0">
-               <size>
-                <width>20</width>
-                <height>15</height>
-               </size>
-              </property>
-             </spacer>
-            </item>
            </layout>
           </widget>
          </item>
@@ -274,40 +215,6 @@
              </widget>
             </item>
             <item>
-             <spacer name="verticalSpacer">
-              <property name="orientation">
-               <enum>Qt::Vertical</enum>
-              </property>
-              <property name="sizeHint" stdset="0">
-               <size>
-                <width>20</width>
-                <height>40</height>
-               </size>
-              </property>
-             </spacer>
-            </item>
-            <item>
-             <widget class="QLineEdit" name="lineEditMetadataKey">
-              <property name="toolTip">
-               <string>Key for accessing the metadata for this Data Input</string>
-              </property>
-             </widget>
-            </item>
-            <item>
-             <widget class="QLineEdit" name="lineEditMetadata">
-              <property name="toolTip">
-               <string>Metadata associated with this Data Input</string>
-              </property>
-             </widget>
-            </item>
-            <item>
-             <widget class="QLineEdit" name="lineEditEvaluation">
-              <property name="toolTip">
-               <string/>
-              </property>
-             </widget>
-            </item>
-            <item>
              <widget class="QDoubleSpinBox" name="doubleSpinBoxMin">
               <property name="toolTip">
                <string>The minimum value for the number</string>
@@ -336,19 +243,6 @@
               </property>
              </widget>
             </item>
-            <item>
-             <spacer name="verticalSpacer_3">
-              <property name="orientation">
-               <enum>Qt::Vertical</enum>
-              </property>
-              <property name="sizeHint" stdset="0">
-               <size>
-                <width>20</width>
-                <height>40</height>
-               </size>
-              </property>
-             </spacer>
-            </item>
            </layout>
           </widget>
          </item>
@@ -356,6 +250,126 @@
        </widget>
       </item>
       <item>
+       <spacer name="verticalSpacer">
+        <property name="orientation">
+         <enum>Qt::Vertical</enum>
+        </property>
+        <property name="sizeType">
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>20</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+      <item>
+       <layout class="QGridLayout" name="gridLayout">
+        <property name="sizeConstraint">
+         <enum>QLayout::SetMaximumSize</enum>
+        </property>
+        <item row="1" column="0">
+         <widget class="QLineEdit" name="lineEditMetadata">
+          <property name="text">
+           <string/>
+          </property>
+          <property name="placeholderText">
+           <string>Metadata value</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="0">
+         <widget class="QLineEdit" name="lineEditMetadataKey">
+          <property name="text">
+           <string/>
+          </property>
+          <property name="placeholderText">
+           <string>Metadata key</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="1" rowspan="2">
+         <widget class="QPushButton" name="pushButtonAddMeta">
+          <property name="sizePolicy">
+           <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+            <horstretch>0</horstretch>
+            <verstretch>1</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="toolTip">
+           <string>Enter metadata</string>
+          </property>
+          <property name="text">
+           <string>OK</string>
+          </property>
+         </widget>
+        </item>
+        <item row="3" column="0" colspan="2">
+         <widget class="QTableWidget" name="tableEditMetadata">
+          <property name="enabled">
+           <bool>true</bool>
+          </property>
+          <property name="sizePolicy">
+           <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
+            <horstretch>5</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
+          <property name="minimumSize">
+           <size>
+            <width>0</width>
+            <height>78</height>
+           </size>
+          </property>
+          <property name="baseSize">
+           <size>
+            <width>0</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="toolTip">
+           <string>Metadata key - value pairs. Double-click to edit.</string>
+          </property>
+          <property name="sizeAdjustPolicy">
+           <enum>QAbstractScrollArea::AdjustIgnored</enum>
+          </property>
+          <property name="alternatingRowColors">
+           <bool>false</bool>
+          </property>
+          <property name="selectionMode">
+           <enum>QAbstractItemView::NoSelection</enum>
+          </property>
+          <property name="selectionBehavior">
+           <enum>QAbstractItemView::SelectRows</enum>
+          </property>
+          <property name="showGrid">
+           <bool>false</bool>
+          </property>
+          <attribute name="horizontalHeaderVisible">
+           <bool>false</bool>
+          </attribute>
+          <attribute name="horizontalHeaderDefaultSectionSize">
+           <number>75</number>
+          </attribute>
+          <attribute name="horizontalHeaderHighlightSections">
+           <bool>false</bool>
+          </attribute>
+          <attribute name="horizontalHeaderStretchLastSection">
+           <bool>true</bool>
+          </attribute>
+          <attribute name="verticalHeaderVisible">
+           <bool>false</bool>
+          </attribute>
+          <attribute name="verticalHeaderHighlightSections">
+           <bool>false</bool>
+          </attribute>
+         </widget>
+        </item>
+       </layout>
+      </item>
+      <item>
        <widget class="QWidget" name="widget_3" native="true">
         <layout class="QHBoxLayout" name="horizontalLayout_2">
          <property name="leftMargin">
diff --git a/src/Authoring/Studio/Application/ProjectFile.cpp b/src/Authoring/Studio/Application/ProjectFile.cpp
index ebec8b53..953a0226 100644
--- a/src/Authoring/Studio/Application/ProjectFile.cpp
+++ b/src/Authoring/Studio/Application/ProjectFile.cpp
@@ -495,8 +495,25 @@ void ProjectFile::parseDataInputElem(const QDomElement &elem,
             item->valueString = elem.attribute(QStringLiteral("evaluator"));
         }
 #endif
-        item->metaDataKey = elem.attribute((QStringLiteral("metadatakey")));
-        item->metaData = elem.attribute((QStringLiteral("metadata")));
+
+        auto metadata = elem.attribute(QStringLiteral("metadata"));
+        if (!metadata.isEmpty()) {
+            auto metadataList = metadata.split(QLatin1Char('$'));
+
+            if (metadataList.size() & 1) {
+                qWarning("Malformed datainput metadata for datainput %s, cannot parse key"
+                         " - value pairs. Stop parsing metadata.", qUtf8Printable(item->name));
+            } else {
+                for (int i = 0; i < metadataList.size(); i += 2) {
+                    if (metadataList[i].isEmpty()) {
+                        qWarning("Malformed datainput metadata for datainput %s - metadata"
+                                 " key empty. Stop parsing metadata.", qUtf8Printable(item->name));
+                        break;
+                    }
+                    item->metadata.insert(metadataList[i], metadataList[i+1]);
+                }
+            }
+        }
         dataInputs.insert(item->name, item);
     }
 }
diff --git a/src/Authoring/Studio/Application/StudioApp.cpp b/src/Authoring/Studio/Application/StudioApp.cpp
index 8ce3d6c0..44127bdc 100644
--- a/src/Authoring/Studio/Application/StudioApp.cpp
+++ b/src/Authoring/Studio/Application/StudioApp.cpp
@@ -1791,13 +1791,17 @@ void CStudioApp::saveDataInputsToProjectFile()
                 diNode.setAttribute(QStringLiteral("evaluator"), item->valueString);
             }
 #endif
-            // Let's allow storing key even if actual metadata is empty, as we
-            // do not know how the user code is going to interpret metadata contents.
-            if (!item->metaDataKey.isEmpty()) {
-                diNode.setAttribute(QStringLiteral("metadatakey"), item->metaDataKey);
-                if (!item->metaData.isEmpty())
-                    diNode.setAttribute(QStringLiteral("metadata"), item->metaData);
+
+            QHashIterator<QString, QString> it(item->metadata);
+            QString metadataStr;
+            while (it.hasNext()) {
+                it.next();
+                metadataStr.append(it.key() + QLatin1Char('$') + it.value() + QLatin1Char('$'));
             }
+            metadataStr.chop(1);
+
+            diNode.setAttribute(QStringLiteral("metadata"), metadataStr.trimmed());
+
             assetsNode.appendChild(diNode);
         }
         StudioUtils::commitDomDocumentSave(file, doc);
diff --git a/src/Authoring/Studio/style.qss b/src/Authoring/Studio/style.qss
index 0636e49c..e26785c0 100644
--- a/src/Authoring/Studio/style.qss
+++ b/src/Authoring/Studio/style.qss
@@ -435,6 +435,17 @@ QDialog#DataInputDlg QComboBox QAbstractItemView::item:disabled {
     color: #727476;
 }
 
+QDialog#DataInputDlg QTableView {
+    selection-background-color: #46a2da;
+    gridline-color: transparent;
+    border: 1px solid #808080;
+    background-color: transparent;
+}
+
+QDialog#DataInputDlg QTableView::item:selected {
+    background-color: #46a2da;
+}
+
 /* QSlider horizontal */
 QSlider {
     background: transparent;