[QgsQuick] Value Relation widget

Added a widget for value relation field time of a feature form.

src/quickgui/plugin/CMakeLists.txt

@@ -15,6 +15,7 @@ SET(QGIS_QUICK_PLUGIN_RESOURCES
   editor/qgsquickexternalresource.qml
   editor/qgsquicktextedit.qml
   editor/qgsquickvaluemap.qml
+  editor/qgsquickvaluerelation.qml
   qgsquickfeatureform.qml
   qgsquickfeatureformstyling.qml
   qgsquickmapcanvas.qml

src/quickgui/plugin/editor/qgsquickvaluerelation.qml

@@ -0,0 +1,126 @@
+/***************************************************************************
+ qgsquickvaluerelation.qml
+  --------------------------------------
+  Date                 : 2017
+  Copyright            : (C) 2019 by Viktor Sklencar
+  Email                : viktor.sklencar@lutraconsulting.co.uk
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+import QtQuick 2.7
+import QtQuick.Controls 2.2
+import QtGraphicalEffects 1.0
+import QgsQuick 0.1 as QgsQuick
+
+/**
+ * Value Relation for QGIS Attribute Form
+ * Requires various global properties set to function, see qgsquickfeatureform Loader section
+ * Do not use directly from Application QML
+ */
+Item {
+  signal valueChanged(var value, bool isNull)
+
+  id: fieldItem
+  enabled: !readOnly
+  height: customStyle.height
+  anchors {
+    left: parent.left
+    right: parent.right
+    rightMargin: 10 * QgsQuick.Utils.dp
+  }
+
+  ComboBox {
+    id: comboBox
+
+    property var reverseConfig: ({})
+    property var currentValue: value
+    property var currentMap
+    property var currentKey
+    height: parent.height
+    anchors { left: parent.left; right: parent.right }
+    currentIndex: find(value)
+
+    ListModel {
+        id: listModel
+    }
+
+    Component.onCompleted: {
+        currentMap = QgsQuick.Utils.createValueRelationCache(config)
+        var keys = Object.keys(currentMap)
+        for(var i=0; i< keys.length; i++)
+        {
+          currentKey = keys[i]
+          var valueText = currentMap[currentKey]
+          listModel.append( { text: valueText } )
+          reverseConfig[valueText] = currentKey;
+        }
+        model=listModel
+        textRole = 'text'
+        currentIndex = find(currentMap[value])
+    }
+
+    onCurrentTextChanged: {
+      valueChanged(reverseConfig[currentText], false)
+    }
+
+    // Workaround to get a signal when the value has changed
+    onCurrentValueChanged: {
+      currentIndex = find(currentMap[value])
+    }
+
+    MouseArea {
+      anchors.fill: parent
+      propagateComposedEvents: true
+
+      onClicked: mouse.accepted = false
+      onPressed: { forceActiveFocus(); mouse.accepted = false; }
+      onReleased: mouse.accepted = false;
+      onDoubleClicked: mouse.accepted = false;
+      onPositionChanged: mouse.accepted = false;
+      onPressAndHold: mouse.accepted = false;
+    }
+
+    // [hidpi fixes]
+    delegate: ItemDelegate {
+      width: comboBox.width
+      height: comboBox.height * 0.8
+      text: modelData
+      font.weight: comboBox.currentIndex === index ? Font.DemiBold : Font.Normal
+      font.pixelSize: customStyle.fontPixelSize
+      highlighted: comboBox.highlightedIndex == index
+      leftPadding: 5 * QgsQuick.Utils.dp
+    }
+
+    contentItem: Text {
+      height: comboBox.height * 0.8
+      text: comboBox.displayText
+      font.pixelSize: customStyle.fontPixelSize
+      horizontalAlignment: Text.AlignLeft
+      verticalAlignment: Text.AlignVCenter
+      elide: Text.ElideRight
+      leftPadding: 5 * QgsQuick.Utils.dp
+      color: customStyle.fontColor
+    }
+
+    background: Item {
+      implicitWidth: 120 * QgsQuick.Utils.dp
+      implicitHeight: comboBox.height * 0.8
+
+      Rectangle {
+        anchors.fill: parent
+        id: backgroundRect
+        border.color: comboBox.pressed ? customStyle.activeColor : customStyle.normalColor
+        border.width: comboBox.visualFocus ? 2 : 1
+        color: customStyle.backgroundColor
+        radius: customStyle.cornerRadius
+      }
+    }
+    // [/hidpi fixes]
+  }
+}

src/quickgui/qgsquickutils.cpp

@@ -25,6 +25,7 @@
 #include "qgsvectorlayer.h"
 #include "qgsfeature.h"
 #include "qgsapplication.h"
+#include "qgsvaluerelationfieldformatter.h"
 
 #include "qgsquickfeaturelayerpair.h"
 #include "qgsquickmapsettings.h"
@@ -135,6 +136,7 @@ const QUrl QgsQuickUtils::getEditorComponentSource( const QString &widgetName )
   QString path( "qgsquick%1.qml" );
   QStringList supportedWidgets = { QStringLiteral( "textedit" ),
                                    QStringLiteral( "valuemap" ),
+                                   QStringLiteral( "valuerelation" ),
                                    QStringLiteral( "checkbox" ),
                                    QStringLiteral( "externalresource" ),
                                    QStringLiteral( "datetime" )
@@ -329,6 +331,18 @@ QString QgsQuickUtils::dumpScreenInfo() const
   return msg;
 }
 
+QVariantMap QgsQuickUtils::createValueRelationCache(const QVariantMap &config, const QgsFeature &formFeature)
+{
+    QVariantMap valueMap;
+    QgsValueRelationFieldFormatter::ValueRelationCache cache = QgsValueRelationFieldFormatter::createCache(config, formFeature);
+
+    for ( const QgsValueRelationFieldFormatter::ValueRelationItem &item : qgis::as_const( cache ) )
+    {
+        valueMap.insert(item.key.toString(), item.value);
+    }
+    return valueMap;
+}
+
 qreal QgsQuickUtils::screenDensity() const
 {
   return mScreenDensity;

src/quickgui/qgsquickutils.h

@@ -229,6 +229,8 @@ class QUICK_EXPORT QgsQuickUtils: public QObject
     //! Returns a string with information about screen size and resolution - useful for debugging
     QString dumpScreenInfo() const;
 
+    Q_INVOKABLE static QVariantMap createValueRelationCache( const QVariantMap &config, const QgsFeature &formFeature = QgsFeature() );
+
   private:
     static void formatToMetricDistance( double srcDistance,
                                         QgsUnitTypes::DistanceUnit srcUnits,