[QgsQuick] Updated value relation widget

Renamed and simplified shared ComboBox component - now its just styled component without functionality. All has to be defined when creating it.

Added docs to QgsQuickUtils::createValueRelationCache

Author: vsklencar

src/quickgui/plugin/CMakeLists.txt

@@ -10,7 +10,7 @@ SET(QGIS_QUICK_PLUGIN_SRC
 )
 
 SET(QGIS_QUICK_PLUGIN_RESOURCES
-  editor/qgsquickcombobox.qml
+  editor/qgsquickeditorwidgetcombobox.qml
   editor/qgsquickcheckbox.qml
   editor/qgsquickdatetime.qml
   editor/qgsquickexternalresource.qml

src/quickgui/plugin/editor/qgsquickcombobox.qml renamed to src/quickgui/plugin/editor/qgsquickeditorwidgetcombobox.qml

@@ -20,19 +20,13 @@ import QgsQuick 0.1 as QgsQuick
 
 /**
  * ComboBox for QGIS Attribute Form - used by QgsQuickValueMap and QgsQuickValueRelation
- * Requires various global properties set to function, see qgsquickfeatureform Loader section
  * Do not use directly from Application QML
  */
 ComboBox {
   id: comboBox
 
-  property var reverseConfig: ({})
-  property var currentValue
-  property var currentMap
-  property var currentKey
   property var comboStyle
   anchors { left: parent.left; right: parent.right }
-  currentIndex: find(reverseConfig[currentValue])
 
   MouseArea {
     anchors.fill: parent

src/quickgui/plugin/editor/qgsquickvaluemap.qml

@@ -35,8 +35,11 @@ Item {
     rightMargin: 10 * QgsQuick.Utils.dp
   }
 
-  QgsQuick.ComboBox {
-    id: comboBox
+  QgsQuick.EditorWidgetComboBox {
+    // Reversed to model's key-value map. It is used to find index according current value
+    property var reverseConfig: ({})
+    property var currentValue: value
+
     comboStyle: customStyle
     textRole: 'text'
     height: parent.height
@@ -52,29 +55,28 @@ Item {
           //it's a list (>=QGIS3.0)
           for(var i=0; i<config['map'].length; i++)
           {
-            currentMap = config['map'][i]
-            currentKey = Object.keys(currentMap)[0]
+            var currentMap = config['map'][i]
+            var currentKey = Object.keys(currentMap)[0]
             listModel.append( { text: currentKey } )
             reverseConfig[currentMap[currentKey]] = currentKey;
           }
         }
         else
         {
           //it's a map (<=QGIS2.18)
-          currentMap= config['map'].length ? config['map'][currentIndex] : config['map']
-          currentKey = Object.keys(currentMap)[0]
+          var currentMap = config['map'].length ? config['map'][currentIndex] : config['map']
+          var currentKey = Object.keys(currentMap)[0]
           for(var key in config['map']) {
             listModel.append( { text: key } )
             reverseConfig[config['map'][key]] = key;
           }
         }
       }
-
       currentIndex = find(reverseConfig[value])
     }
 
     onCurrentTextChanged: {
-      currentMap= config['map'].length ? config['map'][currentIndex] : config['map']
+      var currentMap = config['map'].length ? config['map'][currentIndex] : config['map']
       valueChanged(currentMap[currentText], false)
     }
 

src/quickgui/plugin/editor/qgsquickvaluerelation.qml

@@ -35,30 +35,36 @@ Item {
     rightMargin: 10 * QgsQuick.Utils.dp
   }
 
-  QgsQuick.ComboBox {
+  QgsQuick.EditorWidgetComboBox {
+    // Value relation cache map
+    property var currentMap
+    // Reversed to currentMap. It is used to find key (currentValue) according value (currentText)
+    property var reversedMap: ({})
+    property var currentValue: value
+
     comboStyle: customStyle
+    textRole: 'text'
+    height: parent.height
     model: ListModel {
       id: listModel
     }
-    textRole: 'text'
-    height: parent.height
 
     Component.onCompleted: {
       currentMap = QgsQuick.Utils.createValueRelationCache(config)
       var keys = Object.keys(currentMap)
       for(var i=0; i< keys.length; i++)
       {
-        currentKey = keys[i]
+        var currentKey = keys[i]
         var valueText = currentMap[currentKey]
         listModel.append( { text: valueText } )
-        reverseConfig[valueText] = currentKey;
+        reversedMap[valueText] = currentKey;
       }
-      model=listModel
+      model = listModel
       currentIndex = find(currentMap[value])
     }
 
     onCurrentTextChanged: {
-      valueChanged(reverseConfig[currentText], false)
+      valueChanged(reversedMap[currentText], false)
     }
 
     // Workaround to get a signal when the value has changed

src/quickgui/plugin/qgsquick.qrc

@@ -1,7 +1,7 @@
 <RCC>
     <qresource prefix="/QgsQuick">
         <file>qmldir</file>
-        <file>editor/qgsquickcombobox.qml</file>
+        <file>editor/qgsquickeditorwidgetcombobox.qml</file>
         <file>editor/qgsquickcheckbox.qml</file>
         <file>editor/qgsquickdatetime.qml</file>
         <file>editor/qgsquickexternalresource.qml</file>

src/quickgui/plugin/qmldir

@@ -13,7 +13,9 @@
 module QgsQuick
 plugin qgis_quick_plugin
 
-ComboBox 0.1 qgsquickcombobox.qml
+# suppose to be used only internaly in QgsQuick plugin
+EditorWidgetComboBox  0.1 qgsquickeditorwidgetcombobox.qml
+
 MapCanvas 0.1 qgsquickmapcanvas.qml
 FeatureForm 0.1 qgsquickfeatureform.qml
 FeatureFormStyling 0.1 qgsquickfeatureformstyling.qml

src/quickgui/qgsquickutils.h

@@ -229,6 +229,16 @@ class QUICK_EXPORT QgsQuickUtils: public QObject
     //! Returns a string with information about screen size and resolution - useful for debugging
     QString dumpScreenInfo() const;
 
+    /**
+     * Creates a cache for a value relation field.
+     * This can be used to keep the value map in the local memory
+     * if doing multiple lookups in a loop.
+     * \param config The widget configuration
+     * \param formFeature The feature currently being edited with current attribute values
+     * \return A kvp list of values for the widget
+     *
+     * \since QGIS 3.6
+     */
     Q_INVOKABLE static QVariantMap createValueRelationCache( const QVariantMap &config, const QgsFeature &formFeature = QgsFeature() );
 
   private: