Show special strings for expression preview if result is a geometry

or feature type. Makes it easier to determine what the return type of various functions are for users.
qgis · Nov 4, 2015 · 1d872dc · 1d872dc
1 parent da94223
commit 1d872dc
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 17 deletions.
diff --git a/src/gui/qgsexpressionbuilderwidget.cpp b/src/gui/qgsexpressionbuilderwidget.cpp
@@ -19,6 +19,8 @@
 #include "qgsmessageviewer.h"
 #include "qgsapplication.h"
 #include "qgspythonrunner.h"
+#include "qgsgeometry.h"
+#include "qgsfeature.h"
 
 #include <QSettings>
 #include <QMenu>
@@ -544,7 +546,7 @@ void QgsExpressionBuilderWidget::on_txtExpressionString_textChanged()
       mExpressionContext.setFeature( mFeature );
       QVariant value = exp.evaluate( &mExpressionContext );
       if ( !exp.hasEvalError() )
-        lblPreview->setText( formatPreviewString( value.toString() ) );
+        lblPreview->setText( formatPreviewString( value ) );
     }
     else
     {
@@ -559,7 +561,7 @@ void QgsExpressionBuilderWidget::on_txtExpressionString_textChanged()
     QVariant value = exp.evaluate( &mExpressionContext );
     if ( !exp.hasEvalError() )
     {
-      lblPreview->setText( formatPreviewString( value.toString() ) );
+      lblPreview->setText( formatPreviewString( value ) );
     }
   }
 
@@ -585,15 +587,35 @@ void QgsExpressionBuilderWidget::on_txtExpressionString_textChanged()
   }
 }
 
-QString QgsExpressionBuilderWidget::formatPreviewString( const QString& previewString ) const
+QString QgsExpressionBuilderWidget::formatPreviewString( const QVariant& value ) const
 {
-  if ( previewString.length() > 63 )
+  if ( value.canConvert<QgsGeometry>() )
   {
-    return QString( tr( "%1..." ) ).arg( previewString.left( 60 ) );
+    //result is a geometry
+    QgsGeometry geom = value.value<QgsGeometry>();
+    if ( geom.isEmpty() )
+      return tr( "<i>&lt;empty geometry&gt;</i>" );
+    else
+      return tr( "<i>&lt;geometry: %1&gt;</i>" ).arg( QgsWKBTypes::displayString( geom.geometry()->wkbType() ) );
+  }
+  else if ( value.canConvert< QgsFeature >() )
+  {
+    //result is a feature
+    QgsFeature feat = value.value<QgsFeature>();
+    return tr( "<i>&lt;feature: %1&gt;</i>" ).arg( feat.id() );
   }
   else
   {
-    return previewString;
+    QString previewString = value.toString();
+
+    if ( previewString.length() > 63 )
+    {
+      return QString( tr( "%1..." ) ).arg( previewString.left( 60 ) );
+    }
+    else
+    {
+      return previewString;
+    }
   }
 }
 

diff --git a/src/gui/qgsexpressionbuilderwidget.h b/src/gui/qgsexpressionbuilderwidget.h
@@ -271,9 +271,9 @@ class GUI_EXPORT QgsExpressionBuilderWidget : public QWidget, private Ui::QgsExp
 
     /** Formats an expression preview result for display in the widget
      * by truncating the string
-     * @param previewString expression preview result to format
+     * @param value expression preview result to format
      */
-    QString formatPreviewString( const QString &previewString ) const;
+    QString formatPreviewString( const QVariant& value ) const;
 
     void loadExpressionContext();
 

diff --git a/src/ui/qgsexpressionbuilder.ui b/src/ui/qgsexpressionbuilder.ui
@@ -111,14 +111,6 @@
                     <verstretch>0</verstretch>
                    </sizepolicy>
                   </property>
-                  <property name="font">
-                   <font>
-                    <weight>50</weight>
-                    <italic>true</italic>
-                    <bold>false</bold>
-                    <underline>false</underline>
-                   </font>
-                  </property>
                   <property name="toolTip">
                    <string>Output preview is generated &lt;br&gt; using the first feature from the layer.</string>
                   </property>
@@ -363,7 +355,7 @@
                </item>
               </layout>
              </widget>
-             <widget class="QWidget" name="">
+             <widget class="QWidget" name="layoutWidget_2">
               <layout class="QVBoxLayout" name="verticalLayout_2">
                <item>
                 <widget class="QTextEdit" name="txtHelpText">