Fix for #8052, QGIS 2.0 does not respect labels' scale-based visibility in projects from previous version

- Also fix long standing unreported bug where scales closer than 1:1, e.g. 5:1, could not be set

Author: dakcarto

src/app/qgslabelinggui.cpp

@@ -1006,13 +1006,17 @@ void QgsLabelingGui::populateDataDefinedButtons( QgsPalLayerSettings& s )
   mCoordRotationDDBtn->setUsageInfo( ddPlaceInfo );
 
   // rendering
+  QString ddScaleVisInfo = tr( "Value &lt; 0 represents a scale closer than 1:1, e.g. -10 = 10:1<br>"
+                               "Value of 0 toggles off specific limit" );
   mScaleBasedVisibilityDDBtn->init( mLayer, s.dataDefinedProperty( QgsPalLayerSettings::ScaleVisibility ),
                                     QgsDataDefinedButton::AnyType, QgsDataDefinedButton::boolDesc() );
   mScaleBasedVisibilityDDBtn->registerCheckedWidget( mScaleBasedVisibilityChkBx );
   mScaleBasedVisibilityMinDDBtn->init( mLayer, s.dataDefinedProperty( QgsPalLayerSettings::MinScale ),
-                                       QgsDataDefinedButton::AnyType, QgsDataDefinedButton::intPosOneDesc() );
+                                       QgsDataDefinedButton::AnyType, QgsDataDefinedButton::intDesc() );
+  mScaleBasedVisibilityMinDDBtn->setUsageInfo( ddScaleVisInfo );
   mScaleBasedVisibilityMaxDDBtn->init( mLayer, s.dataDefinedProperty( QgsPalLayerSettings::MaxScale ),
-                                       QgsDataDefinedButton::AnyType, QgsDataDefinedButton::intPosOneDesc() );
+                                       QgsDataDefinedButton::AnyType, QgsDataDefinedButton::intDesc() );
+  mScaleBasedVisibilityMaxDDBtn->setUsageInfo( ddScaleVisInfo );
 
   mFontLimitPixelDDBtn->init( mLayer, s.dataDefinedProperty( QgsPalLayerSettings::FontLimitPixel ),
                               QgsDataDefinedButton::AnyType, QgsDataDefinedButton::boolDesc() );

src/core/qgspallabeling.cpp

@@ -768,6 +768,13 @@ void QgsPalLayerSettings::readDataDefinedProperty( QgsVectorLayer* layer,
         bufferDraw = true;
         layer->setCustomProperty( "labeling/bufferDraw", true );
       }
+
+      // fix for scale visibility limits triggered off of just its data defined values in the past (<2.0)
+      if ( oldIndx == 16 || oldIndx == 17 ) // old minScale and maxScale enums
+      {
+        scaleVisibility = true;
+        layer->setCustomProperty( "labeling/scaleVisibility", true );
+      }
     }
 
     // remove old-style field index-based property
@@ -853,7 +860,7 @@ void QgsPalLayerSettings::readFromLayer( QgsVectorLayer* layer )
   // text buffer
   double bufSize = layer->customProperty( "labeling/bufferSize", QVariant( 0.0 ) ).toDouble();
 
-  // fix for buffer being keyed off of just its size in the past
+  // fix for buffer being keyed off of just its size in the past (<2.0)
   QVariant drawBuffer = layer->customProperty( "labeling/bufferDraw", QVariant() );
   if ( drawBuffer.isValid() )
   {
@@ -937,9 +944,30 @@ void QgsPalLayerSettings::readFromLayer( QgsVectorLayer* layer )
   priority = layer->customProperty( "labeling/priority" ).toInt();
 
   // rendering
-  scaleVisibility = layer->customProperty( "labeling/scaleVisibility" ).toBool();
-  scaleMin = layer->customProperty( "labeling/scaleMin", QVariant( 1 ) ).toInt();
-  scaleMax = layer->customProperty( "labeling/scaleMax", QVariant( 10000000 ) ).toInt();
+  int scalemn = layer->customProperty( "labeling/scaleMin", QVariant( 0 ) ).toInt();
+  int scalemx = layer->customProperty( "labeling/scaleMax", QVariant( 0 ) ).toInt();
+
+  // fix for scale visibility limits being keyed off of just its values in the past (<2.0)
+  QVariant scalevis = layer->customProperty( "labeling/scaleVisibility", QVariant() );
+  if ( scalevis.isValid() )
+  {
+    scaleVisibility = scalevis.toBool();
+    scaleMin = scalemn;
+    scaleMax = scalemx;
+  }
+  else if ( scalemn > 0 || scalemx > 0 )
+  {
+    scaleVisibility = true;
+    scaleMin = scalemn;
+    scaleMax = scalemx;
+  }
+  else
+  {
+    // keep scaleMin and scaleMax at new 1.0 defaults (1 and 10000000, were 0 and 0)
+    scaleVisibility = false;
+  }
+
+
   fontLimitPixelSize = layer->customProperty( "labeling/fontLimitPixelSize", QVariant( false ) ).toBool();
   fontMinPixelSize = layer->customProperty( "labeling/fontMinPixelSize", QVariant( 0 ) ).toInt();
   fontMaxPixelSize = layer->customProperty( "labeling/fontMaxPixelSize", QVariant( 10000 ) ).toInt();
@@ -1496,7 +1524,14 @@ void QgsPalLayerSettings::registerFeature( QgsVectorLayer* layer,  QgsFeature& f
         minScale = mins;
       }
     }
-    if ( context.rendererScale() < minScale )
+
+    // scales closer than 1:1
+    if ( minScale < 0 )
+    {
+      minScale = 1 / qAbs( minScale );
+    }
+
+    if ( minScale != 0 && context.rendererScale() < minScale )
     {
       return;
     }
@@ -1513,7 +1548,14 @@ void QgsPalLayerSettings::registerFeature( QgsVectorLayer* layer,  QgsFeature& f
         maxScale = maxs;
       }
     }
-    if ( context.rendererScale() > maxScale )
+
+    // scales closer than 1:1
+    if ( maxScale < 0 )
+    {
+      maxScale = 1 / qAbs( maxScale );
+    }
+
+    if ( maxScale != 0 && context.rendererScale() > maxScale )
     {
       return;
     }

src/ui/qgslabelingguibase.ui

@@ -5030,11 +5030,14 @@ font-style: italic;</string>
                                   <verstretch>0</verstretch>
                                  </sizepolicy>
                                 </property>
+                                <property name="toolTip">
+                                 <string>Value &amp;lt; 0 represents a scale closer than 1:1, e.g. -10 = 10:1.&lt;br&gt;Value of 0 toggles off specific limit.</string>
+                                </property>
                                 <property name="prefix">
                                  <string>Minimum </string>
                                 </property>
                                 <property name="minimum">
-                                 <number>1</number>
+                                 <number>-999999999</number>
                                 </property>
                                 <property name="maximum">
                                  <number>999999999</number>
@@ -5056,11 +5059,14 @@ font-style: italic;</string>
                                   <verstretch>0</verstretch>
                                  </sizepolicy>
                                 </property>
+                                <property name="toolTip">
+                                 <string>Value &amp;lt; 0 represents a scale closer than 1:1, e.g. -10 = 10:1.&lt;br&gt;Value of 0 toggles off specific limit.</string>
+                                </property>
                                 <property name="prefix">
                                  <string>Maximum </string>
                                 </property>
                                 <property name="minimum">
-                                 <number>1</number>
+                                 <number>-999999999</number>
                                 </property>
                                 <property name="maximum">
                                  <number>999999999</number>