Another WMS improvement:

* The Identify map tool is now disabled if none of the layers from the WMS server are "queryable".  This saves the WMS server the bother of returning an error if we tried to Identify anyway.
Coding:
* The QgsRasterDataProvider now has the concept of "capabilities" like the QgsVectorDataProvider (not to be confused with Capabilities in the WMS Standard).  The only capability dealt with at this time is the ability to Identify.



git-svn-id: http://svn.osgeo.org/qgis/trunk@5080 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: morb_au

src/core/qgsrasterdataprovider.cpp

@@ -30,3 +30,24 @@ QgsRasterDataProvider::QgsRasterDataProvider( QString const & uri )
 }
 
 
+QString QgsRasterDataProvider::capabilitiesString() const
+{
+  QStringList abilitiesList;
+
+  int abilities = capabilities();
+
+  if (abilities & QgsRasterDataProvider::Identify)
+  {
+    abilitiesList += "Identify";
+#ifdef QGISDEBUG
+        std::cerr << "QgsRasterDataProvider::capabilitiesString "
+          << "Identify" << std::endl;
+#endif
+
+  }
+
+  return abilitiesList.join(", ");
+}
+
+
+// ENDS

src/core/qgsrasterdataprovider.h

@@ -43,9 +43,17 @@ class QgsRasterDataProvider : public QgsDataProvider
 {
 
   Q_OBJECT
-     
+
 public:
 
+    //! If you add to this, please also add to capabilitiesString()
+    enum Capability
+    {
+      NoCapabilities =              0,
+      Identify =                    1
+//      Capability2 =           1 <<  1,    , etc
+    };
+
 
     QgsRasterDataProvider();
 
@@ -78,9 +86,21 @@ class QgsRasterDataProvider : public QgsDataProvider
      */
     virtual QImage* draw(QgsRect  const & viewExtent, int pixelWidth, int pixelHeight) = 0;
 
-    
-    
-        
+    /** Returns a bitmask containing the supported capabilities
+        Note, some capabilities may change depending on whether
+        a spatial filter is active on this provider, so it may
+        be prudent to check this value per intended operation.
+      */
+    virtual int capabilities() const 
+    {
+      return QgsRasterDataProvider::NoCapabilities;
+    }
+
+    /**
+     *  Returns the above in friendly format.
+     */
+    QString capabilitiesString() const;
+
 
     // TODO: Get the supported formats by this provider
 

src/gui/qgisapp.cpp

@@ -4863,6 +4863,8 @@ void QgisApp::activateDeactivateLayerRelatedActions(const QgsMapLayer* layer)
     {
       mActionSelect->setEnabled(true);
       mActionOpenTable->setEnabled(true);
+      mActionIdentify->setEnabled(true);
+
       const QgsVectorLayer* vlayer = dynamic_cast<const QgsVectorLayer*>(layer);
       const QgsVectorDataProvider* dprovider = vlayer->getDataProvider();
       if(vlayer)
@@ -4950,6 +4952,21 @@ void QgisApp::activateDeactivateLayerRelatedActions(const QgsMapLayer* layer)
       mActionAddVertex->setEnabled(false);
       mActionDeleteVertex->setEnabled(false);
       mActionMoveVertex->setEnabled(false);
+
+      const QgsRasterLayer* vlayer = dynamic_cast<const QgsRasterLayer*> (layer);
+      const QgsRasterDataProvider* dprovider = vlayer->getDataProvider();
+      if (vlayer)
+      {
+        // does provider allow the identify map tool?
+        if (dprovider->capabilities() & QgsRasterDataProvider::Identify)
+        {
+          mActionIdentify->setEnabled(TRUE);
+        }
+        else
+        {
+          mActionIdentify->setEnabled(FALSE);
+        }
+      }
     }
 }
 

src/providers/wms/qgswmsprovider.cpp

@@ -675,7 +675,7 @@ bool QgsWmsProvider::retrieveServerCapabilities(bool forceRefresh)
 #endif
 
     bool domOK;
-    domOK = parseCapabilitiesDOM(httpcapabilitiesresponse, capabilities);
+    domOK = parseCapabilitiesDOM(httpcapabilitiesresponse, mCapabilities);
 
     if (!domOK)
     {
@@ -1592,6 +1592,8 @@ void QgsWmsProvider::parseLayer(QDomElement const & e, QgsWmsLayerProperty& laye
     // We have all the information we need to properly evaluate a layer definition
     // TODO: Save this somewhere
 
+    // Store if the layer is queryable
+    mQueryableForLayer[ layerProperty.name ] = layerProperty.queryable;
 
     // Store the available Coordinate Reference Systems for the layer so that it
     // can be combined with others later in supportedCrsForLayers()
@@ -1832,7 +1834,7 @@ QString QgsWmsProvider::wmsVersion()
 
 QStringList QgsWmsProvider::supportedImageEncodings()
 {
-  return capabilities.capability.request.getMap.format;
+  return mCapabilities.capability.request.getMap.format;
 } 
 
 
@@ -1842,18 +1844,6 @@ QStringList QgsWmsProvider::subLayers()
 }
 
 
-/*
-int QgsWmsProvider::capabilities() const
-{
-    return ( QgsVectorDataProvider::AddFeatures | 
-	     QgsVectorDataProvider::DeleteFeatures |
-	     QgsVectorDataProvider::ChangeAttributeValues |
-	     QgsVectorDataProvider::AddAttributes |
-	     QgsVectorDataProvider::DeleteAttributes );
-}
-*/
-
-
 void QgsWmsProvider::showStatusMessage(QString const & theMessage)
 {
     // Pass-through
@@ -1929,6 +1919,48 @@ bool QgsWmsProvider::calculateExtent()
 
 }
 
+
+int QgsWmsProvider::capabilities() const
+{
+  int capability = 0;
+  bool canIdentify = FALSE;
+
+#ifdef QGISDEBUG
+  std::cout << "QgsWmsProvider::capabilities: entering." << std::endl;
+#endif
+
+  // Test for the ability to use the Identify map tool
+  for ( QStringList::const_iterator it  = activeSubLayers.begin(); 
+                                    it != activeSubLayers.end(); 
+                                  ++it )
+  {
+    // Is sublayer visible?
+    if (TRUE == activeSubLayerVisibility.find( *it )->second)
+    {
+      // Is sublayer queryable?
+      if (TRUE == mQueryableForLayer.find( *it )->second)
+      {
+#ifdef QGISDEBUG
+  std::cout << "QgsWmsProvider::capabilities: '" << (*it).toLocal8Bit().data() << "' is queryable." << std::endl;
+#endif
+        canIdentify = TRUE;
+      }
+    }
+  }
+
+  // Collect all the test results into one bitmask
+  if (canIdentify)
+  {
+    capability = (capability | QgsRasterDataProvider::Identify);
+  }
+
+#ifdef QGISDEBUG
+  std::cout << "QgsWmsProvider::capabilities: exiting with '" << capability << "'." << std::endl;
+#endif
+  return capability;
+}
+
+
 QString QgsWmsProvider::getMetadata()
 {
 
@@ -1956,31 +1988,31 @@ QString QgsWmsProvider::getMetadata()
   myMetadataQString += tr("WMS Version");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.version;
+  myMetadataQString += mCapabilities.version;
   myMetadataQString += "</td></tr>";
 
   // Service Title
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Title");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.service.title;
+  myMetadataQString += mCapabilities.service.title;
   myMetadataQString += "</td></tr>";
 
   // Service Abstract
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Abstract");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.service.abstract;
+  myMetadataQString += mCapabilities.service.abstract;
   myMetadataQString += "</td></tr>";
 
   // Service Keywords
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Keywords");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.service.keywordList.join("<br />");
+  myMetadataQString += mCapabilities.service.keywordList.join("<br />");
   myMetadataQString += "</td></tr>";
 
   // Service Online Resource
@@ -1996,43 +2028,43 @@ QString QgsWmsProvider::getMetadata()
   myMetadataQString += tr("Contact Person");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.service.contactInformation.contactPersonPrimary.contactPerson;
+  myMetadataQString += mCapabilities.service.contactInformation.contactPersonPrimary.contactPerson;
   myMetadataQString += "<br />";
-  myMetadataQString += capabilities.service.contactInformation.contactPosition;
+  myMetadataQString += mCapabilities.service.contactInformation.contactPosition;
   myMetadataQString += "<br />";
-  myMetadataQString += capabilities.service.contactInformation.contactPersonPrimary.contactOrganization;
+  myMetadataQString += mCapabilities.service.contactInformation.contactPersonPrimary.contactOrganization;
   myMetadataQString += "</td></tr>";
 
   // Service Fees
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Fees");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.service.fees;
+  myMetadataQString += mCapabilities.service.fees;
   myMetadataQString += "</td></tr>";
 
   // Service Access Constraints
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Access Constraints");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.service.accessConstraints;
+  myMetadataQString += mCapabilities.service.accessConstraints;
   myMetadataQString += "</td></tr>";
 
   // GetMap Request Formats
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Image Formats");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.capability.request.getMap.format.join("<br />");
+  myMetadataQString += mCapabilities.capability.request.getMap.format.join("<br />");
   myMetadataQString += "</td></tr>";
 
   // GetFeatureInfo Request Formats
   myMetadataQString += "<tr><td bgcolor=\"gray\">";
   myMetadataQString += tr("Identify Formats");
   myMetadataQString += "</td>";
   myMetadataQString += "<td bgcolor=\"gray\">";
-  myMetadataQString += capabilities.capability.request.getFeatureInfo.format.join("<br />");
+  myMetadataQString += mCapabilities.capability.request.getFeatureInfo.format.join("<br />");
   myMetadataQString += "</td></tr>";
 
   // Layer Count (as managed by this provider)

src/providers/wms/qgswmsprovider.h

@@ -486,15 +486,20 @@ class QgsWmsProvider : public QgsRasterDataProvider
 
   // TODO: Get the table name associated with this provider instance
 
-  /**Returns a bitmask containing the supported capabilities*/
-  // int capabilities() const;
+  /** Returns a bitmask containing the supported capabilities
+      Note, some capabilities may change depending on which
+      sublayers are visible on this provider, so it may
+      be prudent to check this value per intended operation.
+    */
+  int capabilities() const;
 
   /**
    * Get metadata in a format suitable for feeding directly
    * into a subset of the GUI raster properties "Metadata" tab.
    */
   QString getMetadata();
 
+
   /**
    * \brief Identify details from a WMS Server from the last screen update
    *
@@ -732,7 +737,7 @@ public slots:
   /**
    * Parsed capabilities of the WMS Server
    */
-  QgsWmsCapabilitiesProperty capabilities;
+  QgsWmsCapabilitiesProperty mCapabilities;
 
   /**
    * layers hosted by the WMS Server
@@ -749,6 +754,12 @@ public slots:
    */
   std::map<QString, std::vector<QString> > crsForLayer;
 
+  /**
+   * WMS "queryable" per layer
+   * Used in determining if the Identify map tool can be useful on the rendered WMS map layer.
+   */
+  std::map<QString, bool> mQueryableForLayer;
+
   /**
    * Active sublayers managed by this provider in a draw function, in order from bottom to top
    * (some may not be visible in a draw function, cf. activeSubLayerVisibility)

src/raster/qgsrasterlayer.cpp

@@ -5239,4 +5239,16 @@ QString QgsRasterLayer::errorString()
 }
 
 
+QgsRasterDataProvider* QgsRasterLayer::getDataProvider()
+{
+  return dataProvider;
+}
+
+const QgsRasterDataProvider* QgsRasterLayer::getDataProvider() const
+{
+  return dataProvider;
+}
+
+
+
 // ENDS

src/raster/qgsrasterlayer.h

@@ -783,6 +783,19 @@ class QgsRasterLayer : public QgsMapLayer
      */
     QString errorString();
 
+    /** Returns the data provider
+     *
+     *  \retval 0 if not using the data provider model (i.e. directly using GDAL)
+     */
+    QgsRasterDataProvider* getDataProvider();
+
+    /** Returns the data provider in a const-correct manner
+     *
+     *  \retval 0 if not using the data provider model (i.e. directly using GDAL)
+     */
+    const QgsRasterDataProvider* getDataProvider() const;
+
+
 
 public slots:    
     /** \brief Mutator for transparency level. Should be between 0 and 255 */