From fb30b84cfb24e9d95d010ccd968c063a81d64995 Mon Sep 17 00:00:00 2001
From: Denis Rouzaud <denis.rouzaud@gmail.com>
Date: Tue, 16 Sep 2014 09:33:51 +0200
Subject: [PATCH] [QgsMapToolIdentifyFeature] allow initializing without any
 layer

---
 python/gui/qgsmaptoolidentifyfeature.sip           | 10 +++++++++-
 .../editorwidgets/qgsrelationreferencewidget.cpp   |  2 +-
 src/gui/qgsmaptoolidentifyfeature.cpp              |  4 ++--
 src/gui/qgsmaptoolidentifyfeature.h                | 14 +++++++++++---
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/python/gui/qgsmaptoolidentifyfeature.sip b/python/gui/qgsmaptoolidentifyfeature.sip
index c02b796c438..93604d3a705 100644
--- a/python/gui/qgsmaptoolidentifyfeature.sip
+++ b/python/gui/qgsmaptoolidentifyfeature.sip
@@ -5,7 +5,15 @@ class QgsMapToolIdentifyFeature : QgsMapToolIdentify
 %End
 
   public:
-    QgsMapToolIdentifyFeature( QgsVectorLayer* vl, QgsMapCanvas* canvas );
+    /**
+     * @brief QgsMapToolIdentifyFeature is a map tool to identify a feature on a chosen layer
+     * @param canvas the map canvas
+     * @param vl the vector layer. The map tool can be initialized without any layer and can be set afterward.
+     */
+    QgsMapToolIdentifyFeature( QgsMapCanvas* canvas, QgsVectorLayer* vl = 0 );
+
+    //! change the layer used by the map tool to identify
+    void setLayer( QgsVectorLayer* vl );
 
     void canvasReleaseEvent( QMouseEvent* e );
 
diff --git a/src/gui/editorwidgets/qgsrelationreferencewidget.cpp b/src/gui/editorwidgets/qgsrelationreferencewidget.cpp
index 7da05576fb6..f512508f05c 100644
--- a/src/gui/editorwidgets/qgsrelationreferencewidget.cpp
+++ b/src/gui/editorwidgets/qgsrelationreferencewidget.cpp
@@ -516,7 +516,7 @@ void QgsRelationReferenceWidget::mapIdentification()
   if ( !mCanvas )
     return;
 
-  mMapTool = new QgsMapToolIdentifyFeature( mReferencedLayer, mCanvas );
+  mMapTool = new QgsMapToolIdentifyFeature( mCanvas, mReferencedLayer );
   mCanvas->setMapTool( mMapTool );
   mWindowWidget = window();
   mWindowWidget->hide();
diff --git a/src/gui/qgsmaptoolidentifyfeature.cpp b/src/gui/qgsmaptoolidentifyfeature.cpp
index 28d0ca20609..5fb7680904c 100644
--- a/src/gui/qgsmaptoolidentifyfeature.cpp
+++ b/src/gui/qgsmaptoolidentifyfeature.cpp
@@ -18,10 +18,10 @@
 #include "qgsmaptoolidentifyfeature.h"
 #include "qgsmapcanvas.h"
 
-QgsMapToolIdentifyFeature::QgsMapToolIdentifyFeature( QgsVectorLayer* vl, QgsMapCanvas* canvas )
+QgsMapToolIdentifyFeature::QgsMapToolIdentifyFeature( QgsMapCanvas* canvas, QgsVectorLayer* vl )
     : QgsMapToolIdentify( canvas )
-    , mLayer( vl )
     , mCanvas( canvas )
+    , mLayer( vl )
 {
 }
 
diff --git a/src/gui/qgsmaptoolidentifyfeature.h b/src/gui/qgsmaptoolidentifyfeature.h
index 87cbf68bc66..8da70d37782 100644
--- a/src/gui/qgsmaptoolidentifyfeature.h
+++ b/src/gui/qgsmaptoolidentifyfeature.h
@@ -19,7 +19,7 @@
 #include "qgsmaptoolidentify.h"
 
 /**
- * @brief The QgsMapToolIdentifyFeature class is a map tool to be used to identify a feature on a chosen layer.
+ * @brief The QgsMapToolIdentifyFeature class is a map tool to identify a feature on a chosen layer.
  * Once the map tool is enable, user can click on the map canvas to identify a feature.
  * A signal will then be emitted.
  */
@@ -28,7 +28,15 @@ class GUI_EXPORT QgsMapToolIdentifyFeature : public QgsMapToolIdentify
     Q_OBJECT
 
   public:
-    QgsMapToolIdentifyFeature( QgsVectorLayer* vl, QgsMapCanvas* canvas );
+    /**
+     * @brief QgsMapToolIdentifyFeature is a map tool to identify a feature on a chosen layer
+     * @param canvas the map canvas
+     * @param vl the vector layer. The map tool can be initialized without any layer and can be set afterward.
+     */
+    QgsMapToolIdentifyFeature( QgsMapCanvas* canvas, QgsVectorLayer* vl = 0 );
+
+    //! change the layer used by the map tool to identify
+    void setLayer( QgsVectorLayer* vl ){ mLayer = vl; }
 
     virtual void canvasReleaseEvent( QMouseEvent* e );
 
@@ -40,8 +48,8 @@ class GUI_EXPORT QgsMapToolIdentifyFeature : public QgsMapToolIdentify
     virtual void keyPressEvent( QKeyEvent* e );
 
   private:
-    QgsVectorLayer* mLayer;
     QgsMapCanvas* mCanvas;
+    QgsVectorLayer* mLayer;
 };
 
 #endif // QGSMAPTOOLIDENTIFYFEATURE_H