When reading a project, fallback to default view extent if canvas

extents are not set
qgis · Oct 31, 2019 · 8b7447a · 8b7447a
1 parent f602ed3
commit 8b7447a
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diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -74,6 +74,7 @@ email                : sherman at mrcc.com
 #include "qgsmimedatautils.h"
 #include "qgscustomdrophandler.h"
 #include "qgsreferencedgeometry.h"
+#include "qgsprojectviewsettings.h"
 
 /**
  * \ingroup gui
@@ -2137,6 +2138,8 @@ void QgsMapCanvas::setSnappingUtils( QgsSnappingUtils *utils )
 
 void QgsMapCanvas::readProject( const QDomDocument &doc )
 {
+  QgsProject *project = qobject_cast< QgsProject * >( sender() );
+
   QDomNodeList nodes = doc.elementsByTagName( QStringLiteral( "mapcanvas" ) );
   if ( nodes.count() )
   {
@@ -2191,6 +2194,11 @@ void QgsMapCanvas::readProject( const QDomDocument &doc )
   else
   {
     QgsDebugMsg( QStringLiteral( "Couldn't read mapcanvas information from project" ) );
+    if ( !project->viewSettings()->defaultViewExtent().isNull() )
+    {
+      setReferencedExtent( project->viewSettings()->defaultViewExtent() );
+      clearExtentHistory(); // clear the extent history on project load
+    }
   }
 }
 

diff --git a/tests/src/python/test_qgsprojectviewsettings.py b/tests/src/python/test_qgsprojectviewsettings.py
@@ -12,11 +12,15 @@
 
 import qgis  # NOQA
 
-from qgis.core import (QgsProjectViewSettings,
+from qgis.core import (QgsProject,
+                       QgsProjectViewSettings,
                        QgsReadWriteContext,
                        QgsReferencedRectangle,
                        QgsRectangle,
                        QgsCoordinateReferenceSystem)
+from qgis.gui import QgsMapCanvas
+
+from qgis.PyQt.QtCore import QTemporaryDir
 
 from qgis.PyQt.QtTest import QSignalSpy
 from qgis.PyQt.QtXml import QDomDocument, QDomElement
@@ -81,6 +85,43 @@ def testDefaultViewExtent(self):
         p.reset()
         self.assertTrue(p.defaultViewExtent().isNull())
 
+    def testDefaultViewExtentWithCanvas(self):
+        p = QgsProject()
+        p.setCrs(QgsCoordinateReferenceSystem('EPSG:3857'))
+
+        canvas = QgsMapCanvas()
+        canvas.setDestinationCrs(QgsCoordinateReferenceSystem(4326))
+        canvas.setFrameStyle(0)
+        canvas.resize(600, 400)
+        self.assertEqual(canvas.width(), 600)
+        self.assertEqual(canvas.height(), 400)
+        canvas.setExtent(QgsRectangle(10, 30, 20, 35))
+        canvas.show()
+
+        tmpDir = QTemporaryDir()
+        tmpFile = "{}/project.qgz".format(tmpDir.path())
+        self.assertTrue(p.write(tmpFile))
+
+        QgsProject.instance().read(tmpFile)
+
+        # no default view, extent should not change
+        self.assertAlmostEqual(canvas.extent().xMinimum(), 10, 3)
+        self.assertAlmostEqual(canvas.extent().yMinimum(), 29.16666, 3)
+        self.assertAlmostEqual(canvas.extent().xMaximum(), 20, 3)
+        self.assertAlmostEqual(canvas.extent().yMaximum(), 35.833333333, 3)
+        self.assertEqual(canvas.mapSettings().destinationCrs().authid(), 'EPSG:4326')
+
+        p.viewSettings().setDefaultViewExtent(QgsReferencedRectangle(QgsRectangle(1000, 2000, 1500, 2500), QgsCoordinateReferenceSystem('EPSG:3857')))
+
+        self.assertTrue(p.write(tmpFile))
+        QgsProject.instance().read(tmpFile)
+
+        self.assertAlmostEqual(canvas.extent().xMinimum(), 0.0078602, 3)
+        self.assertAlmostEqual(canvas.extent().yMinimum(), 0.017966, 3)
+        self.assertAlmostEqual(canvas.extent().xMaximum(), 0.01459762, 3)
+        self.assertAlmostEqual(canvas.extent().yMaximum(), 0.02245788, 3)
+        self.assertEqual(canvas.mapSettings().destinationCrs().authid(), 'EPSG:4326')
+
     def testReadWrite(self):
         p = QgsProjectViewSettings()
         self.assertFalse(p.mapScales())