Merge pull request #42245 from m-kuhn/getprint_size

Allow specifying width and height for GetPrint images

src/core/layout/qgslayoutexporter.cpp

@@ -199,12 +199,14 @@ QImage QgsLayoutExporter::renderPageToImage( int page, QSize imageSize, double d
 
   QRectF paperRect = QRectF( pageItem->pos().x(), pageItem->pos().y(), pageItem->rect().width(), pageItem->rect().height() );
 
-  if ( imageSize.isValid() && ( !qgsDoubleNear( static_cast< double >( imageSize.width() ) / imageSize.height(),
-                                paperRect.width() / paperRect.height(), 0.008 ) ) )
+  const double imageAspectRatio = static_cast< double >( imageSize.width() ) / imageSize.height();
+  const double paperAspectRatio = paperRect.width() / paperRect.height();
+  if ( imageSize.isValid() && ( !qgsDoubleNear( imageAspectRatio, paperAspectRatio, 0.008 ) ) )
   {
     // specified image size is wrong aspect ratio for paper rect - so ignore it and just use dpi
     // this can happen e.g. as a result of data defined page sizes
     // see https://github.com/qgis/QGIS/issues/26422
+    QgsMessageLog::logMessage( QObject::tr( "Ignoring custom image size because aspect ratio %1 does not match paper ratio %2" ).arg( QString::number( imageAspectRatio, 'g', 3 ), QString::number( paperAspectRatio, 'g', 3 ) ), QStringLiteral( "Layout" ), Qgis::Warning );
     imageSize = QSize();
   }
 

src/server/services/wms/qgswmsrenderer.cpp

@@ -495,9 +495,35 @@ namespace QgsWms
       exportSettings.flags |= QgsLayoutRenderContext::FlagDrawSelection;
       // Destination image size in px
       QgsLayoutSize layoutSize( layout->pageCollection()->page( 0 )->sizeWithUnits() );
+
       QgsLayoutMeasurement width( layout->convertFromLayoutUnits( layoutSize.width(), QgsUnitTypes::LayoutUnit::LayoutMillimeters ) );
       QgsLayoutMeasurement height( layout->convertFromLayoutUnits( layoutSize.height(), QgsUnitTypes::LayoutUnit::LayoutMillimeters ) );
-      exportSettings.imageSize = QSize( static_cast<int>( width.length() * dpi / 25.4 ), static_cast<int>( height.length() * dpi / 25.4 ) );
+
+      const QSize imageSize = QSize( static_cast<int>( width.length() * dpi / 25.4 ), static_cast<int>( height.length() * dpi / 25.4 ) );
+
+      const QString paramWidth = mWmsParameters.width();
+      const QString paramHeight = mWmsParameters.height();
+
+      // Prefer width and height from the http request
+      // Fallback to predefined values from layout
+      // Preserve aspect ratio if only one value is specified
+      if ( !paramWidth.isEmpty() && !paramHeight.isEmpty() )
+      {
+        exportSettings.imageSize = QSize( paramWidth.toInt(), paramHeight.toInt() );
+      }
+      else if ( !paramWidth.isEmpty() && paramHeight.isEmpty() )
+      {
+        exportSettings.imageSize = QSize( paramWidth.toInt(), static_cast<double>( paramWidth.toInt() ) / imageSize.width() * imageSize.height() );
+      }
+      else if ( paramWidth.isEmpty() && !paramHeight.isEmpty() )
+      {
+        exportSettings.imageSize = QSize( static_cast<double>( paramHeight.toInt() ) / imageSize.height() * imageSize.width(), paramHeight.toInt() );
+      }
+      else
+      {
+        exportSettings.imageSize = imageSize;
+      }
+
       // Export first page only (unless it's a pdf, see below)
       exportSettings.pages.append( 0 );
       if ( atlas )

tests/src/python/test_qgsserver_wms_getprint.py

@@ -25,6 +25,8 @@
 
 from test_qgsserver import QgsServerTestBase
 
+from qgis.PyQt.QtCore import QSize
+
 
 class TestQgsServerWMSGetPrint(QgsServerTestBase):
     """QGIS Server WMS Tests for GetPrint request"""
@@ -274,6 +276,24 @@ def test_wms_getprint_scale(self):
         r, h = self._result(self._execute_request(qs))
         self._img_diff_error(r, h, "WMS_GetPrint_Scale")
 
+    def test_wms_getprint_size(self):
+        qs = "?" + "&".join(["%s=%s" % i for i in list({
+            "MAP": urllib.parse.quote(self.projectPath),
+            "SERVICE": "WMS",
+            "VERSION": "1.1.1",
+            "REQUEST": "GetPrint",
+            "TEMPLATE": "layoutA4",
+            "FORMAT": "png",
+            "map0:EXTENT": "-33626185.498,-13032965.185,33978427.737,16020257.031",
+            "map0:LAYERS": "Country,Hello",
+            "map0:SCALE": "36293562",
+            "CRS": "EPSG:3857",
+            "HEIGHT": "100"
+        }.items())])
+
+        r, h = self._result(self._execute_request(qs))
+        self._img_diff_error(r, h, "WMS_GetPrint_Size", max_size_diff=QSize(1, 1))
+
     def test_wms_getprint_grid(self):
         qs = "?" + "&".join(["%s=%s" % i for i in list({
             "MAP": urllib.parse.quote(self.projectPath),