invalidate map settings when ...

parameters of QgsMapToPixel leads to an invalid transform
qgis · May 31, 2021 · 09b5ba4 · 09b5ba4
1 parent 8ff0efd
commit 09b5ba4
Show file tree

Hide file tree

Showing 4 changed files with 50 additions and 8 deletions.
diff --git a/python/core/auto_generated/qgsmaptopixel.sip.in b/python/core/auto_generated/qgsmaptopixel.sip.in
@@ -181,9 +181,14 @@ Set parameters for use in transforming coordinates
 :param heightPixels: Output height, in pixels
 :param rotation: clockwise rotation in degrees
 
+.. note::
+
+   if parameters leads to a non valid transform, parameters are not changed
+
 .. versionadded:: 2.8
 %End
 
+
     QString showParameters() const;
 %Docstring
 String representation of the parameters used in the transform

diff --git a/src/core/qgsmapsettings.cpp b/src/core/qgsmapsettings.cpp
@@ -194,12 +194,16 @@ void QgsMapSettings::updateDerived()
   mScaleCalculator.setDpi( mDpi * mDevicePixelRatio );
   mScale = mScaleCalculator.calculate( mVisibleExtent, mSize.width() );
 
-  mMapToPixel.setParameters( mapUnitsPerPixel(),
-                             visibleExtent().center().x(),
-                             visibleExtent().center().y(),
-                             outputSize().width(),
-                             outputSize().height(),
-                             mRotation );
+  bool ok = true;
+  mMapToPixel.setParameters(
+    mapUnitsPerPixel(),
+    visibleExtent().center().x(),
+    visibleExtent().center().y(),
+    outputSize().width(),
+    outputSize().height(),
+    mRotation, &ok );
+
+  mValid = ok;
 
 #if 1 // set visible extent taking rotation in consideration
   if ( mRotation )
@@ -228,7 +232,6 @@ void QgsMapSettings::updateDerived()
   QgsDebugMsgLevel( QStringLiteral( "Visible Extent: %1" ).arg( mVisibleExtent.asWktCoordinates() ), 5 );
   QgsDebugMsgLevel( QStringLiteral( "Magnification factor: %1" ).arg( mMagnificationFactor ), 5 );
 
-  mValid = true;
 }
 
 

diff --git a/src/core/qgsmaptopixel.cpp b/src/core/qgsmaptopixel.cpp
@@ -118,7 +118,8 @@ void QgsMapToPixel::setParameters( double mapUnitsPerPixel,
                                    double yc,
                                    int width,
                                    int height,
-                                   double rotation )
+                                   double rotation,
+                                   bool *ok )
 {
   double oldMUPP = mMapUnitsPerPixel;
   double oldXCenter = mXCenter;
@@ -148,9 +149,25 @@ void QgsMapToPixel::setParameters( double mapUnitsPerPixel,
     mRotation = oldRotation;
     mXMin = oldXMin;
     mYMin = oldYMin;
+    *ok = false;
+  }
+  else
+  {
+    *ok = true;
   }
 }
 
+void QgsMapToPixel::setParameters( double mapUnitsPerPixel,
+                                   double xc,
+                                   double yc,
+                                   int width,
+                                   int height,
+                                   double rotation )
+{
+  bool ok;
+  setParameters( mapUnitsPerPixel, xc, yc, width, height, rotation, &ok );
+}
+
 QString QgsMapToPixel::showParameters() const
 {
   QString rep;
@@ -185,3 +202,4 @@ QTransform QgsMapToPixel::transform() const
            .translate( -mXCenter, -mYCenter );
   }
 }
+
diff --git a/src/core/qgsmaptopixel.h b/src/core/qgsmaptopixel.h
@@ -237,10 +237,26 @@ class CORE_EXPORT QgsMapToPixel
      * \param widthPixels Output width, in pixels
      * \param heightPixels Output height, in pixels
      * \param rotation clockwise rotation in degrees
+     *
+     * \note if parameters leads to a non valid transform, parameters are not changed
      * \since QGIS 2.8
      */
     void setParameters( double mapUnitsPerPixel, double centerX, double centerY, int widthPixels, int heightPixels, double rotation );
 
+    /**
+     * Set parameters for use in transforming coordinates
+     * \param mapUnitsPerPixel Map units per pixel
+     * \param centerX X coordinate of map center, in geographical units
+     * \param centerY Y coordinate of map center, in geographical units
+     * \param widthPixels Output width, in pixels
+     * \param heightPixels Output height, in pixels
+     * \param rotation clockwise rotation in degrees
+     * \param ok will be set to true if parameters leads to a valid transform, otherwise  parameters are not changed and ok will be set to false
+     *
+     * \since QGIS 3.20
+     */
+    void setParameters( double mapUnitsPerPixel, double centerX, double centerY, int widthPixels, int heightPixels, double rotation, bool *ok ) SIP_SKIP;
+
     //! String representation of the parameters used in the transform
     QString showParameters() const;