Template: Revise trySetTemplateGeoreferenced

Don't return the resulting value, but indicate success or error.
This is necessary to suppress an error message if the user
intentionally cancelled CRS configuration on enabling geoerefencing.

Author: dg0yt

src/gui/widgets/template_list_widget.cpp

@@ -1,6 +1,6 @@
 /*
  *    Copyright 2012, 2013 Thomas Schöps
- *    Copyright 2012-2019 Kai Pastor
+ *    Copyright 2012-2020 Kai Pastor
  *
  *    This file is part of OpenOrienteering.
  *
@@ -1102,7 +1102,7 @@ void TemplateListWidget::changeGeorefClicked()
 			if (position_action->isChecked())
 				position_action->trigger();
 		}
-		if (templ->trySetTemplateGeoreferenced(new_value, this) != new_value)
+		if (!templ->trySetTemplateGeoreferenced(new_value, this))
 		{
 			QMessageBox::warning(this, tr("Error"), tr("Cannot change the georeferencing state."));
 			georef_action->setChecked(templ->isTemplateGeoreferenced());

src/templates/template.cpp

@@ -1,6 +1,6 @@
 /*
  *    Copyright 2012, 2013 Thomas Schöps
- *    Copyright 2013-2019 Kai Pastor
+ *    Copyright 2013-2020 Kai Pastor
  *
  *    This file is part of OpenOrienteering.
  *
@@ -676,9 +676,9 @@ bool Template::canChangeTemplateGeoreferenced()
 }
 
 // virtual
-bool Template::trySetTemplateGeoreferenced(bool /*value*/, QWidget* /*dialog_parent*/)
+bool Template::trySetTemplateGeoreferenced(bool value, QWidget* /*dialog_parent*/)
 {
-	return is_georeferenced;
+	return isTemplateGeoreferenced() == value;
 }
 
 

src/templates/template.h

@@ -1,6 +1,6 @@
 /*
  *    Copyright 2012, 2013 Thomas Schöps
- *    Copyright 2012-2019 Kai Pastor
+ *    Copyright 2012-2020 Kai Pastor
  *
  *    This file is part of OpenOrienteering.
  *
@@ -518,12 +518,11 @@ Q_OBJECT
 	 * Tries to change the usage of georeferencing data.
 	 * 
 	 * If supported by the actual template, this function tries to switch the
-	 * state between non-georeferenced and georeferenced. It returns the final
-	 * state which may be the same as before if the change is not implemented
-	 * or fails for other reasons.
+	 * state between non-georeferenced and georeferenced. It returns false when
+	 * an error occurred, and true if the change was successful or if it was
+	 * explicitly cancelled by the user.
 	 * 
-	 * The default implementation changes nothing, and it just returns the
-	 * current state.
+	 * The default implementation returns true iff the state matches the value.
 	 */
 	virtual bool trySetTemplateGeoreferenced(bool value, QWidget* dialog_parent);
 

src/templates/template_image.cpp

@@ -385,7 +385,7 @@ bool TemplateImage::trySetTemplateGeoreferenced(bool value, QWidget* dialog_pare
 			            dialog_parent,
 			            tr("Select the coordinate reference system of the coordinates in the world file") );
 			if (dialog.exec() == QDialog::Rejected)
-				return isTemplateGeoreferenced();
+				return true;  // not failed!
 
 			setTemplateAreaDirty();
 			available_georef.effective.crs_spec = dialog.currentCRSSpec();
@@ -404,7 +404,7 @@ bool TemplateImage::trySetTemplateGeoreferenced(bool value, QWidget* dialog_pare
 		}
 		map->setTemplatesDirty();
 	}
-	return isTemplateGeoreferenced();
+	return isTemplateGeoreferenced() == value;
 }
 
 void TemplateImage::updateGeoreferencing()