Standardise API for deciding whether the datum transform dialog should be shown

nyalldawson · nyalldawson · commit 0b6fdd9b09f5 · 2019-03-22T15:38:11.000+10:00
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -7855,8 +7855,7 @@ QString QgisApp::saveAsVectorFileGeneral( QgsVectorLayer *vlayer, bool symbology
       //ask user about datum transformation
       QgsSettings settings;
       QgsDatumTransformDialog dlg( vlayer->crs(), destCRS );
-      if ( dlg.availableTransformationCount() > 1 &&
-           settings.value( QStringLiteral( "Projections/showDatumTransformDialog" ), false ).toBool() )
+      if ( dlg.shouldAskUserForSelection() )
       {
         dlg.exec();
       }
@@ -9912,6 +9911,7 @@ void QgisApp::projectCrsChanged()
   }
   else if ( transformsToAskFor.count() > 1 )
   {
+    // TODO - this should actually loop through and ask for each in turn
     bool ask = QgsSettings().value( QStringLiteral( "/Projections/showDatumTransformDialog" ), false ).toBool();
     if ( ask )
     {
@@ -9921,8 +9921,6 @@ void QgisApp::projectCrsChanged()
                                         5 );
     }
   }
-
-
 }
 
 // toggle overview status
@@ -13736,14 +13734,9 @@ bool QgisApp::askUserForDatumTransform( const QgsCoordinateReferenceSystem &sour
   {
     //if several possibilities:  present dialog
     QgsDatumTransformDialog dlg( sourceCrs, destinationCrs );
-    if ( dlg.availableTransformationCount() > 1 )
+    if ( dlg.shouldAskUserForSelection() )
     {
-      bool ask = QgsSettings().value( QStringLiteral( "/Projections/showDatumTransformDialog" ), false ).toBool();
-      if ( !ask )
-      {
-        ok = false;
-      }
-      else if ( dlg.exec() )
+      if ( dlg.exec() )
       {
         QPair< QPair<QgsCoordinateReferenceSystem, int>, QPair<QgsCoordinateReferenceSystem, int > > dt = dlg.selectedDatumTransforms();
         QgsCoordinateTransformContext context = QgsProject::instance()->transformContext();
diff --git a/src/gui/qgsdatumtransformdialog.cpp b/src/gui/qgsdatumtransformdialog.cpp
@@ -195,6 +195,16 @@ int QgsDatumTransformDialog::availableTransformationCount()
   return mDatumTransforms.count();
 }
 
+bool QgsDatumTransformDialog::shouldAskUserForSelection()
+{
+  if ( availableTransformationCount() > 1 )
+  {
+    return QgsSettings().value( QStringLiteral( "/Projections/showDatumTransformDialog" ), false ).toBool();
+  }
+  // TODO: show if transform grids are required, but missing
+  return false;
+}
+
 QPair<QPair<QgsCoordinateReferenceSystem, int>, QPair<QgsCoordinateReferenceSystem, int> > QgsDatumTransformDialog::selectedDatumTransforms()
 {
   int row = mDatumTransformTableWidget->currentRow();
diff --git a/src/gui/qgsdatumtransformdialog.h b/src/gui/qgsdatumtransformdialog.h
@@ -54,6 +54,13 @@ class GUI_EXPORT QgsDatumTransformDialog : public QDialog, private Ui::QgsDatumT
      */
     int availableTransformationCount();
 
+    /**
+     * Returns true if the dialog should be shown and the user prompted to make the transformation selection.
+     *
+     * \since QGIS 3.8
+     */
+    bool shouldAskUserForSelection();
+
     /**
      * Returns the source and destination transforms, each being a pair of QgsCoordinateReferenceSystems and datum transform code
      * \since 3.0

Original file line number	Diff line number	Diff line change
`@@ -7855,8 +7855,7 @@ QString QgisApp::saveAsVectorFileGeneral( QgsVectorLayer *vlayer, bool symbology`
`7855`	`7855`	`//ask user about datum transformation`
`7856`	`7856`	`QgsSettings settings;`
`7857`	`7857`	`QgsDatumTransformDialog dlg( vlayer->crs(), destCRS );`
`7858`		`- if ( dlg.availableTransformationCount() > 1 &&`
`7859`		`- settings.value( QStringLiteral( "Projections/showDatumTransformDialog" ), false ).toBool() )`
	`7858`	`+ if ( dlg.shouldAskUserForSelection() )`
`7860`	`7859`	`{`
`7861`	`7860`	`dlg.exec();`
`7862`	`7861`	`}`
`@@ -9912,6 +9911,7 @@ void QgisApp::projectCrsChanged()`
`9912`	`9911`	`}`
`9913`	`9912`	`else if ( transformsToAskFor.count() > 1 )`
`9914`	`9913`	`{`
	`9914`	`+ // TODO - this should actually loop through and ask for each in turn`
`9915`	`9915`	`bool ask = QgsSettings().value( QStringLiteral( "/Projections/showDatumTransformDialog" ), false ).toBool();`
`9916`	`9916`	`if ( ask )`
`9917`	`9917`	`{`
`@@ -9921,8 +9921,6 @@ void QgisApp::projectCrsChanged()`
`9921`	`9921`	`5 );`
`9922`	`9922`	`}`
`9923`	`9923`	`}`
`9924`		`-`
`9925`		`-`
`9926`	`9924`	`}`
`9927`	`9925`
`9928`	`9926`	`// toggle overview status`
`@@ -13736,14 +13734,9 @@ bool QgisApp::askUserForDatumTransform( const QgsCoordinateReferenceSystem &sour`
`13736`	`13734`	`{`
`13737`	`13735`	`//if several possibilities: present dialog`
`13738`	`13736`	`QgsDatumTransformDialog dlg( sourceCrs, destinationCrs );`
`13739`		`- if ( dlg.availableTransformationCount() > 1 )`
	`13737`	`+ if ( dlg.shouldAskUserForSelection() )`
`13740`	`13738`	`{`
`13741`		`- bool ask = QgsSettings().value( QStringLiteral( "/Projections/showDatumTransformDialog" ), false ).toBool();`
`13742`		`- if ( !ask )`
`13743`		`- {`
`13744`		`- ok = false;`
`13745`		`- }`
`13746`		`- else if ( dlg.exec() )`
	`13739`	`+ if ( dlg.exec() )`
`13747`	`13740`	`{`
`13748`	`13741`	`QPair< QPair<QgsCoordinateReferenceSystem, int>, QPair<QgsCoordinateReferenceSystem, int > > dt = dlg.selectedDatumTransforms();`
`13749`	`13742`	`QgsCoordinateTransformContext context = QgsProject::instance()->transformContext();`