Fix #315237: Don't switch tab when opening a score when a modal is open

- Don't switch tab when opening a score when a modal is open
- Make ScoreMigrationDialog QQuickWidget, so that it gets recognized by QApplication::activeModalWidget()
- (This caused an issue that the QML content wasn't focussed when the dialog was opened, which I fixed too.)

Result:
- When you open one score, it is appended to the tab bar, and its tab is activated
- The ScoreMigrationDialog for that score is shown
- When you open a second score, it is appended to the tab bar, but its tab is not activated, because a modal dialog is open (namely the ScoreMigrationDialog for score 1)
- When you close the dialog for score 1 and then switch to score 2 's tab, the ScoreMigrationDialog is shown for score 2.

mscore/file.cpp

@@ -404,7 +404,7 @@ Score* MuseScore::openScore(const QString& fn, bool switchTab, const bool consid
       QString path = fi.canonicalFilePath();
       for (Score* s : scoreList) {
             if (s->masterScore() && s->masterScore()->fileInfo()->canonicalFilePath() == path) {
-                  if (switchTab)
+                  if (switchTab && QApplication::activeModalWidget() == nullptr)
                         setCurrentScoreView(scoreList.indexOf(s->masterScore()));
                   return 0;
                   }
@@ -438,7 +438,7 @@ Score* MuseScore::openScore(const QString& fn, bool switchTab, const bool consid
 
             if (considerInCurrentSession) {
                   const int tabIdx = appendScore(score);
-                  if (switchTab)
+                  if (switchTab && QApplication::activeModalWidget() == nullptr)
                         setCurrentScoreView(tabIdx);
                   writeSessionFile(false);
                   }

mscore/migration/scoremigrationdialog.cpp

@@ -1,29 +1,34 @@
 #include "scoremigrationdialog.h"
 
-#include <QQuickItem>
-
 ScoreMigrationDialog::ScoreMigrationDialog(QQmlEngine* engine, Ms::Score* score)
-      : QQuickView(engine, nullptr), m_dialogModel(new ScoreMigrationDialogModel(score, this))
+      : QQuickWidget(engine, nullptr), m_dialogModel(new ScoreMigrationDialogModel(score, this))
       {
       setMinimumWidth(600);
       setMinimumHeight(m_dialogModel->isAutomaticPlacementAvailable() ? 570 : 548);
 
-      setFlags(Qt::Dialog);
+      setWindowFlags(Qt::Dialog);
+      setWindowModality(Qt::ApplicationModal);
 
-      setTitle(score->title());
+      setWindowTitle(score->title());
       setSource(QUrl(QStringLiteral("qrc:/qml/migration/ScoreMigrationDialog.qml")));
 
-      setModality(Qt::ApplicationModal);
-      setResizeMode(QQuickView::SizeRootObjectToView);
+      setResizeMode(SizeRootObjectToView);
 
-      connect(m_dialogModel, &ScoreMigrationDialogModel::closeRequested, this, &QQuickView::close);
+      connect(m_dialogModel, &ScoreMigrationDialogModel::closeRequested, this, &QQuickWidget::close);
 
       if (rootObject())
             rootObject()->setProperty("model", QVariant::fromValue(m_dialogModel));
       }
 
 void ScoreMigrationDialog::focusInEvent(QFocusEvent* event)
       {
-      QQuickView::focusInEvent(event);
+      QQuickWidget::focusInEvent(event);
+      rootObject()->forceActiveFocus();
+      }
+
+void ScoreMigrationDialog::showEvent(QShowEvent* event)
+      {
+      QQuickWidget::showEvent(event);
+      setFocus();
       rootObject()->forceActiveFocus();
       }

mscore/migration/scoremigrationdialog.h

@@ -1,19 +1,17 @@
 #ifndef SCOREMIGRATIONDIALOG_H
 #define SCOREMIGRATIONDIALOG_H
 
-#include <QQuickView>
-#include <QQmlEngine>
-
 #include "scoremigrationdialogmodel.h"
 
-class ScoreMigrationDialog : public QQuickView
+class ScoreMigrationDialog : public QQuickWidget
       {
       Q_OBJECT
 
    public:
       explicit ScoreMigrationDialog(QQmlEngine* engine, Ms::Score *score);
 
    private:
+      void showEvent(QShowEvent* event) override;
       void focusInEvent(QFocusEvent* event) override;
 
       ScoreMigrationDialogModel* m_dialogModel = nullptr;

mscore/startcenter.cpp

@@ -124,8 +124,8 @@ void Startcenter::loadScore(QString s)
             newScore();
             }
       else {
-            mscore->openScore(s);
             close();
+            mscore->openScore(s);
             }
       }