"New Project" wizard: Create project parent directory, if needed

There's no reason to force users to the terminal if they want to create
their project in a new subdirectory.

Fixes: QTCREATORBUG-28346
Change-Id: Id92b2194c018274aac6f7f29c7304efa8c1d2d9e
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/pathchooser.h

@@ -53,7 +53,7 @@ public:
     };
     Q_ENUM(Kind)
 
-    // Default is <Directory>
+    // Default is <ExistingDirectory>
     void setExpectedKind(Kind expected);
     Kind expectedKind() const;
 

src/libs/utils/projectintropage.cpp

@@ -78,6 +78,7 @@ ProjectIntroPage::ProjectIntroPage(QWidget *parent) :
     d->m_nameLineEdit = new Utils::FancyLineEdit(frame);
 
     d->m_pathChooser = new Utils::PathChooser(frame);
+    d->m_pathChooser->setExpectedKind(PathChooser::Directory);
     d->m_pathChooser->setDisabled(d->m_forceSubProject);
 
     d->m_projectsDirectoryCheckBox = new QCheckBox(tr("Use as default project location"));
@@ -217,7 +218,12 @@ bool ProjectIntroPage::validate()
         filePath().pathAppended(QDir::fromNativeSeparators(d->m_nameLineEdit->text()));
 
     if (!projectDir.exists()) { // All happy
-        hideStatusLabel();
+        if (!d->m_pathChooser->filePath().exists()) {
+            displayStatusMessage(InfoLabel::Information, tr("Directory \"%1\" will be created.")
+                                 .arg(d->m_pathChooser->filePath().toUserOutput()));
+        } else {
+            hideStatusLabel();
+        }
         return true;
     }