qmdiSplitTab: properly support "new"

When clicking ghenew button from the menu, previously 2 new files were
added. The reason was that I hacked inside the split tab to accept the
new file command.

The correct solution is to leave it to the default `addTab()` method.
However, this broke another thing (which I tried to avoid in the
previous hack): if you click new in a split which was not active, I was
expecting that split to add a new file. Instead - a new tab was added
inside the active tab.

Solution: inside the click handler of the tool buttons, make that tab
active. Now everything works as expected. This is the code in
qmdiSplitTab.

Code in SplitTabsPlugin was removed, as it was wrong to begin  with.

All other code is random cleanups.

Author: diegoiast

src/main.cpp

@@ -90,10 +90,8 @@ int main(int argc, char *argv[]) {
     pluginManager.restoreSettings();
     pluginManager.show();
 
-#if !defined(USE_SPLIT)
     pluginManager.connect(&pluginManager, &PluginManager::newFileRequested,
                           [textEditorPlugin]() { textEditorPlugin->fileNew(); });
-#endif
 
     pluginManager.openFiles(parser.positionalArguments());
     return app.exec();

src/plugins/SplitTabsPlugin/SplitTabsPlugin.cpp

@@ -108,23 +108,6 @@ void SplitTabsPlugin::on_client_merged(qmdiHost *host) {
     manager->replaceMdiServer(split);
     manager->addBuiltinActions();
     manager->updateGUI();
-
-    connect(manager, &PluginManager::newFileRequested, [this](QObject *s) {
-        auto manager = getManager();
-        auto tab = qobject_cast<QTabWidget *>(s->parent());
-        auto index = split->findSplitIndex(tab);
-        if (!tab || index < 0) {
-            // textEditorPlugin->fileNew();
-            return;
-        }
-
-        // we know where exactly to put this
-        auto client = textEditorPlugin->fileNewEditor();
-        auto editor = dynamic_cast<QWidget *>(client);
-        split->addTabToSplit(index, editor, client->mdiClientName, client->mdiClientFileName());
-        client->mdiServer = manager->getMdiServer();
-        editor->setFocus();
-    });
 }
 
 void SplitTabsPlugin::on_client_unmerged(qmdiHost *) {}

src/widgets/SplitTabWidget.cpp

@@ -324,6 +324,8 @@ SplitTabWidget::SplitTabWidget(QWidget *parent)
 void SplitTabWidget::addTab(QWidget *widget, const QString &label, const QString &tooltip) {
     addTabToCurrentSplit(widget, label, tooltip);
 
+    // This code deals with pre-loading. You can configure a the pre-state of the split tab
+    // and then when adding new tabs, the widget will split as requested.
     if (!savedSplitCount.empty()) {
         auto splitsCount = splitter->count();
         auto currentTabIndex = findSplitIndex(currentTabWidget);
@@ -468,6 +470,12 @@ void SplitTabWidget::updateCurrentTabWidget(QTabWidget *newCurrent) {
     if (currentTabWidget == newCurrent) {
         return;
     }
+    if (newCurrent->parentWidget() != splitter) {
+        qDebug()
+            << "updateCurrentTabWidget passing wrong parent, will not update current tab, parent="
+            << newCurrent->parentWidget();
+        return;
+    }
     currentTabWidget = newCurrent;
     if (currentTabWidget && currentTabWidget->currentWidget()) {
         onTabFocusChanged(currentTabWidget->currentWidget(), true);

src/widgets/SplitTabWidget.h

@@ -120,6 +120,8 @@ class SplitTabWidget : public QWidget {
 
     bool closeSplitWhenEmpty = true;
 
+    void updateCurrentTabWidget(QTabWidget *newCurrent);
+
   signals:
     void emptyAreaDoubleClicked(QTabWidget *tabWidget, const QPoint &pos);
 
@@ -129,7 +131,6 @@ class SplitTabWidget : public QWidget {
     SplitterWithWidgetAdded *splitter = nullptr;
     QTabWidget *currentTabWidget = nullptr;
     ButtonsProvider *buttonsProvider = nullptr;
-    void updateCurrentTabWidget(QTabWidget *newCurrent);
     void equalizeWidths();
 
   private slots:

src/widgets/qmdiSplitTab.cpp

@@ -25,7 +25,11 @@ QWidget *DefaultButtonsProvider::requestButton(bool first, int tabIndex, SplitTa
         addNewMdiClient->setAutoRaise(true);
         addNewMdiClient->setIcon(QIcon::fromTheme(QIcon::ThemeIcon::DocumentNew));
         QObject::connect(addNewMdiClient, &QAbstractButton::clicked, addNewMdiClient,
-                         [manager, addNewMdiClient]() {
+                         [manager, addNewMdiClient, split]() {
+                             auto tab = qobject_cast<QTabWidget *>(addNewMdiClient->parentWidget());
+                             if (tab) {
+                                 split->updateCurrentTabWidget(tab);
+                             }
                              if (manager) {
                                  emit manager->newFileRequested(addNewMdiClient);
                              }
@@ -142,8 +146,7 @@ void qmdiSplitTab::addClient(qmdiClient *client) {
     auto w = dynamic_cast<QWidget *>(client);
 
     if (w == nullptr) {
-        qDebug("%s %s %d: warning trying to add a qmdiClient which does not derive "
-               "QWidget",
+        qDebug("%s %s %d: warning trying to add a qmdiClient which does not derive QWidget",
                __FILE__, __FUNCTION__, __LINE__);
         return;
     }