Added DockWidgetBase::hasPreviousDockedLocation()

src/DockWidgetBase.cpp

@@ -110,7 +110,7 @@ public:
     void onDockWidgetHidden();
     void show();
     void close();
-    void restoreToPreviousPosition();
+    bool restoreToPreviousPosition();
     void maybeRestoreToPreviousPosition();
     int currentTabIndex() const;
 
@@ -267,15 +267,12 @@ bool DockWidgetBase::isFloating() const
     return fw && fw->hasSingleDockWidget();
 }
 
-void DockWidgetBase::setFloating(bool floats)
+bool DockWidgetBase::setFloating(bool floats)
 {
     const bool alreadyFloating = isFloating();
 
-    qCDebug(docking) << Q_FUNC_INFO << "yes=" << floats
-                     << "; already floating=" << alreadyFloating;
-
     if ((floats && alreadyFloating) || (!floats && !alreadyFloating))
-        return; // Nothing to do
+        return true; // Nothing to do
 
     if (floats) {
         d->saveTabIndex();
@@ -285,6 +282,7 @@ void DockWidgetBase::setFloating(bool floats)
                 qWarning() << "DockWidget::setFloating: Tabbed but no frame exists"
                            << this;
                 Q_ASSERT(false);
+                return false;
             }
 
             frame->detachTab(this);
@@ -297,9 +295,10 @@ void DockWidgetBase::setFloating(bool floats)
             if (auto fw = floatingWindow())
                 fw->setSuggestedGeometry(lastGeo, /*preserveCenter=*/true);
         }
+        return true;
     } else {
         saveLastFloatingGeometry();
-        d->restoreToPreviousPosition();
+        return d->restoreToPreviousPosition();
     }
 }
 
@@ -511,6 +510,11 @@ SideBarLocation DockWidgetBase::sideBarLocation() const
     return DockRegistry::self()->sideBarLocationForDockWidget(this);
 }
 
+bool DockWidgetBase::hasPreviousDockedLocation() const
+{
+    return d->m_lastPositions.isValid();
+}
+
 FloatingWindow *DockWidgetBase::morphIntoFloatingWindow()
 {
     qCDebug(creation) << "DockWidget::morphIntoFloatingWindow() this=" << this
@@ -680,16 +684,17 @@ void DockWidgetBase::Private::close()
     }
 }
 
-void DockWidgetBase::Private::restoreToPreviousPosition()
+bool DockWidgetBase::Private::restoreToPreviousPosition()
 {
     if (!m_lastPositions.isValid())
-        return;
+        return false;
 
     Layouting::Item *item = m_lastPositions.lastItem();
 
     MultiSplitter *layout = DockRegistry::self()->layoutForItem(item);
     Q_ASSERT(layout);
     layout->restorePlaceholder(q, item, m_lastPositions.lastTabIndex());
+    return true;
 }
 
 void DockWidgetBase::Private::maybeRestoreToPreviousPosition()

src/DockWidgetBase.h

@@ -158,8 +158,10 @@ public:
     /**
      * @brief setter to make the dock widget float or dock.
      * @param floats If true makes the dock widget float, otherwise docks it.
+     *
+     * Returns true if the request was accomplished
      */
-    void setFloating(bool floats);
+    bool setFloating(bool floats);
 
     /**
      * @brief Returns the QAction that allows to hide/show the dock widget
@@ -360,6 +362,12 @@ public:
     /// This is only relevant when using the auto-hide and side-bar feature.
     SideBarLocation sideBarLocation() const;
 
+    /// @brief Returns whether this floating dock widget knows its previous docked location
+    /// Result only makes sense if it's floating.
+    ///
+    /// When you call dockWidget->setFloating(false) it will only dock if it knows where to.
+    bool hasPreviousDockedLocation() const;
+
 Q_SIGNALS:
     ///@brief signal emitted when the parent changed
     void parentChanged();

tests/tst_common.cpp

@@ -61,6 +61,7 @@ private Q_SLOTS:
     void tst_simple1();
     void tst_doesntHaveNativeTitleBar();
     void tst_resizeWindow2();
+    void tst_hasLastDockedLocation();
 };
 
 void TestCommon::tst_simple1()
@@ -117,6 +118,30 @@ void TestCommon::tst_resizeWindow2()
     delete fw2;
 }
 
+void TestCommon::tst_hasLastDockedLocation()
+{
+    // Tests DockWidgetBase::hasPreviousDockedLocation()
+
+    EnsureTopLevelsDeleted e;
+    auto m = createMainWindow(QSize(501, 500), MainWindowOption_None);
+    auto dock1 = createDockWidget("1");
+    auto window1 = dock1->window();
+    QVERIFY(dock1->isFloating());
+    QVERIFY(!dock1->hasPreviousDockedLocation());
+    QVERIFY(dock1->setFloating(true));
+    QVERIFY(!dock1->setFloating(false)); // No docking location, so it's not docked
+    QVERIFY(dock1->isFloating());
+    QVERIFY(!dock1->hasPreviousDockedLocation());
+
+    m->addDockWidget(dock1, Location_OnBottom);
+    QVERIFY(!dock1->isFloating());
+    QVERIFY(dock1->setFloating(true));
+    QVERIFY(dock1->hasPreviousDockedLocation());
+    QVERIFY(dock1->setFloating(false));
+
+    delete window1;
+}
+
 int main(int argc, char *argv[])
 {
     if (!qpaPassedAsArgument(argc, argv)) {