Alternatives to QToolBar::floatable for Docking Functionality in Qt

QToolBar::floatable

In Qt Widgets, the QToolBar class provides a convenient way to create toolbars that can be docked within a window or become floating windows themselves. The floatable property of QToolBar controls this behavior.

Functionality

• When floatable is set to false, the toolbar remains fixed in its docked position and cannot be made to float.
• When floatable is set to true (the default), the user can drag the toolbar away from its docked position, transforming it into a separate floating window. This window remains on top of the main application window, allowing for easy access to the toolbar's actions and widgets.

Controlling Floatable Behavior

• You can also check the current floating state using the isFloating method:

  if (toolbar->isFloating()) {
      // Toolbar is currently floating
  } else {
      // Toolbar is docked
  }
  

• You can set the floatable property using the setFloatable method:

  QToolBar* toolbar = new QToolBar(this);
  toolbar->setFloatable(true); // Allow floating
  // ... (add actions or widgets to the toolbar)
  addToolBar(Qt::TopToolBarArea, toolbar);
  

• The topLevelChanged(bool) signal is emitted whenever the floating property changes. This can be useful for reacting to the toolbar becoming floating or docked again.
• The allowedAreas property of QToolBar can be used to restrict where the toolbar can be docked within the main window. This can be helpful in conjunction with floatable to create a more controlled docking experience.

---

#include <QApplication>
#include <QMainWindow>
#include <QToolBar>
#include <QPushButton>

class MainWindow : public QMainWindow {
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);

private:
    QToolBar *fileToolBar;
    QPushButton *openButton;
    QPushButton *saveButton;
};

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) {
    // Create a toolbar
    fileToolBar = new QToolBar(this);
    fileToolBar->setFloatable(true); // Allow floating
    fileToolBar->setWindowTitle("File Toolbar"); // Set title for floating window

    // Create buttons
    openButton = new QPushButton(QIcon(":/icons/open.png"), "Open", this);
    saveButton = new QPushButton(QIcon(":/icons/save.png"), "Save", this);

    // Add buttons to the toolbar
    fileToolBar->addWidget(openButton);
    fileToolBar->addWidget(saveButton);

    // Add the toolbar to the main window (optional, can be left floating)
    addToolBar(Qt::TopToolBarArea, fileToolBar);

    // ... (other window setup code)
}

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    MainWindow window;
    window.show();
    return app.exec();
}

1. We create a QMainWindow class named MainWindow.
2. Inside the MainWindow constructor:
   • We create a QToolBar instance called fileToolBar and set its floatable property to true.
   • We optionally set a title for the floating window using setWindowTitle().
   • We create two QPushButton instances for "Open" and "Save" actions.
   • We add these buttons to the toolbar using addWidget().
   • We can optionally add the toolbar to the main window using addToolBar(). However, setting floatable allows it to exist as a separate window.

---

QDockWidget

• It's a more complex solution compared to QToolBar::floatable but offers greater flexibility.
• You can control docking behavior (auto-hide, tabbed docking), and even create custom dock widget areas.
• QDockWidget provides a more powerful and customizable docking framework. It allows for docking widgets in various locations within the main window (top, bottom, sides) and even nesting dock widgets within other dock widgets.

Custom Docking System

• This can be time-consuming to develop but provides the ultimate level of customization.
• If you need even more control over docking behavior, you can create your own custom docking system. This approach involves implementing the dragging, dropping, and positioning logic yourself.

Third-Party Docking Libraries

• Several third-party libraries provide advanced docking functionality for Qt applications. Examples include KDDockWidgets and Qt Advanced Docking System. These libraries offer features like:
  • Tabbed docking within dock widgets
  • Docking to the center of the main window
  • Enhanced customization options

Choosing the Right Option

• For maximum customization or specific needs not met by Qt's built-in solutions, explore creating a custom docking system or using a third-party library.
• If you need more advanced docking features with nested dock widgets and auto-hide behavior, consider using QDockWidget.
• If you need simple detachable toolbars, QToolBar::floatable is a good starting point.

• Creating a custom docking system requires significant development effort.
• Third-party libraries can add complexity and may require additional licensing considerations.
• QToolBar::floatable offers a lightweight solution but doesn't provide the same level of control as QDockWidget.