Understanding QDockWidget::windowTitle in Qt Widgets

What is QDockWidget::windowTitle?

In Qt Widgets, QDockWidget::windowTitle is a property that allows you to get or set the title displayed in the caption bar of a QDockWidget. Dock widgets are secondary windows commonly used within a QMainWindow to provide additional functionality or tools.

How to Use QDockWidget::windowTitle

There are two main ways to interact with windowTitle:

1. • Use the getter syntax:

     QString currentTitle = dockWidget->windowTitle();
     

     This stores the current title of the dockWidget in the currentTitle string variable.

2. Setting a New Title
   

   • dockWidget->setWindowTitle("My Custom Title");
     

     This sets the title of the dockWidget to "My Custom Title".

Key Points

• The initial title can also be specified during construction:

  QDockWidget* dockWidget = new QDockWidget("Initial Title", parentWidget);
  

• Setting the title updates the caption bar of the dock widget dynamically.

• windowTitle returns a QString, which is Qt's string class.

Additional Notes

• The toggleViewAction() method of QDockWidget uses the windowTitle property to set the text of the associated action. This action, however, cannot be directly used to show or hide the dock widget; you should use the visible property for that purpose.

Example

#include <QApplication>
#include <QMainWindow>
#include <QDockWidget>
#include <QLabel>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QMainWindow window;

    QDockWidget* dockWidget = new QDockWidget("My Dock Widget", &window);
    QLabel* label = new QLabel("This is content inside the dock widget.");
    dockWidget->setWidget(label);

    window.addDockWidget(Qt::LeftDockWidgetArea, dockWidget);

    // Change the title dynamically
    QTimer* timer = new QTimer(&window);
    connect(timer, &QTimer::timeout, [&dockWidget]() {
        static int counter = 0;
        dockWidget->setWindowTitle(QString("Dynamic Title: %1").arg(counter++));
    });
    timer->start(1000); // Update title every second

    window.show();

    return app.exec();
}

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Setting Title Based on Dock Widget Position

#include <QApplication>
#include <QMainWindow>
#include <QDockWidget>
#include <QLabel>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QMainWindow window;

    QDockWidget* dockWidget1 = new QDockWidget("Dock Widget 1", &window);
    QLabel* label1 = new QLabel("Content in Dock 1");
    dockWidget1->setWidget(label1);

    QDockWidget* dockWidget2 = new QDockWidget("Dock Widget 2", &window);
    QLabel* label2 = new QLabel("Content in Dock 2");
    dockWidget2->setWidget(label2);

    window.addDockWidget(Qt::LeftDockWidgetArea, dockWidget1);
    window.addDockWidget(Qt::RightDockWidgetArea, dockWidget2);

    // Set titles based on position
    dockWidget1->setWindowTitle(QString("Left Dock: %1").arg(dockWidget1->objectName()));
    dockWidget2->setWindowTitle(QString("Right Dock: %1").arg(dockWidget2->objectName()));

    window.show();

    return app.exec();
}

This code creates two dock widgets, one on the left and one on the right. It sets their titles based on their positions using the objectName() method to retrieve a unique identifier.

Using windowTitle in a Toggle Action

#include <QApplication>
#include <QMainWindow>
#include <QDockWidget>
#include <QLabel>
#include <QAction>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QMainWindow window;

    QDockWidget* dockWidget = new QDockWidget("My Dock Widget", &window);
    QLabel* label = new QLabel("Content inside the dock widget.");
    dockWidget->setWidget(label);

    window.addDockWidget(Qt::LeftDockWidgetArea, dockWidget);

    // Create a toggle action using windowTitle
    QAction* toggleAction = dockWidget->toggleViewAction();
    toggleAction->setText(dockWidget->windowTitle()); // Set text from windowTitle

    // Optionally, customize the toggle action text
    toggleAction->setText(QString("Show/Hide %1").arg(dockWidget->windowTitle()));

    window.statusBar()->addPermanentWidget(toggleAction);

    window.show();

    return app.exec();
}

This code creates a dock widget with a toggle action displayed in the status bar. While toggleViewAction() uses windowTitle internally, you can customize the text further (e.g., adding "Show/Hide").

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Customizing the Title Bar Widget

• Handle user interactions (e.g., clicking) within your custom widget to potentially perform actions related to the dock widget.
• Use QDockWidget::setTitleBarWidget() to set your custom widget as the title bar.
• While QDockWidget doesn't offer built-in customization of the title bar itself, you can achieve a similar effect by creating a custom widget for the title bar. This widget could display text, icons, or other elements you desire.

Leveraging objectName

• Access the object name using dockWidget->objectName().
• If you need to identify the dock widget programmatically, you can use the objectName() property instead of a title. This property allows you to assign a unique identifier to the dock widget during creation.

Using a Separate Label

• Position the label appropriately within the dock widget's layout.
• If the title needs to be displayed within the dock widget itself rather than the caption bar, you can create a QLabel widget and set its text to the desired title.

• Use a separate label if you want the title to be displayed within the dock widget itself.
• Use objectName if you primarily need to identify the dock widget programmatically.
• Consider a custom title bar widget if you need more control over the title bar's appearance or want to add interactive elements.
• Use QDockWidget::windowTitle if you simply want to set a standard title displayed in the caption bar.