Qt GUI: Unveiling QStandardItem::setToolTip() for Enhanced Tooltips

Purpose

• The setToolTip() method of QStandardItem allows you to set a short, informative text that appears as a tooltip when the user hovers the mouse cursor over the item in a view (like QTreeView or QTableView).
• In Qt's model/view architecture, QStandardItem is a data container used for representing items in models like QStandardItemModel.

How it Works

1. • You call setToolTip() on a QStandardItem object, passing the desired tooltip text as a string argument.

   QStandardItem* item = new QStandardItem("Item Text");
   item->setToolTip("This is a more detailed description of the item.");
   

2. Displaying the Tooltip
   

   • When the user hovers the mouse cursor over the item in the view, the view widget (e.g., QTreeView or QTableView) retrieves the tooltip text using item->toolTip() and displays it as a popup.

Benefits

• They enhance the user experience by making the application more intuitive and user-friendly.
• Tooltips provide users with additional context or information about items without cluttering the view itself.

Example Usage

#include <QApplication>
#include <QStandardItemModel>
#include <QTreeView>

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

    // Create a model and items
    QStandardItemModel model;
    QStandardItem* item1 = new QStandardItem("Item 1");
    item1->setToolTip("This is the first item.");
    model.appendRow(item1);

    QStandardItem* item2 = new QStandardItem("Item 2");
    item2->setToolTip("This is the second item with a longer description.");
    model.appendRow(item2);

    // Create a tree view and set the model
    QTreeView treeView;
    treeView.setModel(&model);

    treeView.show();

    return app.exec();
}

In this example, hovering over "Item 1" or "Item 2" in the tree view will display the corresponding tooltip text.

Additional Considerations

• Consider using rich text formatting with HTML tags in setToolTip() for more complex formatting needs (Qt supports basic HTML for tooltips).
• Tooltips should be concise and informative, avoiding cluttering the screen with excessively long text.

---

#include <QApplication>
#include <QStandardItemModel>
#include <QTreeView>

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

    // Create a model and items
    QStandardItemModel model;
    QStandardItem* item1 = new QStandardItem("Item 1");
    // Set tooltip with bold and italic text
    item1->setToolTip("<b>This is the first item</b> (<italic>with formatting</italic>).");
    model.appendRow(item1);

    QStandardItem* item2 = new QStandardItem("Item 2");
    // Set tooltip with a bulleted list
    item2->setToolTip("<ul>"
                       "<li>This is the second item.</li>"
                       "<li>It has a bulleted list.</li>"
                       "</ul>");
    model.appendRow(item2);

    // Create a tree view and set the model
    QTreeView treeView;
    treeView.setModel(&model);

    treeView.show();

    return app.exec();
}

Now, hovering over the items in the tree view will display the tooltip text with the applied HTML formatting:

• Item 2
  The tooltip will display a bulleted list.
• Item 1
  The text will be bold and italic.

---

1. • QStatusTip is a widget specifically designed for displaying short messages in the status bar at the bottom of the application window.
   • It's useful when you want to provide general context or feedback related to the entire application or a specific area.

   QStatusBar* statusBar = new QStatusBar;
   QStatusTip* statusTip = new QStatusTip(statusBar);
   statusBar->addWidget(statusTip);
   
   // Connect a signal from the view (e.g., QTreeView) to update the status tip
   connect(treeView, &QTreeView::itemEntered, statusTip, &QStatusTip::showMessage);
   
   void updateStatusTip(const QModelIndex& index) {
       if (index.isValid()) {
           QStandardItem* item = static_cast<QStandardItem*>(index.model()->itemFromIndex(index));
           statusTip->showMessage(item->text()); // Or item->toolTip() for more detailed info
       } else {
           statusTip->showMessage("");
       }
   }
   

2. Custom Tooltips with Widgets
   

   • For more complex tooltip content beyond plain text, you can create custom widgets and display them as tooltips.
   • This approach offers greater flexibility for layouts, including images, buttons, or other interactive elements.

   class CustomTooltip : public QWidget {
       Q_OBJECT
   
   public:
       CustomTooltip(const QString& text, QWidget* parent = nullptr) : QWidget(parent) {
           // Create layout and add text or other widgets here
           QVBoxLayout* layout = new QVBoxLayout(this);
           QLabel* label = new QLabel(text, this);
           layout->addWidget(label);
       }
   
       // ... (other methods for layout management, etc.)
   };
   
   // In your code...
   QStandardItem* item = new QStandardItem("Item Text");
   CustomTooltip* tooltip = new CustomTooltip("This is a custom tooltip with more content.");
   item->setData(tooltip, Qt::ToolTipRole); // Set data for custom tooltip retrieval
   
   // In the view's paintEvent or similar handler...
   void paintEvent(QPaintEvent* event) {
       // ... (standard painting code)
   
       // Check for hovered item and display custom tooltip if needed
       QPoint cursorPos = mapFromGlobal(QCursor::pos());
       QModelIndex index = treeView->indexAt(cursorPos);
       if (index.isValid()) {
           CustomTooltip* customTooltip = static_cast<CustomTooltip*>(index.model()->data(index, Qt::ToolTipRole).value<QWidget*>());
           if (customTooltip) {
               // Position and show the custom tooltip widget
               QPoint tooltipPos = cursorPos + QPoint(10, 10); // Adjust offset as needed
               customTooltip->move(tooltipPos);
               customTooltip->show();
           }
       }
   }
   

3. Item Delegate's paint() Method
   

   • For advanced customization of item appearance, you can use an item delegate's paint() method.
   • Within paint(), you can draw additional text or icons to provide visual cues or information directly on the item itself.