Alternative Approaches to QTextCharFormat::toolTip() for Tooltips in Qt GUIs

Purpose

• QTextCharFormat::toolTip() allows you to associate a tooltip with a formatted text fragment. This tooltip is a short, informative message that appears when the user hovers their mouse cursor over the formatted text.
• In Qt text widgets like QTextEdit or QRichTextEdit, you can apply character formatting to specific portions of text. This formatting can include font styles, colors, and other visual attributes.

Functionality

• To retrieve the previously set tooltip for a QTextCharFormat object, use the toolTip() const method. This returns a QString representing the tooltip text.
• Use the setToolTip(const QString &text) method to set the tooltip for a QTextCharFormat object. Here, text is a QString containing the tooltip message you want to display.

Example

#include <QApplication>
#include <QTextEdit>

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

    QTextEdit editor;
    QTextCharFormat format;

    // Set font style and tooltip
    format.setFontWeight(QFont::Bold);
    format.setToolTip("This text is bold.");

    // Apply formatting to a selected text range
    int cursorPosition = editor.textCursor().position();
    editor.textCursor().select(QTextCursor::WordUnderCursor);
    editor.setTextColor(Qt::red);
    editor.setCurrentCharFormat(format);

    editor.show();

    return app.exec();
}

In this example:

1. We create a QTextEdit object for rich text editing.
2. We define a QTextCharFormat object.
3. We set the font weight to bold using setFontWeight().
4. We set the tooltip using setToolTip("This text is bold.").
5. We select the word under the cursor using textCursor().select(QTextCursor::WordUnderCursor).
6. We set the text color to red using setTextColor(Qt::red).
7. We apply the format with the tooltip to the selected text using setCurrentCharFormat().
8. Finally, we display the QTextEdit with the formatted text.

When the user hovers their mouse cursor over the bold red text, the tooltip "This text is bold." will appear.

• You can set different tooltips for different character formats, giving users more specific information about the formatting applied to various parts of the text.
• Tooltips are a convenient way to provide extra information or context to formatted text in your Qt GUI applications.

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Dynamic Tooltip Based on Text Content (Python/PyQt)

from PyQt5.QtWidgets import QApplication, QTextEdit

def update_tooltip(text_edit):
    cursor = text_edit.textCursor()
    word = cursor.selectedText()  # Get the selected word under the cursor
    tooltip = f"Selected word: '{word}'"  # Dynamically create tooltip based on word
    format = text_edit.currentCharFormat()
    format.setToolTip(tooltip)
    text_edit.setCurrentCharFormat(format)  # Apply format with updated tooltip

app = QApplication([])
text_edit = QTextEdit()

# Connect signal to update tooltip dynamically
text_edit.selectionChanged.connect(update_tooltip)

text_edit.show()
app.exec_()

This code updates the tooltip dynamically based on the selected word. When the user selects a word, the selectionChanged signal is emitted, triggering the update_tooltip function. This function retrieves the selected word, formats the tooltip text, and updates the QTextCharFormat object with the new tooltip before applying it to the selected text.

Highlighting Specific Words with Tooltips (C++/Qt)

#include <QApplication>
#include <QTextEdit>
#include <QRegularExpression>

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

    QTextEdit editor;
    QTextCharFormat format;

    // Highlight and set tooltip for specific keywords (regular expression)
    format.setFontColor(Qt::blue);
    format.setToolTip("This is a keyword.");
    QRegularExpression keywords("\\b(keyword1|keyword2)\\b");

    QString text = "This text contains some keywords like keyword1 and keyword2.";
    editor.setPlainText(text);
    QTextDocument *document = editor.document();

    QTextCharFormat matchFormat;
    matchFormat.merge(format);  // Merge keyword format with base format

    QTextCursor cursor = document->find(keywords);
    while (cursor.isValid()) {
        cursor.mergeCharFormat(matchFormat);
        cursor = document->find(keywords, cursor.positionInBlock() + 1);
    }

    editor.show();

    return app.exec();
}

This code highlights specific keywords using a regular expression and sets a common tooltip for all matched keywords. It iterates through the document, finding occurrences of the keywords and applying the combined character format (including font color and tooltip) to those matches.

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Using QStatusbar

• Update the status bar text dynamically based on user interactions (e.g., mouse hover over the formatted text) or selection changes.
• If you want to display a more general tooltip that applies to the entire formatted text area or a specific selection, you can use a QStatusbar at the bottom of your window.

Custom Widgets with Tooltips

• Within the event() method, you can check for hover events and display a custom tooltip widget with the desired information using QToolTip::showText().
• For more complex tooltip behavior or richer content, you might create custom widgets that inherit from QWidget and override the event() method to handle mouse hover events.

Third-Party Tooltip Libraries

• These libraries can be integrated into your Qt application to enhance the tooltip experience.
• Qt offers various third-party libraries that provide more advanced tooltip functionality, such as richer formatting, animations, or custom positioning.

Choosing the Right Approach

The best alternative depends on your specific needs:

• For complex tooltip behavior or richer content, consider custom widgets or third-party libraries.
• If you require a more general tooltip for the entire formatted area or selection, a QStatusbar might be suitable.
• If you simply need basic tooltips for formatted text, QTextCharFormat::toolTip() is a good choice.

Feature	QTextCharFormat::toolTip()	QStatusbar	Custom Widgets/Libraries
Complexity	Simplest	Moderate	Most complex
Applicability	Specific formatted text	Entire area/selection	Flexible
Content richness	Basic text	Basic text	Richer content (formatting, images)
Customization	Limited	Moderate	Highly customizable