CODEWITHSUNDEEP
c++linuxqtqcomboboxqkeyevent
Muhammad Ummar
Muhammad Ummar

Reputation: 3631

Capturing text change events in a QComboBox

I am developing a Qt application on Red Hat Linux. I want to capture Carriage Return key press events in a QComboBox.

I have connected a slot to the signal editTextChanged() which is emitted for every key press but not for the Enter Key.
Why so? Is there any other way to detect Carriage Returns?

Upvotes: 1

Views: 5308

Answers (2)

zweihander
zweihander

Reputation: 6295

I am assuming you wrote a slot and connected it to QComboBox::editTextChanged() signal.
This signal is fired when the text changes and Enter does not change the text, it accepts it. If you want to capture Carriage Return, there are a number of ways you can follow.

  1. Subclass QComboBox.
    Override keyPressEvent() : first call QComboBox::keyPressEvent() and then check if the pressed key is Enter. If it is, emit a signal.
    Use this subclass whenever you need. Search about promoting widgets in QDesigner if you don't know how.

  2. Implement a new class which inherits QObject. In this class, override eventFilter() : check if the event is a key press. If it is, check if it is the Enter key. If it is, emit a signal.
    Then, create an instance of this class and set it as event filter to your QComboBox. Connect a slot to this instance's signal, which you implemented.

If these are not clear, i recommend reading the following pages:

Using Custom Widgets with Qt designer

Qt Events & Event Filters

Upvotes: 4

Caleb Huitt - cjhuitt
Caleb Huitt - cjhuitt

Reputation: 14941

You could also look into the activated( const QString& ) signal. It might be emitted when the user hits enter.

Upvotes: 3

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