GestureDetector in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the GestureDetector widget in Flutter?

The GestureDetector widget detects gestures like taps, drags, and swipes on its child widget and lets you respond to them.

beginner

Which property of GestureDetector handles a tap event?

The onTap property is a callback that runs when the user taps the widget.

beginner

How do you make a widget respond to a double tap using GestureDetector?

Use the onDoubleTap property and provide a function to run when the user double taps the widget.

intermediate

Can GestureDetector detect drag gestures? If yes, which callback is used?

Yes, it can detect drag gestures using callbacks like onPanUpdate which gives the drag movement details.

intermediate

What happens if you wrap a button with GestureDetector and use onTap?

The GestureDetector will detect taps on the button and run your onTap code, allowing you to customize tap behavior.

Which GestureDetector property detects a single tap?

A onTap

B onDoubleTap

C onLongPress

D onPanUpdate

The onTap callback runs when the user taps once on the widget.

What type of widget must GestureDetector have inside it?

A A text widget only

B A parent widget

C No widget needed

D A child widget to detect gestures on

GestureDetector wraps a child widget to detect gestures on that widget.

Which callback detects when the user drags their finger across the screen?

A onTap

B onPanUpdate

C onDoubleTap

D onLongPress

onPanUpdate detects drag movements and provides details about the drag.

If you want to detect a long press, which GestureDetector property do you use?

A onTap

B onDoubleTap

C onLongPress

D onPanEnd

onLongPress runs when the user presses and holds on the widget.

What happens if you do not provide any gesture callbacks to GestureDetector?

A It does nothing on gestures

B It disables child widget

C It throws an error

D It still detects gestures automatically

Without callbacks, GestureDetector does not respond to gestures.

Explain how to use GestureDetector to detect a tap and change the color of a box.

Think about wrapping a colored box and changing its color inside onTap.

Describe the difference between onTap and onDoubleTap in GestureDetector.

Consider how users interact with buttons or images differently.