Dialogs can be modal, in which case the user is required to provide necessary information before work in the main window can continue, or modeless. Modeless dialogs do not prevent the user from interacting with any of the other windows in the application.
Qt provides a set of ready-made dialogs for file, font, color-selection and more.
Dialog widget for specifying colors
Dialog that allow users to select files or directories
Dialog widget for selecting a font
Simple convenience dialog to get a single value from the user
Modal dialog for informing the user or for asking the user a question and receiving an answer
Feedback on the progress of a slow operation
Custom dialogs can be easily created by composing regular widgets into a QDialog. These classes are specifically designed for building custom dialogs: