Module fltk::examples::threads_windows

How to show a window from another thread.

The code can be found in the examples directory next to the src directory in the source distribution.

Description

A standard counter containing a button for increment and decrement each. The callback for each button spawns a thread for a long-running task. During the task, we deactivate the buttons to avoid confusing UI behavior. After the task is done, we show a message window to the user.

A window can only be shown from the main thread, so we use a channel to send a message that makes the main thread show the notification window. We also use messages to increment/decrement the counter and activate/deactivate the buttons. Those things can be done without messages, too, but the example keeps a consistent approach.

The notification window itself contains a HelpView to show the message. It takes HTML syntax, which we make no use of.