Events and Bindings

One very cool thing we can do is define event bindings on tags. That allows us to easily do things like recognize mouse clicks on particular ranges of text and popup a menu or dialog in response. Different tags can have different bindings. This saves the hassle of sorting out questions like "what does a click at this location mean?". Bindings on tags are implemented using the tag_bind method:

#![allow(unused)]
fn main() {
txt.tag_bind( "important", event::button_press_1(), popup_important_menu )?;
}

Widget-wide event bindings continue to work as they do for every other widget, e.g., to capture a mouse click anywhere in the text. Besides the normal low-level events, the text widget generates a Modified virtual event whenever a change is made to the content of the widget, and a Selection virtual event whenever there is a change made to which text is selected.