Standard checkbox button implementation. This behavior is pretty simple: on click it toggles :checked state flag on the element. You can assign this behavior to other elements that you would like to behave as a “toggle”.

that have this behavior applied by default:

• <input type=“checkbox”> - standard HTML inline radio button;
• <widget type=“checkbox”> - radio button - block;
• <button type=“checkbox”> - Windows like inline radio button, use it as <button type=“radio”>caption</button>.

And tristate checkbox:

• <input type=“checkbox” mixed> - standard HTML inline radio button;
• <widget type=“checkbox” mixed> - radio button - block;
• <button type=“checkbox” mixed> - Windows like inline radio button, use it as <button type=“radio”>caption</button>.

that this behavior knows about:

• checked - if provided will initialize value of runtime state of the flag :checked.

For the tristate checkbox the checked value may have following values

• checked=true - checkbox is “on”;
• checked=false - checkbox is “off”;
• checked=undefined - checkbox is in undetermined state (mixed state);

Together with the standard set of events (mouse, keyboard, focus) behavior: radio generates:

• BUTTON_STATE_CHANGED event - the button just changed its state to checked. Asynchronous event.
• BUTTON_PRESS event - mouse down or spacebar key down when button is in focus. Synchronous event.

type json::value::V_BOOL, reflects current status of :checked state flag.

Tristate checkbox accepts three values:

json::value(true), json::value(false) and json::value() (undefined)