diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/Fl_Button.cxx | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/src/Fl_Button.cxx b/src/Fl_Button.cxx index 5d40c37da..fb70114d6 100644 --- a/src/Fl_Button.cxx +++ b/src/Fl_Button.cxx @@ -254,10 +254,19 @@ void Fl_Button::key_release_timeout(void *d) Derived classes may handle this differently. - A button may request callbacks with \p when() \p FL_WHEN_CHANGED, - \p FL_WHEN_NOT_CHANGED, and \p FL_WHEN_RELEASE, triggering the callback - reasons \p FL_REASON_CHANGED, \p FL_REASON_SELECTED, - and \p FL_REASON_DESELECTED. + Calling `when()` will tell the button widget when to call the callback. + + Setting `FL_WHEN_RELEASE` will call the callback only if the button value + changed. It's called during `FL_RELEASE` and `FL_KEYBOARD` events with + `FL_REASON_RELEASED` set as the callback reason. + + Setting `FL_WHEN_CHANGED` will call the callback with `FL_REASON_CHANGED` + every time the value of the button changes during `FL_DRAG`, `FL_RELEASE`, + and `FL_KEYBOARD` events. + + Setting `FL_WHEN_NOT_CHANGED` will trigger a callback during `FL_RELEASE` + events, even if the value of the button die *not* change. For radio buttons, + this is also true during `FL_KEYBOARD` events. \param[in] X, Y, W, H position and size of the widget \param[in] L widget label, default is no label |