[API categories](API-categories.md) | [API index](API-index.md) # FocusHandler (interface) Implement this interface to handle events related to focus. The methods of this class will be called on the UI thread. Table of contents: * [Callbacks](#callbacks) * [OnTakeFocus](#ontakefocus) * [OnSetFocus](#onsetfocus) * [OnGotFocus](#ongotfocus) ## Callbacks ### OnTakeFocus | Parameter | Type | | --- | --- | | browser | [Browser](Browser.md) | | next_component | bool | | __Return__ | void | Description from upstream CEF: > Called when the browser component is about to loose focus. For instance, if > focus was on the last HTML element and the user pressed the TAB key. |next| > will be true if the browser is giving focus to the next component and false > if the browser is giving focus to the previous component. ### OnSetFocus | Parameter | Type | | --- | --- | | browser | [Browser](Browser.md) | | source | cef_focus_source_t | | __Return__ | bool | Description from upstream CEF: > Called when the browser component is requesting focus. |source| indicates > where the focus request is originating from. Return false to allow the > focus to be set or true to cancel setting the focus. The `cef_focus_source_t` enum constants in the cefpython module: * FOCUS_SOURCE_NAVIGATION (The source is explicit navigation via the API (LoadURL(), etc)) * FOCUS_SOURCE_SYSTEM (The source is a system-generated focus event) ### OnGotFocus | Parameter | Type | | --- | --- | | browser | [Browser](Browser.md) | | __Return__ | void | Description from upstream CEF: > Called when the browser component has received focus.