This defines AssetServer specific options. It allows to customize the AssetServer with static assets, serving assets dynamically with an `http.Handler` or hook into the request chain with an `assetserver.Middleware`.
A GET request is first tried to be served from this `fs.FS`. If the `fs.FS` returns `os.ErrNotExist` for that file, the request handling will fallback to the [Handler](#handler) and tries to serve the GET request from it.
The handler will be called for every GET request that can't be served from [Assets](#assets), due to `os.ErrNotExist`. Furthermore all non GET requests will always be served from this Handler. If not defined, the result is the following in cases where the Handler would have been called:
NOTE: When used in combination with a Frontend DevServer there might be limitations, eg. Vite serves the index.html on every path, that does not contain a file extension.
Middleware is a HTTP Middleware which allows to hook into the AssetServer request chain. It allows to skip the default request handler dynamically, e.g. implement specialized Routing etc. The Middleware is called to build a new `http.Handler` used by the AssetSever and it also receives the default handler used by the AssetServer as an argument.
If this callback is set, it will be called when the application is about to quit, either by clicking the window close button or calling `runtime.Quit`. Returning true will cause the application to continue, false will continue shutdown as normal. This is good for confirming with the user that they wish to exit the program.
By default, the browser's default context-menu is only available in development and in a `-debug` [build](../reference/cli.mdx#build) along with the devtools inspector, Using this option you can enable the default context-menu in `production` while the devtools inspector won't be available unless the `-devtools` build flag is used.
When this option is enabled, by default the context-menu will only be shown for text contexts (where Cut/Copy/Paste is needed), to override this behavior, you can use the CSS property `--default-contextmenu` on any HTML element (including the `body`) with the following values :
| `--default-contextmenu: auto;` | (**default**) will show the default context menu only if :<br/> contentEditable is true OR text has been selected OR element is input or textarea |
| `--default-contextmenu: show;` | will always show the default context menu |
| `--default-contextmenu: hide;` | will always hide the default context menu |
This rule is inherited like any normal CSS rule, so nesting works as expected.
:::note
This filtering functionality is only enabled in production, so in development and in debug build, the full context-menu is always available everywhere.
:::
:::warning
This filtering functionality is NOT a security measure, the developer should expect that the full context-menu could be leaked anytime which could contain commands like (Download image, Reload, Save webpage), if this is a concern, the developer SHOULD NOT enable the default context-menu.
EnableFraudulentWebsiteDetection enables scan services for fraudulent content, such as malware or phishing attempts. These services might send information from your app like URLs navigated to and possibly other content to cloud services of Apple and Microsoft.
This defines the zoom factor for the WebView2. This is the option matching the Edge user activated zoom in or out.
### IsZoomControlEnabled
Name: IsZoomControlEnabled<br/> Type: `bool`
This enables the zoom factor to be changed by the user. Please note that the zoom factor can be set in the options while disallowing the user to change it at runtime (f.e. for a kiosk application or similar).
Setting this to `true` will make the webview background transparent when an alpha value of `0` is used. This means that if you use `rgba(0,0,0,0)` for `background-color` in your CSS, the host window will show through. Often combined with [WindowIsTranslucent](#WindowIsTranslucent) to make frosty-looking applications.
For Windows 11 versions before build 22621, this will use the [BlurBehind](https://learn.microsoft.com/en-us/windows/win32/dwm/blur-ovw) method for translucency, which can be slow. For Windows 11 versions after build 22621, this will enable the newer translucency types that are much faster. By default, the type of translucency used will be determined by Windows. To configure this, use the [BackdropType](#BackdropType) option.
Setting this to `true` will remove the window decorations in [Frameless](#Frameless) mode. This means there will be no 'Aero Shadow' and no 'Rounded Corners' shown for the window. Please note that 'Rounded Corners' are only supported on Windows 11.
This defines the path to a directory with WebView2 executable files and libraries. If empty, webview2 installed in the system will be used.
Important information about distribution of fixed version runtime:
- [How to get and extract runtime](https://docs.microsoft.com/en-us/microsoft-edge/webview2/concepts/distribution#details-about-the-fixed-version-runtime-distribution-mode)
- [Known issues for fixed version](https://docs.microsoft.com/en-us/microsoft-edge/webview2/concepts/distribution#known-issues-for-fixed-version)
- [The path of fixed version of the WebView2 Runtime should not contain \Edge\Application\.](https://docs.microsoft.com/en-us/microsoft-edge/webview2/reference/win32/webview2-idl?view=webview2-1.0.1245.22#createcorewebview2environmentwithoptions)
| SystemDefault | _Default_. The theme will be based on the system default. If the user changes their theme, the application will update to use the new setting |
| Dark | The application will use a dark theme exclusively |
| Light | The application will use a light theme exclusively |
Allows you to specify custom colours for TitleBar, TitleText and Border for both light and dark mode, as well as when the window is active or inactive.
The CustomTheme struct uses `int32` to specify the colour values. These are in the standard(!) Windows format of: `0x00BBGGAA`. A helper function is provided to do RGB conversions into this format: `windows.RGB(r,g,b uint8)`.
ResizeDebounceMS is the amount of time to debounce redraws of webview2 when resizing the window. The default value (0) will perform redraws as fast as it can.
| TitlebarAppearsTransparent | Makes the titlebar transparent. This has the effect of hiding the titlebar and the content fill the window. [Apple Docs](https://developer.apple.com/documentation/appkit/nswindow/1419167-titlebarappearstransparent?language=objc) |
| HideTitle | Hides the title of the window. [Apple Docs](https://developer.apple.com/documentation/appkit/nswindowtitlevisibility?language=objc) |
| HideTitleBar | Removes [NSWindowStyleMaskTitled](https://developer.apple.com/documentation/appkit/nswindowstylemask/nswindowstylemasktitled/) from the style mask |
| FullSizeContent | Makes the webview fill the entire window. [Apple Docs](https://developer.apple.com/documentation/appkit/nswindowstylemask/nswindowstylemaskfullsizecontentview) |
| UseToolbar | Adds a default toolbar to the window. [Apple Docs](https://developer.apple.com/documentation/appkit/nstoolbar?language=objc) |
| HideToolbarSeparator | Removes the line beneath the toolbar. [Apple Docs](https://developer.apple.com/documentation/appkit/nstoolbar/1516954-showsbaselineseparator?language=objc) |
Click [here](https://github.com/lukakerr/NSWindowStyles) for some inspiration on customising the titlebar.
#### Appearance
Appearance is used to set the style of your app in accordance with Apple's [NSAppearance](https://developer.apple.com/documentation/appkit/nsappearancename?language=objc) names.
Setting this to `true` will make the webview background transparent when an alpha value of `0` is used. This means that if you use `rgba(0,0,0,0)` for `background-color` in your CSS, the host window will show through. Often combined with [WindowIsTranslucent](#WindowIsTranslucent) to make frosty-looking applications.
Setting this to `true` will make the window background translucent. Often combined with [WebviewIsTransparent](#WebviewIsTransparent) to make frosty-looking applications.
| TabFocusesLinks | A Boolean value that indicates whether pressing the tab key changes the focus to links and form controls. [Apple Docs](https://developer.apple.com/documentation/webkit/wkpreferences/2818595-tabfocuseslinks?language=objc) |
| TextInteractionEnabled | A Boolean value that indicates whether to allow people to select or otherwise interact with text. [Apple Docs](https://developer.apple.com/documentation/webkit/wkpreferences/3727362-textinteractionenabled?language=objc) |
| FullscreenEnabled | A Boolean value that indicates whether a web view can display content full screen. [Apple Docs](https://developer.apple.com/documentation/webkit/wkpreferences/3917769-elementfullscreenenabled?language=objc) |
Some window managers or desktop environments may also place it in the window frame, or display it in other contexts. On others, the icon is not used at all, so your mileage may vary.
The icon should be provided in whatever size it was naturally drawn; that is, don’t scale the image before passing it. Scaling is postponed until the last minute, when the desired final size is known, to allow best quality.
This option is used to set the program's name for the window manager via GTK's g_set_prgname(). This name should not be localized, [see the docs](https://docs.gtk.org/glib/func.set_prgname.html).
When a .desktop file is created this value helps with window grouping and desktop icons when the .desktop file's `Name` property differs form the executable's filename.
[^1]: This requires WebKit2GTK 2.36+ support and your app needs to be build with the build tag `webkit2_36` to activate support for this feature. This also bumps the minimum requirement of WebKit2GTK to 2.36 for your app.
[^2]: This requires WebKit2GTK 2.40+ support and your app needs to be build with the build tag `webkit2_40` to activate support for this feature. This also bumps the minimum requirement of WebKit2GTK to 2.40 for your app.
