The WebView class

A WebView is one open page. You get it from WebUi.Open.

WebView one open page

WebUi.Open gives you one of these for each page. Use Show, Hide, SetBounds or Close to control it, and Post to send it a JSON string.

public sealed class WebView
{
    public string ModId { get; }
    public string Origin { get; }
    public bool IsVisible { get; }
    public bool IsClosed { get; }
    public bool Modal { get; }
    public bool EscapeHides { get; set; }
    public event Action<string> Message;
    public event Action<int> KeyPressed;
    public event Action Dismissed;
    public bool Show();
    public bool Hide();
    public bool SetBounds(int x, int y, int width, int height);
    public bool FullWindow();
    public bool PinTo(RectTransform target);
    public bool Navigate(string page);
    public bool MapFolder(string name, string folder);
    public bool AllowFrameHost(string host);
    public bool Post(string json);
    public void Close();
}

Property	Type	What it means
`ModId`	`string`	The mod id the view was opened with.
`Origin`	`string`	The start of every web address this view loads, such as `https://example-webuihello.obx/`.
`IsVisible`	`bool`	`true` when the view is shown.
`IsClosed`	`bool`	`true` once the view is closed for good.
`Modal`	`bool`	`true` when the view takes over the player’s controls.
`EscapeHides`	`bool`	Set it to `true` to hide the view when the player presses Escape.

Method	Returns	What it does
`Show()`	`bool`	Shows the view at its place.
`Hide()`	`bool`	Hides the view.
`SetBounds(x, y, width, height)`	`bool`	Places the view at a spot on the screen, in pixels of the game window. It stops the view from covering the whole window.
`FullWindow()`	`bool`	Makes the view cover the whole game window.
`PinTo(target)`	`bool`	Makes the view cover a `RectTransform` on the screen, such as a monitor. `null` lets go and goes back to the whole window.
`Navigate(page)`	`bool`	Loads another page from your folder.
`MapFolder(name, folder)`	`bool`	Makes another folder of yours available at its own web address.
`AllowFrameHost(host)`	`bool`	Lets frames in your page load one live website.
`Post(json)`	`bool`	Sends a JSON object to the page.
`Close()`	`void`	Closes the view for good.

Event	Gives you	When it fires
`Message`	`string`, the raw JSON text	The page sent a message with `chrome.webview.postMessage`.
`KeyPressed`	`int`, the key code	Escape (27) or F10 (121) was pressed in the view.
`Dismissed`	Nothing	The framework hid the view because of Escape.

Things to know

Modal is set when you call Open.
Show() gives false for a modal view while the game is busy, as listed under Open in The WebUi class. A modal view that shows also takes over the player’s controls and shows the cursor (see Step 2 of the UI guide).
A modal view that never says it is ready is closed after 20 seconds. The page does not have to do anything for this. The shim says it by itself once it has set the view up, whether or not the page has loaded, so a plain page needs no code for it. If it never does, the view is closed and an error is logged. (The shim sends obx.status. The framework closes a modal view that gets none within 20 seconds of showing.)
Hide() hides the view, and a modal view gives the controls back.
Close() hides the view, destroys it and gives the controls back. A closed view stays closed. Call Open for a new one.
SetBounds gives false for a width or height of zero or less.
FullWindow() is how a view starts. It follows the window each frame, and only tells the shim when the size changed.
PinTo(target) gives false when the view is closed or you are not calling from your mod’s normal code. See Pinning.
Navigate(page) loads another page from your folder. The path has to be relative (see Navigation). If the page cannot be loaded, the view keeps its current page.
MapFolder gives an extra folder of yours its own web address. For example, frames gives frames.example-webuihello.obx. The address of an extra folder is the name, then a dot, then your view’s host.
Names are turned into a safe form the same way as mod ids. A name of at most 63 lowercase letters and digits with single dots between them has each dot turned into -, so frames stays frames. Any other name, such as Frames, gets an h-- form, so Frames and frames get different addresses.
MapFolder gives false for a view that is closed, a call that is not from your mod’s normal code, an empty name, or a folder that does not exist.
AllowFrameHost(host) lets frames in your page load one live website, such as stalburg.net. See Frame hosts. It gives false and sets LastError when the host is not allowed. You can call it before or after the page loads.
Post(json) sends a JSON object to the page. The page gets it in its chrome.webview message event. It gives false for a view that is closed, a call that is not from your mod’s normal code, a null text, or when the shim call fails.
Message gives you the raw JSON text, not the parts. A message with no type, or one that is not a JSON object, still reaches you as raw text.
KeyPressed runs your handlers first. Then Escape may hide the view (see Step 7 of the UI guide). (The code is the Windows virtual-key code that the shim forwards.)
Dismissed fires right after the framework hides the view because of Escape. See Step 7 of the UI guide. It does not fire when your mod calls Hide, and not when a scene load that replaces the whole scene hides a modal view.

Limits

A message longer than 16384 characters is dropped. A message whose type starts with obx. is dropped too, because those names belong to the shim.
Post queues the message for the shim, so a message that you queue before the web core is ready is lost. Send it from inside a Message handler, or after the page has sent its first message.
In composition and windowed modes, a Navigate that fails gives false and sets LastError. In thread mode, Navigate gives true at once, and the shim loads the page on its own thread, so a failure arrives later as an error report with where set to Obx_Navigate.
The extra folder from MapFolder can load content, but its pages cannot send messages to your mod. Only the page at your view’s own host can. (The shim accepts messages only from the view’s own host.)
On an open view, a folder that the shim cannot map is not kept, so the address stays refused. In thread mode, MapFolder gives true at once and the shim does it on its own thread, so a failure arrives later as an error report with where set to Obx_MapFolder, and LastError is set.