content/public/browser/xr_integration_client.h

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_PUBLIC_BROWSER_XR_INTEGRATION_CLIENT_H_
#define CONTENT_PUBLIC_BROWSER_XR_INTEGRATION_CLIENT_H_

#include <memory>

#include "content/common/content_export.h"
#include "content/public/browser/browser_xr_runtime.h"
#include "device/vr/public/mojom/isolated_xr_service.mojom-forward.h"
#include "device/vr/public/mojom/vr_service.mojom-forward.h"
#include "device/vr/public/mojom/xr_device.mojom-forward.h"
#include "mojo/public/cpp/bindings/pending_remote.h"

namespace device {
class VRDeviceProvider;
}

namespace content {
class XrInstallHelper;

using XRProviderList = std::vector<std::unique_ptr<device::VRDeviceProvider>>;

// This class is intended to provide implementers a means of accessing the
// the XRCompositorHost returned from a create session call to allow embedders
// to implement overlay UI code that they want. Content will notify of the
// events described below so that the UI may adjust accordingly. This class
// will be created when a session starts and destroyed when it ends.
class CONTENT_EXPORT VrUiHost {
 public:
  virtual ~VrUiHost() = default;

  // Called when the currently active immersive WebXR session has its frames
  // [un/]throttled by the compositor.
  virtual void WebXRFramesThrottledChanged(bool throttled) = 0;
};

// A helper class for |ContentBrowserClient| to wrap for XR-specific
// integration that may be needed from content/. Currently it only provides
// access to relevant XrInstallHelpers, but will eventually be expanded to
// include integration points for VrUiHost.
// This should be implemented by embedders.
class CONTENT_EXPORT XrIntegrationClient {
 public:
  XrIntegrationClient() = default;
  virtual ~XrIntegrationClient() = default;
  XrIntegrationClient(const XrIntegrationClient&) = delete;
  XrIntegrationClient& operator=(const XrIntegrationClient&) = delete;

  // Returns the |XrInstallHelper| for the corresponding |XRDeviceId|, or
  // nullptr if the requested |XRDeviceId| does not have any required extra
  // installation steps.
  virtual std::unique_ptr<XrInstallHelper> GetInstallHelper(
      device::mojom::XRDeviceId device_id);

  // Returns a vector of device providers that should be used in addition to
  // any default providers built-in to //content.
  virtual XRProviderList GetAdditionalProviders();

  // Creates a runtime observer that will respond to browser XR runtime state
  // changes. May return null if the integraton client does not need to observe
  // state changes.
  virtual std::unique_ptr<BrowserXRRuntime::Observer> CreateRuntimeObserver();

  // Called by the BrowserXRRuntime to create a VrUiHost object for it, and
  // takes ownership of the supplied XRCompositor.
  virtual std::unique_ptr<VrUiHost> CreateVrUiHost(
      WebContents& contents,
      const std::vector<device::mojom::XRViewPtr>& views,
      mojo::PendingRemote<device::mojom::ImmersiveOverlay> overlay);
};

}  // namespace content

#endif  // CONTENT_PUBLIC_BROWSER_XR_INTEGRATION_CLIENT_H_