UI: Fix some webui launch corner cases (#1952)

* On windows insist on the presence of webview2 as the embeddable
browser for `ui=app`. If we can't find it, effectively switch back to
`ui=web`. This should prevent pywebview trying to use MSHTML, whilst
saying its deprecated, and apparently we are too much for poor old IE11
* Add webview2 runtime droppings to .gitignore.
* If we can't bind to args.server_port get another suitable port from
the OS and advise the user that we did this in the UI.
* Make `ui=web` mode use 'SHARK AI Studio' as its title. This makes it
consistent with `ui=app`.
* Replace the generic gradio favicon with a nod swirl one instead.

.gitignore

@@ -199,3 +199,6 @@ apps/stable_diffusion/web/EBWebView/
 
 # Llama2 tokenizer configs
 llama2_tokenizer_configs/
+
+# Webview2 runtime artefacts
+EBWebView/

apps/stable_diffusion/web/index.py

@@ -1,7 +1,8 @@
-from multiprocessing import Process, freeze_support
+from multiprocessing import freeze_support
 import os
 import sys
 import logging
+import apps.stable_diffusion.web.utils.app as app
 
 if sys.platform == "darwin":
     # import before IREE to avoid torch-MLIR library issues
@@ -21,26 +22,6 @@ if args.clear_all:
     clear_all()
 
 
-def launch_app(address):
-    from tkinter import Tk
-    import webview
-
-    window = Tk()
-
-    # get screen width and height of display and make it more reasonably
-    # sized as we aren't making it full-screen or maximized
-    width = int(window.winfo_screenwidth() * 0.81)
-    height = int(window.winfo_screenheight() * 0.91)
-    webview.create_window(
-        "SHARK AI Studio",
-        url=address,
-        width=width,
-        height=height,
-        text_select=True,
-    )
-    webview.start(private_mode=False, storage_path=os.getcwd())
-
-
 if __name__ == "__main__":
     if args.debug:
         logging.basicConfig(level=logging.DEBUG)
@@ -59,27 +40,27 @@ if __name__ == "__main__":
         # init global sd pipeline and config
         global_obj._init()
 
-        app = FastAPI()
-        app.mount("/sdapi/", sdapi)
+        api = FastAPI()
+        api.mount("/sdapi/", sdapi)
 
         # chat APIs needed for compatibility with multiple extensions using OpenAI API
-        app.add_api_route(
+        api.add_api_route(
             "/v1/chat/completions", llm_chat_api, methods=["post"]
         )
-        app.add_api_route("/v1/completions", llm_chat_api, methods=["post"])
-        app.add_api_route("/chat/completions", llm_chat_api, methods=["post"])
-        app.add_api_route("/completions", llm_chat_api, methods=["post"])
-        app.add_api_route(
+        api.add_api_route("/v1/completions", llm_chat_api, methods=["post"])
+        api.add_api_route("/chat/completions", llm_chat_api, methods=["post"])
+        api.add_api_route("/completions", llm_chat_api, methods=["post"])
+        api.add_api_route(
             "/v1/engines/codegen/completions", llm_chat_api, methods=["post"]
         )
-        app.include_router(APIRouter())
+        api.include_router(APIRouter())
 
         # deal with CORS requests if CORS accept origins are set
         if args.api_accept_origin:
             print(
                 f"API Configured for CORS. Accepting origins: { args.api_accept_origin }"
             )
-            app.add_middleware(
+            api.add_middleware(
                 CORSMiddleware,
                 allow_origins=args.api_accept_origin,
                 allow_methods=["GET", "POST"],
@@ -88,7 +69,7 @@ if __name__ == "__main__":
         else:
             print("API not configured for CORS")
 
-        uvicorn.run(app, host="0.0.0.0", port=args.server_port)
+        uvicorn.run(api, host="0.0.0.0", port=args.server_port)
         sys.exit(0)
 
     # Setup to use shark_tmp for gradio's temporary image files and clear any
@@ -102,7 +83,10 @@ if __name__ == "__main__":
     import gradio as gr
 
     # Create custom models folders if they don't exist
-    from apps.stable_diffusion.web.ui.utils import create_custom_models_folders
+    from apps.stable_diffusion.web.ui.utils import (
+        create_custom_models_folders,
+        nodicon_loc,
+    )
 
     create_custom_models_folders()
 
@@ -216,7 +200,7 @@ if __name__ == "__main__":
         )
 
     with gr.Blocks(
-        css=dark_theme, analytics_enabled=False, title="Stable Diffusion"
+        css=dark_theme, analytics_enabled=False, title="SHARK AI Studio"
     ) as sd_web:
         with gr.Tabs() as tabs:
             # NOTE: If adding, removing, or re-ordering tabs, make sure that they
@@ -270,6 +254,15 @@ if __name__ == "__main__":
             # with gr.TabItem(label="DocuChat(Experimental)", id=12):
             #     h2ogpt_web.render()
 
+            actual_port = app.usable_port()
+            if actual_port != args.server_port:
+                sd_web.load(
+                    fn=lambda: gr.Info(
+                        f"Port {args.server_port} is in use by another application. "
+                        f"Shark is running on port {actual_port} instead."
+                    )
+                )
+
         # send to buttons
         register_button_click(
             txt2img_sendto_img2img,
@@ -430,14 +423,10 @@ if __name__ == "__main__":
         )
 
     sd_web.queue()
-    if args.ui == "app":
-        t = Process(
-            target=launch_app, args=[f"http://localhost:{args.server_port}"]
-        )
-        t.start()
     sd_web.launch(
         share=args.share,
-        inbrowser=args.ui == "web",
+        inbrowser=not app.launch(actual_port),
         server_name="0.0.0.0",
-        server_port=args.server_port,
+        server_port=actual_port,
+        favicon_path=nodicon_loc,
     )

apps/stable_diffusion/web/ui/utils.py

@@ -170,4 +170,5 @@ def cancel_sd():
 
 
 nodlogo_loc = resource_path("logos/nod-logo.png")
+nodicon_loc = resource_path("logos/nod-icon.png")
 available_devices = get_available_devices()

apps/stable_diffusion/web/utils/app.py

@@ -0,0 +1,104 @@
+import os
+import sys
+import webview
+import webview.util
+import winreg
+import socket
+
+from contextlib import closing
+from multiprocessing import Process
+from tkinter import Tk
+
+from apps.stable_diffusion.src import args
+
+
+def webview2_installed():
+    # On windows we want to ensure we have MS webview2 available so we don't fall back
+    # to MSHTML (aka ye olde Internet Explorer) which is deprecated by pywebview, and
+    # apparently causes SHARK not to load in properly.
+
+    # Checking these registry entries is how Microsoft says to detect a webview2 installation:
+    # https://learn.microsoft.com/en-us/microsoft-edge/webview2/concepts/distribution
+
+    if sys.platform != "win32":
+        return False
+
+    path = r"SOFTWARE\WOW6432Node\Microsoft\EdgeUpdate\Clients\{F3017226-FE2A-4295-8BDF-00C3A9A7E4C5}"
+
+    # only way can find if a registry entry even exists is to try and open it
+    try:
+        # check for an all user install
+        with winreg.OpenKey(
+            winreg.HKEY_LOCAL_MACHINE,
+            path,
+            0,
+            winreg.KEY_QUERY_VALUE | winreg.KEY_WOW64_64KEY,
+        ) as registry_key:
+            value, type = winreg.QueryValueEx(registry_key, "pv")
+
+    # if it didn't exist, we want to continue on...
+    except WindowsError:
+        try:
+            # ...to check for a current user install
+            with winreg.OpenKey(
+                winreg.HKEY_CURRENT_USER,
+                path,
+                0,
+                winreg.KEY_QUERY_VALUE | winreg.KEY_WOW64_64KEY,
+            ) as registry_key:
+                value, type = winreg.QueryValueEx(registry_key, "pv")
+        except WindowsError:
+            value = None
+    finally:
+        return (value is not None) and value != "" and value != "0.0.0.0"
+
+
+def window(address):
+    window = Tk()
+
+    # get screen width and height of display and make it more reasonably
+    # sized as we aren't making it full-screen or maximized
+    width = int(window.winfo_screenwidth() * 0.81)
+    height = int(window.winfo_screenheight() * 0.91)
+    webview.create_window(
+        "SHARK AI Studio",
+        url=address,
+        width=width,
+        height=height,
+        text_select=True,
+    )
+    webview.start(private_mode=False, storage_path=os.getcwd())
+
+
+def usable_port():
+    # Make sure we can actually use the port given in args.server_port. If
+    # not ask the OS for a port and return that as our port to use.
+
+    port = args.server_port
+
+    with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as sock:
+        try:
+            sock.bind(("0.0.0.0", port))
+        except OSError:
+            with closing(
+                socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            ) as sock:
+                sock.bind(("0.0.0.0", 0))
+                sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+                return sock.getsockname()[1]
+
+    return port
+
+
+def launch(port):
+    # setup to launch as an app if app mode has been requested and we're able
+    # to do it, answering whether we succeeded.
+    if args.ui == "app" and (sys.platform != "win32" or webview2_installed()):
+        try:
+            t = Process(target=window, args=[f"http://localhost:{port}"])
+            t.start()
+            return True
+        except webview.util.WebViewException:
+            return False
+    else:
+        return False