New Feature: ChartAsync

- Added the ChartAsync class, allowing for more sophisticated Charts and SubCharts.
- Symbol searching, timeframe selectors, and more is now possible with this varation of Chart.

`QtChart` and `WxChart` have access to all the methods that `ChartAsync` has, however they utilize their own respective event loops rather than asyncio.

New Feature: `StreamlitChart`
- Chart window that can display static data within a Streamlit application.

Removed the `subscribe_click` method.

lightweight_charts/chart.py

@@ -4,15 +4,25 @@ import multiprocessing as mp
 from lightweight_charts.js import LWC
 
 
+class CallbackAPI:
+    def __init__(self, emit): self.emit = emit
+
+    def callback(self, message: str):
+        messages = message.split('__')
+        name, chart_id = messages[:2]
+        args = messages[2:]
+        self.emit.put((name, chart_id, *args))
+
+
 class PyWV:
-    def __init__(self, q, exit, loaded, html, js_api, width, height, x, y, on_top, debug):
+    def __init__(self, q, exit, loaded, html, width, height, x, y, on_top, debug, emit=None):
         self.queue = q
         self.exit = exit
         self.loaded = loaded
         self.debug = debug
-        self.js_api = js_api
-        self.webview = webview.create_window('', html=html, on_top=on_top, js_api=js_api,
-                                             width=width, height=height, x=x, y=y, background_color='#000000')
+        js_api = CallbackAPI(emit) if emit else None
+        self.webview = webview.create_window('', html=html, on_top=on_top, js_api=js_api, width=width, height=height,
+                                             x=x, y=y, background_color='#000000')
         self.webview.events.loaded += self.on_js_load
         self.loop()
 
@@ -22,9 +32,6 @@ class PyWV:
             if arg in ('start', 'show', 'hide', 'exit'):
                 webview.start(debug=self.debug) if arg == 'start' else getattr(self.webview, arg)()
                 self.exit.set() if arg in ('start', 'exit') else None
-            elif arg == 'subscribe':
-                func, c_id = (self.queue.get() for _ in range(2))
-                self.js_api.click_funcs[str(c_id)] = func
             else:
                 try:
                     self.webview.evaluate_js(arg)
@@ -40,12 +47,11 @@ class Chart(LWC):
                  on_top: bool = False, debug: bool = False,
                  inner_width: float = 1.0, inner_height: float = 1.0, dynamic_loading: bool = False):
         super().__init__(volume_enabled, inner_width, inner_height, dynamic_loading)
-        self._js_api_code = 'pywebview.api.onClick'
         self._q = mp.Queue()
         self._script_func = self._q.put
         self._exit = mp.Event()
         self._loaded = mp.Event()
-        self._process = mp.Process(target=PyWV, args=(self._q, self._exit, self._loaded, self._html, self._js_api,
+        self._process = mp.Process(target=PyWV, args=(self._q, self._exit, self._loaded, self._html,
                                                       width, height, x, y, on_top, debug,), daemon=True)
         self._process.start()
         self._create_chart()
@@ -83,9 +89,3 @@ class Chart(LWC):
         self._process.terminate()
         del self
 
-    def subscribe_click(self, function: object):
-        self._q.put('subscribe')
-        self._q.put(function)
-        self._q.put(self.id)
-        super().subscribe_click(function)
-