Files
lightweight-charts-python/lightweight_charts/chart.py
louisnw 527130e618 Ability to save drawings
- Added `toolbox` to the common methods.
- `toolbox.save_drawings_under` can save drawings under a specific `topbar` widget. eg `chart.toolbox.save_drawings_under(chart.topbar[’symbol’]`)
- `toolbox.load_drawings` will load and display drawings stored under the tag/string given.
- `toolbox.export_drawings` will export all currently saved drawings to the given file path.
- `toolbox.import_drawings` will import the drawings stored at the given file path.

Fixes/Enhancements:
- `update` methods are no longer case sensitive.
- HorizontalLines no longer throw cyclic structure errors in the web console.
- `API` methods can now be normal methods or coroutines.
2023-07-20 21:52:17 +01:00

123 lines
4.8 KiB
Python

import asyncio
import multiprocessing as mp
import webview
from lightweight_charts.abstract import LWC
class CallbackAPI:
def __init__(self, emit_queue, return_queue):
self.emit_q, self.return_q = emit_queue, return_queue
def callback(self, message: str):
messages = message.split('__')
name, chart_id = messages[:2]
args = messages[2:]
self.return_q.put(*args) if name == 'return' else self.emit_q.put((name, chart_id, *args))
class PyWV:
def __init__(self, q, exit, loaded, html, width, height, x, y, on_top, maximize, debug, emit_queue, return_queue):
if maximize:
width, height = webview.screens[0].width, webview.screens[0].height
self.queue = q
self.exit = exit
self.loaded = loaded
self.debug = debug
js_api = CallbackAPI(emit_queue, return_queue)
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()
def loop(self):
while 1:
arg = self.queue.get()
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
else:
try:
self.webview.evaluate_js(arg)
except KeyError:
return
def on_js_load(self): self.loaded.set(), self.loop()
class Chart(LWC):
def __init__(self, volume_enabled: bool = True, width: int = 800, height: int = 600, x: int = None, y: int = None,
on_top: bool = False, maximize: bool = False, debug: bool = False,
api: object = None, topbar: bool = False, searchbox: bool = False, toolbox: bool = False,
inner_width: float = 1.0, inner_height: float = 1.0, dynamic_loading: bool = False, scale_candles_only: bool = False):
super().__init__(volume_enabled, inner_width, inner_height, dynamic_loading, scale_candles_only, topbar, searchbox, toolbox, 'pywebview.api.callback')
self._q, self._emit_q, self._return_q = (mp.Queue() for _ in range(3))
self._exit, self._loaded = mp.Event(), mp.Event()
self._script_func = self._q.put
self._api = api
self._process = mp.Process(target=PyWV, args=(self._q, self._exit, self._loaded, self._html,
width, height, x, y, on_top, maximize, debug,
self._emit_q, self._return_q), daemon=True)
self._process.start()
def show(self, block: bool = False):
"""
Shows the chart window.\n
:param block: blocks execution until the chart is closed.
"""
if not self.loaded:
self._q.put('start')
self._loaded.wait()
self._on_js_load()
else:
self._q.put('show')
if block:
asyncio.run(self.show_async(block=True))
async def show_async(self, block=False):
self.show(block=False)
if not block:
asyncio.create_task(self.show_async(block=True))
return
try:
while 1:
while self._emit_q.empty() and not self._exit.is_set() and self.polygon._q.empty():
await asyncio.sleep(0.05)
if self._exit.is_set():
self._exit.clear()
return
elif not self._emit_q.empty():
name, chart_id, arg = self._emit_q.get()
self._api.chart = self._charts[chart_id]
if name == 'save_drawings':
self._api.chart.toolbox._save_drawings(arg)
continue
method = getattr(self._api, name)
if hasattr(self._api.chart, 'topbar') and (widget := self._api.chart.topbar._widget_with_method(name)):
widget.value = arg
await method() if asyncio.iscoroutinefunction(method) else method()
else:
await method(*arg.split(';;;')) if asyncio.iscoroutinefunction(method) else method(arg)
continue
value = self.polygon._q.get()
func, args = value[0], value[1:]
func(*args)
except KeyboardInterrupt:
return
def hide(self):
"""
Hides the chart window.\n
"""
self._q.put('hide')
def exit(self):
"""
Exits and destroys the chart window.\n
"""
self._q.put('exit')
self._exit.wait()
self._process.terminate()
del self