import os
from datetime import timedelta, datetime
from base64 import b64decode
import pandas as pd
from typing import Union, Literal, Dict, List
from lightweight_charts.util import LINE_STYLE, MARKER_POSITION, MARKER_SHAPE, CROSSHAIR_MODE, _crosshair_mode, \
_line_style, \
MissingColumn, _js_bool, _price_scale_mode, PRICE_SCALE_MODE, _marker_position, _marker_shape, IDGen
JS = {}
current_dir = os.path.dirname(os.path.abspath(__file__))
for file in ('pkg', 'funcs', 'callback'):
with open(os.path.join(current_dir, 'js', f'{file}.js'), 'r') as f:
JS[file] = f.read()
HTML = f"""
lightweight-charts-python
"""
class SeriesCommon:
def _set_interval(self, df: pd.DataFrame):
common_interval = pd.to_datetime(df['time']).diff().value_counts()
try:
self._interval = common_interval.index[0]
except IndexError:
raise IndexError('Not enough bars within the given data to calculate the interval/timeframe.')
self.run_script(f'''
if ({self.id}.toolBox) {{
{self.id}.toolBox.interval = {self._interval.total_seconds()*1000}
}}
''')
def _df_datetime_format(self, df: pd.DataFrame):
df = df.copy()
if 'date' in df.columns:
df = df.rename(columns={'date': 'time'})
self._set_interval(df)
df['time'] = self._datetime_format(df['time'])
return df
def _series_datetime_format(self, series):
series = series.copy()
if 'date' in series.keys():
series = series.rename({'date': 'time'})
series['time'] = self._datetime_format(series['time'])
return series
def _datetime_format(self, arg: Union[pd.Series, str]):
arg = pd.to_datetime(arg)
if self._interval != timedelta(days=1):
arg = arg.astype('int64') // 10 ** 9 if isinstance(arg, pd.Series) else arg.timestamp()
arg = self._interval.total_seconds() * (arg // self._interval.total_seconds())
else:
arg = arg.dt.strftime('%Y-%m-%d') if isinstance(arg, pd.Series) else arg.strftime('%Y-%m-%d')
return arg
def marker(self, time: datetime = None, position: MARKER_POSITION = 'below', shape: MARKER_SHAPE = 'arrow_up',
color: str = '#2196F3', text: str = '') -> str:
"""
Creates a new marker.\n
:param time: The time that the marker will be placed at. If no time is given, it will be placed at the last bar.
:param position: The position of the marker.
:param color: The color of the marker (rgb, rgba or hex).
:param shape: The shape of the marker.
:param text: The text to be placed with the marker.
:return: The id of the marker placed.
"""
try:
time = self._last_bar['time'] if not time else self._datetime_format(time)
except TypeError:
raise TypeError('Chart marker created before data was set.')
marker_id = self._rand.generate()
self.run_script(f"""
{self.id}.markers.push({{
time: {time if isinstance(time, float) else f"'{time}'"},
position: '{_marker_position(position)}',
color: '{color}',
shape: '{_marker_shape(shape)}',
text: '{text}',
id: '{marker_id}'
}});
{self.id}.series.setMarkers({self.id}.markers)""")
return marker_id
def remove_marker(self, marker_id: str):
"""
Removes the marker with the given id.\n
"""
self.run_script(f'''
{self.id}.markers.forEach(function (marker) {{
if ('{marker_id}' === marker.id) {{
{self.id}.markers.splice({self.id}.markers.indexOf(marker), 1)
{self.id}.series.setMarkers({self.id}.markers)
}}
}});''')
def horizontal_line(self, price: Union[float, int], color: str = 'rgb(122, 146, 202)', width: int = 1,
style: LINE_STYLE = 'solid', text: str = '', axis_label_visible=True):
"""
Creates a horizontal line at the given price.\n
"""
line_id = self._rand.generate()
self.run_script(f"""
makeHorizontalLine({self.id}, '{line_id}', {price}, '{color}', {width}, {_line_style(style)}, {_js_bool(axis_label_visible)}, '{text}')
""")
return line_id
def remove_horizontal_line(self, price: Union[float, int]):
"""
Removes a horizontal line at the given price.
"""
self.run_script(f'''
{self.id}.horizontal_lines.forEach(function (line) {{
if ({price} === line.price) {{
{self.id}.series.removePriceLine(line.line);
{self.id}.horizontal_lines.splice({self.id}.horizontal_lines.indexOf(line), 1)
}}
}});''')
def clear_markers(self):
"""
Clears the markers displayed on the data.\n
"""
self.run_script(f'''{self.id}.markers = []; {self.id}.series.setMarkers([])''')
def clear_horizontal_lines(self):
"""
Clears the horizontal lines displayed on the data.\n
"""
self.run_script(f'''
{self.id}.horizontal_lines.forEach(function (line) {{{self.id}.series.removePriceLine(line.line);}});
{self.id}.horizontal_lines = [];
''')
def title(self, title: str): self.run_script(f'{self.id}.series.applyOptions({{title: "{title}"}})')
def price_line(self, label_visible: bool = True, line_visible: bool = True):
self.run_script(f'''
{self.id}.series.applyOptions({{
lastValueVisible: {_js_bool(label_visible)},
priceLineVisible: {_js_bool(line_visible)},
}})''')
def hide_data(self): self._toggle_data(False)
def show_data(self): self._toggle_data(True)
def _toggle_data(self, arg):
self.run_script(f'''
{self.id}.series.applyOptions({{visible: {_js_bool(arg)}}})
{f'{self.id}.volumeSeries.applyOptions({{visible: {_js_bool(arg)}}})' if hasattr(self, 'volume_enabled') and self.volume_enabled else ''}
''')
class Line(SeriesCommon):
def __init__(self, chart, color, width, price_line, price_label):
self.color = color
self.name = ''
self._chart = chart
self._rand = chart._rand
self.id = f'window.{self._rand.generate()}'
self.run_script = self._chart.run_script
self.run_script(f'''
{self.id} = {{
series: {self._chart.id}.chart.addLineSeries({{
color: '{color}',
lineWidth: {width},
lastValueVisible: {_js_bool(price_label)},
priceLineVisible: {_js_bool(price_line)},
{"""autoscaleInfoProvider: () => ({
priceRange: {
minValue: 1_000_000_000,
maxValue: 0,
},
}),""" if self._chart._scale_candles_only else ''}
}}),
markers: [],
horizontal_lines: [],
}}''')
def set(self, data: pd.DataFrame, name=None):
"""
Sets the line data.\n
:param data: If the name parameter is not used, the columns should be named: date/time, value.
:param name: The column of the DataFrame to use as the line value. When used, the Line will be named after this column.
"""
df = self._df_datetime_format(data)
if name:
if name not in data:
raise NameError(f'No column named "{name}".')
self.name = name
df = df.rename(columns={name: 'value'})
self._last_bar = df.iloc[-1]
self.run_script(f'{self.id}.series.setData({df.to_dict("records")})')
def update(self, series: pd.Series):
"""
Updates the line data.\n
:param series: labels: date/time, value
"""
series = self._series_datetime_format(series)
self._last_bar = series
self.run_script(f'{self.id}.series.update({series.to_dict()})')
def delete(self):
"""
Irreversibly deletes the line, as well as the object that contains the line.
"""
self._chart._lines.remove(self)
self.run_script(f'''
{self._chart.id}.chart.removeSeries({self.id}.series)
delete {self.id}
''')
del self
class Widget:
def __init__(self, topbar):
self._chart = topbar._chart
self._method = None
class TextWidget(Widget):
def __init__(self, topbar, initial_text):
super().__init__(topbar)
self.value = initial_text
self.id = f"window.{self._chart._rand.generate()}"
self._chart.run_script(f'''{self.id} = makeTextBoxWidget({self._chart.id}, "{initial_text}")''')
def set(self, string):
self.value = string
self._chart.run_script(f'{self.id}.innerText = "{string}"')
class SwitcherWidget(Widget):
def __init__(self, topbar, method, *options, default):
super().__init__(topbar)
self.value = default
self._method = method.__name__
self._chart.run_script(f'''
makeSwitcher({self._chart.id}, {list(options)}, '{default}', {self._chart._js_api_code}, '{method.__name__}',
'{topbar.active_background_color}', '{topbar.active_text_color}', '{topbar.text_color}', '{topbar.hover_color}')
{self._chart.id}.chart.resize(window.innerWidth*{self._chart._inner_width}, (window.innerHeight*{self._chart._inner_height})-{self._chart.id}.topBar.offsetHeight)
''')
class TopBar:
def __init__(self, chart):
self._chart = chart
self._widgets: Dict[str, Widget] = {}
self._chart.run_script(f'''
makeTopBar({self._chart.id})
{self._chart.id}.chart.resize(window.innerWidth*{self._chart._inner_width},
(window.innerHeight*{self._chart._inner_height})-{self._chart.id}.topBar.offsetHeight)
''')
self.active_background_color = 'rgba(0, 122, 255, 0.7)'
self.active_text_color = 'rgb(240, 240, 240)'
self.text_color = 'lightgrey'
self.hover_color = 'rgb(60, 60, 60)'
def __getitem__(self, item): return self._widgets.get(item)
def switcher(self, name, method, *options, default=None):
self._widgets[name] = SwitcherWidget(self, method, *options, default=default if default else options[0])
def textbox(self, name, initial_text=''): self._widgets[name] = TextWidget(self, initial_text)
def _widget_with_method(self, method_name):
for widget in self._widgets.values():
if widget._method == method_name:
return widget
class LWC(SeriesCommon):
def __init__(self, volume_enabled: bool = True, inner_width: float = 1.0, inner_height: float = 1.0, dynamic_loading: bool = False,
scale_candles_only: bool = False):
self.volume_enabled = volume_enabled
self._scale_candles_only = scale_candles_only
self._inner_width = inner_width
self._inner_height = inner_height
self._dynamic_loading = dynamic_loading
self._rand = IDGen()
self.id = f'window.{self._rand.generate()}'
self._position = 'left'
self.loaded = False
self._html = HTML
self._scripts = []
self._final_scripts = []
self._script_func = None
self._last_bar = None
self._interval = None
self._charts = {self.id: self}
self._lines = []
self._js_api_code = None
self._return_q = None
self._background_color = '#000000'
self._volume_up_color = 'rgba(83,141,131,0.8)'
self._volume_down_color = 'rgba(200,127,130,0.8)'
from lightweight_charts.polygon import PolygonAPI
self.polygon: PolygonAPI = PolygonAPI(self)
def _on_js_load(self):
if self.loaded:
return
self.loaded = True
[self.run_script(script) for script in self._scripts]
[self.run_script(script) for script in self._final_scripts]
def _create_chart(self, autosize=True):
self.run_script(f'''
{self.id} = makeChart({self._inner_width}, {self._inner_height}, autoSize={_js_bool(autosize)})
{self.id}.id = '{self.id}'
{self.id}.wrapper.style.float = "{self._position}"
''')
def _make_search_box(self):
self.run_script(f'{self.id}.search = makeSearchBox({self.id}, {self._js_api_code})')
def run_script(self, script, run_last=False):
"""
For advanced users; evaluates JavaScript within the Webview.
"""
if self.loaded:
self._script_func(script)
return
self._scripts.append(script) if not run_last else self._final_scripts.append(script)
def set(self, df: pd.DataFrame):
"""
Sets the initial data for the chart.\n
:param df: columns: date/time, open, high, low, close, volume (if volume enabled).
"""
if df.empty:
self.run_script(f'{self.id}.series.setData([])')
self.run_script(f'{self.id}.volumeSeries.setData([])')
return
bars = self._df_datetime_format(df)
self._last_bar = bars.iloc[-1]
if self.volume_enabled:
if 'volume' not in bars:
raise MissingColumn("Volume enabled, but 'volume' column was not found.")
volume = bars.drop(columns=['open', 'high', 'low', 'close']).rename(columns={'volume': 'value'})
volume['color'] = self._volume_down_color
volume.loc[bars['close'] > bars['open'], 'color'] = self._volume_up_color
self.run_script(f'{self.id}.volumeSeries.setData({volume.to_dict(orient="records")})')
bars = bars.drop(columns=['volume'])
bars = bars.to_dict(orient='records')
self.run_script(f'''
{self.id}.candleData = {bars}
{self.id}.shownData = ({self.id}.candleData.length >= 190) ? {self.id}.candleData.slice(-190) : {self.id}.candleData
{self.id}.series.setData({self.id}.shownData);
var timer = null;
{self.id}.chart.timeScale().subscribeVisibleLogicalRangeChange(() => {{
if (timer !== null) {{
return;
}}
timer = setTimeout(() => {{
let chart = {self.id}
let logicalRange = chart.chart.timeScale().getVisibleLogicalRange();
if (logicalRange !== null) {{
let barsInfo = chart.series.barsInLogicalRange(logicalRange);
if (barsInfo === null || barsInfo.barsBefore === null || barsInfo.barsAfter === null) {{return}}
if (barsInfo !== null && barsInfo.barsBefore < 20 || barsInfo.barsAfter < 20) {{
let newBeginning = chart.candleData.indexOf(chart.shownData[0])+Math.round(barsInfo.barsBefore)-20
let newEnd = chart.candleData.indexOf(chart.shownData[chart.shownData.length-2])-Math.round(barsInfo.barsAfter)+20
if (newBeginning < 0) {{
newBeginning = 0
}}
chart.shownData = chart.candleData.slice(newBeginning, newEnd)
if (newEnd-17 <= chart.candleData.length-1) {{
chart.shownData[chart.shownData.length - 1] = Object.assign({{}}, chart.shownData[chart.shownData.length - 1]);
chart.shownData[chart.shownData.length - 1].open = chart.candleData[chart.candleData.length - 1].close;
chart.shownData[chart.shownData.length - 1].high = chart.candleData[chart.candleData.length - 1].close;
chart.shownData[chart.shownData.length - 1].low = chart.candleData[chart.candleData.length - 1].close;
chart.shownData[chart.shownData.length - 1].close = chart.candleData[chart.candleData.length - 1].close;
}}
chart.series.setData(chart.shownData);
}}
}}
timer = null;
}}, 50);
}});
''') if self._dynamic_loading else self.run_script(f'{self.id}.candleData = {bars}; {self.id}.series.setData({self.id}.candleData)')
def fit(self):
"""
Fits the maximum amount of the chart data within the viewport.
"""
self.run_script(f'{self.id}.chart.timeScale().fitContent()')
def update(self, series, from_tick=False):
"""
Updates the data from a bar;
if series['time'] is the same time as the last bar, the last bar will be overwritten.\n
:param series: labels: date/time, open, high, low, close, volume (if volume enabled).
"""
series = self._series_datetime_format(series) if not from_tick else series
self._last_bar = series
if self.volume_enabled:
if 'volume' not in series:
raise MissingColumn("Volume enabled, but 'volume' column was not found.")
volume = series.drop(['open', 'high', 'low', 'close']).rename({'volume': 'value'})
volume['color'] = self._volume_up_color if series['close'] > series['open'] else self._volume_down_color
self.run_script(f'{self.id}.volumeSeries.update({volume.to_dict()})')
series = series.drop(['volume'])
bar = series.to_dict()
self.run_script(f'''
let logicalRange = {self.id}.chart.timeScale().getVisibleLogicalRange();
let barsInfo = {self.id}.series.barsInLogicalRange(logicalRange);
if ({self.id}.candleData[{self.id}.candleData.length-1].time === {bar['time']}) {{
{self.id}.shownData[{self.id}.shownData.length-1] = {bar}
{self.id}.candleData[{self.id}.candleData.length-1] = {bar}
}}
else {{
if (barsInfo.barsAfter > 0) {{
{self.id}.shownData[{self.id}.shownData.length-1] = {bar}
}}
else {{
{self.id}.shownData.push({bar})
}}
{self.id}.candleData.push({bar})
}}
{self.id}.series.update({self.id}.shownData[{self.id}.shownData.length-1])
''') if self._dynamic_loading else self.run_script(f'{self.id}.series.update({bar})')
def update_from_tick(self, series, cumulative_volume=False):
"""
Updates the data from a tick.\n
:param series: labels: date/time, price, volume (if volume enabled).
:param cumulative_volume: Adds the given volume onto the latest bar.
"""
series = self._series_datetime_format(series)
bar = pd.Series()
if series['time'] == self._last_bar['time']:
bar = self._last_bar
bar['high'] = max(self._last_bar['high'], series['price'])
bar['low'] = min(self._last_bar['low'], series['price'])
bar['close'] = series['price']
if self.volume_enabled:
if 'volume' not in series:
raise MissingColumn("Volume enabled, but 'volume' column was not found.")
elif cumulative_volume:
bar['volume'] += series['volume']
else:
bar['volume'] = series['volume']
else:
for key in ('open', 'high', 'low', 'close'):
bar[key] = series['price']
bar['time'] = series['time']
bar['volume'] = 0
self.update(bar, from_tick=True)
def create_line(self, color: str = 'rgba(214, 237, 255, 0.6)', width: int = 2,
price_line: bool = True, price_label: bool = True) -> Line:
"""
Creates and returns a Line object.)\n
"""
self._lines.append(Line(self, color, width, price_line, price_label))
return self._lines[-1]
def lines(self) -> List[Line]:
"""
Returns all lines for the chart.
"""
return self._lines.copy()
def price_scale(self, mode: PRICE_SCALE_MODE = 'normal', align_labels: bool = True, border_visible: bool = False,
border_color: str = None, text_color: str = None, entire_text_only: bool = False,
ticks_visible: bool = False, scale_margin_top: float = 0.2, scale_margin_bottom: float = 0.2):
self.run_script(f'''
{self.id}.series.priceScale().applyOptions({{
mode: {_price_scale_mode(mode)},
alignLabels: {_js_bool(align_labels)},
borderVisible: {_js_bool(border_visible)},
{f'borderColor: "{border_color}",' if border_color else ''}
{f'textColor: "{text_color}",' if text_color else ''}
entireTextOnly: {_js_bool(entire_text_only)},
ticksVisible: {_js_bool(ticks_visible)},
scaleMargins: {{top: {scale_margin_top}, bottom: {scale_margin_bottom}}}
}})''')
def time_scale(self, right_offset: int = 0, min_bar_spacing: float = 0.5,
visible: bool = True, time_visible: bool = True, seconds_visible: bool = False,
border_visible: bool = True, border_color: str = None):
"""
Options for the time scale of the chart.
"""
self.run_script(f'''
{self.id}.chart.applyOptions({{
timeScale: {{
rightOffset: {right_offset},
minBarSpacing: {min_bar_spacing},
visible: {_js_bool(visible)},
timeVisible: {_js_bool(time_visible)},
secondsVisible: {_js_bool(seconds_visible)},
borderVisible: {_js_bool(border_visible)},
{f'borderColor: "{border_color}",' if border_color else ''}
}}
}})''')
def layout(self, background_color: str = None, text_color: str = None, font_size: int = None,
font_family: str = None):
"""
Global layout options for the chart.
"""
self._background_color = background_color if background_color else self._background_color
self.run_script(f"""
document.getElementById('wrapper').style.backgroundColor = '{self._background_color}'
{self.id}.chart.applyOptions({{
layout: {{
background: {{
color: "{self._background_color}",
}},
{f'textColor: "{text_color}",' if text_color else ''}
{f'fontSize: {font_size},' if font_size else ''}
{f'fontFamily: "{font_family}",' if font_family else ''}
}}}})""")
def grid(self, vert_enabled: bool = True, horz_enabled: bool = True, color: str = 'rgba(29, 30, 38, 5)', style: LINE_STYLE = 'solid'):
"""
Grid styling for the chart.
"""
self.run_script(f"""
{self.id}.chart.applyOptions({{
grid: {{
vertLines: {{
visible: {_js_bool(vert_enabled)},
color: "{color}",
style: {_line_style(style)},
}},
horzLines: {{
visible: {_js_bool(horz_enabled)},
color: "{color}",
style: {_line_style(style)},
}},
}}
}})""")
def candle_style(self, up_color: str = 'rgba(39, 157, 130, 100)', down_color: str = 'rgba(200, 97, 100, 100)',
wick_enabled: bool = True, border_enabled: bool = True, border_up_color: str = '',
border_down_color: str = '', wick_up_color: str = '', wick_down_color: str = ''):
"""
Candle styling for each of its parts.
"""
self.run_script(f"""
{self.id}.series.applyOptions({{
upColor: "{up_color}",
downColor: "{down_color}",
wickVisible: {_js_bool(wick_enabled)},
borderVisible: {_js_bool(border_enabled)},
{f'borderUpColor: "{border_up_color}",' if border_up_color else up_color if border_enabled else ''}
{f'borderDownColor: "{border_down_color}",' if border_down_color else down_color if border_enabled else ''}
{f'wickUpColor: "{wick_up_color}",' if wick_up_color else wick_up_color if wick_enabled else ''}
{f'wickDownColor: "{wick_down_color}",' if wick_down_color else wick_down_color if wick_enabled else ''}
}})""")
def volume_config(self, scale_margin_top: float = 0.8, scale_margin_bottom: float = 0.0,
up_color='rgba(83,141,131,0.8)', down_color='rgba(200,127,130,0.8)'):
"""
Configure volume settings.\n
Numbers for scaling must be greater than 0 and less than 1.\n
Volume colors must be applied prior to setting/updating the bars.\n
:param scale_margin_top: Scale the top of the margin.
:param scale_margin_bottom: Scale the bottom of the margin.
:param up_color: Volume color for upward direction (rgb, rgba or hex)
:param down_color: Volume color for downward direction (rgb, rgba or hex)
"""
self._volume_up_color = up_color if up_color else self._volume_up_color
self._volume_down_color = down_color if down_color else self._volume_down_color
self.run_script(f'''
{self.id}.volumeSeries.priceScale().applyOptions({{
scaleMargins: {{
top: {scale_margin_top},
bottom: {scale_margin_bottom},
}}
}})''')
def crosshair(self, mode: CROSSHAIR_MODE = 'normal', vert_visible: bool = True, vert_width: int = 1, vert_color: str = None,
vert_style: LINE_STYLE = 'large_dashed', vert_label_background_color: str = 'rgb(46, 46, 46)', horz_visible: bool = True,
horz_width: int = 1, horz_color: str = None, horz_style: LINE_STYLE = 'large_dashed', horz_label_background_color: str = 'rgb(55, 55, 55)'):
"""
Crosshair formatting for its vertical and horizontal axes.
"""
self.run_script(f'''
{self.id}.chart.applyOptions({{
crosshair: {{
mode: {_crosshair_mode(mode)},
vertLine: {{
visible: {_js_bool(vert_visible)},
width: {vert_width},
{f'color: "{vert_color}",' if vert_color else ''}
style: {_line_style(vert_style)},
labelBackgroundColor: "{vert_label_background_color}"
}},
horzLine: {{
visible: {_js_bool(horz_visible)},
width: {horz_width},
{f'color: "{horz_color}",' if horz_color else ''}
style: {_line_style(horz_style)},
labelBackgroundColor: "{horz_label_background_color}"
}}
}}}})''')
def watermark(self, text: str, font_size: int = 44, color: str = 'rgba(180, 180, 200, 0.5)'):
"""
Adds a watermark to the chart.
"""
self.run_script(f'''
{self.id}.chart.applyOptions({{
watermark: {{
visible: true,
fontSize: {font_size},
horzAlign: 'center',
vertAlign: 'center',
color: '{color}',
text: '{text}',
}}
}})''')
def legend(self, visible: bool = False, ohlc: bool = True, percent: bool = True, lines: bool = True, color: str = None,
font_size: int = None, font_family: str = None):
"""
Configures the legend of the chart.
"""
if not visible:
return
lines_code = ''
for i, line in enumerate(self._lines):
lines_code += f'''finalString += `▨{f' {line.name}'} :
${{legendItemFormat(param.seriesData.get({line.id}.series).value)}}
`;'''
self.run_script(f'''
{f"{self.id}.legend.style.color = '{color}'" if color else ''}
{f"{self.id}.legend.style.fontSize = {font_size}" if font_size else ''}
{f"{self.id}.legend.style.fontFamily = '{font_family}'" if font_family else ''}
{self.id}.chart.subscribeCrosshairMove((param) => {{
if (param.time){{
let data = param.seriesData.get({self.id}.series);
let finalString = ''
if (data) {{
let ohlc = `O ${{legendItemFormat(data.open)}}
| H ${{legendItemFormat(data.high)}}
| L ${{legendItemFormat(data.low)}}
| C ${{legendItemFormat(data.close)}} `
let percentMove = ((data.close-data.open)/data.open)*100
let percent = `| ${{percentMove >= 0 ? '+' : ''}}${{percentMove.toFixed(2)}} %`
{'finalString += ohlc' if ohlc else ''}
{'finalString += percent' if percent else ''}
{'finalString += "
"' if ohlc or percent else ''}
}}
{lines_code if lines else ''}
{self.id}.legend.innerHTML = finalString+''
}}
else {{
{self.id}.legend.innerHTML = ''
}}
}});''')
def spinner(self, visible): self.run_script(f"{self.id}.spinner.style.display = '{'block' if visible else 'none'}'")
def screenshot(self) -> bytes:
"""
Takes a screenshot. This method can only be used after the chart window is visible.
:return: a bytes object containing a screenshot of the chart.
"""
self.run_script(f'''
let canvas = {self.id}.chart.takeScreenshot()
canvas.toBlob(function(blob) {{
const reader = new FileReader();
reader.onload = function(event) {{
{self._js_api_code}(`return__{self.id}__${{event.target.result}}`)
}};
reader.readAsDataURL(blob);
}})
''')
serial_data = self._return_q.get()
return b64decode(serial_data.split(',')[1])
def create_subchart(self, volume_enabled: bool = True, position: Literal['left', 'right', 'top', 'bottom'] = 'left',
width: float = 0.5, height: float = 0.5, sync: Union[bool, str] = False,
topbar: bool = False, searchbox: bool = False):
subchart = SubChart(self, volume_enabled, position, width, height, sync, topbar, searchbox)
self._charts[subchart.id] = subchart
return subchart
class SubChart(LWC):
def __init__(self, parent, volume_enabled, position, width, height, sync, topbar, searchbox):
super().__init__(volume_enabled, width, height)
self._chart = parent._chart if isinstance(parent, SubChart) else parent
self._parent = parent
self._position = position
self._rand = self._chart._rand
self._js_api_code = self._chart._js_api_code
self._return_q = self._chart._return_q
self.run_script = self._chart.run_script
self._charts = self._chart._charts
self.id = f'window.{self._rand.generate()}'
self.polygon = self._chart.polygon._subchart(self)
self._create_chart()
self.topbar = TopBar(self) if topbar else None
self._make_search_box() if searchbox else None
if not sync:
return
sync_parent_id = self._parent.id if isinstance(sync, bool) else sync
self.run_script(f'''
{sync_parent_id}.chart.timeScale().subscribeVisibleLogicalRangeChange((timeRange) => {{
{self.id}.chart.timeScale().setVisibleLogicalRange(timeRange)
}});
syncCrosshairs({self.id}.chart, {sync_parent_id}.chart)
''')
self.run_script(f'''
{self.id}.chart.timeScale().setVisibleLogicalRange({sync_parent_id}.chart.timeScale().getVisibleLogicalRange())
''', run_last=True)