34ce3f7199
Breaking Changes:
- Removed the `api` parameter; callbacks no longer need to be in a specific class.
- Topbar callbacks now take a chart as an argument (see updated callback examples)
- Removed the `topbar` parameter from chart declaration. The Topbar will be automatically created upon declaration of a topbar widget.
- Removed the `searchbox` parameter from charts. It will be created upon subscribing to it in `chart.events`.
- Removed `dynamic_loading`.
- Removed ‘volume_enabled’ parameter. Volume will be enabled if the volumn column is present in the dataframe.
- Widgets’ `func` parameter is now declared last.
- Switchers take a tuple of options rather than a variable number of arguments.
- `add_hotkey` renamed to `hotkey`
- Horizontal lines now take a `func` argument rather than `interactive`. This event will emit the Line object that was moved.
- Removed the `name` parameter from `line.set`. Line object names are now declared upon creation.
Enhancements:
- Added the `button` widget to the Topbar.
- Added the color picker to the drawing context menu.
- Charts now have a `candle_data` method, which returns the current data displayed on the chart as a DataFrame.
- Fixed callbacks are now located in the `chart.events` object:
- search (e.g `chart.events.search += on_search`)
- new_bar
- range_change
- Added volume to the legend
- Drawings can now be accessed through `chart.toolbox.drawings`
- added the `style` and `name` parameters to `create_line`
Bug Fixes:
- Fixed a bug causing new charts not to load after `exit` was called.
- Refactored rayline placement to ensure they do not move the visible range.
- Fixed a bug causing the visible range to shift when trendlines are moved past the final candlestick.
- Fixed a bug preventing trendlines and raylines on irregular timeframes.
- Fixed a bug causing the legend to prevent mouse input into the chart.
2.7 KiB
2.7 KiB
Toolbox
The Toolbox allows for trendlines, ray lines and horizontal lines to be drawn and edited directly on the chart.
It can be used within any Chart object, and is enabled by setting the toolbox parameter to True upon Chart declaration.
The following hotkeys can also be used when the Toolbox is enabled:
- Alt+T: Trendline
- Alt+H: Horizontal Line
- Alt+R: Ray Line
- Meta+Z or Ctrl+Z: Undo
Right-clicking on a drawing will open a context menu, allowing for color selection and deletion.
save_drawings_under
widget: Widget
Saves drawings under a specific topbar text widget. For example:
chart.toolbox.save_drawings_under(chart.topbar['symbol'])
load_drawings
tag: str
Loads and displays drawings stored under the tag given.
import_drawings
file_path: str
Imports the drawings stored at the JSON file given in file_path.
export_drawings
file_path: str
Exports all currently saved drawings to the JSON file given in file_path.
Example:
To get started, create a file called drawings.json, which should only contain {}.
import pandas as pd
from lightweight_charts import Chart
def get_bar_data(symbol, timeframe):
if symbol not in ('AAPL', 'GOOGL', 'TSLA'):
print(f'No data for "{symbol}"')
return pd.DataFrame()
return pd.read_csv(f'bar_data/{symbol}_{timeframe}.csv')
def on_search(chart, searched_string):
new_data = get_bar_data(searched_string, chart.topbar['timeframe'].value)
if new_data.empty:
return
chart.topbar['symbol'].set(searched_string)
chart.set(new_data)
chart.toolbox.load_drawings(searched_string) # Loads the drawings saved under the symbol.
def on_timeframe_selection(chart):
new_data = get_bar_data(chart.topbar['symbol'].value, chart.topbar['timeframe'].value)
if new_data.empty:
return
chart.set(new_data, render_drawings=True) # The symbol has not changed, so we want to re-render the drawings.
if __name__ == '__main__':
chart = Chart(toolbox=True)
chart.legend(True)
chart.events.search += on_search
chart.topbar.textbox('symbol', 'TSLA')
chart.topbar.switcher('timeframe', ('1min', '5min', '30min'), default='5min', func=on_timeframe_selection)
df = get_bar_data('TSLA', '5min')
chart.set(df)
chart.toolbox.import_drawings('drawings.json') # Imports the drawings saved in the JSON file.
chart.toolbox.load_drawings(chart.topbar['symbol'].value) # Loads the drawings under the default symbol.
chart.toolbox.save_drawings_under(chart.topbar['symbol']) # Saves drawings based on the symbol.
chart.show(block=True)
chart.toolbox.export_drawings('drawings.json') # Exports the drawings to the JSON file upon close.