LineCharts with custom bottom_axis labels stop rendering after list max length is reached #16
Description
Duplicate Check
- I have searched the opened issues and there are no duplicates
Describe the bug
List for bottom_axis.labels is passed through a deque of certain maxlen (in this example, 20). Charts start rendering as expected, but when length of deque reaches maxlen, charts stop rendering. If bottom_axis.labels is not modified, charts do not freeze. List for bottom_axis.labels and rest of data_series keep being produced as expected. Also, if chart.min_x is modified, lines start rendering outside of plot area.
Code sample
Code
import flet as ft
import random
from collections import deque
from time import localtime, strftime, perf_counter_ns, sleep
def main(page: ft.Page):
page.title = "Chart bug demo"
page.vertical_alignment = ft.MainAxisAlignment.CENTER
def temp_chart(name: str, max_y: float, min_y: float) -> ft.Card:
return ft.Card(
content=ft.LineChart(
border=ft.border.all(3, ft.colors.with_opacity(0.4, ft.colors.ON_SURFACE)),
horizontal_grid_lines=ft.ChartGridLines(interval=1, color=ft.colors.with_opacity(0.2, ft.colors.ON_SURFACE), width=1),
vertical_grid_lines=ft.ChartGridLines(interval=6, color=ft.colors.with_opacity(0.2, ft.colors.ON_SURFACE), width=1),
expand=True,
tooltip_bgcolor=ft.colors.with_opacity(0.8, ft.colors.GREY_200),
left_axis=ft.ChartAxis(labels_size=40, title=ft.Text(value="Temperatura (°C)", size=15), title_size=30),
bottom_axis=ft.ChartAxis(
labels_size=20,
show_labels=True,
title=ft.Text(value="Hora", size=15),
title_size=30
),
top_axis=ft.ChartAxis(title=ft.Text(value=name, size=20), title_size=40, show_labels=False),
right_axis=ft.ChartAxis(title=ft.Text(value=""), title_size=20, show_labels=False),
height=400,
width=600,
max_y=max_y,
min_y=min_y
)
)
d_size = 144
pt_dict = {
"H.LCS.025": {
"name": "H.LCS.025",
"max_y": 8.0,
"min_y": 0.0,
"upper_limit_dp": deque(maxlen=d_size),
"upper_limit_val": 6.0,
"upper_limit_color": ft.colors.BLACK,
"left_sensor_dp": deque(maxlen=d_size),
"left_sensor_idx": 0,
"left_sensor_color": ft.colors.GREEN,
"right_sensor_dp": deque(maxlen=d_size),
"right_sensor_idx": 1,
"right_sensor_color": ft.colors.LIGHT_GREEN,
"lower_limit_dp": deque(maxlen=d_size),
"lower_limit_val": 2.0,
"lower_limit_color": ft.colors.BLACK
},
"H.LCS.027": {
"name": "H.LCS.027",
"max_y": 10.0,
"min_y": 0.0,
"upper_limit_dp": deque(maxlen=d_size),
"upper_limit_val": 8.0,
"upper_limit_color": ft.colors.BLACK,
"left_sensor_dp": deque(maxlen=d_size),
"left_sensor_idx": 2,
"left_sensor_color": ft.colors.GREEN,
"right_sensor_dp": deque(maxlen=d_size),
"right_sensor_idx": 3,
"right_sensor_color": ft.colors.LIGHT_GREEN,
"lower_limit_dp": deque(maxlen=d_size),
"lower_limit_val": 4.0,
"lower_limit_color": ft.colors.BLACK
},
"H.LCS.024": {
"name": "H.LCS.024",
"max_y": 8.0,
"min_y": 0.0,
"upper_limit_dp": deque(maxlen=d_size),
"upper_limit_val": 6.0,
"upper_limit_color": ft.colors.BLACK,
"left_sensor_dp": deque(maxlen=d_size),
"left_sensor_idx": 4,
"left_sensor_color": ft.colors.GREEN,
"right_sensor_dp": deque(maxlen=d_size),
"right_sensor_idx": 5,
"right_sensor_color": ft.colors.LIGHT_GREEN,
"lower_limit_dp": deque(maxlen=d_size),
"lower_limit_val": 2.0,
"lower_limit_color": ft.colors.BLACK
},
"H.LCS.026": {
"name": "H.LCS.026",
"max_y": 8.0,
"min_y": 0.0,
"upper_limit_dp": deque(maxlen=d_size),
"upper_limit_val": 6.0,
"upper_limit_color": ft.colors.BLACK,
"left_sensor_dp": deque(maxlen=d_size),
"left_sensor_idx": 6,
"left_sensor_color": ft.colors.GREEN,
"right_sensor_dp": deque(maxlen=d_size),
"right_sensor_idx": 7,
"right_sensor_color": ft.colors.LIGHT_GREEN,
"lower_limit_dp": deque(maxlen=d_size),
"lower_limit_val": 2.0,
"lower_limit_color": ft.colors.BLACK
},
"F.LCS.002/003": {
"name": "F.LCS.002/003",
"max_y": 8.0,
"min_y": 0.0,
"upper_limit_dp": deque(maxlen=d_size),
"upper_limit_val": 6.0,
"upper_limit_color": ft.colors.BLACK,
"left_sensor_dp": deque(maxlen=d_size),
"left_sensor_idx": 8,
"left_sensor_color": ft.colors.BLUE,
"right_sensor_dp": deque(maxlen=d_size),
"right_sensor_idx": 9,
"right_sensor_color": ft.colors.LIGHT_BLUE,
"lower_limit_dp": deque(maxlen=d_size),
"lower_limit_val": 2.0,
"lower_limit_color": ft.colors.BLACK
}
}
temp_charts = [
temp_chart(
name=pt_dict[key]["name"],
max_y=pt_dict[key]["max_y"],
min_y=pt_dict[key]["min_y"]
)
for key in pt_dict
]
page.add(
ft.Row(
[
temp_charts[0],
temp_charts[1],
temp_charts[2]
],
alignment=ft.MainAxisAlignment.CENTER,
),
ft.Row(
[
temp_charts[3],
temp_charts[4]
],
alignment=ft.MainAxisAlignment.CENTER,
)
)
def gen_yaxis_data():
return [random.random() * 4 + 2 for _ in range(10)]
def build_data_series(data_points: deque, tracker: float, y: float, color: ft.colors) -> ft.LineChartData:
data_points.append(ft.LineChartDataPoint(tracker, y))
data_series = ft.LineChartData(
data_points=list(data_points),
stroke_width=5,
color=color,
curved=True,
stroke_cap_round=True,
prevent_curve_over_shooting=True
)
return data_series
def build_time_labels(time_labels: deque, tracker: float) -> deque([ft.ChartAxisLabel]):
time_labels.append(ft.ChartAxisLabel(label=ft.Text(value=strftime("%H", localtime()), size=10), value=tracker))
return time_labels
def update_chart(data_series: [ft.LineChartData], time_labels: [ft.ChartAxisLabel], chart: ft.LineChart) -> None:
chart.data_series = data_series
chart.bottom_axis.labels = time_labels
#chart.min_x = time_labels[0].value
#chart.max_x = time_labels[-1].value
def pt_main(page: ft.Page, pt_dict: {}, temp_charts: [ft.LineChart]) -> None:
time_labels = deque(maxlen=20)
tracker = 0.0
while True:
t0 = perf_counter_ns()
temps = gen_yaxis_data()
time_labels = build_time_labels(time_labels, tracker)
for _, chart in zip(pt_dict, temp_charts):
upper_limit = build_data_series(
pt_dict[_]["upper_limit_dp"],
tracker,
pt_dict[_]["upper_limit_val"],
pt_dict[_]["upper_limit_color"]
)
left_sensor = build_data_series(
pt_dict[_]["left_sensor_dp"],
tracker,
temps[pt_dict[_]["left_sensor_idx"]],
pt_dict[_]["left_sensor_color"]
)
right_sensor = build_data_series(
pt_dict[_]["right_sensor_dp"],
tracker,
temps[pt_dict[_]["right_sensor_idx"]],
pt_dict[_]["right_sensor_color"]
)
lower_limit = build_data_series(
pt_dict[_]["lower_limit_dp"],
tracker,
pt_dict[_]["lower_limit_val"],
pt_dict[_]["lower_limit_color"]
)
data_series = [
upper_limit,
left_sensor,
right_sensor,
lower_limit
]
update_chart(data_series, list(time_labels), chart.content)
page.update()
tracker += 1
t1 = perf_counter_ns()
sleep(1 - (t1 - t0) / 1_000_000_000)
pt_main(page, pt_dict, temp_charts)
ft.app(main)To reproduce
Run repro code and wait for maxlen to reach 20 (20 seconds), modify maxlen accordingly to see problem sooner.
Expected behavior
Expected to see charts not freezing and rendering continuously.
Screenshots / Videos
Captures
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Operating System
Windows
Operating system details
Windows 11
Flet version
0.23.2
Regression
I'm not sure / I don't know
Suggestions
No response
Logs
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