team-10/env/Lib/site-packages/streamlit/elements/widgets/camera_input.py
2025-08-02 07:34:44 +02:00

283 lines
10 KiB
Python

# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2025)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations
from dataclasses import dataclass
from textwrap import dedent
from typing import TYPE_CHECKING, Union, cast
from typing_extensions import TypeAlias
from streamlit.elements.lib.file_uploader_utils import enforce_filename_restriction
from streamlit.elements.lib.form_utils import current_form_id
from streamlit.elements.lib.layout_utils import LayoutConfig, validate_width
from streamlit.elements.lib.policies import (
check_widget_policies,
maybe_raise_label_warnings,
)
from streamlit.elements.lib.utils import (
Key,
LabelVisibility,
compute_and_register_element_id,
get_label_visibility_proto_value,
to_key,
)
from streamlit.elements.widgets.file_uploader import _get_upload_files
from streamlit.proto.CameraInput_pb2 import CameraInput as CameraInputProto
from streamlit.proto.Common_pb2 import FileUploaderState as FileUploaderStateProto
from streamlit.proto.Common_pb2 import UploadedFileInfo as UploadedFileInfoProto
from streamlit.runtime.metrics_util import gather_metrics
from streamlit.runtime.scriptrunner import ScriptRunContext, get_script_run_ctx
from streamlit.runtime.state import (
WidgetArgs,
WidgetCallback,
WidgetKwargs,
register_widget,
)
from streamlit.runtime.uploaded_file_manager import DeletedFile, UploadedFile
if TYPE_CHECKING:
from streamlit.delta_generator import DeltaGenerator
from streamlit.elements.lib.layout_utils import WidthWithoutContent
SomeUploadedSnapshotFile: TypeAlias = Union[UploadedFile, DeletedFile, None]
@dataclass
class CameraInputSerde:
def serialize(
self,
snapshot: SomeUploadedSnapshotFile,
) -> FileUploaderStateProto:
state_proto = FileUploaderStateProto()
if snapshot is None or isinstance(snapshot, DeletedFile):
return state_proto
file_info: UploadedFileInfoProto = state_proto.uploaded_file_info.add()
file_info.file_id = snapshot.file_id
file_info.name = snapshot.name
file_info.size = snapshot.size
file_info.file_urls.CopyFrom(snapshot._file_urls)
return state_proto
def deserialize(
self, ui_value: FileUploaderStateProto | None
) -> SomeUploadedSnapshotFile:
upload_files = _get_upload_files(ui_value)
return_value = None if len(upload_files) == 0 else upload_files[0]
if return_value is not None and not isinstance(return_value, DeletedFile):
enforce_filename_restriction(return_value.name, [".jpg"])
return return_value
class CameraInputMixin:
@gather_metrics("camera_input")
def camera_input(
self,
label: str,
key: Key | None = None,
help: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
width: WidthWithoutContent = "stretch",
) -> UploadedFile | None:
r"""Display a widget that returns pictures from the user's webcam.
Parameters
----------
label : str
A short label explaining to the user what this widget is used for.
The label can optionally contain GitHub-flavored Markdown of the
following types: Bold, Italics, Strikethroughs, Inline Code, Links,
and Images. Images display like icons, with a max height equal to
the font height.
Unsupported Markdown elements are unwrapped so only their children
(text contents) render. Display unsupported elements as literal
characters by backslash-escaping them. E.g.,
``"1\. Not an ordered list"``.
See the ``body`` parameter of |st.markdown|_ for additional,
supported Markdown directives.
For accessibility reasons, you should never set an empty label, but
you can hide it with ``label_visibility`` if needed. In the future,
we may disallow empty labels by raising an exception.
.. |st.markdown| replace:: ``st.markdown``
.. _st.markdown: https://docs.streamlit.io/develop/api-reference/text/st.markdown
key : str or int
An optional string or integer to use as the unique key for the widget.
If this is omitted, a key will be generated for the widget
based on its content. No two widgets may have the same key.
help : str or None
A tooltip that gets displayed next to the widget label. Streamlit
only displays the tooltip when ``label_visibility="visible"``. If
this is ``None`` (default), no tooltip is displayed.
The tooltip can optionally contain GitHub-flavored Markdown,
including the Markdown directives described in the ``body``
parameter of ``st.markdown``.
on_change : callable
An optional callback invoked when this camera_input's value
changes.
args : tuple
An optional tuple of args to pass to the callback.
kwargs : dict
An optional dict of kwargs to pass to the callback.
disabled : bool
An optional boolean that disables the camera input if set to
``True``. Default is ``False``.
label_visibility : "visible", "hidden", or "collapsed"
The visibility of the label. The default is ``"visible"``. If this
is ``"hidden"``, Streamlit displays an empty spacer instead of the
label, which can help keep the widget aligned with other widgets.
If this is ``"collapsed"``, Streamlit displays no label or spacer.
width : "stretch" or int
The width of the camera input widget. This can be one of the
following:
- ``"stretch"`` (default): The width of the widget matches the
width of the parent container.
- An integer specifying the width in pixels: The widget has a
fixed width. If the specified width is greater than the width of
the parent container, the width of the widget matches the width
of the parent container.
Returns
-------
None or UploadedFile
The UploadedFile class is a subclass of BytesIO, and therefore is
"file-like". This means you can pass an instance of it anywhere a
file is expected.
Examples
--------
>>> import streamlit as st
>>>
>>> enable = st.checkbox("Enable camera")
>>> picture = st.camera_input("Take a picture", disabled=not enable)
>>>
>>> if picture:
... st.image(picture)
.. output::
https://doc-camera-input.streamlit.app/
height: 600px
"""
ctx = get_script_run_ctx()
return self._camera_input(
label=label,
key=key,
help=help,
on_change=on_change,
args=args,
kwargs=kwargs,
disabled=disabled,
label_visibility=label_visibility,
width=width,
ctx=ctx,
)
def _camera_input(
self,
label: str,
key: Key | None = None,
help: str | None = None,
on_change: WidgetCallback | None = None,
args: WidgetArgs | None = None,
kwargs: WidgetKwargs | None = None,
*, # keyword-only arguments:
disabled: bool = False,
label_visibility: LabelVisibility = "visible",
width: WidthWithoutContent = "stretch",
ctx: ScriptRunContext | None = None,
) -> UploadedFile | None:
key = to_key(key)
check_widget_policies(
self.dg,
key,
on_change,
default_value=None,
writes_allowed=False,
)
maybe_raise_label_warnings(label, label_visibility)
element_id = compute_and_register_element_id(
"camera_input",
user_key=key,
form_id=current_form_id(self.dg),
dg=self.dg,
label=label,
help=help,
width=width,
)
camera_input_proto = CameraInputProto()
camera_input_proto.id = element_id
camera_input_proto.label = label
camera_input_proto.form_id = current_form_id(self.dg)
camera_input_proto.disabled = disabled
camera_input_proto.label_visibility.value = get_label_visibility_proto_value(
label_visibility
)
if help is not None:
camera_input_proto.help = dedent(help)
validate_width(width)
layout_config = LayoutConfig(width=width)
serde = CameraInputSerde()
camera_input_state = register_widget(
camera_input_proto.id,
on_change_handler=on_change,
args=args,
kwargs=kwargs,
deserializer=serde.deserialize,
serializer=serde.serialize,
ctx=ctx,
value_type="file_uploader_state_value",
)
self.dg._enqueue(
"camera_input", camera_input_proto, layout_config=layout_config
)
if isinstance(camera_input_state.value, DeletedFile):
return None
return camera_input_state.value
@property
def dg(self) -> DeltaGenerator:
"""Get our DeltaGenerator."""
return cast("DeltaGenerator", self)