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headless_experimental

ScreenshotParams dataclass

Encoding options for a screenshot.

Source code in zendriver/cdp/headless_experimental.py 
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@dataclass
class ScreenshotParams:
    """
    Encoding options for a screenshot.
    """

    #: Image compression format (defaults to png).
    format_: typing.Optional[str] = None

    #: Compression quality from range [0..100] (jpeg and webp only).
    quality: typing.Optional[int] = None

    #: Optimize image encoding for speed, not for resulting size (defaults to false)
    optimize_for_speed: typing.Optional[bool] = None

    def to_json(self) -> T_JSON_DICT:
        json: T_JSON_DICT = dict()
        if self.format_ is not None:
            json["format"] = self.format_
        if self.quality is not None:
            json["quality"] = self.quality
        if self.optimize_for_speed is not None:
            json["optimizeForSpeed"] = self.optimize_for_speed
        return json

    @classmethod
    def from_json(cls, json: T_JSON_DICT) -> ScreenshotParams:
        return cls(
            format_=(
                str(json["format"]) if json.get("format", None) is not None else None
            ),
            quality=(
                int(json["quality"]) if json.get("quality", None) is not None else None
            ),
            optimize_for_speed=(
                bool(json["optimizeForSpeed"])
                if json.get("optimizeForSpeed", None) is not None
                else None
            ),
        )

format_: typing.Optional[str] = None class-attribute instance-attribute

optimize_for_speed: typing.Optional[bool] = None class-attribute instance-attribute

quality: typing.Optional[int] = None class-attribute instance-attribute

__init__(format_=None, quality=None, optimize_for_speed=None)

from_json(json) classmethod

Source code in zendriver/cdp/headless_experimental.py 
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@classmethod
def from_json(cls, json: T_JSON_DICT) -> ScreenshotParams:
    return cls(
        format_=(
            str(json["format"]) if json.get("format", None) is not None else None
        ),
        quality=(
            int(json["quality"]) if json.get("quality", None) is not None else None
        ),
        optimize_for_speed=(
            bool(json["optimizeForSpeed"])
            if json.get("optimizeForSpeed", None) is not None
            else None
        ),
    )

to_json()

Source code in zendriver/cdp/headless_experimental.py 
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def to_json(self) -> T_JSON_DICT:
    json: T_JSON_DICT = dict()
    if self.format_ is not None:
        json["format"] = self.format_
    if self.quality is not None:
        json["quality"] = self.quality
    if self.optimize_for_speed is not None:
        json["optimizeForSpeed"] = self.optimize_for_speed
    return json

begin_frame(frame_time_ticks=None, interval=None, no_display_updates=None, screenshot=None)

Sends a BeginFrame to the target and returns when the frame was completed. Optionally captures a screenshot from the resulting frame. Requires that the target was created with enabled BeginFrameControl. Designed for use with --run-all-compositor-stages-before-draw, see also https://goo.gle/chrome-headless-rendering for more background.

Parameters:

Name Type Description Default
frame_time_ticks Optional[float]

(Optional) Timestamp of this BeginFrame in Renderer TimeTicks (milliseconds of uptime). If not set, the current time will be used.

 None
interval Optional[float]

(Optional) The interval between BeginFrames that is reported to the compositor, in milliseconds. Defaults to a 60 frames/second interval, i.e. about 16.666 milliseconds.

 None
no_display_updates Optional[bool]

(Optional) Whether updates should not be committed and drawn onto the display. False by default. If true, only side effects of the BeginFrame will be run, such as layout and animations, but any visual updates may not be visible on the display or in screenshots.

 None
screenshot Optional[ScreenshotParams]

(Optional) If set, a screenshot of the frame will be captured and returned in the response. Otherwise, no screenshot will be captured. Note that capturing a screenshot can fail, for example, during renderer initialization. In such a case, no screenshot data will be returned.

 None

Returns:

Type Description
Generator[T_JSON_DICT, T_JSON_DICT, Tuple[bool, Optional[str]]]

A tuple with the following items: 0. hasDamage - Whether the BeginFrame resulted in damage and, thus, a new frame was committed to the display. Reported for diagnostic uses, may be removed in the future. 1. screenshotData - (Optional) Base64-encoded image data of the screenshot, if one was requested and successfully taken. (Encoded as a base64 string when passed over JSON)
Source code in zendriver/cdp/headless_experimental.py 
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def begin_frame(
    frame_time_ticks: typing.Optional[float] = None,
    interval: typing.Optional[float] = None,
    no_display_updates: typing.Optional[bool] = None,
    screenshot: typing.Optional[ScreenshotParams] = None,
) -> typing.Generator[
    T_JSON_DICT, T_JSON_DICT, typing.Tuple[bool, typing.Optional[str]]
]:
    """
    Sends a BeginFrame to the target and returns when the frame was completed. Optionally captures a
    screenshot from the resulting frame. Requires that the target was created with enabled
    BeginFrameControl. Designed for use with --run-all-compositor-stages-before-draw, see also
    https://goo.gle/chrome-headless-rendering for more background.

    :param frame_time_ticks: *(Optional)* Timestamp of this BeginFrame in Renderer TimeTicks (milliseconds of uptime). If not set, the current time will be used.
    :param interval: *(Optional)* The interval between BeginFrames that is reported to the compositor, in milliseconds. Defaults to a 60 frames/second interval, i.e. about 16.666 milliseconds.
    :param no_display_updates: *(Optional)* Whether updates should not be committed and drawn onto the display. False by default. If true, only side effects of the BeginFrame will be run, such as layout and animations, but any visual updates may not be visible on the display or in screenshots.
    :param screenshot: *(Optional)* If set, a screenshot of the frame will be captured and returned in the response. Otherwise, no screenshot will be captured. Note that capturing a screenshot can fail, for example, during renderer initialization. In such a case, no screenshot data will be returned.
    :returns: A tuple with the following items:

        0. **hasDamage** - Whether the BeginFrame resulted in damage and, thus, a new frame was committed to the display. Reported for diagnostic uses, may be removed in the future.
        1. **screenshotData** - *(Optional)* Base64-encoded image data of the screenshot, if one was requested and successfully taken. (Encoded as a base64 string when passed over JSON)
    """
    params: T_JSON_DICT = dict()
    if frame_time_ticks is not None:
        params["frameTimeTicks"] = frame_time_ticks
    if interval is not None:
        params["interval"] = interval
    if no_display_updates is not None:
        params["noDisplayUpdates"] = no_display_updates
    if screenshot is not None:
        params["screenshot"] = screenshot.to_json()
    cmd_dict: T_JSON_DICT = {
        "method": "HeadlessExperimental.beginFrame",
        "params": params,
    }
    json = yield cmd_dict
    return (
        bool(json["hasDamage"]),
        (
            str(json["screenshotData"])
            if json.get("screenshotData", None) is not None
            else None
        ),
    )

disable()

Disables headless events for the target.

.. deprecated:: 1.3

Source code in zendriver/cdp/headless_experimental.py 
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@deprecated(version="1.3")
def disable() -> typing.Generator[T_JSON_DICT, T_JSON_DICT, None]:
    """
    Disables headless events for the target.

    .. deprecated:: 1.3
    """
    cmd_dict: T_JSON_DICT = {
        "method": "HeadlessExperimental.disable",
    }
    json = yield cmd_dict

enable()

Enables headless events for the target.

.. deprecated:: 1.3

Source code in zendriver/cdp/headless_experimental.py 
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@deprecated(version="1.3")
def enable() -> typing.Generator[T_JSON_DICT, T_JSON_DICT, None]:
    """
    Enables headless events for the target.

    .. deprecated:: 1.3
    """
    cmd_dict: T_JSON_DICT = {
        "method": "HeadlessExperimental.enable",
    }
    json = yield cmd_dict