[libcamera-devel] [PATCH v3 03/13] libcamera: controls: Allow read only access to control values

[Laurent Pinchart]

Hi Niklas,

Thank you for the patch.

On Fri, Sep 27, 2019 at 04:44:07AM +0200, Niklas Söderlund wrote:
> Allow the control values in a ControlList to be examined from a const
> environment.

I think this patch and the next one can be dropped if you rebase on top
of the control rework series I've just sent.

> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  include/libcamera/controls.h |  1 +
>  src/libcamera/controls.cpp   | 35 +++++++++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+)
> 
> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
> index fbb3a62274c64259..eee5ef87b8fd2633 100644
> --- a/include/libcamera/controls.h
> +++ b/include/libcamera/controls.h
> @@ -124,6 +124,7 @@ public:
>  	void clear() { controls_.clear(); }
>  
>  	ControlValue &operator[](ControlId id);
> +	const ControlValue &operator[](ControlId id) const;
>  	ControlValue &operator[](const ControlInfo *info) { return controls_[info]; }
>  
>  	void update(const ControlList &list);
> diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
> index 44cb09d9102d93f6..6271a0bd7518dda5 100644
> --- a/src/libcamera/controls.cpp
> +++ b/src/libcamera/controls.cpp
> @@ -523,6 +523,41 @@ ControlValue &ControlList::operator[](ControlId id)
>  	return controls_[&iter->second];
>  }
>  
> +/**
> + * \brief Access the control specified by \a id
> + * \param[in] id The control ID
> + *
> + * This method returns a const reference to the control identified by \a id. If
> + * no such controls is present in the list, a const reference to an empty
> + * control value is returned.
> + *
> + * The behaviour is undefined if the control \a id is not supported by the
> + * camera that the ControlList refers to.
> + *
> + * \return A const reference to the value of the control identified by \a id
> + */
> +const ControlValue &ControlList::operator[](ControlId id) const
> +{
> +	const ControlInfoMap &controls = camera_->controls();
> +	static ControlValue empty;
> +
> +	const auto camctrl = controls.find(id);
> +	if (camctrl == controls.end()) {
> +		LOG(Controls, Error)
> +			<< "Camera " << camera_->name()
> +			<< " does not support control " << id;
> +		return empty;
> +	}
> +
> +	const auto ctrl = controls_.find(&camctrl->second);
> +	if (ctrl == controls_.end()) {
> +		LOG(Controls, Error) << "list does not have control " << id;
> +		return empty;
> +	}
> +
> +	return ctrl->second;
> +}
> +
>  /**
>   * \fn ControlList::operator[](const ControlInfo *info)
>   * \brief Access or insert the control specified by \a info

-- 
Regards,

Laurent Pinchart