[libcamera-devel,v2,3/6] libcamera: formats: Make ImageFormats iterable

3998 diff mbox series

Make ImageFormats an iterable class by exposing the type definitions
for forward iterators and begin() and end() function from the internal
formats map.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 include/libcamera/internal/formats.h |  8 +++++++
 src/libcamera/formats.cpp            | 36 ++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

Hi Jacopo,

Thank you for the patch.

On Tue, Jun 09, 2020 at 01:28:41AM +0200, Jacopo Mondi wrote:
> Make ImageFormats an iterable class by exposing the type definitions
> for forward iterators and begin() and end() function from the internal
> formats map.
> 
> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> ---
>  include/libcamera/internal/formats.h |  8 +++++++
>  src/libcamera/formats.cpp            | 36 ++++++++++++++++++++++++++++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/include/libcamera/internal/formats.h b/include/libcamera/internal/formats.h
> index 5668f3744c5d..cb840014cbd7 100644
> --- a/include/libcamera/internal/formats.h
> +++ b/include/libcamera/internal/formats.h
> @@ -22,6 +22,14 @@ template<typename T>
>  class ImageFormats
>  {
>  public:
> +	using iterator = typename std::map<T, std::vector<SizeRange>>::iterator;
> +	using const_iterator = typename std::map<T, std::vector<SizeRange>>::const_iterator;
> +
> +	iterator begin() { return data_.begin(); }
> +	const_iterator begin() const { return data_.begin(); }
> +	iterator end() { return data_.end(); }
> +	const_iterator end() const { return data_.end(); }

This exposes a subset of the std::map API, excluding for instance reverse
iterators. I wonder if we should really go in this direction, which
would lead to potentially exposing more of the std::map API in the
future, when users could iterate over data().

> +
>  	int addFormat(T format, const std::vector<SizeRange> &sizes);
>  
>  	bool isEmpty() const;
> diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
> index 62fd46686d7d..fe50b9aaa1f2 100644
> --- a/src/libcamera/formats.cpp
> +++ b/src/libcamera/formats.cpp
> @@ -34,6 +34,42 @@ LOG_DEFINE_CATEGORY(Formats)
>   * Sizes are stored as a list of SizeRange.
>   */
>  
> +/**
> + * \typedef ImageFormats::iterator
> + * \brief Iterator for the formats map
> + */
> +
> +/**
> + * \typedef ImageFormats::const_iterator
> + * \brief Const iterator for the formats map
> + */
> +
> +/**
> + * \fn iterator ImageFormats<T>::begin()
> + * \brief Retrieve an iterator to the first element in the formats map
> + * \return An iterator to the first format map
> + */
> +
> +/**
> + * \fn const_iterator ImageFormats<T>::begin() const
> + * \brief Retrieve an const iterator to the first element in the formats map
> + * \return A const iterator to the first format map
> + */
> +
> +/**
> + * \fn iterator ImageFormats<T>::end()
> + * \brief Retrieve an iterator pointing to the past-the-end element in the
> + * formats map
> + * \return An iterator to the element following the last format
> + */
> +
> +/**
> + * \fn const_iterator ImageFormats<T>::end() const
> + * \brief Retrieve a const iterator pointing to the past-the-end element in the
> + * formats map
> + * \return A const iterator to the element following the last format
> + */
> +
>  /**
>   * \brief Add a format and corresponding sizes to the description
>   * \param[in] format Pixel format or media bus code to describe