cam: options: Support parent-child relationship between options

Add support for creating a tree-based hieararchy of options instead of a
flat list. This is useful to support options that need to be interpreted
in the context of a particular occurrence of an array option.

The usage text automatically documents the options in their
corresponding context:

Options:
  -c, --camera camera ...                               Specify which camera to operate on, by id or by index
  -h, --help                                            Display this help message
  -I, --info                                            Display information about stream(s)
  -l, --list                                            List all cameras
      --list-controls                                   List cameras controls
  -p, --list-properties                                 List cameras properties
  -m, --monitor                                         Monitor for hotplug and unplug camera events

Options valid in the context of --camera:
  -C, --capture[=count]                                 Capture until interrupted by user or until <count> frames captured
  -F, --file[=filename]                                 Write captured frames to disk
                                                        If the file name ends with a '/', it sets the directory in which
                                                        to write files, using the default file name. Otherwise it sets the
                                                        full file path and name. The first '#' character in the file name
                                                        is expanded to the camera index, stream name and frame sequence number.
                                                        The default file name is 'frame-#.bin'.
  -s, --stream key=value[,key=value,...] ...            Set configuration of a camera stream
          height=integer                                Height in pixels
          pixelformat=string                            Pixel format name
          role=string                                   Role for the stream (viewfinder, video, still, raw)
          width=integer                                 Width in pixels
      --strict-formats                                  Do not allow requested stream format(s) to be adjusted
      --metadata                                        Print the metadata for completed requests

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/src/cam/options.h b/src/cam/options.h
index 5c51a94c..e894822c 100644
--- a/src/cam/options.h
+++ b/src/cam/options.h
@@ -10,6 +10,7 @@
 #include <ctype.h>
 #include <list>
 #include <map>
+#include <tuple>
 #include <vector>
 
 class KeyValueParser;
@@ -91,9 +92,11 @@ public:
 	bool addOption(int opt, OptionType type, const char *help,
 		       const char *name = nullptr,
 		       OptionArgument argument = ArgumentNone,
-		       const char *argumentName = nullptr, bool array = false);
+		       const char *argumentName = nullptr, bool array = false,
+		       int parent = 0);
 	bool addOption(int opt, KeyValueParser *parser, const char *help,
-		       const char *name = nullptr, bool array = false);
+		       const char *name = nullptr, bool array = false,
+		       int parent = 0);
 
 	Options parse(int argc, char *argv[]);
 	void usage();
@@ -104,6 +107,10 @@ private:
 
 	void usageOptions(const std::list<Option> &options, unsigned int indent);
 
+	std::tuple<OptionsParser::Options *, const Option *>
+	childOption(const Option *parent, Options *options);
+	bool parseValue(const Option &option, const char *arg, Options *options);
+
 	std::list<Option> options_;
 	std::map<unsigned int, Option *> optionsMap_;
 };
@@ -139,12 +146,15 @@ public:
 	KeyValueParser::Options toKeyValues() const;
 	std::vector<OptionValue> toArray() const;
 
+	const OptionsParser::Options &children() const;
+
 private:
 	ValueType type_;
 	int integer_;
 	std::string string_;
 	KeyValueParser::Options keyValues_;
 	std::vector<OptionValue> array_;
+	OptionsParser::Options children_;
 };
 
 #endif /* __CAM_OPTIONS_H__ */