cam: options: Move key string left in usage() for key-value parser

When printing usage information for a key-value parser, the
documentation of the keys and values is printed in the second column of
the usage text:

  -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
  -h, --help                                            Display this help message

This results in long lines. Improve this by moving the key description
to the first column, and aligning the value description as other option
description text:

  -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
  -h, --help                                            Display this help message

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

2 files changed, 19 insertions, 10 deletions

diff --git a/src/cam/options.cpp b/src/cam/options.cpp
index 350c8084..379b68c3 100644
--- a/src/cam/options.cpp
+++ b/src/cam/options.cpp
@@ -410,27 +410,30 @@ KeyValueParser::Options KeyValueParser::parse(const char *arguments)
 	return options;
 }
 
-void KeyValueParser::usage(int indent)
+unsigned int KeyValueParser::maxOptionLength() const
 {
-	unsigned int space = 0;
+	unsigned int maxLength = 0;
 
 	for (auto const &iter : optionsMap_) {
 		const Option &option = iter.second;
-		unsigned int length = 14;
+		unsigned int length = 10 + strlen(option.name);
 		if (option.argument != ArgumentNone)
 			length += 1 + strlen(option.typeName());
 		if (option.argument == ArgumentOptional)
 			length += 2;
 
-		if (length > space)
-			space = length;
+		if (length > maxLength)
+			maxLength = length;
 	}
 
-	space = (space + 7) / 8 * 8;
+	return maxLength;
+}
 
+void KeyValueParser::usage(int indent)
+{
 	for (auto const &iter : optionsMap_) {
 		const Option &option = iter.second;
-		std::string argument = option.name;
+		std::string argument = std::string("          ") + option.name;
 
 		if (option.argument != ArgumentNone) {
 			if (option.argument == ArgumentOptional)
@@ -442,14 +445,13 @@ void KeyValueParser::usage(int indent)
 				argument += "]";
 		}
 
-		std::cerr << std::setw(indent) << std::right << " "
-			  << std::setw(space) << std::left << argument;
+		std::cerr << std::setw(indent) << std::left << argument;
 
 		for (const char *help = option.help, *end = help; end;) {
 			end = strchr(help, '\n');
 			if (end) {
 				std::cerr << std::string(help, end - help + 1);
-				std::cerr << std::setw(indent + space) << " ";
+				std::cerr << std::setw(indent) << " ";
 				help = end + 1;
 			} else {
 				std::cerr << help << std::endl;
@@ -917,6 +919,12 @@ void OptionsParser::usage()
 
 		if (length > indent)
 			indent = length;
+
+		if (option->keyValueParser) {
+			length = option->keyValueParser->maxOptionLength();
+			if (length > indent)
+				indent = length;
+		}
 	}
 
 	indent = (indent + 7) / 8 * 8;
diff --git a/src/cam/options.h b/src/cam/options.h
index 4418e201..5c51a94c 100644
--- a/src/cam/options.h
+++ b/src/cam/options.h
@@ -72,6 +72,7 @@ private:
 	KeyValueParser &operator=(const KeyValueParser &) = delete;
 
 	friend class OptionsParser;
+	unsigned int maxOptionLength() const;
 	void usage(int indent);
 
 	std::map<std::string, Option> optionsMap_;