controls: Add boolean constructors for ControlInfo

It would be convenient to be able to iterate over available boolean
values, for example for controls that designate if some function can be
enabled/disabled. The current min/max/def constructor is insufficient,
as .values() is empty, so the values cannot be easily iterated over, and
creating a Span of booleans does not work for the values constructor.

Add new constructors to ControlInfo that takes a set of booleans (if
both booleans are valid values) plus a default, and another that takes
only one boolean (if only one boolean is a valid value).

Update the ControlInfo test accordingly.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/controls.h

@@ -9,6 +9,7 @@
 #define __LIBCAMERA_CONTROLS_H__
 
 #include <assert.h>
+#include <set>
 #include <stdint.h>
 #include <string>
 #include <unordered_map>
@@ -272,6 +273,8 @@ public:
 			     const ControlValue &def = 0);
 	explicit ControlInfo(Span<const ControlValue> values,
 			     const ControlValue &def = {});
+	explicit ControlInfo(std::set<bool> values, bool def);
+	explicit ControlInfo(bool value);
 
 	const ControlValue &min() const { return min_; }
 	const ControlValue &max() const { return max_; }

src/libcamera/controls.cpp

@@ -514,6 +514,35 @@ ControlInfo::ControlInfo(Span<const ControlValue> values,
 		values_.push_back(value);
 }
 
+/**
+ * \brief Construct a boolean ControlInfo with both boolean values
+ * \param[in] values The control valid boolean values (both true and false)
+ * \param[in] def The control default boolean value
+ *
+ * Construct a ControlInfo for a boolean control, where both true and false are
+ * valid values. \a values must be { false, true } (the order is irrelevant).
+ * The minimum value will always be false, and the maximum always true. The
+ * default value is \a def.
+ */
+ControlInfo::ControlInfo(std::set<bool> values, bool def)
+	: min_(false), max_(true), def_(def), values_({ false, true })
+{
+	assert(values.count(def) && values.size() == 2);
+}
+
+/**
+ * \brief Construct a boolean ControlInfo with only one valid value
+ * \param[in] value The control valid boolean value
+ *
+ * Construct a ControlInfo for a boolean control, where there is only valid
+ * value. The minimum, maximum, and default values will all be \a value.
+ */
+ControlInfo::ControlInfo(bool value)
+	: min_(value), max_(value), def_(value)
+{
+	values_ = { value };
+}
+
 /**
  * \fn ControlInfo::min()
  * \brief Retrieve the minimum value of the control

test/controls/control_info.cpp

@@ -44,6 +44,39 @@ protected:
 			return TestFail;
 		}
 
+		/*
+		 * Test information retrieval from a control with boolean
+		 * values.
+		 */
+		ControlInfo aeEnable({ false, true }, false);
+
+		if (aeEnable.min().get<bool>() != false ||
+		    aeEnable.def().get<bool>() != false ||
+		    aeEnable.max().get<bool>() != true) {
+			cout << "Invalid control range for AeEnable" << endl;
+			return TestFail;
+		}
+
+		if (aeEnable.values()[0].get<bool>() != false ||
+		    aeEnable.values()[1].get<bool>() != true) {
+			cout << "Invalid control values for AeEnable" << endl;
+			return TestFail;
+		}
+
+		ControlInfo awbEnable(true);
+
+		if (awbEnable.min().get<bool>() != true ||
+		    awbEnable.def().get<bool>() != true ||
+		    awbEnable.max().get<bool>() != true) {
+			cout << "Invalid control range for AwbEnable" << endl;
+			return TestFail;
+		}
+
+		if (awbEnable.values()[0].get<bool>() != true) {
+			cout << "Invalid control values for AwbEnable" << endl;
+			return TestFail;
+		}
+
 		return TestPass;
 	}
 };