[libcamera-devel] [RFC PATCH v4 01/21] controls: Add boolean constructor for ControlInfo

[Paul Elder]

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 a new constructor to ControlInfo that takes a set of booleans (to
allow specifiying one or two available values), and a default. The
default value is not optional, as it doesn't make sense to have a silent
default for boolean values.

Update the ControlInfo test accordingly.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>

---
Changes in v2:
- use set instead of span of bools
- add assertion to make sure that the default is a valid value
- update the test
---
 include/libcamera/controls.h   |  2 ++
 src/libcamera/controls.cpp     | 28 ++++++++++++++++++++++++++++
 test/controls/control_info.cpp | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index 1bc958a4..707dc335 100644
--- a/include/libcamera/controls.h
+++ b/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 +273,7 @@ public:
 			     const ControlValue &def = 0);
 	explicit ControlInfo(Span<const ControlValue> values,
 			     const ControlValue &def = {});
+	explicit ControlInfo(std::set<bool> values, bool def);
 
 	const ControlValue &min() const { return min_; }
 	const ControlValue &max() const { return max_; }
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 34317fa0..f6351c01 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -514,6 +514,34 @@ ControlInfo::ControlInfo(Span<const ControlValue> values,
 		values_.push_back(value);
 }
 
+/**
+ * \brief Construct a ControlInfo from a list of valid boolean values
+ * \param[in] values The control valid boolean vaalues
+ * \param[in] def The control default boolean value
+ *
+ * Construct a ControlInfo from a list of valid boolean values. The ControlInfo
+ * minimum and maximum values are set to the first and last members of the
+ * values list respectively. The default value is set to \a def.
+ */
+ControlInfo::ControlInfo(std::set<bool> values, bool def)
+	: def_(def)
+{
+	if (values.size() == 1) {
+		min_ = max_ = *values.begin();
+	} else {
+		min_ = false;
+		max_ = true;
+	}
+
+	def_ = def;
+
+	assert(values.count(def));
+
+	values_.reserve(2);
+	for (const bool &value : values)
+		values_.push_back(value);
+}
+
 /**
  * \fn ControlInfo::min()
  * \brief Retrieve the minimum value of the control
diff --git a/test/controls/control_info.cpp b/test/controls/control_info.cpp
index 1e05e131..b3d2bd54 100644
--- a/test/controls/control_info.cpp
+++ b/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 }, 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;
 	}
 };
-- 
2.27.0