libcamera: controls: Make ControlValue get/set accessors template methods

The ControlValue get accessors are implemented with functions of
different names, whlie the set accessors use polymorphism to support
different control types. This isn't very consistent and intuitive. Make
the API clearer by using template methods. This will also have the added
advantage that support for the new types will only require adding
template specialisations, without adding new methods.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

7 files changed, 67 insertions, 79 deletions

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index ffba880a..0886370f 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -36,13 +36,10 @@ public:
 	ControlType type() const { return type_; };
 	bool isNone() const { return type_ == ControlTypeNone; };
 
-	void set(bool value);
-	void set(int value);
-	void set(int64_t value);
-
-	bool getBool() const;
-	int getInt() const;
-	int64_t getInt64() const;
+	template<typename T>
+	const T &get() const;
+	template<typename T>
+	void set(const T &value);
 
 	std::string toString() const;
 
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 9960a30d..88aab88d 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -90,77 +90,68 @@ ControlValue::ControlValue(int64_t value)
  */
 
 /**
- * \brief Set the value with a boolean
- * \param[in] value Boolean value to store
+ * \fn template<typename T> const T &ControlValue::get() const
+ * \brief Get the control value
+ *
+ * The control value type shall match the type T, otherwise the behaviour is
+ * undefined.
+ *
+ * \return The control value
  */
-void ControlValue::set(bool value)
-{
-	type_ = ControlTypeBool;
-	bool_ = value;
-}
 
 /**
- * \brief Set the value with an integer
- * \param[in] value Integer value to store
+ * \fn template<typename T> void ControlValue::set(const T &value)
+ * \brief Set the control value to \a value
+ * \param[in] value The control value
  */
-void ControlValue::set(int value)
-{
-	type_ = ControlTypeInteger;
-	integer_ = value;
-}
 
-/**
- * \brief Set the value with a 64 bit integer
- * \param[in] value 64 bit integer value to store
- */
-void ControlValue::set(int64_t value)
-{
-	type_ = ControlTypeInteger64;
-	integer64_ = value;
-}
-
-/**
- * \brief Get the boolean value
- *
- * The value type must be Boolean.
- *
- * \return The boolean value
- */
-bool ControlValue::getBool() const
+#ifndef __DOXYGEN__
+template<>
+const bool &ControlValue::get<bool>() const
 {
 	ASSERT(type_ == ControlTypeBool);
 
 	return bool_;
 }
 
-/**
- * \brief Get the integer value
- *
- * The value type must be Integer or Integer64.
- *
- * \return The integer value
- */
-int ControlValue::getInt() const
+template<>
+const int &ControlValue::get<int>() const
 {
 	ASSERT(type_ == ControlTypeInteger || type_ == ControlTypeInteger64);
 
 	return integer_;
 }
 
-/**
- * \brief Get the 64-bit integer value
- *
- * The value type must be Integer or Integer64.
- *
- * \return The 64-bit integer value
- */
-int64_t ControlValue::getInt64() const
+template<>
+const int64_t &ControlValue::get<int64_t>() const
 {
 	ASSERT(type_ == ControlTypeInteger || type_ == ControlTypeInteger64);
 
 	return integer64_;
 }
 
+template<>
+void ControlValue::set<bool>(const bool &value)
+{
+	type_ = ControlTypeBool;
+	bool_ = value;
+}
+
+template<>
+void ControlValue::set<int>(const int &value)
+{
+	type_ = ControlTypeInteger;
+	integer_ = value;
+}
+
+template<>
+void ControlValue::set<int64_t>(const int64_t &value)
+{
+	type_ = ControlTypeInteger64;
+	integer64_ = value;
+}
+#endif /* __DOXYGEN__ */
+
 /**
  * \brief Assemble and return a string describing the value
  * \return A string describing the ControlValue
diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 89652105..81c548af 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -235,24 +235,24 @@ int PipelineHandlerUVC::processControls(UVCCameraData *data, Request *request)
 
 		switch (ci->id()) {
 		case Brightness:
-			controls.add(V4L2_CID_BRIGHTNESS, value.getInt());
+			controls.add(V4L2_CID_BRIGHTNESS, value.get<int>());
 			break;
 
 		case Contrast:
-			controls.add(V4L2_CID_CONTRAST, value.getInt());
+			controls.add(V4L2_CID_CONTRAST, value.get<int>());
 			break;
 
 		case Saturation:
-			controls.add(V4L2_CID_SATURATION, value.getInt());
+			controls.add(V4L2_CID_SATURATION, value.get<int>());
 			break;
 
 		case ManualExposure:
 			controls.add(V4L2_CID_EXPOSURE_AUTO, 1);
-			controls.add(V4L2_CID_EXPOSURE_ABSOLUTE, value.getInt());
+			controls.add(V4L2_CID_EXPOSURE_ABSOLUTE, value.get<int>());
 			break;
 
 		case ManualGain:
-			controls.add(V4L2_CID_GAIN, value.getInt());
+			controls.add(V4L2_CID_GAIN, value.get<int>());
 			break;
 
 		default:
diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
index f26a91f8..3e34e7a0 100644
--- a/src/libcamera/pipeline/vimc.cpp
+++ b/src/libcamera/pipeline/vimc.cpp
@@ -288,15 +288,15 @@ int PipelineHandlerVimc::processControls(VimcCameraData *data, Request *request)
 
 		switch (ci->id()) {
 		case Brightness:
-			controls.add(V4L2_CID_BRIGHTNESS, value.getInt());
+			controls.add(V4L2_CID_BRIGHTNESS, value.get<int>());
 			break;
 
 		case Contrast:
-			controls.add(V4L2_CID_CONTRAST, value.getInt());
+			controls.add(V4L2_CID_CONTRAST, value.get<int>());
 			break;
 
 		case Saturation:
-			controls.add(V4L2_CID_SATURATION, value.getInt());
+			controls.add(V4L2_CID_SATURATION, value.get<int>());
 			break;
 
 		default:
diff --git a/test/controls/control_info.cpp b/test/controls/control_info.cpp
index 8cda860b..faefaaa4 100644
--- a/test/controls/control_info.cpp
+++ b/test/controls/control_info.cpp
@@ -32,7 +32,7 @@ protected:
 			return TestFail;
 		}
 
-		if (info.min().getInt() != 0 || info.max().getInt() != 0) {
+		if (info.min().get<int>() != 0 || info.max().get<int>() != 0) {
 			cout << "Invalid control range for Brightness" << endl;
 			return TestFail;
 		}
@@ -50,7 +50,7 @@ protected:
 			return TestFail;
 		}
 
-		if (info.min().getInt() != 10 || info.max().getInt() != 200) {
+		if (info.min().get<int>() != 10 || info.max().get<int>() != 200) {
 			cout << "Invalid control range for Contrast" << endl;
 			return TestFail;
 		}
diff --git a/test/controls/control_list.cpp b/test/controls/control_list.cpp
index f1d79ff8..0402e7c2 100644
--- a/test/controls/control_list.cpp
+++ b/test/controls/control_list.cpp
@@ -96,7 +96,7 @@ protected:
 			return TestFail;
 		}
 
-		if (list[Brightness].getInt() != 255) {
+		if (list[Brightness].get<int>() != 255) {
 			cout << "Incorrest Brightness control value" << endl;
 			return TestFail;
 		}
@@ -125,8 +125,8 @@ protected:
 		/*
 		 * Test control value retrieval and update through ControlInfo.
 		 */
-		if (list[brightness].getInt() != 64 ||
-		    list[contrast].getInt() != 128) {
+		if (list[brightness].get<int>() != 64 ||
+		    list[contrast].get<int>() != 128) {
 			cout << "Failed to retrieve control value" << endl;
 			return TestFail;
 		}
@@ -134,8 +134,8 @@ protected:
 		list[brightness] = 10;
 		list[contrast] = 20;
 
-		if (list[brightness].getInt() != 10 ||
-		    list[contrast].getInt() != 20) {
+		if (list[brightness].get<int>() != 10 ||
+		    list[contrast].get<int>() != 20) {
 			cout << "Failed to update control value" << endl;
 			return TestFail;
 		}
@@ -185,9 +185,9 @@ protected:
 			return TestFail;
 		}
 
-		if (newList[Brightness].getInt() != 10 ||
-		    newList[Contrast].getInt() != 20 ||
-		    newList[Saturation].getInt() != 255) {
+		if (newList[Brightness].get<int>() != 10 ||
+		    newList[Contrast].get<int>() != 20 ||
+		    newList[Saturation].get<int>() != 255) {
 			cout << "New list contains incorrect values" << endl;
 			return TestFail;
 		}
diff --git a/test/controls/control_value.cpp b/test/controls/control_value.cpp
index 778efe5c..397c43f7 100644
--- a/test/controls/control_value.cpp
+++ b/test/controls/control_value.cpp
@@ -27,12 +27,12 @@ protected:
 		     << " Bool: " << boolean.toString()
 		     << endl;
 
-		if (integer.getInt() != 1234) {
+		if (integer.get<int>() != 1234) {
 			cerr << "Failed to get Integer" << endl;
 			return TestFail;
 		}
 
-		if (boolean.getBool() != true) {
+		if (boolean.get<bool>() != true) {
 			cerr << "Failed to get Boolean" << endl;
 			return TestFail;
 		}
@@ -45,19 +45,19 @@ protected:
 			return TestFail;
 		}
 
-		value.set(true);
+		value.set<bool>(true);
 		if (value.isNone()) {
 			cerr << "Failed to set an empty object" << endl;
 			return TestFail;
 		}
 
-		if (value.getBool() != true) {
+		if (value.get<bool>() != true) {
 			cerr << "Failed to get Booleans" << endl;
 			return TestFail;
 		}
 
-		value.set(10);
-		if (value.getInt() != 10) {
+		value.set<int>(10);
+		if (value.get<int>() != 10) {
 			cerr << "Failed to get Integer" << endl;
 			return TestFail;
 		}