#156 reintroduce MAX_KEYS for upfront switches sizing.

Author: davetcc

library.json

@@ -25,7 +25,7 @@
       "name": "TaskManagerIO"
     }
   ],
-  "version": "2.3.1",
+  "version": "2.3.2",
   "license": "Apache-2.0",
   "frameworks": "arduino, mbed",
   "platforms": "*",

library.properties

@@ -4,7 +4,7 @@
 #
 
 name=IoAbstraction
-version=2.3.1
+version=2.3.2
 maintainer=https://www.thecoderscorner.com
 author=davetcc
 category=Other

src/SwitchInput.cpp

@@ -121,7 +121,7 @@ void KeyboardItem::checkAndTrigger(uint8_t buttonState){
 	}
 }
 
-SwitchInput::SwitchInput() : encoder{} {
+SwitchInput::SwitchInput() : encoder{}, keys(MAX_KEYS) {
 	this->ioDevice = nullptr;
 	this->swFlags = 0;
     this->lastSyncStatus = true;

src/SwitchInput.h

@@ -22,6 +22,14 @@
 #ifndef HOLD_THRESHOLD
 #define HOLD_THRESHOLD 20
 #endif
+/*
+ * If you want more buttons, the library will reallocate as needed, however this is not efficient and in production
+ * probably better to set this value to about the number of switches needed.  Each button adds about 10 bytes of RAM,
+ * so on a tiny you could adjust downwards for example.
+ */
+#ifndef MAX_KEYS
+#define MAX_KEYS DEFAULT_LIST_SIZE
+#endif // MAX_KEYS defined
 
 // START user adjustable section
 
@@ -364,7 +372,7 @@ class SwitchInput {
 	 * always use the global switches instance.
 	 * @see switches
 	 */
-	SwitchInput();
+	explicit SwitchInput();
 
 	/**
 	 * initialise switch input so that it can start managing switches using polling via task manager every 1/20 of a second. If the switches are