Make the first byte of KeyAction items purely denote their type. Make the binary representation of KeyAction items variable-length.

config-serializer/config-items/KeystrokeWithModifiersAction.ts

@@ -0,0 +1,48 @@
+class KeystrokeWithModifiersAction extends KeyAction implements Serializable<KeystrokeWithModifiersAction> {
+
+    static keyActionTypeString = 'keystrokeWithModifiers';
+
+    modifierMask: number;
+
+    private _scancode: number;
+
+    get scancode(): number {
+        return this._scancode;
+    }
+
+    set scancode(value) {
+        if (!TypeChecker.isScancodeValid(value)) {
+            throw 'Invalid KeystrokeWithModifiersAction.scancode: ${scancode}';
+        }
+        this._scancode = value;
+    }
+
+    fromJsObject(jsObject: any): KeystrokeWithModifiersAction {
+        this.assertKeyActionType(
+            jsObject, KeystrokeWithModifiersAction.keyActionTypeString, 'KeystrokeWithModifiersAction');
+        this.scancode = jsObject.scancode;
+        this.modifierMask = jsObject.modifierMask;
+        return this;
+    }
+
+    fromBinary(buffer: UhkBuffer): KeystrokeWithModifiersAction {
+        this.readAndAssertKeyActionId(buffer, KeyActionId.KeystrokeWithModifiersAction, 'KeystrokeWithModifiersAction');
+        this.scancode = buffer.readUInt8();
+        this.modifierMask = buffer.readUInt8();
+        return this;
+    }
+
+    toJsObject(): any {
+        return {
+            keyActionType: KeystrokeWithModifiersAction.keyActionTypeString,
+            scancode: this.scancode,
+            modifierMask: this.modifierMask
+        };
+    }
+
+    toBinary(buffer: UhkBuffer) {
+        buffer.writeUInt8(KeyActionId.KeystrokeWithModifiersAction);
+        buffer.writeUInt8(this.scancode);
+        buffer.writeUInt8(this.modifierMask);
+    }
+}