Pulled over working features from regression branch. Found that macOS behavior is the issue.

include/state.hpp

@@ -45,6 +45,7 @@ class State {
 		void setImage(json& msgData);
 		void setMode(json& msgData);
 		void setExposure(json& msgData);
+		void setNoExposure();
 		void setPosition(json& msgData);
 		void setActive () { active = true; }
 

src/main.cpp

@@ -152,14 +152,20 @@ void display () {
             actionStop();
         }
         state.setInactive();
-        postAction();
     }
+
+    if (completed) {
+        postAction();
+        completed = false;
+    }
+
     if (displaying && timing) {
         auto currentTime = steady_clock::now();
         auto elapsedTime = duration_cast<milliseconds>(currentTime - startTime).count();
         if (elapsedTime > exposureTime) {
             cout << "Exposed = " << elapsedTime << " ms" << endl;
             displaying = false;
+            timing = false;
             completed = true;
         }
     }

src/state.cpp

@@ -56,7 +56,9 @@ void State::setPosition (json& msgData) {
 }
 
 void State::setExposure (json& msgData) {
-	if (msgData["exposure"].size() == 1) {
+	if (msgData["exposure"].size() == 0) {
+		setNoExposure();
+	} else if (msgData["exposure"].size() == 1) {
 		exposure = { msgData["exposure"][0] };
 		cout << "Exposure = " << msgData["exposure"][0] << " ms" << endl;
 	} /*else if (msgData["exposure"].size() == 3) {
@@ -69,6 +71,11 @@ void State::setExposure (json& msgData) {
 	}
 }
 
+void State::setNoExposure () {
+	exposure = {};
+	cout << "No exposure, display indefinitely" << endl;
+}
+
 void State::receiveMessage (string msgString) {
 	ERROR = false;
 	json msgData = json::parse(msgString);
@@ -95,6 +102,8 @@ void State::receiveMessage (string msgString) {
 
 	if (action == DISPLAY && msgData.contains("exposure")) {
 		setExposure(msgData);
+	} else if (action == DISPLAY && !msgData.contains("exposure")) {
+		setNoExposure();
 	}
 
 	setActive();

test/test_messages.js

@@ -1,10 +1,22 @@
 const net = require('net');
 const  { resolve } = require('path');
 
+/**
+
+Actions
+
+0 =    NONE,
+1 =    LOAD,
+2 =    DISPLAY,
+3 =    STOP
+
+**/
+
 const serverAddress = 'localhost';
 const serverPort = 8081;
 
 const client = new net.Socket();
+let sent = 0;
 
 console.log(`Connecting to ${serverAddress}:${serverPort}...`);
 
@@ -14,49 +26,74 @@ async function delay (ms) {
     });
 }
 
-client.connect(serverPort, serverAddress, async () => {
-    const data = {
-        action : 1,
-        image: resolve('./img/4kSnake.png'),
+function send (data) {
+    const str = JSON.stringify(data);
+    sent = +new Date();
+    console.log(`[${sent}]  SENDING ` + str);
+    client.write(str);
+}
+
+function actionLoad (img, x, y, w, h) {
+    const obj = {
+        action : 1, //LOAD
+        image : resolve(img),
         position : {
-            x: 100,
-            y : 100,
-            w : 320,
-            h : 320
+            x,
+            y,
+            w,
+            h
         }
     };
-    console.log('SENDING');
-    console.log(data);
-    client.write(JSON.stringify(data));
+    send(obj);
+}
+
+function actionExpose (img, exposure) {
+    const obj = {
+        action : 2, //DISPLAY
+        image : resolve(img),
+        exposure : [ exposure ]
+    };
+    send(obj);
+}
+
+function actionStart (img) {
+    const obj = {
+        action : 2, //DISPLAY
+        image : resolve(img)
+    };
+    send(obj);
+}
+
+function actionStop (img) {
+    const obj = {
+        action : 3, //STOP
+        image : resolve(img)
+    }
+}
+
+client.connect(serverPort, serverAddress, async () => {
+    const img = './img/4kSnake.png';
+    actionLoad(img, 0, 0, 320, 320);
+    //
     await delay(2000);
-    data.action = 2;
-    delete data.position
-    data.exposure = [ 4000 ];
-    console.log('SENDING');
-    console.log(data);
-    client.write(JSON.stringify(data));
-    await delay(6000);
-    data.action = 1;
-    data.position = { x: 50, y : 50, w : 320, h : 320 };
-    console.log('SENDING');
-    console.log(data);
-    client.write(JSON.stringify(data));
+    actionExpose(img, 4000);
+    //actionStart(img);
+    //
+    await delay(8000);
+    actionLoad(img, 100, 100, 640, 640);
+    //
     await delay(1000);
-    data.action = 2;
-    delete data.position;
-    console.log('SENDING');
-    console.log(data);
-    client.write(JSON.stringify(data));
+    actionExpose(img, 4000);
+    //actionStart(img);
+    //
     await delay(2000);
-    data.action = 3;
-    console.log('SENDING');
-    console.log(data);
-    client.write(JSON.stringify(data));
+    //actionStop(img);
 });
 
 client.on('data', (data) => {
-    console.log('RECEIVED');
-    console.log(data.toString());
+    const received = +new Date();
+    console.log(`[${received}] RECEIVED ` + data.toString());
+    console.log(`DIFF ${received - sent}`);
 });
 
 client.on('close', () => {