prep for additional bottom line displays

server/scripts/modules/currentweatherscroll.mjs

@@ -5,10 +5,14 @@ import { currentDisplay } from './navigation.mjs';
 
 // constants
 const degree = String.fromCharCode(176);
+const SCROLL_SPEED = 75; // pixels/second
+const DEFAULT_UPDATE = 8; // 0.5s ticks
 
 // local variables
 let interval;
 let screenIndex = 0;
+let sinceLastUpdate = 0;
+let nextUpdate = DEFAULT_UPDATE;
 
 // start drawing conditions
 // reset starts from the first item in the text scroll list
@@ -17,7 +21,7 @@ const start = () => {
 
 	// set up the interval if needed
 	if (!interval) {
-		interval = setInterval(incrementInterval, 4000);
+		interval = setInterval(incrementInterval, 500);
 	}
 
 	// draw the data
@@ -29,14 +33,24 @@ const stop = (reset) => {
 };
 
 // increment interval, roll over
-const incrementInterval = () => {
+// forcing is used when drawScreen receives an invalid screen and needs to request the next one in line
+const incrementInterval = (force) => {
+	if (!force) {
+		// test for elapsed time (0.5s ticks);
+		sinceLastUpdate += 1;
+		if (sinceLastUpdate < nextUpdate) return;
+	}
+	// reset flags
+	sinceLastUpdate = 0;
+	nextUpdate = DEFAULT_UPDATE;
+
 	// test current screen
 	const display = currentDisplay();
 	if (!display?.okToDrawCurrentConditions) {
 		stop(display?.elemId === 'progress');
 		return;
 	}
-	screenIndex = (screenIndex + 1) % (screens.length);
+	screenIndex = (screenIndex + 1) % (lastScreen);
 	// draw new text
 	drawScreen();
 };
@@ -48,7 +62,22 @@ const drawScreen = async () => {
 	// nothing to do if there's no data yet
 	if (!data) return;
 
-	drawCondition(screens[screenIndex](data));
+	const thisScreen = screens[screenIndex](data);
+	if (typeof thisScreen === 'string') {
+		// only a string
+		drawCondition(thisScreen);
+	} else if (typeof thisScreen === 'object') {
+		// an object was provided with additional parameters
+		switch (thisScreen.type) {
+			case 'scroll':
+				drawScrollCondition(thisScreen);
+				break;
+			default: drawCondition(thisScreen);
+		}
+	} else {
+		// can't identify screen, get another one
+		incrementInterval(true);
+	}
 };
 
 // the "screens" are stored in an array for easy addition and removal
@@ -71,7 +100,7 @@ const screens = [
 	(data) => `Humidity: ${data.Humidity}%   Dewpoint: ${data.DewPoint}${degree}${data.TemperatureUnit}`,
 
 	// barometric pressure
-	(data) => `Barometric Pressure: ${data.Pressure} ${data.PressureUnit} ${data.PressureDirection}`,
+	(data) => `Barometric Pressure: ${data.Pressure} ${data.PressureDirection}`,
 
 	// wind
 	(data) => {
@@ -102,3 +131,56 @@ const drawCondition = (text) => {
 document.addEventListener('DOMContentLoaded', () => {
 	start();
 });
+
+// store the original number of screens
+const originalScreens = screens.length;
+let lastScreen = originalScreens;
+
+// reset the number of screens
+const reset = () => {
+	lastScreen = originalScreens;
+};
+
+// add screen
+const addScreen = (screen) => {
+	screens.push(screen);
+	lastScreen += 1;
+};
+
+const drawScrollCondition = (screen) => {
+	// create the scroll element
+	const scrollElement = document.createElement('div');
+	scrollElement.classList.add('scroll-area');
+	scrollElement.innerHTML = screen.text;
+	// add it to the page to get the width
+	document.querySelector('.weather-display .scroll .fixed').innerHTML = scrollElement.outerHTML;
+	// grab the width
+	const { scrollWidth, clientWidth } = document.querySelector('.weather-display .scroll .fixed .scroll-area');
+
+	// calculate the scroll distance and set a minimum scroll
+	const scrollDistance = Math.max(scrollWidth - clientWidth, 0);
+	// calculate the scroll time
+	const scrollTime = scrollDistance / SCROLL_SPEED;
+	// calculate a new minimum on-screen time +1.0s at start and end
+	nextUpdate = Math.round(Math.ceil(scrollTime / 0.5) + 4);
+
+	// update the element transition and set initial left position
+	scrollElement.style.left = '0px';
+	scrollElement.style.transition = `left linear ${scrollTime.toFixed(1)}s`;
+	elemForEach('.weather-display .scroll .fixed', (elem) => {
+		elem.innerHTML = '';
+		elem.append(scrollElement.cloneNode(true));
+	});
+	// start the scroll after a short delay
+	setTimeout(() => {
+		// change the left position to trigger the scroll
+		elemForEach('.weather-display .scroll .fixed .scroll-area', (elem) => {
+			elem.style.left = `-${scrollDistance.toFixed(0)}px`;
+		});
+	}, 1000);
+};
+
+window.CurrentWeatherScroll = {
+	addScreen,
+	reset,
+};

server/styles/scss/_weather-display.scss

@@ -113,7 +113,7 @@
 
 	.scroll {
 		@include u.text-shadow(3px, 1.5px);
-		width: 640px;
+		width: calc(640px - 2 * 30px);
 		height: 70px;
 		overflow: hidden;
 		margin-top: 10px;
@@ -122,6 +122,15 @@
 			font-family: 'Star4000';
 			font-size: 24pt;
 			margin-left: 55px;
+			overflow: hidden;
+
+			.scroll-area {
+				text-wrap: nowrap;
+				position: relative;
+				// the following added by js code as it is dependent on the content of the element
+				// transition: left (x)s;
+				// left: calc((elem width) - 640px);
+			}
 		}
 	}
 }