Auto-resize canvas

src/main/java/dev/kruhlmann/imgfloat/model/CanvasEvent.java

@@ -0,0 +1,32 @@
+package dev.kruhlmann.imgfloat.model;
+
+public class CanvasEvent {
+
+    public enum Type {
+        CANVAS,
+    }
+
+    private Type type;
+    private String channel;
+    private CanvasSettingsRequest payload;
+
+    public static CanvasEvent updated(String channel, CanvasSettingsRequest payload) {
+        CanvasEvent event = new CanvasEvent();
+        event.type = Type.CANVAS;
+        event.channel = channel;
+        event.payload = payload;
+        return event;
+    }
+
+    public Type getType() {
+        return type;
+    }
+
+    public String getChannel() {
+        return channel;
+    }
+
+    public CanvasSettingsRequest getPayload() {
+        return payload;
+    }
+}

src/main/java/dev/kruhlmann/imgfloat/service/ChannelDirectoryService.java

@@ -7,6 +7,7 @@ import dev.kruhlmann.imgfloat.model.Asset;
 import dev.kruhlmann.imgfloat.model.AssetEvent;
 import dev.kruhlmann.imgfloat.model.AssetPatch;
 import dev.kruhlmann.imgfloat.model.AssetView;
+import dev.kruhlmann.imgfloat.model.CanvasEvent;
 import dev.kruhlmann.imgfloat.model.CanvasSettingsRequest;
 import dev.kruhlmann.imgfloat.model.Channel;
 import dev.kruhlmann.imgfloat.model.PlaybackRequest;
@@ -121,7 +122,9 @@ public class ChannelDirectoryService {
         channel.setCanvasWidth(req.getWidth());
         channel.setCanvasHeight(req.getHeight());
         channelRepository.save(channel);
-        return new CanvasSettingsRequest(channel.getCanvasWidth(), channel.getCanvasHeight());
+        CanvasSettingsRequest response = new CanvasSettingsRequest(channel.getCanvasWidth(), channel.getCanvasHeight());
+        messagingTemplate.convertAndSend(topicFor(broadcaster), CanvasEvent.updated(broadcaster, response));
+        return response;
     }
 
     public Optional<AssetView> createAsset(String broadcaster, MultipartFile file) throws IOException {

src/main/resources/static/js/admin.js

@@ -2,8 +2,6 @@ const canvas = document.getElementById("admin-canvas");
 const ctx = canvas.getContext("2d");
 const overlay = document.getElementById("admin-overlay");
 let canvasSettings = { width: 1920, height: 1080 };
-canvas.width = canvasSettings.width;
-canvas.height = canvasSettings.height;
 const assets = new Map();
 const mediaCache = new Map();
 const renderStates = new Map();
@@ -66,6 +64,8 @@ let interactionState = null;
 let lastSizeInputChanged = null;
 let stompClient;
 
+applyCanvasSettings(canvasSettings);
+
 audioUnlockEvents.forEach((eventName) => {
     window.addEventListener(eventName, () => {
         if (!pendingAudioUnlock.size) return;
@@ -467,8 +467,7 @@ function fetchCanvasSettings() {
             return r.json();
         })
         .then((settings) => {
-            canvasSettings = settings;
-            resizeCanvas();
+            applyCanvasSettings(settings);
         })
         .catch(() => {
             resizeCanvas();
@@ -476,6 +475,16 @@ function fetchCanvasSettings() {
         });
 }
 
+function applyCanvasSettings(settings) {
+    if (!settings) {
+        return;
+    }
+    const width = Number.isFinite(settings.width) ? settings.width : canvasSettings.width;
+    const height = Number.isFinite(settings.height) ? settings.height : canvasSettings.height;
+    canvasSettings = { width, height };
+    resizeCanvas();
+}
+
 function resizeCanvas() {
     if (!overlay) {
         return;
@@ -540,6 +549,10 @@ function updateRenderState(asset) {
 }
 
 function handleEvent(event) {
+    if (event.type === "CANVAS" && event.payload) {
+        applyCanvasSettings(event.payload);
+        return;
+    }
     const assetId = event.assetId || event?.patch?.id || event?.payload?.id;
     if (event.type === "DELETED") {
         assets.delete(assetId);

src/main/resources/static/js/broadcast.js

@@ -5,8 +5,6 @@ const supportsAnimatedDecode =
 const canPlayProbe = document.createElement("video");
 const ctx = canvas.getContext("2d");
 let canvasSettings = { width: 1920, height: 1080 };
-canvas.width = canvasSettings.width;
-canvas.height = canvasSettings.height;
 const assets = new Map();
 const mediaCache = new Map();
 const renderStates = new Map();
@@ -27,6 +25,8 @@ const pendingRemovals = new Set();
 const audioUnlockEvents = ["pointerdown", "keydown", "touchstart"];
 let layerOrder = [];
 
+applyCanvasSettings(canvasSettings);
+
 audioUnlockEvents.forEach((eventName) => {
     window.addEventListener(eventName, () => {
         if (!pendingAudioUnlock.size) return;
@@ -144,8 +144,7 @@ function fetchCanvasSettings() {
             return r.json();
         })
         .then((settings) => {
-            canvasSettings = settings;
-            resizeCanvas();
+            applyCanvasSettings(settings);
         })
         .catch(() => {
             resizeCanvas();
@@ -153,11 +152,31 @@ function fetchCanvasSettings() {
         });
 }
 
+function applyCanvasSettings(settings) {
+    if (!settings) {
+        return;
+    }
+    const width = Number.isFinite(settings.width) ? settings.width : canvasSettings.width;
+    const height = Number.isFinite(settings.height) ? settings.height : canvasSettings.height;
+    canvasSettings = { width, height };
+    resizeCanvas();
+}
+
 function resizeCanvas() {
+    if (Number.isFinite(canvasSettings.width) && Number.isFinite(canvasSettings.height)) {
+        canvas.width = canvasSettings.width;
+        canvas.height = canvasSettings.height;
+        canvas.style.width = `${canvasSettings.width}px`;
+        canvas.style.height = `${canvasSettings.height}px`;
+    }
     draw();
 }
 
 function handleEvent(event) {
+    if (event.type === "CANVAS" && event.payload) {
+        applyCanvasSettings(event.payload);
+        return;
+    }
     const assetId = event.assetId || event?.patch?.id || event?.payload?.id;
     if (event.type === "VISIBILITY") {
         handleVisibilityEvent(event);