feat(rfb): add encoding, FPS and bandwidth event emissions

- Add encodingchange event when encoding type changes
- Add FPS counter event emitted every second
- Add bandwidth tracking in websock.js (bytes sent/received)
- Add bandwidth event with download/upload kbps every 2 seconds

core/rfb.js

@@ -187,6 +187,12 @@ export default class RFB extends EventTargetMixin {
             encoding: null,
         };
 
+        // Encoding and FPS tracking
+        this._lastEncoding = null;
+        this._frameCount = 0;
+        this._lastFpsTime = performance.now();
+        this._lastBandwidthTime = performance.now();
+
         // Mouse state
         this._mousePos = {};
         this._mouseButtonMask = 0;
@@ -2663,6 +2669,13 @@ export default class RFB extends EventTargetMixin {
                 this._FBU.encoding = this._sock.rQshift32();
                 /* Encodings are signed */
                 this._FBU.encoding >>= 0;
+
+                // Emit encoding change event for real encodings (not pseudo-encodings)
+                if (this._lastEncoding !== this._FBU.encoding && this._FBU.encoding >= 0) {
+                    this._lastEncoding = this._FBU.encoding;
+                    this.dispatchEvent(new CustomEvent("encodingchange",
+                        { detail: { encoding: this._FBU.encoding } }));
+                }
             }
 
             if (!this._handleRect()) {
@@ -2675,6 +2688,25 @@ export default class RFB extends EventTargetMixin {
 
         this._display.flip();
 
+        // FPS counter
+        this._frameCount++;
+        const now = performance.now();
+        if (now - this._lastFpsTime >= 1000) {
+            this.dispatchEvent(new CustomEvent("fps",
+                { detail: { fps: this._frameCount } }));
+            this._frameCount = 0;
+            this._lastFpsTime = now;
+        }
+
+        // Bandwidth counter (every 2 seconds for smoother readings)
+        if (now - this._lastBandwidthTime >= 2000) {
+            const stats = this._sock.getBandwidthStats();
+            this.dispatchEvent(new CustomEvent("bandwidth",
+                { detail: stats }));
+            this._sock.resetBandwidthStats();
+            this._lastBandwidthTime = now;
+        }
+
         return true;  // We finished this FBU
     }
 

core/websock.js

@@ -68,6 +68,34 @@ export default class Websock {
             close: () => {},
             error: () => {}
         };
+
+        // Bandwidth tracking
+        this._bytesReceived = 0;
+        this._bytesSent = 0;
+        this._bandwidthStartTime = performance.now();
+    }
+
+    // Bandwidth statistics
+    getBandwidthStats() {
+        const now = performance.now();
+        const elapsed = (now - this._bandwidthStartTime) / 1000; // seconds
+        if (elapsed < 0.1) return { down: 0, up: 0, totalDown: 0, totalUp: 0 };
+
+        const downKbps = (this._bytesReceived * 8 / 1000) / elapsed;
+        const upKbps = (this._bytesSent * 8 / 1000) / elapsed;
+
+        return {
+            down: downKbps,
+            up: upKbps,
+            totalDown: this._bytesReceived,
+            totalUp: this._bytesSent
+        };
+    }
+
+    resetBandwidthStats() {
+        this._bytesReceived = 0;
+        this._bytesSent = 0;
+        this._bandwidthStartTime = performance.now();
     }
 
     // Getters and setters
@@ -220,6 +248,7 @@ export default class Websock {
 
     flush() {
         if (this._sQlen > 0 && this.readyState === 'open') {
+            this._bytesSent += this._sQlen;
             this._websocket.send(new Uint8Array(this._sQ.buffer, 0, this._sQlen));
             this._sQlen = 0;
         }
@@ -354,6 +383,7 @@ export default class Websock {
             this._rQi = 0;
         }
         const u8 = new Uint8Array(e.data);
+        this._bytesReceived += u8.length;
         if (u8.length > this._rQbufferSize - this._rQlen) {
             this._expandCompactRQ(u8.length);
         }