lazily add bus event listeners for interface

dbusjs · Aug 2, 2019 · bd08f64 · leonardo-k · Aug 5, 2019 · bd08f64
1 parent 8ffad88
commit bd08f64
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Showing 2 changed files with 59 additions and 18 deletions.
diff --git a/lib/client/proxy-interface.js b/lib/client/proxy-interface.js
@@ -44,6 +44,65 @@ class ProxyInterface extends EventEmitter {
     this.$properties = [];
     this.$methods = [];
     this.$signals = [];
+    this.$listeners = {};
+
+    let getEventDetails = (eventName) => {
+      let signal = this.$signals.find((s) => s.name === eventName);
+      if (!signal) {
+        return [null, null];
+      }
+
+      let detailedEvent = JSON.stringify({
+        path: this.$object.path,
+        interface: this.$name,
+        member: eventName
+      });
+
+      return [signal, detailedEvent];
+    }
+
+    this.on('removeListener', (eventName, listener) => {
+      let [signal, detailedEvent] = getEventDetails(eventName);
+
+      if (!signal) {
+        return;
+      }
+
+      this.$object.bus._signals.off(detailedEvent, this._getEventListener(signal));
+    });
+
+    this.on('newListener', (eventName, listener) => {
+      let [signal, detailedEvent] = getEventDetails(eventName);
+
+      if (!signal) {
+        return;
+      }
+
+      this.$object.bus._signals.on(detailedEvent, this._getEventListener(signal));
+    });
+  }
+
+  _getEventListener(signal) {
+    if (this.$listeners[signal.name]) {
+      return this.$listeners[signal.name];
+    }
+
+    let obj = this.$object;
+    let bus = obj.bus;
+
+    this.$listeners[signal.name] = (msg) => {
+      let {body, signature, sender} = msg;
+      if (bus._nameOwners[obj.name] !== sender) {
+        return;
+      }
+      if (signature !== signal.signature) {
+        console.error(`warning: got signature ${signature} for signal ${iface.$name}.${signal.name} (expected ${signal.signature})`);
+        return;
+      }
+      this.emit.apply(this, [signal.name].concat(body));
+    };
+
+    return this.$listeners[signal.name];
   }
 
   static _fromXml(object, xml) {

diff --git a/lib/client/proxy-object.js b/lib/client/proxy-object.js
@@ -108,24 +108,6 @@ class ProxyObject {
         if (iface !== null) {
           this.interfaces[iface.$name] = iface;
           this.bus._addMatch(`type='signal',sender=${this.name},interface='${iface.$name}',path='${this.path}'`);
-          for (let signal of iface.$signals) {
-            let event = JSON.stringify({
-              path: this.path,
-              interface: iface.$name,
-              member: signal.name
-            });
-            this.bus._signals.on(event, (msg) => {
-              let {body, signature, sender} = msg;
-              if (this.bus._nameOwners[this.name] !== sender) {
-                return;
-              }
-              if (signature !== signal.signature) {
-                console.error(`warning: got signature ${signature} for signal ${iface.$name}.${signal.name} (expected ${signal.signature})`);
-                return;
-              }
-              iface.emit.apply(iface, [signal.name].concat(body));
-            });
-          }
         }
       }
     }