hooks for custom control sequences

This fixes (at least partially) issue #1176
"Add a way to plugin a custom control sequence handler".

src/EscapeSequenceParser.ts

@@ -301,9 +301,39 @@ export class EscapeSequenceParser extends Disposable implements IEscapeSequenceP
     this._executeHandlerFb = callback;
   }
 
-  setCsiHandler(flag: string, callback: (params: number[], collect: string) => void): void {
-    this._csiHandlers[flag.charCodeAt(0)] = callback;
+  private _removeHandler(array: any[], callback: any): void {
+    if (array) {
+      for (let i = array.length; --i >= 0; ) {
+        if (array[i] == callback) {
+          array.splice(i, 1);
+            return;
+        }
+      }
+    }
   }
+
+  addCsiHandler(flag: string, callback: (params: number[], collect: string) => boolean): void {
+    let index = flag.charCodeAt(0);
+    let array = this._csiHandlers[index];
+    if (! array) { this._csiHandlers[index] = array = new Array(); }
+    array.push(callback);
+  }
+
+  removeCsiHandler(flag: string, callback: (params: number[], collect: string) => boolean): void {
+    let index = flag.charCodeAt(0);
+    let array = this._csiHandlers[index];
+    this._removeHandler(array, callback);
+    if (array && array.length == 0)
+      delete this._csiHandlers[index];
+  }
+  /* deprecated */
+  setCsiHandler(flag: string, callback: (params: number[], collect: string) => void): void {
+    this.clearCsiHandler(flag);
+    this.addCsiHandler(flag, (params: number[], collect: string): boolean => {
+        callback(params, collect); return true;
+    });
+  }
+  /* deprecated */
   clearCsiHandler(flag: string): void {
     if (this._csiHandlers[flag.charCodeAt(0)]) delete this._csiHandlers[flag.charCodeAt(0)];
   }
@@ -321,9 +351,25 @@ export class EscapeSequenceParser extends Disposable implements IEscapeSequenceP
     this._escHandlerFb = callback;
   }
 
-  setOscHandler(ident: number, callback: (data: string) => void): void {
-    this._oscHandlers[ident] = callback;
+  addOscHandler(ident: number, callback: (data: string) => boolean): void {
+    let array = this._oscHandlers[ident];
+    if (! array) { this._oscHandlers[ident] = array = new Array(); }
+    array.push(callback);
   }
+  removeOscHandler(ident: number, callback: (data: string) => boolean): void {
+    let array = this._oscHandlers[ident];
+    this._removeHandler(array, callback);
+    if (array && array.length == 0)
+      delete this._oscHandlers[ident];
+  }
+  /* deprecated */
+  setOscHandler(ident: number, callback: (data: string) => void): void {
+    this.clearOscHandler(ident);
+    this.addOscHandler(ident, (data: string): boolean => {
+      callback(data); return true;
+    });
+  }
+  /* deprecated */
   clearOscHandler(ident: number): void {
     if (this._oscHandlers[ident]) delete this._oscHandlers[ident];
   }
@@ -463,9 +509,15 @@ export class EscapeSequenceParser extends Disposable implements IEscapeSequenceP
           }
           break;
         case ParserAction.CSI_DISPATCH:
-          callback = this._csiHandlers[code];
-          if (callback) callback(params, collect);
-          else this._csiHandlerFb(collect, params, code);
+          let cHandler = this._csiHandlers[code];
+          if (cHandler) {
+            for (let i = cHandler.length; ;) {
+              if (--i < 0) { cHandler = null; break; }
+              if ((cHandler[i])(params, collect))
+                break;
+            }
+          }
+          if (! cHandler) this._csiHandlerFb(collect, params, code);
           break;
         case ParserAction.PARAM:
           if (code === 0x3b) params.push(0);
@@ -532,9 +584,15 @@ export class EscapeSequenceParser extends Disposable implements IEscapeSequenceP
               // or with an explicit NaN OSC handler
               const identifier = parseInt(osc.substring(0, idx));
               const content = osc.substring(idx + 1);
-              callback = this._oscHandlers[identifier];
-              if (callback) callback(content);
-              else this._oscHandlerFb(identifier, content);
+              let oHandler = this._oscHandlers[identifier];
+              if (oHandler) {
+                for (let i = oHandler.length; ;) {
+                  if (--i < 0) { oHandler = null; break; }
+                  if ((oHandler[i])(content))
+                    break;
+                }
+              }
+              if (! oHandler) this._oscHandlerFb(identifier, content);
             }
           }
           if (code === 0x1b) transition |= ParserState.ESCAPE;