add stub imagerenderer code

src/imagerenderer.ts

@@ -0,0 +1,71 @@
+import * as mobx from "mobx";
+import {WindowSize} from "./types";
+
+const InitialSize = 10*1024;
+const IncreaseFactor = 1.5;
+
+class ImageRenderer {
+    dataSize : number;
+    imageData : Uint8Array;
+    brokenData : boolean;
+    isDone : mobx.IObservableValue<boolean>;
+
+    constructor() {
+        this._resetData();
+        this.isDone = mobx.observable.box(false, {name: "isDone"});
+    }
+
+    _resetData() {
+        this.dataSize = 0;
+        this.imageData = new Uint8Array(InitialSize);
+        this.brokenData = false;
+    }
+
+    dispose() : void {
+        this._resetData();
+    }
+    
+    reload(delayMs : number) : void {
+    }
+
+    _growArray(minSize : number) : void {
+        let newSize = Math.round(this.imageData.length * IncreaseFactor);
+        if (newSize < minSize) {
+            newSize = minSize;
+        }
+        let newData = new Uint8Array(newSize);
+        newData.set(this.imageData);
+        this.imageData = newData;
+    }
+
+    receiveData(pos : number, data : Uint8Array, reason? : string) : void {
+        if (pos != this.dataSize) {
+            this.brokenData = true;
+            return;
+        }
+        if (this.dataSize + data.length > this.imageData.length) {
+            this._growArray(this.dataSize + data.length);
+        }
+        this.imageData.set(data, pos);
+        this.dataSize += data.length;
+    }
+
+    cmdDone() : void {
+    }
+
+    resizeWindow(size : WindowSize) : void {
+    }
+    
+    resizeCols(cols : number) : void {
+    }
+    
+    giveFocus() : void {
+    }
+    
+    getUsedRows() : number {
+        return -1;
+    }
+}
+
+export {ImageRenderer};
+