Added additional MSP helper functions

js/injected_methods.js

@@ -10,3 +10,48 @@ Array.prototype.push16 = function(val) {
   // chainable
   return this;
 };
+DataView.prototype.offset = 0;
+DataView.prototype.readU8 = function() {
+    if (this.byteLength >= this.offset+1) {
+        return this.getUint8(this.offset++);
+    } else {
+        return null;
+    }
+}
+DataView.prototype.readU16 = function() {
+    if (this.byteLength >= this.offset+2) {
+        return this.readU8() + this.readU8()*256;
+    } else {
+        return null;
+    }
+}
+DataView.prototype.readU32 = function() {
+    if (this.byteLength >= this.offset+4) {
+        return this.readU16() + this.readU16()*65536;
+    } else {
+        return null;
+    }
+}
+DataView.prototype.read8 = function() {
+    if (this.byteLength >= this.offset+1) {
+        return this.getInt8(this.offset++, 1);
+    } else {
+        return null;
+    }
+}
+DataView.prototype.read16 = function() {
+    this.offset += 2;
+    if (this.byteLength >= this.offset) {
+        return this.getInt16(this.offset-2, 1); 
+    } else {
+        return null;
+    }
+}
+DataView.prototype.read32 = function() {
+    this.offset += 4;
+    if (this.byteLength >= this.offset) {
+        return this.getInt32(this.offset-4, 1); 
+    } else {
+        return null;
+    }
+}