add support for floating drawings

- added need elements and test for them

src/file/drawing/floating/horizontal-position.ts

@@ -0,0 +1,35 @@
+// http://officeopenxml.com/drwPicFloating-position.php
+import { XmlComponent, XmlAttributeComponent } from "file/xml-components";
+import { HorizontalPositionRelativeFrom, HorizontalPositionOptions } from "./floating-position";
+import { Align } from "./align";
+import { PositionOffset } from "./position-offset";
+
+interface IHorizontalPositionAttributes {
+    relativeFrom: HorizontalPositionRelativeFrom;
+}
+
+class HorizontalPositionAttributes extends XmlAttributeComponent<IHorizontalPositionAttributes> {
+    protected xmlKeys = {
+        relativeFrom: "relativeFrom",
+    };
+}
+
+export class HorizontalPosition extends XmlComponent {
+    constructor(horizontalPosition: HorizontalPositionOptions) {
+        super("wp:positionH");
+
+        this.root.push(
+            new HorizontalPositionAttributes({
+                relativeFrom: horizontalPosition.relative,
+            }),
+        );
+
+        if (horizontalPosition.align) {
+            this.root.push(new Align(horizontalPosition.align));
+        } else if (horizontalPosition.offset !== undefined) {
+            this.root.push(new PositionOffset(horizontalPosition.offset));
+        } else {
+            throw new Error("There is no configuration provided for floating position (Align or offset)");
+        }
+    }
+}