1 files changed, 49 insertions, 1 deletions

diff --git a/src/client/views/DocComponent.tsx b/src/client/views/DocComponent.tsx
index d6562492f..93e852bef 100644
--- a/src/client/views/DocComponent.tsx
+++ b/src/client/views/DocComponent.tsx
@@ -1,6 +1,8 @@
 import * as React from 'react';
 import { Doc } from '../../new_fields/Doc';
-import { computed } from 'mobx';
+import { computed, action } from 'mobx';
+import { Cast } from '../../new_fields/Types';
+import { listSpec } from '../../new_fields/Schema';
 
 export function DocComponent<P extends { Document: Doc }, T>(schemaCtor: (doc: Doc) => T) {
     class Component extends React.Component<P> {
@@ -11,4 +13,50 @@ export function DocComponent<P extends { Document: Doc }, T>(schemaCtor: (doc: D
         }
     }
     return Component;
+}
+
+interface DocAnnotatableProps {
+    Document: Doc;
+    DataDoc?: Doc;
+    fieldKey: string;
+    fieldExt: string;
+    whenActiveChanged: (isActive: boolean) => void;
+    isSelected: () => boolean, renderDepth: number
+}
+export function DocAnnotatableComponent<P extends DocAnnotatableProps, T>(schemaCtor: (doc: Doc) => T) {
+    class Component extends React.Component<P> {
+        //TODO This might be pretty inefficient if doc isn't observed, because computed doesn't cache then
+        @computed
+        get Document(): T {
+            return schemaCtor(this.props.Document);
+        }
+        _isChildActive = false;
+        @action.bound
+        removeDocument(doc: Doc): boolean {
+            Doc.GetProto(doc).annotationOn = undefined;
+            let value = Cast(this.extensionDoc[this.props.fieldExt], listSpec(Doc), []);
+            let index = value ? Doc.IndexOf(doc, value.map(d => d as Doc), true) : -1;
+            return index !== -1 && value.splice(index, 1) ? true : false;
+        }
+
+        @computed get dataDoc() { return (this.props.DataDoc && this.props.Document.isTemplate ? this.props.DataDoc : Doc.GetProto(this.props.Document)) as Doc; }
+
+        @computed get extensionDoc() { return Doc.fieldExtensionDoc(this.dataDoc, this.props.fieldKey); }
+
+        // if the moved document is already in this overlay collection nothing needs to be done.
+        // otherwise, if the document can be removed from where it was, it will then be added to this document's overlay collection. 
+        @action.bound
+        moveDocument(doc: Doc, targetCollection: Doc, addDocument: (doc: Doc) => boolean): boolean {
+            return Doc.AreProtosEqual(this.props.Document, targetCollection) ? true : this.removeDocument(doc) ? addDocument(doc) : false;
+        }
+
+        @action.bound
+        addDocument(doc: Doc): boolean {
+            Doc.GetProto(doc).annotationOn = this.props.Document;
+            return Doc.AddDocToList(this.extensionDoc, this.props.fieldExt, doc);
+        }
+        whenActiveChanged = (isActive: boolean) => this.props.whenActiveChanged(this._isChildActive = isActive);
+        active = () => this.props.isSelected() || this._isChildActive || this.props.renderDepth === 0;
+    }
+    return Component;
 }
\ No newline at end of file