1 files changed, 115 insertions, 0 deletions
diff --git a/web/src/js/store/view.js b/web/src/js/store/view.js
new file mode 100644
index 00000000..d628d46b
--- /dev/null
+++ b/web/src/js/store/view.js
@@ -0,0 +1,115 @@
+var EventEmitter = require('events').EventEmitter;
+var _ = require("lodash");
+
+var utils = require("../utils.js");
+
+function SortByStoreOrder(elem) {
+    return this.store.index(elem.id);
+}
+
+var default_sort = SortByStoreOrder;
+var default_filt = function (elem) {
+    return true;
+};
+
+function StoreView(store, filt, sortfun) {
+    EventEmitter.call(this);
+
+    this.store = store;
+
+    this.add = this.add.bind(this);
+    this.update = this.update.bind(this);
+    this.remove = this.remove.bind(this);
+    this.recalculate = this.recalculate.bind(this);
+    this.store.addListener("add", this.add);
+    this.store.addListener("update", this.update);
+    this.store.addListener("remove", this.remove);
+    this.store.addListener("recalculate", this.recalculate);
+
+    this.recalculate(filt, sortfun);
+}
+
+_.extend(StoreView.prototype, EventEmitter.prototype, {
+    close: function () {
+        this.store.removeListener("add", this.add);
+        this.store.removeListener("update", this.update);
+        this.store.removeListener("remove", this.remove);
+        this.store.removeListener("recalculate", this.recalculate);
+        this.removeAllListeners();
+    },
+    recalculate: function (filt, sortfun) {
+        filt = filt || this.filt || default_filt;
+        sortfun = sortfun || this.sortfun || default_sort;
+        filt = filt.bind(this);
+        sortfun = sortfun.bind(this);
+        this.filt = filt;
+        this.sortfun = sortfun;
+
+        this.list = this.store.list.filter(filt);
+        this.list.sort(function (a, b) {
+            var akey = sortfun(a);
+            var bkey = sortfun(b);
+            if(akey < bkey){
+                return -1;
+            } else if(akey > bkey){
+                return 1;
+            } else {
+                return 0;
+            }
+        });
+        this.emit("recalculate");
+    },
+    index: function (elem) {
+        return _.sortedIndex(this.list, elem, this.sortfun);
+    },
+    add: function (elem) {
+        if (this.filt(elem)) {
+            var idx = this.index(elem);
+            if (idx === this.list.length) { //happens often, .push is way faster.
+                this.list.push(elem);
+            } else {
+                this.list.splice(idx, 0, elem);
+            }
+            this.emit("add", elem, idx);
+        }
+    },
+    update: function (elem) {
+        var idx;
+        var i = this.list.length;
+        // Search from the back, we usually update the latest entries.
+        while (i--) {
+            if (this.list[i].id === elem.id) {
+                idx = i;
+                break;
+            }
+        }
+
+        if (idx === -1) { //not contained in list
+            this.add(elem);
+        } else if (!this.filt(elem)) {
+            this.remove(elem.id);
+        } else {
+            if (this.sortfun(this.list[idx]) !== this.sortfun(elem)) { //sortpos has changed
+                this.remove(this.list[idx]);
+                this.add(elem);
+            } else {
+                this.list[idx] = elem;
+                this.emit("update", elem, idx);
+            }
+        }
+    },
+    remove: function (elem_id) {
+        var idx = this.list.length;
+        while (idx--) {
+            if (this.list[idx].id === elem_id) {
+                this.list.splice(idx, 1);
+                this.emit("remove", elem_id, idx);
+                break;
+            }
+        }
+    }
+});
+
+module.exports = {
+    StoreView: StoreView
+};
+\ No newline at end of file