WIP

src/resizer/item.js

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+/*
+Copyright 2018 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+export default class ResizeItem {
+    constructor(domNode, id, reverse, resizer, sizer) {
+        this.domNode = domNode;
+        this.id = id;
+        this.reverse = reverse;
+        this.resizer = resizer;
+        this.sizer = sizer;
+    }
+
+    static fromResizeHandle(handle, resizer, sizer) {
+        const id = handle.getAttribute("data-id");
+        const reverse = resizer.isReverseResizeHandle(handle);
+        const domNode = reverse ? handle.nextElementSibling : handle.previousElementSibling;
+        return new ResizeItem(domNode, id, reverse, resizer, sizer);
+    }
+
+    _advance(forwards) {
+        // opposite direction from fromResizeHandle to get back to handle
+        let handle = this.reverse ?
+            this.domNode.previousElementSibling :
+            this.domNode.nextElementSibling;
+        const moveNext = forwards !== this.reverse; // xor
+        // iterate at least once to avoid infinite loop
+        do {
+            if (moveNext) {
+                handle = handle.nextElementSibling;
+            } else {
+                handle = handle.previousElementSibling;
+            }
+        } while(handle && !this.resizer.isResizeHandle(handle));
+        if (handle) {
+            const nextHandle = ResizeItem.fromResizeHandle(handle, this.resizer, this.sizer);
+            nextHandle.reverse = this.reverse;
+            return nextHandle;
+        }
+    }
+
+    next() {
+        return this._advance(true);
+    }
+
+    previous() {
+        return this._advance(false);
+    }
+
+    size() {
+        return this.sizer.getItemSize(this.domNode);
+    }
+
+    offset() {
+        return this.sizer.getItemOffset(this.domNode);
+    }
+
+    setSize(size) {
+        this.sizer.setItemSize(this.domNode, size);
+        console.log("resizing", this.domNode, "to", size, this.size());
+        const callback = this.resizer.distributorCtor.onResized;
+        if (callback) {
+            callback(size, this.id, this.domNode);
+        }
+    }
+}