add dragging to catalog contents

cateditor/src/pagination.js

@@ -0,0 +1,45 @@
+
+export function paginateModels(models) {
+  for (let model of models) {
+    // ensure sizes
+    model.size = modelSize(model)
+  }
+
+  let pages = []
+  let currentSize = 0
+  let currentPage = []
+  for (let model of models) {
+    currentSize += model.size
+    if (currentSize > 3) {
+      pages.push(currentPage)
+      currentPage = [model]
+      currentSize = model.size
+    } else {
+      currentPage.push(model)
+    }
+  }
+  if (currentPage.length > 0) {
+    pages.push(currentPage)
+  }
+
+  return pages
+}
+
+export function modelSize(model) {
+  if (!model || !model.ids) return 0
+  if (model.ids.length <= 4) return 1
+  if (model.ids.length <= 8) return 2
+  return 3
+}
+
+export function sectionModels(section) {
+  // remove pages, return models (blocks) in order
+  let models = []
+  if (section && section.pages) {
+    for (let page of section.pages) {
+      models.push(...page)
+    }
+  }
+
+  return models
+}