1 files changed, 98 insertions, 0 deletions
diff --git a/chromium/chrome/browser/resources/settings/printing_page/cups_printers_entry_list_behavior.js b/chromium/chrome/browser/resources/settings/printing_page/cups_printers_entry_list_behavior.js
new file mode 100644
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+++ b/chromium/chrome/browser/resources/settings/printing_page/cups_printers_entry_list_behavior.js
@@ -0,0 +1,98 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview Polymer behavior for observing CupsPrintersEntryManager events.
+ * Use this behavior if you want to receive a dynamically updated list of both
+ * saved and nearby printers.
+ */
+
+/** @polymerBehavior */
+const CupsPrintersEntryListBehavior = {
+  properties: {
+    /** @private {!settings.printing.CupsPrintersEntryManager} */
+    entryManager_: Object,
+
+    /** @type {!Array<!PrinterListEntry>} */
+    savedPrinters: {
+      type: Array,
+      value: () => [],
+    },
+
+    /** @type {!Array<!PrinterListEntry>} */
+    nearbyPrinters: {
+      type: Array,
+      value: () => [],
+    },
+  },
+
+  /** @override */
+  created: function() {
+    this.entryManager_ =
+        settings.printing.CupsPrintersEntryManager.getInstance();
+  },
+
+  /** @override */
+  attached: function() {
+    this.entryManager_.addOnSavedPrintersChangedListener(
+        this.onSavedPrintersChanged_.bind(this));
+    this.entryManager_.addOnNearbyPrintersChangedListener(
+        this.onNearbyPrintersChanged_.bind(this));
+
+    // Initialize saved and nearby printers list.
+    this.onSavedPrintersChanged_(
+        this.entryManager_.savedPrinters, [] /* printerAdded */,
+        [] /* printerRemoved */);
+    this.onNearbyPrintersChanged_(this.entryManager_.nearbyPrinters);
+  },
+
+  /** @override */
+  detached: function() {
+    this.entryManager_.removeOnSavedPrintersChangedListener(
+        this.onSavedPrintersChanged_.bind(this));
+    this.entryManager_.removeOnNearbyPrintersChangedListener(
+        this.onNearbyPrintersChanged_.bind(this));
+  },
+
+  /**
+   * Non-empty params indicate the applicable change to be notified.
+   * @param {!Array<!PrinterListEntry>} savedPrinters
+   * @param {!Array<!PrinterListEntry>} addedPrinters
+   * @param {!Array<!PrinterListEntry>} removedPrinters
+   * @private
+   */
+  onSavedPrintersChanged_: function(
+      savedPrinters, addedPrinters, removedPrinters) {
+    this.updateList(
+        'savedPrinters', printer => printer.printerInfo.printerId,
+        savedPrinters);
+
+    assert(!(addedPrinters.length && removedPrinters.length));
+
+    if (addedPrinters.length) {
+      this.onSavedPrintersAdded(addedPrinters);
+    } else if (removedPrinters.length) {
+      this.onSavedPrintersRemoved(removedPrinters);
+    }
+  },
+
+  /**
+   * @param {!Array<!PrinterListEntry>} printerList
+   * @private
+   */
+  onNearbyPrintersChanged_: function(printerList) {
+    this.updateList(
+        'nearbyPrinters', printer => printer.printerInfo.printerId,
+        printerList);
+  },
+
+  // CupsPrintersEntryListBehavior methods. Override these in the
+  // implementations.
+
+  /** @param{!Array<!PrinterListEntry>} addedPrinters */
+  onSavedPrintersAdded: function(addedPrinters) {},
+
+  /** @param{!Array<!PrinterListEntry>} removedPrinters */
+  onSavedPrintersRemoved: function(removedPrinters) {},
+};
+\ No newline at end of file