bluetooth: Componentize device list in chrome://bluetooth-internals.

chrome/browser/resources/bluetooth_internals/device.js

+// Copyright 2016 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.
+
+/**
+ * Javascript for Device-related features, served from
+ *     chrome://bluetooth-internals/.
+ */
+
+cr.define('device', function() {

[ortuno, 2016/10/26 03:26:11]

Split the DeviceTable code into a separate file. We should try to keep UI code
separated and give the modules more meaningful names e.g. device-collection,
device-table, etc.

[mbrunson, 2016/10/29 00:49:43]

Done.

+
+  var REMOVED_CSS = 'removed';
+
+  /**
+   * A table that lists the devices and responds to changes in the given
+   *     DeviceCollection.
+   * @constructor
+   * @extends {HTMLTableElement}
+   */
+  var DeviceTable = cr.ui.define(function() {
+    this.devices_ = null;
+
+    return document.importNode($('table-template').content.children[0],
+                                   true /* deep */);
+  });
+  DeviceTable.prototype = {
+    __proto__: HTMLTableElement.prototype,
+
+    /**
+     * Decorates an element as a UI element class. Caches references to the
+     *    table body and headers.
+     */
+    decorate: function() {
+      this.body_ = this.tBodies[0];
+      this.headers_ = this.tHead.rows[0].cells;
+    },
+
+    /**
+     * Sets the tables device collection.
+     * @param {!DeviceCollection} deviceCollection
+     */
+    setDevices: function(deviceCollection) {
+      if (this.devices_) {
+        this.devices_.removeEventListener('sorted', this.redraw_.bind(this));
+        this.devices_.removeEventListener('change',
+                                          this.handleChange_.bind(this));
+        this.devices_.removeEventListener('splice',
+                                          this.handleSplice_.bind(this));
+      }
+
+      this.devices_ = deviceCollection;
+      this.devices_.addEventListener('sorted', this.redraw_.bind(this));
+      this.devices_.addEventListener('change', this.handleChange_.bind(this));
+      this.devices_.addEventListener('splice', this.handleSplice_.bind(this));
+
+      this.redraw_();
+    },
+
+    /**
+     * Updates table row on change event of the device collection.
+     * @param {!Event} event
+     */
+    handleChange_: function(event) {
+      this.updateRow_(this.devices_.item(event.index), event.index);
+    },
+
+    /**
+     * Updates table row on splice event of the device collection.
+     * @param {!Event} event
+     */
+    handleSplice_: function(event) {
+      event.removed.forEach(function() {
+        this.removeRow(event.index);
+      }, this);
+
+      event.added.forEach(function(device, index) {
+        this.newRowForDevice_(device, event.index + index);
+      }, this);
+    },
+
+    /**
+     * Inserts a new row at |index| and updates it with info from |device|.
+     * @param {!Device} device
+     * @param {?number} index
+     */
+    newRowForDevice_: function(device, index) {
+      var row = this.body_.insertRow(index);
+      row.id = device.info.address;
+
+      for (var i = 0; i < this.headers_.length; i++) {
+        row.insertCell();
+      }
+
+      this.updateRow_(device, row.sectionRowIndex);
+    },
+
+    /**
+     * Deletes and recreates the table using the cached |devices_|.
+     */
+    redraw_: function() {
+      this.removeChild(this.body_);
+      this.appendChild(document.createElement('tbody'));
+      this.body_ = this.tBodies[0];
+      this.body_.classList.add('table-body');
+
+      for (var i = 0; i < this.devices_.length; i++) {
+        this.newRowForDevice_(this.devices_.item(i));
+      }
+    },
+
+    /**
+     * Updates the row at |index| with the info from |device|.
+     * @param {!Device} device
+     * @param {!number} index
+     */
+    updateRow_: function(device, index) {
+      var row = this.body_.rows[index];
+
+      if (device.removed) {
+        row.classList.add(REMOVED_CSS);
+      } else {
+        row.classList.remove(REMOVED_CSS);
+      }
+
+      // Update the properties based on the header field path.
+      for (var i = 0; i < this.headers_.length; i++) {
+        var header = this.headers_[i];
+        var propName = header.dataset.field;
+
+        var parts = propName.split('.');
+        var obj = device.info;
+        while (obj != null && parts.length > 0) {
+          var part = parts.shift();
+          obj = obj[part];
+        }
+
+        var cell = row.cells[i];
+        cell.textContent = obj || 'Unknown';
+        cell.dataset.label = header.innerText;
+      }
+    },
+  };
+
+  /*
+   * Collection of devices with helper functions for searching and updating by
+   *     device address.
+   * @constructor
+   * @param {!Array} array the starting collection of devices.
+   * @extends {cr.ui.ArrayDataModel}
+   */
+  var DeviceCollection = function(array) {
+    cr.ui.ArrayDataModel.call(this, array);
+  };
+  DeviceCollection.prototype = {
+    __proto__: cr.ui.ArrayDataModel.prototype,
+    getByAddress: function(address) {
+      for (var i = 0; i < this.length; i++) {
+        var device = this.item(i);
+        if (address == device.info.address)
+          return device;
+      }
+      return null;
+    },
+    update: function(device) {

[ortuno, 2016/10/26 03:26:11]

Would it make sense to move all of the device info logic here? You would have
only two functions and no need to expose Device:

addOrUpdate(DeviceInfo device_info) which would get the device from the list and
update it's fields.

remove(DeviceInfo device_info) would mark the device as removed.

Also I think a Design doc would be useful here to get a sense of the overall
structure of the list and how you plan implementing services, characteristics,
etc.

[mbrunson, 2016/10/29 00:49:43]

Hmm...ok. A few other places could have better separation after these
suggestions. 

I created global access to the Mojo interfaces for better separation in the
future. That way I can put all the Device connection code in the
device_collection.Device class[1].

[1]
https://codereview.chromium.org/2448713002/diff/60001/chrome/browser/resource...

+      var oldDevice = this.getByAddress(device.info.address);
+      if (oldDevice) {
+        this.replaceItem(oldDevice, device);
+      } else {
+        this.push(device);
+      }
+    }
+  };
+
+  /*
+   * Data model for a cached device.
+   * @constructor
+   * @param {!bluetoothDevice.DeviceInfo} info
+   */
+  var Device = function(info) {
+    this.info = info;
+    this.removed = false;
+  };
+
+  return {
+    Device: Device,
+    DeviceCollection, DeviceCollection,
+    DeviceTable: DeviceTable,
+  };
+});