michael@0: /* -*- Mode: javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: "use strict";
michael@0: 
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: const Cu = Components.utils;
michael@0: 
michael@0: const PANE_APPEARANCE_DELAY = 50;
michael@0: const PAGE_SIZE_ITEM_COUNT_RATIO = 5;
michael@0: const WIDGET_FOCUSABLE_NODES = new Set(["vbox", "hbox"]);
michael@0: 
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: Cu.import("resource://gre/modules/Timer.jsm");
michael@0: Cu.import("resource://gre/modules/devtools/DevToolsUtils.jsm");
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = [
michael@0:   "Heritage", "ViewHelpers", "WidgetMethods",
michael@0:   "setNamedTimeout", "clearNamedTimeout",
michael@0:   "setConditionalTimeout", "clearConditionalTimeout",
michael@0: ];
michael@0: 
michael@0: /**
michael@0:  * Inheritance helpers from the addon SDK's core/heritage.
michael@0:  * Remove these when all devtools are loadered.
michael@0:  */
michael@0: this.Heritage = {
michael@0:   /**
michael@0:    * @see extend in sdk/core/heritage.
michael@0:    */
michael@0:   extend: function(aPrototype, aProperties = {}) {
michael@0:     return Object.create(aPrototype, this.getOwnPropertyDescriptors(aProperties));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * @see getOwnPropertyDescriptors in sdk/core/heritage.
michael@0:    */
michael@0:   getOwnPropertyDescriptors: function(aObject) {
michael@0:     return Object.getOwnPropertyNames(aObject).reduce((aDescriptor, aName) => {
michael@0:       aDescriptor[aName] = Object.getOwnPropertyDescriptor(aObject, aName);
michael@0:       return aDescriptor;
michael@0:     }, {});
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Helper for draining a rapid succession of events and invoking a callback
michael@0:  * once everything settles down.
michael@0:  *
michael@0:  * @param string aId
michael@0:  *        A string identifier for the named timeout.
michael@0:  * @param number aWait
michael@0:  *        The amount of milliseconds to wait after no more events are fired.
michael@0:  * @param function aCallback
michael@0:  *        Invoked when no more events are fired after the specified time.
michael@0:  */
michael@0: this.setNamedTimeout = function setNamedTimeout(aId, aWait, aCallback) {
michael@0:   clearNamedTimeout(aId);
michael@0: 
michael@0:   namedTimeoutsStore.set(aId, setTimeout(() =>
michael@0:     namedTimeoutsStore.delete(aId) && aCallback(), aWait));
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Clears a named timeout.
michael@0:  * @see setNamedTimeout
michael@0:  *
michael@0:  * @param string aId
michael@0:  *        A string identifier for the named timeout.
michael@0:  */
michael@0: this.clearNamedTimeout = function clearNamedTimeout(aId) {
michael@0:   if (!namedTimeoutsStore) {
michael@0:     return;
michael@0:   }
michael@0:   clearTimeout(namedTimeoutsStore.get(aId));
michael@0:   namedTimeoutsStore.delete(aId);
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Same as `setNamedTimeout`, but invokes the callback only if the provided
michael@0:  * predicate function returns true. Otherwise, the timeout is re-triggered.
michael@0:  *
michael@0:  * @param string aId
michael@0:  *        A string identifier for the conditional timeout.
michael@0:  * @param number aWait
michael@0:  *        The amount of milliseconds to wait after no more events are fired.
michael@0:  * @param function aPredicate
michael@0:  *        The predicate function used to determine whether the timeout restarts.
michael@0:  * @param function aCallback
michael@0:  *        Invoked when no more events are fired after the specified time, and
michael@0:  *        the provided predicate function returns true.
michael@0:  */
michael@0: this.setConditionalTimeout = function setConditionalTimeout(aId, aWait, aPredicate, aCallback) {
michael@0:   setNamedTimeout(aId, aWait, function maybeCallback() {
michael@0:     if (aPredicate()) {
michael@0:       aCallback();
michael@0:       return;
michael@0:     }
michael@0:     setConditionalTimeout(aId, aWait, aPredicate, aCallback);
michael@0:   });
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Clears a conditional timeout.
michael@0:  * @see setConditionalTimeout
michael@0:  *
michael@0:  * @param string aId
michael@0:  *        A string identifier for the conditional timeout.
michael@0:  */
michael@0: this.clearConditionalTimeout = function clearConditionalTimeout(aId) {
michael@0:   clearNamedTimeout(aId);
michael@0: };
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "namedTimeoutsStore", () => new Map());
michael@0: 
michael@0: /**
michael@0:  * Helpers for creating and messaging between UI components.
michael@0:  */
michael@0: this.ViewHelpers = {
michael@0:   /**
michael@0:    * Convenience method, dispatching a custom event.
michael@0:    *
michael@0:    * @param nsIDOMNode aTarget
michael@0:    *        A custom target element to dispatch the event from.
michael@0:    * @param string aType
michael@0:    *        The name of the event.
michael@0:    * @param any aDetail
michael@0:    *        The data passed when initializing the event.
michael@0:    * @return boolean
michael@0:    *         True if the event was cancelled or a registered handler
michael@0:    *         called preventDefault.
michael@0:    */
michael@0:   dispatchEvent: function(aTarget, aType, aDetail) {
michael@0:     if (!(aTarget instanceof Ci.nsIDOMNode)) {
michael@0:       return true; // Event cancelled.
michael@0:     }
michael@0:     let document = aTarget.ownerDocument || aTarget;
michael@0:     let dispatcher = aTarget.ownerDocument ? aTarget : document.documentElement;
michael@0: 
michael@0:     let event = document.createEvent("CustomEvent");
michael@0:     event.initCustomEvent(aType, true, true, aDetail);
michael@0:     return dispatcher.dispatchEvent(event);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Helper delegating some of the DOM attribute methods of a node to a widget.
michael@0:    *
michael@0:    * @param object aWidget
michael@0:    *        The widget to assign the methods to.
michael@0:    * @param nsIDOMNode aNode
michael@0:    *        A node to delegate the methods to.
michael@0:    */
michael@0:   delegateWidgetAttributeMethods: function(aWidget, aNode) {
michael@0:     aWidget.getAttribute =
michael@0:       aWidget.getAttribute || aNode.getAttribute.bind(aNode);
michael@0:     aWidget.setAttribute =
michael@0:       aWidget.setAttribute || aNode.setAttribute.bind(aNode);
michael@0:     aWidget.removeAttribute =
michael@0:       aWidget.removeAttribute || aNode.removeAttribute.bind(aNode);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Helper delegating some of the DOM event methods of a node to a widget.
michael@0:    *
michael@0:    * @param object aWidget
michael@0:    *        The widget to assign the methods to.
michael@0:    * @param nsIDOMNode aNode
michael@0:    *        A node to delegate the methods to.
michael@0:    */
michael@0:   delegateWidgetEventMethods: function(aWidget, aNode) {
michael@0:     aWidget.addEventListener =
michael@0:       aWidget.addEventListener || aNode.addEventListener.bind(aNode);
michael@0:     aWidget.removeEventListener =
michael@0:       aWidget.removeEventListener || aNode.removeEventListener.bind(aNode);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Checks if the specified object looks like it's been decorated by an
michael@0:    * event emitter.
michael@0:    *
michael@0:    * @return boolean
michael@0:    *         True if it looks, walks and quacks like an event emitter.
michael@0:    */
michael@0:   isEventEmitter: function(aObject) {
michael@0:     return aObject && aObject.on && aObject.off && aObject.once && aObject.emit;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Checks if the specified object is an instance of a DOM node.
michael@0:    *
michael@0:    * @return boolean
michael@0:    *         True if it's a node, false otherwise.
michael@0:    */
michael@0:   isNode: function(aObject) {
michael@0:     return aObject instanceof Ci.nsIDOMNode ||
michael@0:            aObject instanceof Ci.nsIDOMElement ||
michael@0:            aObject instanceof Ci.nsIDOMDocumentFragment;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Prevents event propagation when navigation keys are pressed.
michael@0:    *
michael@0:    * @param Event e
michael@0:    *        The event to be prevented.
michael@0:    */
michael@0:   preventScrolling: function(e) {
michael@0:     switch (e.keyCode) {
michael@0:       case e.DOM_VK_UP:
michael@0:       case e.DOM_VK_DOWN:
michael@0:       case e.DOM_VK_LEFT:
michael@0:       case e.DOM_VK_RIGHT:
michael@0:       case e.DOM_VK_PAGE_UP:
michael@0:       case e.DOM_VK_PAGE_DOWN:
michael@0:       case e.DOM_VK_HOME:
michael@0:       case e.DOM_VK_END:
michael@0:         e.preventDefault();
michael@0:         e.stopPropagation();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Sets a side pane hidden or visible.
michael@0:    *
michael@0:    * @param object aFlags
michael@0:    *        An object containing some of the following properties:
michael@0:    *        - visible: true if the pane should be shown, false to hide
michael@0:    *        - animated: true to display an animation on toggle
michael@0:    *        - delayed: true to wait a few cycles before toggle
michael@0:    *        - callback: a function to invoke when the toggle finishes
michael@0:    * @param nsIDOMNode aPane
michael@0:    *        The element representing the pane to toggle.
michael@0:    */
michael@0:   togglePane: function(aFlags, aPane) {
michael@0:     // Make sure a pane is actually available first.
michael@0:     if (!aPane) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     // Hiding is always handled via margins, not the hidden attribute.
michael@0:     aPane.removeAttribute("hidden");
michael@0: 
michael@0:     // Add a class to the pane to handle min-widths, margins and animations.
michael@0:     if (!aPane.classList.contains("generic-toggled-side-pane")) {
michael@0:       aPane.classList.add("generic-toggled-side-pane");
michael@0:     }
michael@0: 
michael@0:     // Avoid useless toggles.
michael@0:     if (aFlags.visible == !aPane.hasAttribute("pane-collapsed")) {
michael@0:       if (aFlags.callback) aFlags.callback();
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     // The "animated" attributes enables animated toggles (slide in-out).
michael@0:     if (aFlags.animated) {
michael@0:       aPane.setAttribute("animated", "");
michael@0:     } else {
michael@0:       aPane.removeAttribute("animated");
michael@0:     }
michael@0: 
michael@0:     // Computes and sets the pane margins in order to hide or show it.
michael@0:     let doToggle = () => {
michael@0:       if (aFlags.visible) {
michael@0:         aPane.style.marginLeft = "0";
michael@0:         aPane.style.marginRight = "0";
michael@0:         aPane.removeAttribute("pane-collapsed");
michael@0:       } else {
michael@0:         let margin = ~~(aPane.getAttribute("width")) + 1;
michael@0:         aPane.style.marginLeft = -margin + "px";
michael@0:         aPane.style.marginRight = -margin + "px";
michael@0:         aPane.setAttribute("pane-collapsed", "");
michael@0:       }
michael@0: 
michael@0:       // Invoke the callback when the transition ended.
michael@0:       if (aFlags.animated) {
michael@0:         aPane.addEventListener("transitionend", function onEvent() {
michael@0:           aPane.removeEventListener("transitionend", onEvent, false);
michael@0:           if (aFlags.callback) aFlags.callback();
michael@0:         }, false);
michael@0:       }
michael@0:       // Invoke the callback immediately since there's no transition.
michael@0:       else {
michael@0:         if (aFlags.callback) aFlags.callback();
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // Sometimes it's useful delaying the toggle a few ticks to ensure
michael@0:     // a smoother slide in-out animation.
michael@0:     if (aFlags.delayed) {
michael@0:       aPane.ownerDocument.defaultView.setTimeout(doToggle, PANE_APPEARANCE_DELAY);
michael@0:     } else {
michael@0:       doToggle();
michael@0:     }
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Localization convenience methods.
michael@0:  *
michael@0:  * @param string aStringBundleName
michael@0:  *        The desired string bundle's name.
michael@0:  */
michael@0: ViewHelpers.L10N = function(aStringBundleName) {
michael@0:   XPCOMUtils.defineLazyGetter(this, "stringBundle", () =>
michael@0:     Services.strings.createBundle(aStringBundleName));
michael@0: 
michael@0:   XPCOMUtils.defineLazyGetter(this, "ellipsis", () =>
michael@0:     Services.prefs.getComplexValue("intl.ellipsis", Ci.nsIPrefLocalizedString).data);
michael@0: };
michael@0: 
michael@0: ViewHelpers.L10N.prototype = {
michael@0:   stringBundle: null,
michael@0: 
michael@0:   /**
michael@0:    * L10N shortcut function.
michael@0:    *
michael@0:    * @param string aName
michael@0:    * @return string
michael@0:    */
michael@0:   getStr: function(aName) {
michael@0:     return this.stringBundle.GetStringFromName(aName);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * L10N shortcut function.
michael@0:    *
michael@0:    * @param string aName
michael@0:    * @param array aArgs
michael@0:    * @return string
michael@0:    */
michael@0:   getFormatStr: function(aName, ...aArgs) {
michael@0:     return this.stringBundle.formatStringFromName(aName, aArgs, aArgs.length);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * L10N shortcut function for numeric arguments that need to be formatted.
michael@0:    * All numeric arguments will be fixed to 2 decimals and given a localized
michael@0:    * decimal separator. Other arguments will be left alone.
michael@0:    *
michael@0:    * @param string aName
michael@0:    * @param array aArgs
michael@0:    * @return string
michael@0:    */
michael@0:   getFormatStrWithNumbers: function(aName, ...aArgs) {
michael@0:     let newArgs = aArgs.map(x => typeof x == "number" ? this.numberWithDecimals(x, 2) : x);
michael@0:     return this.stringBundle.formatStringFromName(aName, newArgs, newArgs.length);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Converts a number to a locale-aware string format and keeps a certain
michael@0:    * number of decimals.
michael@0:    *
michael@0:    * @param number aNumber
michael@0:    *        The number to convert.
michael@0:    * @param number aDecimals [optional]
michael@0:    *        Total decimals to keep.
michael@0:    * @return string
michael@0:    *         The localized number as a string.
michael@0:    */
michael@0:   numberWithDecimals: function(aNumber, aDecimals = 0) {
michael@0:     // If this is an integer, don't do anything special.
michael@0:     if (aNumber == (aNumber | 0)) {
michael@0:       return aNumber;
michael@0:     }
michael@0:     // Remove {n} trailing decimals. Can't use toFixed(n) because
michael@0:     // toLocaleString converts the number to a string. Also can't use
michael@0:     // toLocaleString(, { maximumFractionDigits: n }) because it's not
michael@0:     // implemented on OS X (bug 368838). Gross.
michael@0:     let localized = aNumber.toLocaleString(); // localize
michael@0:     let padded = localized + new Array(aDecimals).join("0"); // pad with zeros
michael@0:     let match = padded.match("([^]*?\\d{" + aDecimals + "})\\d*$");
michael@0:     return match.pop();
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Shortcuts for lazily accessing and setting various preferences.
michael@0:  * Usage:
michael@0:  *   let prefs = new ViewHelpers.Prefs("root.path.to.branch", {
michael@0:  *     myIntPref: ["Int", "leaf.path.to.my-int-pref"],
michael@0:  *     myCharPref: ["Char", "leaf.path.to.my-char-pref"],
michael@0:  *     ...
michael@0:  *   });
michael@0:  *
michael@0:  *   prefs.myCharPref = "foo";
michael@0:  *   let aux = prefs.myCharPref;
michael@0:  *
michael@0:  * @param string aPrefsRoot
michael@0:  *        The root path to the required preferences branch.
michael@0:  * @param object aPrefsObject
michael@0:  *        An object containing { accessorName: [prefType, prefName] } keys.
michael@0:  */
michael@0: ViewHelpers.Prefs = function(aPrefsRoot = "", aPrefsObject = {}) {
michael@0:   this.root = aPrefsRoot;
michael@0: 
michael@0:   for (let accessorName in aPrefsObject) {
michael@0:     let [prefType, prefName] = aPrefsObject[accessorName];
michael@0:     this.map(accessorName, prefType, prefName);
michael@0:   }
michael@0: };
michael@0: 
michael@0: ViewHelpers.Prefs.prototype = {
michael@0:   /**
michael@0:    * Helper method for getting a pref value.
michael@0:    *
michael@0:    * @param string aType
michael@0:    * @param string aPrefName
michael@0:    * @return any
michael@0:    */
michael@0:   _get: function(aType, aPrefName) {
michael@0:     if (this[aPrefName] === undefined) {
michael@0:       this[aPrefName] = Services.prefs["get" + aType + "Pref"](aPrefName);
michael@0:     }
michael@0:     return this[aPrefName];
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Helper method for setting a pref value.
michael@0:    *
michael@0:    * @param string aType
michael@0:    * @param string aPrefName
michael@0:    * @param any aValue
michael@0:    */
michael@0:   _set: function(aType, aPrefName, aValue) {
michael@0:     Services.prefs["set" + aType + "Pref"](aPrefName, aValue);
michael@0:     this[aPrefName] = aValue;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Maps a property name to a pref, defining lazy getters and setters.
michael@0:    * Supported types are "Bool", "Char", "Int" and "Json" (which is basically
michael@0:    * just sugar for "Char" using the standard JSON serializer).
michael@0:    *
michael@0:    * @param string aAccessorName
michael@0:    * @param string aType
michael@0:    * @param string aPrefName
michael@0:    * @param array aSerializer
michael@0:    */
michael@0:   map: function(aAccessorName, aType, aPrefName, aSerializer = { in: e => e, out: e => e }) {
michael@0:     if (aType == "Json") {
michael@0:       this.map(aAccessorName, "Char", aPrefName, { in: JSON.parse, out: JSON.stringify });
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     Object.defineProperty(this, aAccessorName, {
michael@0:       get: () => aSerializer.in(this._get(aType, [this.root, aPrefName].join("."))),
michael@0:       set: (e) => this._set(aType, [this.root, aPrefName].join("."), aSerializer.out(e))
michael@0:     });
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * A generic Item is used to describe children present in a Widget.
michael@0:  *
michael@0:  * This is basically a very thin wrapper around an nsIDOMNode, with a few
michael@0:  * characteristics, like a `value` and an `attachment`.
michael@0:  *
michael@0:  * The characteristics are optional, and their meaning is entirely up to you.
michael@0:  * - The `value` should be a string, passed as an argument.
michael@0:  * - The `attachment` is any kind of primitive or object, passed as an argument.
michael@0:  *
michael@0:  * Iterable via "for (let childItem of parentItem) { }".
michael@0:  *
michael@0:  * @param object aOwnerView
michael@0:  *        The owner view creating this item.
michael@0:  * @param nsIDOMNode aElement
michael@0:  *        A prebuilt node to be wrapped.
michael@0:  * @param string aValue
michael@0:  *        A string identifying the node.
michael@0:  * @param any aAttachment
michael@0:  *        Some attached primitive/object.
michael@0:  */
michael@0: function Item(aOwnerView, aElement, aValue, aAttachment) {
michael@0:   this.ownerView = aOwnerView;
michael@0:   this.attachment = aAttachment;
michael@0:   this._value = aValue + "";
michael@0:   this._prebuiltNode = aElement;
michael@0: };
michael@0: 
michael@0: Item.prototype = {
michael@0:   get value() { return this._value; },
michael@0:   get target() { return this._target; },
michael@0: 
michael@0:   /**
michael@0:    * Immediately appends a child item to this item.
michael@0:    *
michael@0:    * @param nsIDOMNode aElement
michael@0:    *        An nsIDOMNode representing the child element to append.
michael@0:    * @param object aOptions [optional]
michael@0:    *        Additional options or flags supported by this operation:
michael@0:    *          - attachment: some attached primitive/object for the item
michael@0:    *          - attributes: a batch of attributes set to the displayed element
michael@0:    *          - finalize: function invoked when the child item is removed
michael@0:    * @return Item
michael@0:    *         The item associated with the displayed element.
michael@0:    */
michael@0:   append: function(aElement, aOptions = {}) {
michael@0:     let item = new Item(this, aElement, "", aOptions.attachment);
michael@0: 
michael@0:     // Entangle the item with the newly inserted child node.
michael@0:     // Make sure this is done with the value returned by appendChild(),
michael@0:     // to avoid storing a potential DocumentFragment.
michael@0:     this._entangleItem(item, this._target.appendChild(aElement));
michael@0: 
michael@0:     // Handle any additional options after entangling the item.
michael@0:     if (aOptions.attributes) {
michael@0:       aOptions.attributes.forEach(e => item._target.setAttribute(e[0], e[1]));
michael@0:     }
michael@0:     if (aOptions.finalize) {
michael@0:       item.finalize = aOptions.finalize;
michael@0:     }
michael@0: 
michael@0:     // Return the item associated with the displayed element.
michael@0:     return item;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Immediately removes the specified child item from this item.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item associated with the element to remove.
michael@0:    */
michael@0:   remove: function(aItem) {
michael@0:     if (!aItem) {
michael@0:       return;
michael@0:     }
michael@0:     this._target.removeChild(aItem._target);
michael@0:     this._untangleItem(aItem);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Entangles an item (model) with a displayed node element (view).
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    * @param nsIDOMNode aElement
michael@0:    *        The element displaying the item.
michael@0:    */
michael@0:   _entangleItem: function(aItem, aElement) {
michael@0:     this._itemsByElement.set(aElement, aItem);
michael@0:     aItem._target = aElement;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Untangles an item (model) from a displayed node element (view).
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    */
michael@0:   _untangleItem: function(aItem) {
michael@0:     if (aItem.finalize) {
michael@0:       aItem.finalize(aItem);
michael@0:     }
michael@0:     for (let childItem of aItem) {
michael@0:       aItem.remove(childItem);
michael@0:     }
michael@0: 
michael@0:     this._unlinkItem(aItem);
michael@0:     aItem._target = null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Deletes an item from the its parent's storage maps.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    */
michael@0:   _unlinkItem: function(aItem) {
michael@0:     this._itemsByElement.delete(aItem._target);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Returns a string representing the object.
michael@0:    * @return string
michael@0:    */
michael@0:   toString: function() {
michael@0:     return this._value + " :: " + this._target + " :: " + this.attachment;
michael@0:   },
michael@0: 
michael@0:   _value: "",
michael@0:   _target: null,
michael@0:   _prebuiltNode: null,
michael@0:   finalize: null,
michael@0:   attachment: null
michael@0: };
michael@0: 
michael@0: // Creating maps thousands of times for widgets with a large number of children
michael@0: // fills up a lot of memory. Make sure these are instantiated only if needed.
michael@0: DevToolsUtils.defineLazyPrototypeGetter(Item.prototype, "_itemsByElement", Map);
michael@0: 
michael@0: /**
michael@0:  * Some generic Widget methods handling Item instances.
michael@0:  * Iterable via "for (let childItem of wrappedView) { }".
michael@0:  *
michael@0:  * Usage:
michael@0:  *   function MyView() {
michael@0:  *     this.widget = new MyWidget(document.querySelector(".my-node"));
michael@0:  *   }
michael@0:  *
michael@0:  *   MyView.prototype = Heritage.extend(WidgetMethods, {
michael@0:  *     myMethod: function() {},
michael@0:  *     ...
michael@0:  *   });
michael@0:  *
michael@0:  * See https://gist.github.com/victorporof/5749386 for more details.
michael@0:  * The devtools/shared/widgets/SimpleListWidget.jsm is an implementation example.
michael@0:  *
michael@0:  * Language:
michael@0:  *   - An "item" is an instance of an Item.
michael@0:  *   - An "element" or "node" is a nsIDOMNode.
michael@0:  *
michael@0:  * The supplied widget can be any object implementing the following methods:
michael@0:  *   - function:nsIDOMNode insertItemAt(aIndex:number, aNode:nsIDOMNode, aValue:string)
michael@0:  *   - function:nsIDOMNode getItemAtIndex(aIndex:number)
michael@0:  *   - function removeChild(aChild:nsIDOMNode)
michael@0:  *   - function removeAllItems()
michael@0:  *   - get:nsIDOMNode selectedItem()
michael@0:  *   - set selectedItem(aChild:nsIDOMNode)
michael@0:  *   - function getAttribute(aName:string)
michael@0:  *   - function setAttribute(aName:string, aValue:string)
michael@0:  *   - function removeAttribute(aName:string)
michael@0:  *   - function addEventListener(aName:string, aCallback:function, aBubbleFlag:boolean)
michael@0:  *   - function removeEventListener(aName:string, aCallback:function, aBubbleFlag:boolean)
michael@0:  *
michael@0:  * Optional methods that can be implemented by the widget:
michael@0:  *   - function ensureElementIsVisible(aChild:nsIDOMNode)
michael@0:  *
michael@0:  * Optional attributes that may be handled (when calling get/set/removeAttribute):
michael@0:  *   - "emptyText": label temporarily added when there are no items present
michael@0:  *   - "headerText": label permanently added as a header
michael@0:  *
michael@0:  * For automagical keyboard and mouse accessibility, the widget should be an
michael@0:  * event emitter with the following events:
michael@0:  *   - "keyPress" -> (aName:string, aEvent:KeyboardEvent)
michael@0:  *   - "mousePress" -> (aName:string, aEvent:MouseEvent)
michael@0:  */
michael@0: this.WidgetMethods = {
michael@0:   /**
michael@0:    * Sets the element node or widget associated with this container.
michael@0:    * @param nsIDOMNode | object aWidget
michael@0:    */
michael@0:   set widget(aWidget) {
michael@0:     this._widget = aWidget;
michael@0: 
michael@0: 
michael@0:     // Can't use a WeakMap for _itemsByValue because keys are strings, and
michael@0:     // can't use one for _itemsByElement either, since it needs to be iterable.
michael@0:     XPCOMUtils.defineLazyGetter(this, "_itemsByValue", () => new Map());
michael@0:     XPCOMUtils.defineLazyGetter(this, "_itemsByElement", () => new Map());
michael@0:     XPCOMUtils.defineLazyGetter(this, "_stagedItems", () => []);
michael@0: 
michael@0:     // Handle internal events emitted by the widget if necessary.
michael@0:     if (ViewHelpers.isEventEmitter(aWidget)) {
michael@0:       aWidget.on("keyPress", this._onWidgetKeyPress.bind(this));
michael@0:       aWidget.on("mousePress", this._onWidgetMousePress.bind(this));
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the element node or widget associated with this container.
michael@0:    * @return nsIDOMNode | object
michael@0:    */
michael@0:   get widget() this._widget,
michael@0: 
michael@0:   /**
michael@0:    * Prepares an item to be added to this container. This allows, for example,
michael@0:    * for a large number of items to be batched up before being sorted & added.
michael@0:    *
michael@0:    * If the "staged" flag is *not* set to true, the item will be immediately
michael@0:    * inserted at the correct position in this container, so that all the items
michael@0:    * still remain sorted. This can (possibly) be much slower than batching up
michael@0:    * multiple items.
michael@0:    *
michael@0:    * By default, this container assumes that all the items should be displayed
michael@0:    * sorted by their value. This can be overridden with the "index" flag,
michael@0:    * specifying on which position should an item be appended. The "staged" and
michael@0:    * "index" flags are mutually exclusive, meaning that all staged items
michael@0:    * will always be appended.
michael@0:    *
michael@0:    * @param nsIDOMNode aElement
michael@0:    *        A prebuilt node to be wrapped.
michael@0:    * @param string aValue
michael@0:    *        A string identifying the node.
michael@0:    * @param object aOptions [optional]
michael@0:    *        Additional options or flags supported by this operation:
michael@0:    *          - attachment: some attached primitive/object for the item
michael@0:    *          - staged: true to stage the item to be appended later
michael@0:    *          - index: specifies on which position should the item be appended
michael@0:    *          - attributes: a batch of attributes set to the displayed element
michael@0:    *          - finalize: function invoked when the item is removed
michael@0:    * @return Item
michael@0:    *         The item associated with the displayed element if an unstaged push,
michael@0:    *         undefined if the item was staged for a later commit.
michael@0:    */
michael@0:   push: function([aElement, aValue], aOptions = {}) {
michael@0:     let item = new Item(this, aElement, aValue, aOptions.attachment);
michael@0: 
michael@0:     // Batch the item to be added later.
michael@0:     if (aOptions.staged) {
michael@0:       // An ulterior commit operation will ignore any specified index, so
michael@0:       // no reason to keep it around.
michael@0:       aOptions.index = undefined;
michael@0:       return void this._stagedItems.push({ item: item, options: aOptions });
michael@0:     }
michael@0:     // Find the target position in this container and insert the item there.
michael@0:     if (!("index" in aOptions)) {
michael@0:       return this._insertItemAt(this._findExpectedIndexFor(item), item, aOptions);
michael@0:     }
michael@0:     // Insert the item at the specified index. If negative or out of bounds,
michael@0:     // the item will be simply appended.
michael@0:     return this._insertItemAt(aOptions.index, item, aOptions);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Flushes all the prepared items into this container.
michael@0:    * Any specified index on the items will be ignored. Everything is appended.
michael@0:    *
michael@0:    * @param object aOptions [optional]
michael@0:    *        Additional options or flags supported by this operation:
michael@0:    *          - sorted: true to sort all the items before adding them
michael@0:    */
michael@0:   commit: function(aOptions = {}) {
michael@0:     let stagedItems = this._stagedItems;
michael@0: 
michael@0:     // Sort the items before adding them to this container, if preferred.
michael@0:     if (aOptions.sorted) {
michael@0:       stagedItems.sort((a, b) => this._currentSortPredicate(a.item, b.item));
michael@0:     }
michael@0:     // Append the prepared items to this container.
michael@0:     for (let { item, options } of stagedItems) {
michael@0:       this._insertItemAt(-1, item, options);
michael@0:     }
michael@0:     // Recreate the temporary items list for ulterior pushes.
michael@0:     this._stagedItems.length = 0;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Immediately removes the specified item from this container.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item associated with the element to remove.
michael@0:    */
michael@0:   remove: function(aItem) {
michael@0:     if (!aItem) {
michael@0:       return;
michael@0:     }
michael@0:     this._widget.removeChild(aItem._target);
michael@0:     this._untangleItem(aItem);
michael@0: 
michael@0:     if (!this._itemsByElement.size) {
michael@0:       this._preferredValue = this.selectedValue;
michael@0:       this._widget.selectedItem = null;
michael@0:       this._widget.setAttribute("emptyText", this._emptyText);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Removes the item at the specified index from this container.
michael@0:    *
michael@0:    * @param number aIndex
michael@0:    *        The index of the item to remove.
michael@0:    */
michael@0:   removeAt: function(aIndex) {
michael@0:     this.remove(this.getItemAtIndex(aIndex));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Removes all items from this container.
michael@0:    */
michael@0:   empty: function() {
michael@0:     this._preferredValue = this.selectedValue;
michael@0:     this._widget.selectedItem = null;
michael@0:     this._widget.removeAllItems();
michael@0:     this._widget.setAttribute("emptyText", this._emptyText);
michael@0: 
michael@0:     for (let [, item] of this._itemsByElement) {
michael@0:       this._untangleItem(item);
michael@0:     }
michael@0: 
michael@0:     this._itemsByValue.clear();
michael@0:     this._itemsByElement.clear();
michael@0:     this._stagedItems.length = 0;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Ensures the specified item is visible in this container.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item to bring into view.
michael@0:    */
michael@0:   ensureItemIsVisible: function(aItem) {
michael@0:     this._widget.ensureElementIsVisible(aItem._target);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Ensures the item at the specified index is visible in this container.
michael@0:    *
michael@0:    * @param number aIndex
michael@0:    *        The index of the item to bring into view.
michael@0:    */
michael@0:   ensureIndexIsVisible: function(aIndex) {
michael@0:     this.ensureItemIsVisible(this.getItemAtIndex(aIndex));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Sugar for ensuring the selected item is visible in this container.
michael@0:    */
michael@0:   ensureSelectedItemIsVisible: function() {
michael@0:     this.ensureItemIsVisible(this.selectedItem);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * If supported by the widget, the label string temporarily added to this
michael@0:    * container when there are no child items present.
michael@0:    */
michael@0:   set emptyText(aValue) {
michael@0:     this._emptyText = aValue;
michael@0: 
michael@0:     // Apply the emptyText attribute right now if there are no child items.
michael@0:     if (!this._itemsByElement.size) {
michael@0:       this._widget.setAttribute("emptyText", aValue);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * If supported by the widget, the label string permanently added to this
michael@0:    * container as a header.
michael@0:    * @param string aValue
michael@0:    */
michael@0:   set headerText(aValue) {
michael@0:     this._headerText = aValue;
michael@0:     this._widget.setAttribute("headerText", aValue);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Toggles all the items in this container hidden or visible.
michael@0:    *
michael@0:    * This does not change the default filtering predicate, so newly inserted
michael@0:    * items will always be visible. Use WidgetMethods.filterContents if you care.
michael@0:    *
michael@0:    * @param boolean aVisibleFlag
michael@0:    *        Specifies the intended visibility.
michael@0:    */
michael@0:   toggleContents: function(aVisibleFlag) {
michael@0:     for (let [element, item] of this._itemsByElement) {
michael@0:       element.hidden = !aVisibleFlag;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Toggles all items in this container hidden or visible based on a predicate.
michael@0:    *
michael@0:    * @param function aPredicate [optional]
michael@0:    *        Items are toggled according to the return value of this function,
michael@0:    *        which will become the new default filtering predicate in this container.
michael@0:    *        If unspecified, all items will be toggled visible.
michael@0:    */
michael@0:   filterContents: function(aPredicate = this._currentFilterPredicate) {
michael@0:     this._currentFilterPredicate = aPredicate;
michael@0: 
michael@0:     for (let [element, item] of this._itemsByElement) {
michael@0:       element.hidden = !aPredicate(item);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Sorts all the items in this container based on a predicate.
michael@0:    *
michael@0:    * @param function aPredicate [optional]
michael@0:    *        Items are sorted according to the return value of the function,
michael@0:    *        which will become the new default sorting predicate in this container.
michael@0:    *        If unspecified, all items will be sorted by their value.
michael@0:    */
michael@0:   sortContents: function(aPredicate = this._currentSortPredicate) {
michael@0:     let sortedItems = this.items.sort(this._currentSortPredicate = aPredicate);
michael@0: 
michael@0:     for (let i = 0, len = sortedItems.length; i < len; i++) {
michael@0:       this.swapItems(this.getItemAtIndex(i), sortedItems[i]);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Visually swaps two items in this container.
michael@0:    *
michael@0:    * @param Item aFirst
michael@0:    *        The first item to be swapped.
michael@0:    * @param Item aSecond
michael@0:    *        The second item to be swapped.
michael@0:    */
michael@0:   swapItems: function(aFirst, aSecond) {
michael@0:     if (aFirst == aSecond) { // We're just dandy, thank you.
michael@0:       return;
michael@0:     }
michael@0:     let { _prebuiltNode: firstPrebuiltTarget, _target: firstTarget } = aFirst;
michael@0:     let { _prebuiltNode: secondPrebuiltTarget, _target: secondTarget } = aSecond;
michael@0: 
michael@0:     // If the two items were constructed with prebuilt nodes as DocumentFragments,
michael@0:     // then those DocumentFragments are now empty and need to be reassembled.
michael@0:     if (firstPrebuiltTarget instanceof Ci.nsIDOMDocumentFragment) {
michael@0:       for (let node of firstTarget.childNodes) {
michael@0:         firstPrebuiltTarget.appendChild(node.cloneNode(true));
michael@0:       }
michael@0:     }
michael@0:     if (secondPrebuiltTarget instanceof Ci.nsIDOMDocumentFragment) {
michael@0:       for (let node of secondTarget.childNodes) {
michael@0:         secondPrebuiltTarget.appendChild(node.cloneNode(true));
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // 1. Get the indices of the two items to swap.
michael@0:     let i = this._indexOfElement(firstTarget);
michael@0:     let j = this._indexOfElement(secondTarget);
michael@0: 
michael@0:     // 2. Remeber the selection index, to reselect an item, if necessary.
michael@0:     let selectedTarget = this._widget.selectedItem;
michael@0:     let selectedIndex = -1;
michael@0:     if (selectedTarget == firstTarget) {
michael@0:       selectedIndex = i;
michael@0:     } else if (selectedTarget == secondTarget) {
michael@0:       selectedIndex = j;
michael@0:     }
michael@0: 
michael@0:     // 3. Silently nuke both items, nobody needs to know about this.
michael@0:     this._widget.removeChild(firstTarget);
michael@0:     this._widget.removeChild(secondTarget);
michael@0:     this._unlinkItem(aFirst);
michael@0:     this._unlinkItem(aSecond);
michael@0: 
michael@0:     // 4. Add the items again, but reversing their indices.
michael@0:     this._insertItemAt.apply(this, i < j ? [i, aSecond] : [j, aFirst]);
michael@0:     this._insertItemAt.apply(this, i < j ? [j, aFirst] : [i, aSecond]);
michael@0: 
michael@0:     // 5. Restore the previous selection, if necessary.
michael@0:     if (selectedIndex == i) {
michael@0:       this._widget.selectedItem = aFirst._target;
michael@0:     } else if (selectedIndex == j) {
michael@0:       this._widget.selectedItem = aSecond._target;
michael@0:     }
michael@0: 
michael@0:     // 6. Let the outside world know that these two items were swapped.
michael@0:     ViewHelpers.dispatchEvent(aFirst.target, "swap", [aSecond, aFirst]);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Visually swaps two items in this container at specific indices.
michael@0:    *
michael@0:    * @param number aFirst
michael@0:    *        The index of the first item to be swapped.
michael@0:    * @param number aSecond
michael@0:    *        The index of the second item to be swapped.
michael@0:    */
michael@0:   swapItemsAtIndices: function(aFirst, aSecond) {
michael@0:     this.swapItems(this.getItemAtIndex(aFirst), this.getItemAtIndex(aSecond));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Checks whether an item with the specified value is among the elements
michael@0:    * shown in this container.
michael@0:    *
michael@0:    * @param string aValue
michael@0:    *        The item's value.
michael@0:    * @return boolean
michael@0:    *         True if the value is known, false otherwise.
michael@0:    */
michael@0:   containsValue: function(aValue) {
michael@0:     return this._itemsByValue.has(aValue) ||
michael@0:            this._stagedItems.some(({ item }) => item._value == aValue);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the "preferred value". This is the latest selected item's value,
michael@0:    * remembered just before emptying this container.
michael@0:    * @return string
michael@0:    */
michael@0:   get preferredValue() {
michael@0:     return this._preferredValue;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Retrieves the item associated with the selected element.
michael@0:    * @return Item | null
michael@0:    */
michael@0:   get selectedItem() {
michael@0:     let selectedElement = this._widget.selectedItem;
michael@0:     if (selectedElement) {
michael@0:       return this._itemsByElement.get(selectedElement);
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Retrieves the selected element's index in this container.
michael@0:    * @return number
michael@0:    */
michael@0:   get selectedIndex() {
michael@0:     let selectedElement = this._widget.selectedItem;
michael@0:     if (selectedElement) {
michael@0:       return this._indexOfElement(selectedElement);
michael@0:     }
michael@0:     return -1;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Retrieves the value of the selected element.
michael@0:    * @return string
michael@0:    */
michael@0:   get selectedValue() {
michael@0:     let selectedElement = this._widget.selectedItem;
michael@0:     if (selectedElement) {
michael@0:       return this._itemsByElement.get(selectedElement)._value;
michael@0:     }
michael@0:     return "";
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Retrieves the attachment of the selected element.
michael@0:    * @return object | null
michael@0:    */
michael@0:   get selectedAttachment() {
michael@0:     let selectedElement = this._widget.selectedItem;
michael@0:     if (selectedElement) {
michael@0:       return this._itemsByElement.get(selectedElement).attachment;
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Selects the element with the entangled item in this container.
michael@0:    * @param Item | function aItem
michael@0:    */
michael@0:   set selectedItem(aItem) {
michael@0:     // A predicate is allowed to select a specific item.
michael@0:     // If no item is matched, then the current selection is removed.
michael@0:     if (typeof aItem == "function") {
michael@0:       aItem = this.getItemForPredicate(aItem);
michael@0:     }
michael@0: 
michael@0:     // A falsy item is allowed to invalidate the current selection.
michael@0:     let targetElement = aItem ? aItem._target : null;
michael@0:     let prevElement = this._widget.selectedItem;
michael@0: 
michael@0:     // Make sure the selected item's target element is focused and visible.
michael@0:     if (this.autoFocusOnSelection && targetElement) {
michael@0:       targetElement.focus();
michael@0:     }
michael@0:     if (this.maintainSelectionVisible && targetElement) {
michael@0:       if ("ensureElementIsVisible" in this._widget) {
michael@0:         this._widget.ensureElementIsVisible(targetElement);
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // Prevent selecting the same item again and avoid dispatching
michael@0:     // a redundant selection event, so return early.
michael@0:     if (targetElement != prevElement) {
michael@0:       this._widget.selectedItem = targetElement;
michael@0:       let dispTarget = targetElement || prevElement;
michael@0:       let dispName = this.suppressSelectionEvents ? "suppressed-select" : "select";
michael@0:       ViewHelpers.dispatchEvent(dispTarget, dispName, aItem);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Selects the element at the specified index in this container.
michael@0:    * @param number aIndex
michael@0:    */
michael@0:   set selectedIndex(aIndex) {
michael@0:     let targetElement = this._widget.getItemAtIndex(aIndex);
michael@0:     if (targetElement) {
michael@0:       this.selectedItem = this._itemsByElement.get(targetElement);
michael@0:       return;
michael@0:     }
michael@0:     this.selectedItem = null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Selects the element with the specified value in this container.
michael@0:    * @param string aValue
michael@0:    */
michael@0:   set selectedValue(aValue) {
michael@0:     this.selectedItem = this._itemsByValue.get(aValue);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Specifies if this container should try to keep the selected item visible.
michael@0:    * (For example, when new items are added the selection is brought into view).
michael@0:    */
michael@0:   maintainSelectionVisible: true,
michael@0: 
michael@0:   /**
michael@0:    * Specifies if "select" events dispatched from the elements in this container
michael@0:    * when their respective items are selected should be suppressed or not.
michael@0:    *
michael@0:    * If this flag is set to true, then consumers of this container won't
michael@0:    * be normally notified when items are selected.
michael@0:    */
michael@0:   suppressSelectionEvents: false,
michael@0: 
michael@0:   /**
michael@0:    * Focus this container the first time an element is inserted?
michael@0:    *
michael@0:    * If this flag is set to true, then when the first item is inserted in
michael@0:    * this container (and thus it's the only item available), its corresponding
michael@0:    * target element is focused as well.
michael@0:    */
michael@0:   autoFocusOnFirstItem: true,
michael@0: 
michael@0:   /**
michael@0:    * Focus on selection?
michael@0:    *
michael@0:    * If this flag is set to true, then whenever an item is selected in
michael@0:    * this container (e.g. via the selectedIndex or selectedItem setters),
michael@0:    * its corresponding target element is focused as well.
michael@0:    *
michael@0:    * You can disable this flag, for example, to maintain a certain node
michael@0:    * focused but visually indicate a different selection in this container.
michael@0:    */
michael@0:   autoFocusOnSelection: true,
michael@0: 
michael@0:   /**
michael@0:    * Focus on input (e.g. mouse click)?
michael@0:    *
michael@0:    * If this flag is set to true, then whenever an item receives user input in
michael@0:    * this container, its corresponding target element is focused as well.
michael@0:    */
michael@0:   autoFocusOnInput: true,
michael@0: 
michael@0:   /**
michael@0:    * When focusing on input, allow right clicks?
michael@0:    * @see WidgetMethods.autoFocusOnInput
michael@0:    */
michael@0:   allowFocusOnRightClick: false,
michael@0: 
michael@0:   /**
michael@0:    * The number of elements in this container to jump when Page Up or Page Down
michael@0:    * keys are pressed. If falsy, then the page size will be based on the
michael@0:    * number of visible items in the container.
michael@0:    */
michael@0:   pageSize: 0,
michael@0: 
michael@0:   /**
michael@0:    * Focuses the first visible item in this container.
michael@0:    */
michael@0:   focusFirstVisibleItem: function() {
michael@0:     this.focusItemAtDelta(-this.itemCount);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Focuses the last visible item in this container.
michael@0:    */
michael@0:   focusLastVisibleItem: function() {
michael@0:     this.focusItemAtDelta(+this.itemCount);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Focuses the next item in this container.
michael@0:    */
michael@0:   focusNextItem: function() {
michael@0:     this.focusItemAtDelta(+1);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Focuses the previous item in this container.
michael@0:    */
michael@0:   focusPrevItem: function() {
michael@0:     this.focusItemAtDelta(-1);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Focuses another item in this container based on the index distance
michael@0:    * from the currently focused item.
michael@0:    *
michael@0:    * @param number aDelta
michael@0:    *        A scalar specifying by how many items should the selection change.
michael@0:    */
michael@0:   focusItemAtDelta: function(aDelta) {
michael@0:     // Make sure the currently selected item is also focused, so that the
michael@0:     // command dispatcher mechanism has a relative node to work with.
michael@0:     // If there's no selection, just select an item at a corresponding index
michael@0:     // (e.g. the first item in this container if aDelta <= 1).
michael@0:     let selectedElement = this._widget.selectedItem;
michael@0:     if (selectedElement) {
michael@0:       selectedElement.focus();
michael@0:     } else {
michael@0:       this.selectedIndex = Math.max(0, aDelta - 1);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     let direction = aDelta > 0 ? "advanceFocus" : "rewindFocus";
michael@0:     let distance = Math.abs(Math[aDelta > 0 ? "ceil" : "floor"](aDelta));
michael@0:     while (distance--) {
michael@0:       if (!this._focusChange(direction)) {
michael@0:         break; // Out of bounds.
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // Synchronize the selected item as being the currently focused element.
michael@0:     this.selectedItem = this.getItemForElement(this._focusedElement);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Focuses the next or previous item in this container.
michael@0:    *
michael@0:    * @param string aDirection
michael@0:    *        Either "advanceFocus" or "rewindFocus".
michael@0:    * @return boolean
michael@0:    *         False if the focus went out of bounds and the first or last item
michael@0:    *         in this container was focused instead.
michael@0:    */
michael@0:   _focusChange: function(aDirection) {
michael@0:     let commandDispatcher = this._commandDispatcher;
michael@0:     let prevFocusedElement = commandDispatcher.focusedElement;
michael@0:     let currFocusedElement;
michael@0: 
michael@0:     do {
michael@0:       commandDispatcher.suppressFocusScroll = true;
michael@0:       commandDispatcher[aDirection]();
michael@0:       currFocusedElement = commandDispatcher.focusedElement;
michael@0: 
michael@0:       // Make sure the newly focused item is a part of this container. If the
michael@0:       // focus goes out of bounds, revert the previously focused item.
michael@0:       if (!this.getItemForElement(currFocusedElement)) {
michael@0:         prevFocusedElement.focus();
michael@0:         return false;
michael@0:       }
michael@0:     } while (!WIDGET_FOCUSABLE_NODES.has(currFocusedElement.tagName));
michael@0: 
michael@0:     // Focus remained within bounds.
michael@0:     return true;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the command dispatcher instance associated with this container's DOM.
michael@0:    * If there are no items displayed in this container, null is returned.
michael@0:    * @return nsIDOMXULCommandDispatcher | null
michael@0:    */
michael@0:   get _commandDispatcher() {
michael@0:     if (this._cachedCommandDispatcher) {
michael@0:       return this._cachedCommandDispatcher;
michael@0:     }
michael@0:     let someElement = this._widget.getItemAtIndex(0);
michael@0:     if (someElement) {
michael@0:       let commandDispatcher = someElement.ownerDocument.commandDispatcher;
michael@0:       return this._cachedCommandDispatcher = commandDispatcher;
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the currently focused element in this container.
michael@0:    *
michael@0:    * @return nsIDOMNode
michael@0:    *         The focused element, or null if nothing is found.
michael@0:    */
michael@0:   get _focusedElement() {
michael@0:     let commandDispatcher = this._commandDispatcher;
michael@0:     if (commandDispatcher) {
michael@0:       return commandDispatcher.focusedElement;
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the item in the container having the specified index.
michael@0:    *
michael@0:    * @param number aIndex
michael@0:    *        The index used to identify the element.
michael@0:    * @return Item
michael@0:    *         The matched item, or null if nothing is found.
michael@0:    */
michael@0:   getItemAtIndex: function(aIndex) {
michael@0:     return this.getItemForElement(this._widget.getItemAtIndex(aIndex));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the item in the container having the specified value.
michael@0:    *
michael@0:    * @param string aValue
michael@0:    *        The value used to identify the element.
michael@0:    * @return Item
michael@0:    *         The matched item, or null if nothing is found.
michael@0:    */
michael@0:   getItemByValue: function(aValue) {
michael@0:     return this._itemsByValue.get(aValue);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the item in the container associated with the specified element.
michael@0:    *
michael@0:    * @param nsIDOMNode aElement
michael@0:    *        The element used to identify the item.
michael@0:    * @param object aFlags [optional]
michael@0:    *        Additional options for showing the source. Supported options:
michael@0:    *          - noSiblings: if siblings shouldn't be taken into consideration
michael@0:    *                        when searching for the associated item.
michael@0:    * @return Item
michael@0:    *         The matched item, or null if nothing is found.
michael@0:    */
michael@0:   getItemForElement: function(aElement, aFlags = {}) {
michael@0:     while (aElement) {
michael@0:       let item = this._itemsByElement.get(aElement);
michael@0: 
michael@0:       // Also search the siblings if allowed.
michael@0:       if (!aFlags.noSiblings) {
michael@0:         item = item ||
michael@0:           this._itemsByElement.get(aElement.nextElementSibling) ||
michael@0:           this._itemsByElement.get(aElement.previousElementSibling);
michael@0:       }
michael@0:       if (item) {
michael@0:         return item;
michael@0:       }
michael@0:       aElement = aElement.parentNode;
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets a visible item in this container validating a specified predicate.
michael@0:    *
michael@0:    * @param function aPredicate
michael@0:    *        The first item which validates this predicate is returned
michael@0:    * @return Item
michael@0:    *         The matched item, or null if nothing is found.
michael@0:    */
michael@0:   getItemForPredicate: function(aPredicate, aOwner = this) {
michael@0:     // Recursively check the items in this widget for a predicate match.
michael@0:     for (let [element, item] of aOwner._itemsByElement) {
michael@0:       let match;
michael@0:       if (aPredicate(item) && !element.hidden) {
michael@0:         match = item;
michael@0:       } else {
michael@0:         match = this.getItemForPredicate(aPredicate, item);
michael@0:       }
michael@0:       if (match) {
michael@0:         return match;
michael@0:       }
michael@0:     }
michael@0:     // Also check the staged items. No need to do this recursively since
michael@0:     // they're not even appended to the view yet.
michael@0:     for (let { item } of this._stagedItems) {
michael@0:       if (aPredicate(item)) {
michael@0:         return item;
michael@0:       }
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Shortcut function for getItemForPredicate which works on item attachments.
michael@0:    * @see getItemForPredicate
michael@0:    */
michael@0:   getItemForAttachment: function(aPredicate, aOwner = this) {
michael@0:     return this.getItemForPredicate(e => aPredicate(e.attachment));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Finds the index of an item in the container.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item get the index for.
michael@0:    * @return number
michael@0:    *         The index of the matched item, or -1 if nothing is found.
michael@0:    */
michael@0:   indexOfItem: function(aItem) {
michael@0:     return this._indexOfElement(aItem._target);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Finds the index of an element in the container.
michael@0:    *
michael@0:    * @param nsIDOMNode aElement
michael@0:    *        The element get the index for.
michael@0:    * @return number
michael@0:    *         The index of the matched element, or -1 if nothing is found.
michael@0:    */
michael@0:   _indexOfElement: function(aElement) {
michael@0:     for (let i = 0; i < this._itemsByElement.size; i++) {
michael@0:       if (this._widget.getItemAtIndex(i) == aElement) {
michael@0:         return i;
michael@0:       }
michael@0:     }
michael@0:     return -1;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Gets the total number of items in this container.
michael@0:    * @return number
michael@0:    */
michael@0:   get itemCount() {
michael@0:     return this._itemsByElement.size;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Returns a list of items in this container, in the displayed order.
michael@0:    * @return array
michael@0:    */
michael@0:   get items() {
michael@0:     let store = [];
michael@0:     let itemCount = this.itemCount;
michael@0:     for (let i = 0; i < itemCount; i++) {
michael@0:       store.push(this.getItemAtIndex(i));
michael@0:     }
michael@0:     return store;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Returns a list of values in this container, in the displayed order.
michael@0:    * @return array
michael@0:    */
michael@0:   get values() {
michael@0:     return this.items.map(e => e._value);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Returns a list of attachments in this container, in the displayed order.
michael@0:    * @return array
michael@0:    */
michael@0:   get attachments() {
michael@0:     return this.items.map(e => e.attachment);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Returns a list of all the visible (non-hidden) items in this container,
michael@0:    * in the displayed order
michael@0:    * @return array
michael@0:    */
michael@0:   get visibleItems() {
michael@0:     return this.items.filter(e => !e._target.hidden);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Checks if an item is unique in this container. If an item's value is an
michael@0:    * empty string, "undefined" or "null", it is considered unique.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item for which to verify uniqueness.
michael@0:    * @return boolean
michael@0:    *         True if the item is unique, false otherwise.
michael@0:    */
michael@0:   isUnique: function(aItem) {
michael@0:     let value = aItem._value;
michael@0:     if (value == "" || value == "undefined" || value == "null") {
michael@0:       return true;
michael@0:     }
michael@0:     return !this._itemsByValue.has(value);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Checks if an item is eligible for this container. By default, this checks
michael@0:    * whether an item is unique and has a prebuilt target node.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item for which to verify eligibility.
michael@0:    * @return boolean
michael@0:    *         True if the item is eligible, false otherwise.
michael@0:    */
michael@0:   isEligible: function(aItem) {
michael@0:     return this.isUnique(aItem) && aItem._prebuiltNode;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Finds the expected item index in this container based on the default
michael@0:    * sort predicate.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item for which to get the expected index.
michael@0:    * @return number
michael@0:    *         The expected item index.
michael@0:    */
michael@0:   _findExpectedIndexFor: function(aItem) {
michael@0:     let itemCount = this.itemCount;
michael@0:     for (let i = 0; i < itemCount; i++) {
michael@0:       if (this._currentSortPredicate(this.getItemAtIndex(i), aItem) > 0) {
michael@0:         return i;
michael@0:       }
michael@0:     }
michael@0:     return itemCount;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Immediately inserts an item in this container at the specified index.
michael@0:    *
michael@0:    * @param number aIndex
michael@0:    *        The position in the container intended for this item.
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    * @param object aOptions [optional]
michael@0:    *        Additional options or flags supported by this operation:
michael@0:    *          - attributes: a batch of attributes set to the displayed element
michael@0:    *          - finalize: function when the item is untangled (removed)
michael@0:    * @return Item
michael@0:    *         The item associated with the displayed element, null if rejected.
michael@0:    */
michael@0:   _insertItemAt: function(aIndex, aItem, aOptions = {}) {
michael@0:     if (!this.isEligible(aItem)) {
michael@0:       return null;
michael@0:     }
michael@0: 
michael@0:     // Entangle the item with the newly inserted node.
michael@0:     // Make sure this is done with the value returned by insertItemAt(),
michael@0:     // to avoid storing a potential DocumentFragment.
michael@0:     let node = aItem._prebuiltNode;
michael@0:     let attachment = aItem.attachment;
michael@0:     this._entangleItem(aItem, this._widget.insertItemAt(aIndex, node, attachment));
michael@0: 
michael@0:     // Handle any additional options after entangling the item.
michael@0:     if (!this._currentFilterPredicate(aItem)) {
michael@0:       aItem._target.hidden = true;
michael@0:     }
michael@0:     if (this.autoFocusOnFirstItem && this._itemsByElement.size == 1) {
michael@0:       aItem._target.focus();
michael@0:     }
michael@0:     if (aOptions.attributes) {
michael@0:       aOptions.attributes.forEach(e => aItem._target.setAttribute(e[0], e[1]));
michael@0:     }
michael@0:     if (aOptions.finalize) {
michael@0:       aItem.finalize = aOptions.finalize;
michael@0:     }
michael@0: 
michael@0:     // Hide the empty text if the selection wasn't lost.
michael@0:     this._widget.removeAttribute("emptyText");
michael@0: 
michael@0:     // Return the item associated with the displayed element.
michael@0:     return aItem;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Entangles an item (model) with a displayed node element (view).
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    * @param nsIDOMNode aElement
michael@0:    *        The element displaying the item.
michael@0:    */
michael@0:   _entangleItem: function(aItem, aElement) {
michael@0:     this._itemsByValue.set(aItem._value, aItem);
michael@0:     this._itemsByElement.set(aElement, aItem);
michael@0:     aItem._target = aElement;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Untangles an item (model) from a displayed node element (view).
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    */
michael@0:   _untangleItem: function(aItem) {
michael@0:     if (aItem.finalize) {
michael@0:       aItem.finalize(aItem);
michael@0:     }
michael@0:     for (let childItem of aItem) {
michael@0:       aItem.remove(childItem);
michael@0:     }
michael@0: 
michael@0:     this._unlinkItem(aItem);
michael@0:     aItem._target = null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Deletes an item from the its parent's storage maps.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item describing a target element.
michael@0:    */
michael@0:   _unlinkItem: function(aItem) {
michael@0:     this._itemsByValue.delete(aItem._value);
michael@0:     this._itemsByElement.delete(aItem._target);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * The keyPress event listener for this container.
michael@0:    * @param string aName
michael@0:    * @param KeyboardEvent aEvent
michael@0:    */
michael@0:   _onWidgetKeyPress: function(aName, aEvent) {
michael@0:     // Prevent scrolling when pressing navigation keys.
michael@0:     ViewHelpers.preventScrolling(aEvent);
michael@0: 
michael@0:     switch (aEvent.keyCode) {
michael@0:       case aEvent.DOM_VK_UP:
michael@0:       case aEvent.DOM_VK_LEFT:
michael@0:         this.focusPrevItem();
michael@0:         return;
michael@0:       case aEvent.DOM_VK_DOWN:
michael@0:       case aEvent.DOM_VK_RIGHT:
michael@0:         this.focusNextItem();
michael@0:         return;
michael@0:       case aEvent.DOM_VK_PAGE_UP:
michael@0:         this.focusItemAtDelta(-(this.pageSize || (this.itemCount / PAGE_SIZE_ITEM_COUNT_RATIO)));
michael@0:         return;
michael@0:       case aEvent.DOM_VK_PAGE_DOWN:
michael@0:         this.focusItemAtDelta(+(this.pageSize || (this.itemCount / PAGE_SIZE_ITEM_COUNT_RATIO)));
michael@0:         return;
michael@0:       case aEvent.DOM_VK_HOME:
michael@0:         this.focusFirstVisibleItem();
michael@0:         return;
michael@0:       case aEvent.DOM_VK_END:
michael@0:         this.focusLastVisibleItem();
michael@0:         return;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * The mousePress event listener for this container.
michael@0:    * @param string aName
michael@0:    * @param MouseEvent aEvent
michael@0:    */
michael@0:   _onWidgetMousePress: function(aName, aEvent) {
michael@0:     if (aEvent.button != 0 && !this.allowFocusOnRightClick) {
michael@0:       // Only allow left-click to trigger this event.
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     let item = this.getItemForElement(aEvent.target);
michael@0:     if (item) {
michael@0:       // The container is not empty and we clicked on an actual item.
michael@0:       this.selectedItem = item;
michael@0:       // Make sure the current event's target element is also focused.
michael@0:       this.autoFocusOnInput && item._target.focus();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * The predicate used when filtering items. By default, all items in this
michael@0:    * view are visible.
michael@0:    *
michael@0:    * @param Item aItem
michael@0:    *        The item passing through the filter.
michael@0:    * @return boolean
michael@0:    *         True if the item should be visible, false otherwise.
michael@0:    */
michael@0:   _currentFilterPredicate: function(aItem) {
michael@0:     return true;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * The predicate used when sorting items. By default, items in this view
michael@0:    * are sorted by their label.
michael@0:    *
michael@0:    * @param Item aFirst
michael@0:    *        The first item used in the comparison.
michael@0:    * @param Item aSecond
michael@0:    *        The second item used in the comparison.
michael@0:    * @return number
michael@0:    *         -1 to sort aFirst to a lower index than aSecond
michael@0:    *          0 to leave aFirst and aSecond unchanged with respect to each other
michael@0:    *          1 to sort aSecond to a lower index than aFirst
michael@0:    */
michael@0:   _currentSortPredicate: function(aFirst, aSecond) {
michael@0:     return +(aFirst._value.toLowerCase() > aSecond._value.toLowerCase());
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Call a method on this widget named `aMethodName`. Any further arguments are
michael@0:    * passed on to the method. Returns the result of the method call.
michael@0:    *
michael@0:    * @param String aMethodName
michael@0:    *        The name of the method you want to call.
michael@0:    * @param aArgs
michael@0:    *        Optional. Any arguments you want to pass through to the method.
michael@0:    */
michael@0:   callMethod: function(aMethodName, ...aArgs) {
michael@0:     return this._widget[aMethodName].apply(this._widget, aArgs);
michael@0:   },
michael@0: 
michael@0:   _widget: null,
michael@0:   _emptyText: "",
michael@0:   _headerText: "",
michael@0:   _preferredValue: "",
michael@0:   _cachedCommandDispatcher: null
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * A generator-iterator over all the items in this container.
michael@0:  */
michael@0: Item.prototype["@@iterator"] =
michael@0: WidgetMethods["@@iterator"] = function*() {
michael@0:   yield* this._itemsByElement.values();
michael@0: };