Jamie Gennis | 0105835 | 2012-05-06 12:48:05 -0700 | [diff] [blame^] | 1 | // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | |
| 6 | /** |
| 7 | * @fileoverview Implements an element that is hidden by default, but |
| 8 | * when shown, dims and (attempts to) disable the main document. |
| 9 | * |
| 10 | * You can turn any div into an overlay. Note that while an |
| 11 | * overlay element is shown, its parent is changed. Hiding the overlay |
| 12 | * restores its original parentage. |
| 13 | * |
| 14 | */ |
| 15 | cr.define('tracing', function() { |
| 16 | /** |
| 17 | * Manages a full-window div that darkens the window, disables |
| 18 | * input, and hosts the currently-visible overlays. You shouldn't |
| 19 | * have to instantiate this directly --- it gets set automatically. |
| 20 | * @param {Object=} opt_propertyBag Optional properties. |
| 21 | * @constructor |
| 22 | * @extends {HTMLDivElement} |
| 23 | */ |
| 24 | var OverlayRoot = cr.ui.define('div'); |
| 25 | OverlayRoot.prototype = { |
| 26 | __proto__: HTMLDivElement.prototype, |
| 27 | decorate: function() { |
| 28 | this.classList.add('overlay-root'); |
| 29 | this.visible = false; |
| 30 | |
| 31 | this.contentHost = this.ownerDocument.createElement('div'); |
| 32 | this.contentHost.classList.add('content-host'); |
| 33 | |
| 34 | this.tabCatcher = this.ownerDocument.createElement('span'); |
| 35 | this.tabCatcher.tabIndex = 0; |
| 36 | |
| 37 | this.appendChild(this.contentHost); |
| 38 | |
| 39 | this.onKeydownBoundToThis_ = this.onKeydown_.bind(this); |
| 40 | this.onFocusInBoundToThis_ = this.onFocusIn_.bind(this); |
| 41 | this.addEventListener('mousedown', this.onMousedown_.bind(this)); |
| 42 | }, |
| 43 | |
| 44 | /** |
| 45 | * Adds an overlay, attaching it to the contentHost so that it is visible. |
| 46 | */ |
| 47 | showOverlay: function(overlay) { |
| 48 | // Reparent this to the overlay content host. |
| 49 | overlay.oldParent_ = overlay.parentNode; |
| 50 | this.contentHost.appendChild(overlay); |
| 51 | this.contentHost.appendChild(this.tabCatcher); |
| 52 | |
| 53 | // Show the overlay root. |
| 54 | this.ownerDocument.body.classList.add('disabled-by-overlay'); |
| 55 | this.visible = true; |
| 56 | |
| 57 | // Bring overlay into focus. |
| 58 | overlay.tabIndex = 0; |
| 59 | var focusElement = |
| 60 | overlay.querySelector('button, input, list, select, a'); |
| 61 | if (!focusElement) { |
| 62 | focusElement = overlay; |
| 63 | } |
| 64 | focusElement.focus(); |
| 65 | |
| 66 | // Listen to key and focus events to prevent focus from |
| 67 | // leaving the overlay. |
| 68 | this.ownerDocument.addEventListener('focusin', |
| 69 | this.onFocusInBoundToThis_, true); |
| 70 | overlay.addEventListener('keydown', this.onKeydownBoundToThis_); |
| 71 | }, |
| 72 | |
| 73 | /** |
| 74 | * Clicking outside of the overlay will de-focus the overlay. The |
| 75 | * next tab will look at the entire document to determine the focus. |
| 76 | * For certain documents, this can cause focus to "leak" outside of |
| 77 | * the overlay. |
| 78 | */ |
| 79 | onMousedown_: function(e) { |
| 80 | if (e.target == this) { |
| 81 | e.preventDefault(); |
| 82 | } |
| 83 | }, |
| 84 | |
| 85 | /** |
| 86 | * Prevents forward-tabbing out of the overlay |
| 87 | */ |
| 88 | onFocusIn_: function(e) { |
| 89 | if (e.target == this.tabCatcher) { |
| 90 | window.setTimeout(this.focusOverlay_.bind(this), 0); |
| 91 | } |
| 92 | }, |
| 93 | |
| 94 | focusOverlay_: function() { |
| 95 | this.contentHost.firstChild.focus(); |
| 96 | }, |
| 97 | |
| 98 | /** |
| 99 | * Prevent the user from shift-tabbing backwards out of the overlay. |
| 100 | */ |
| 101 | onKeydown_: function(e) { |
| 102 | if (e.keyCode == 9 && |
| 103 | e.shiftKey && |
| 104 | e.target == this.contentHost.firstChild) { |
| 105 | e.preventDefault(); |
| 106 | } |
| 107 | }, |
| 108 | |
| 109 | /** |
| 110 | * Hides an overlay, attaching it to its original parent if needed. |
| 111 | */ |
| 112 | hideOverlay: function(overlay) { |
| 113 | // hide the overlay root |
| 114 | this.visible = false; |
| 115 | this.ownerDocument.body.classList.remove('disabled-by-overlay'); |
| 116 | this.lastFocusOut_ = undefined; |
| 117 | |
| 118 | // put the overlay back on its previous parent |
| 119 | overlay.parentNode.removeChild(this.tabCatcher); |
| 120 | if (overlay.oldParent_) { |
| 121 | overlay.oldParent_.appendChild(overlay); |
| 122 | delete overlay.oldParent_; |
| 123 | } else { |
| 124 | this.contentHost.removeChild(overlay); |
| 125 | } |
| 126 | |
| 127 | // remove listeners |
| 128 | overlay.removeEventListener('keydown', this.onKeydownBoundToThis_); |
| 129 | this.ownerDocument.removeEventListener('focusin', |
| 130 | this.onFocusInBoundToThis_); |
| 131 | } |
| 132 | }; |
| 133 | |
| 134 | cr.defineProperty(OverlayRoot, 'visible', cr.PropertyKind.BOOL_ATTR); |
| 135 | |
| 136 | /** |
| 137 | * Creates a new overlay element. It will not be visible until shown. |
| 138 | * @param {Object=} opt_propertyBag Optional properties. |
| 139 | * @constructor |
| 140 | * @extends {HTMLDivElement} |
| 141 | */ |
| 142 | var Overlay = cr.ui.define('div'); |
| 143 | |
| 144 | Overlay.prototype = { |
| 145 | __proto__: HTMLDivElement.prototype, |
| 146 | |
| 147 | /** |
| 148 | * Initializes the overlay element. |
| 149 | */ |
| 150 | decorate: function() { |
| 151 | // create the overlay root on this document if its not present |
| 152 | if (!this.ownerDocument.querySelector('.overlay-root')) { |
| 153 | var overlayRoot = this.ownerDocument.createElement('div'); |
| 154 | cr.ui.decorate(overlayRoot, OverlayRoot); |
| 155 | this.ownerDocument.body.appendChild(overlayRoot); |
| 156 | } |
| 157 | |
| 158 | this.classList.add('overlay'); |
| 159 | this.visible = false; |
| 160 | }, |
| 161 | |
| 162 | onVisibleChanged_: function() { |
| 163 | var overlayRoot = this.ownerDocument.querySelector('.overlay-root'); |
| 164 | if (this.visible) { |
| 165 | overlayRoot.showOverlay(this); |
| 166 | } else { |
| 167 | overlayRoot.hideOverlay(this); |
| 168 | } |
| 169 | } |
| 170 | }; |
| 171 | |
| 172 | /** |
| 173 | * Shows and hides the overlay. Note that while visible == true, the overlay |
| 174 | * element will be tempoarily reparented to another place in the DOM. |
| 175 | */ |
| 176 | cr.defineProperty(Overlay, 'visible', cr.PropertyKind.BOOL_ATTR, |
| 177 | Overlay.prototype.onVisibleChanged_); |
| 178 | |
| 179 | return { |
| 180 | Overlay: Overlay |
| 181 | }; |
| 182 | }); |