/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview Utilties for working with the styles of DOM nodes, and
* related to rich text editing.
*
* Many of these are not general enough to go into goog.style, and use
* constructs (like "isContainer") that only really make sense inside
* of an HTML editor.
*
* The API has been optimized for iterating over large, irregular DOM
* structures (with lots of text nodes), and so the API tends to be a bit
* more permissive than the goog.style API should be. For example,
* goog.style.getComputedStyle will throw an exception if you give it a
* text node.
*/
goog.provide('goog.editor.style');
goog.require('goog.asserts');
goog.require('goog.dom');
goog.require('goog.dom.NodeType');
goog.require('goog.dom.TagName');
goog.require('goog.editor.BrowserFeature');
goog.require('goog.events.EventHandler');
goog.require('goog.events.EventType');
goog.require('goog.object');
goog.require('goog.style');
goog.require('goog.userAgent');
goog.requireType('goog.events.Event');
/**
* Gets the computed or cascaded style.
*
* This is different than goog.style.getStyle_ because it returns null
* for text nodes (instead of throwing an exception), and never reads
* inline style. These two functions may need to be reconciled.
*
* @param {!Node} node Node to get style of.
* @param {string} stylePropertyName Property to get (must be camelCase,
* not css-style).
* @return {?string} Style value, or null if this is not an element node.
* @private
*/
goog.editor.style.getComputedOrCascadedStyle_ = function(
node, stylePropertyName) {
'use strict';
if (node.nodeType != goog.dom.NodeType.ELEMENT) {
// Only element nodes have style.
return null;
}
return goog.userAgent.IE ?
goog.style.getCascadedStyle(
/** @type {!Element} */ (node), stylePropertyName) :
goog.style.getComputedStyle(
/** @type {!Element} */ (node), stylePropertyName);
};
/**
* Checks whether the given element inherits display: block.
* @param {!Node} node The Node to check.
* @return {boolean} Whether the element inherits CSS display: block.
*/
goog.editor.style.isDisplayBlock = function(node) {
'use strict';
return goog.editor.style.getComputedOrCascadedStyle_(node, 'display') ==
'block';
};
/**
* Returns true if the element is a container of other non-inline HTML
* Note that span, strong and em tags, being inline can only contain
* other inline elements and are thus, not containers. Containers are elements
* that should not be broken up when wrapping selections with a node of an
* inline block styling.
* @param {Node} element The element to check.
* @return {boolean} Whether the element is a container.
*/
goog.editor.style.isContainer = function(element) {
'use strict';
var nodeName = element && element.nodeName;
return !!(
element &&
(goog.editor.style.isDisplayBlock(element) ||
nodeName == goog.dom.TagName.TD || nodeName == goog.dom.TagName.TABLE ||
nodeName == goog.dom.TagName.LI));
};
/**
* Return the first ancestor of this node that is a container, inclusive.
* @see isContainer
* @param {Node} node Node to find the container of.
* @return {Element} The element which contains node.
*/
goog.editor.style.getContainer = function(node) {
'use strict';
// We assume that every node must have a container.
return /** @type {Element} */ (
goog.dom.getAncestor(node, goog.editor.style.isContainer, true));
};
/**
* Set of input types that should be kept selectable even when their ancestors
* are made unselectable.
* @type {Object}
* @private
*/
goog.editor.style.SELECTABLE_INPUT_TYPES_ =
goog.object.createSet('text', 'file', 'url');
/**
* Prevent the default action on mousedown events.
* @param {goog.events.Event} e The mouse down event.
* @private
* @suppress {strictMissingProperties} Part of the go/strict_warnings_migration
*/
goog.editor.style.cancelMouseDownHelper_ = function(e) {
'use strict';
var targetTagName = e.target.tagName;
if (targetTagName != goog.dom.TagName.TEXTAREA &&
targetTagName != goog.dom.TagName.INPUT) {
e.preventDefault();
}
};
/**
* Makes the given element unselectable, as well as all of its children, except
* for text areas, text, file and url inputs.
* @param {Element} element The element to make unselectable.
* @param {goog.events.EventHandler} eventHandler An EventHandler to register
* the event with. Assumes when the node is destroyed, the eventHandler's
* listeners are destroyed as well.
*/
goog.editor.style.makeUnselectable = function(element, eventHandler) {
'use strict';
if (goog.editor.BrowserFeature.HAS_UNSELECTABLE_STYLE) {
// The mousing down on a node should not blur the focused node.
// This is consistent with how IE works.
// TODO: Consider using just the mousedown handler and not the css property.
eventHandler.listen(
element, goog.events.EventType.MOUSEDOWN,
goog.editor.style.cancelMouseDownHelper_, true);
}
goog.style.setUnselectable(element, true);
// Make inputs and text areas selectable.
var inputs = goog.dom.getElementsByTagName(
goog.dom.TagName.INPUT, goog.asserts.assert(element));
for (var i = 0, len = inputs.length; i < len; i++) {
var input = inputs[i];
if (input.type in goog.editor.style.SELECTABLE_INPUT_TYPES_) {
goog.editor.style.makeSelectable(input);
}
}
Array.prototype.forEach.call(
goog.dom.getElementsByTagName(
goog.dom.TagName.TEXTAREA, goog.asserts.assert(element)),
goog.editor.style.makeSelectable);
};
/**
* Make the given element selectable.
*
* For IE this simply turns off the "unselectable" property.
*
* Under FF no descendant of an unselectable node can be selectable:
*
* https://bugzilla.mozilla.org/show_bug.cgi?id=203291
*
* So we make each ancestor of node selectable, while trying to preserve the
* unselectability of other nodes along that path
*
* This may cause certain text nodes which should be unselectable, to become
* selectable. For example:
*
* <div id=div1 style="-moz-user-select: none">
* Text1
* <span id=span1>Text2</span>
* </div>
*
* If we call makeSelectable on span1, then it will cause "Text1" to become
* selectable, since it had to make div1 selectable in order for span1 to be
* selectable.
*
* If "Text1" were enclosed within a `<p>` or `<span>`, then this problem would
* not arise. Text nodes do not have styles, so its style can't be set to
* unselectable.
*
* @param {!Element} element The element to make selectable.
*/
goog.editor.style.makeSelectable = function(element) {
'use strict';
goog.style.setUnselectable(element, false);
if (goog.editor.BrowserFeature.HAS_UNSELECTABLE_STYLE) {
// Go up ancestor chain, searching for nodes that are unselectable.
// If such a node exists, mark it as selectable but mark its other children
// as unselectable so the minimum set of nodes is changed.
var child = element;
var current = /** @type {Element} */ (element.parentNode);
while (current && current.tagName != goog.dom.TagName.HTML) {
if (goog.style.isUnselectable(current)) {
goog.style.setUnselectable(current, false, true);
for (var i = 0, len = current.childNodes.length; i < len; i++) {
var node = current.childNodes[i];
if (node != child && node.nodeType == goog.dom.NodeType.ELEMENT) {
goog.style.setUnselectable(
/** @type {!Element} */ (current.childNodes[i]), true);
}
}
}
child = current;
current = /** @type {Element} */ (current.parentNode);
}
}
};