/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview A plugin to enable the First Strong Bidi algorithm. The First
* Strong algorithm as a heuristic used to automatically set paragraph direction
* depending on its content.
*
* In the documentation below, a 'paragraph' is the local element which we
* evaluate as a whole for purposes of determining directionality. It may be a
* block-level element (e.g. <div>) or a whole list (e.g. <ul>).
*
* This implementation is based on, but is not identical to, the original
* First Strong algorithm defined in Unicode
* @see http://www.unicode.org/reports/tr9/
* The central difference from the original First Strong algorithm is that this
* implementation decides the paragraph direction based on the first strong
* character that is <em>typed</em> into the paragraph, regardless of its
* location in the paragraph, as opposed to the original algorithm where it is
* the first character in the paragraph <em>by location</em>, regardless of
* whether other strong characters already appear in the paragraph, further its
* start.
*
* <em>Please note</em> that this plugin does not perform the direction change
* itself. Rather, it fires editor commands upon the key up event when a
* direction change needs to be performed; `goog.editor.Command.DIR_RTL`
* or `goog.editor.Command.DIR_RTL`.
*/
goog.provide('goog.editor.plugins.FirstStrong');
goog.require('goog.dom.NodeType');
goog.require('goog.dom.TagIterator');
goog.require('goog.dom.TagName');
goog.require('goog.editor.Command');
goog.require('goog.editor.Field');
goog.require('goog.editor.Plugin');
goog.require('goog.editor.node');
goog.require('goog.editor.range');
goog.require('goog.i18n.bidi');
goog.require('goog.i18n.uChar');
goog.require('goog.iter');
goog.require('goog.userAgent');
/**
* First Strong plugin.
* @constructor
* @extends {goog.editor.Plugin}
* @final
*/
goog.editor.plugins.FirstStrong = function() {
'use strict';
goog.editor.plugins.FirstStrong.base(this, 'constructor');
/**
* Indicates whether or not the cursor is in a paragraph we have not yet
* finished evaluating for directionality. This is set to true whenever the
* cursor is moved, and set to false after seeing a strong character in the
* paragraph the cursor is currently in.
*
* @type {boolean}
* @private
*/
this.isNewBlock_ = true;
/**
* Indicates whether or not the current paragraph the cursor is in should be
* set to Right-To-Left directionality.
*
* @type {boolean}
* @private
*/
this.switchToRtl_ = false;
/**
* Indicates whether or not the current paragraph the cursor is in should be
* set to Left-To-Right directionality.
*
* @type {boolean}
* @private
*/
this.switchToLtr_ = false;
};
goog.inherits(goog.editor.plugins.FirstStrong, goog.editor.Plugin);
/** @override */
goog.editor.plugins.FirstStrong.prototype.getTrogClassId = function() {
'use strict';
return 'FirstStrong';
};
/** @override */
goog.editor.plugins.FirstStrong.prototype.queryCommandValue = function(
command) {
'use strict';
return false;
};
/** @override */
goog.editor.plugins.FirstStrong.prototype.handleSelectionChange = function(
e, node) {
'use strict';
this.isNewBlock_ = true;
return false;
};
/**
* The name of the attribute which records the input text.
*
* @type {string}
* @const
*/
goog.editor.plugins.FirstStrong.INPUT_ATTRIBUTE = 'fs-input';
/** @override */
goog.editor.plugins.FirstStrong.prototype.handleKeyPress = function(e) {
'use strict';
if (goog.editor.Field.SELECTION_CHANGE_KEYCODES[e.keyCode]) {
// Key triggered selection change event (e.g. on ENTER) is throttled and a
// later LTR/RTL strong keypress may come before it. Need to capture it.
this.isNewBlock_ = true;
return false; // A selection-changing key is not LTR/RTL strong.
}
if (!this.isNewBlock_) {
return false; // We've already determined this paragraph's direction.
}
// Ignore non-character key press events.
if (e.ctrlKey || e.metaKey) {
return false;
}
var newInput = goog.i18n.uChar.fromCharCode(e.charCode);
// IME's may return 0 for the charCode, which is a legitimate, non-Strong
// charCode, or they may return an illegal charCode (for which newInput will
// be false).
if (!newInput || !e.charCode) {
var browserEvent = e.getBrowserEvent();
if (browserEvent) {
if (goog.userAgent.IE && browserEvent['getAttribute']) {
newInput = browserEvent['getAttribute'](
goog.editor.plugins.FirstStrong.INPUT_ATTRIBUTE);
} else {
newInput =
browserEvent[goog.editor.plugins.FirstStrong.INPUT_ATTRIBUTE];
}
}
}
if (!newInput) {
return false; // Unrecognized key.
}
var isLtr = goog.i18n.bidi.isLtrChar(newInput);
var isRtl = !isLtr && goog.i18n.bidi.isRtlChar(newInput);
if (!isLtr && !isRtl) {
return false; // This character cannot change anything (it is not Strong).
}
// This character is Strongly LTR or Strongly RTL. We might switch direction
// on it now, but in any case we do not need to check any more characters in
// this paragraph after it.
this.isNewBlock_ = false;
// Are there no Strong characters already in the paragraph?
if (this.isNeutralBlock_()) {
this.switchToRtl_ = isRtl;
this.switchToLtr_ = isLtr;
}
return false;
};
/**
* Calls the flip directionality commands. This is done here so things go into
* the redo-undo stack at the expected order; fist enter the input, then flip
* directionality.
* @override
*/
goog.editor.plugins.FirstStrong.prototype.handleKeyUp = function(e) {
'use strict';
if (this.switchToRtl_) {
var field = this.getFieldObject();
field.dispatchChange(true);
field.execCommand(goog.editor.Command.DIR_RTL);
this.switchToRtl_ = false;
} else if (this.switchToLtr_) {
var field = this.getFieldObject();
field.dispatchChange(true);
field.execCommand(goog.editor.Command.DIR_LTR);
this.switchToLtr_ = false;
}
return false;
};
/**
* @return {Element} The lowest Block element ancestor of the node where the
* next character will be placed.
* @private
*/
goog.editor.plugins.FirstStrong.prototype.getBlockAncestor_ = function() {
'use strict';
var start = this.getFieldObject().getRange().getStartNode();
// Go up in the DOM until we reach a Block element.
while (!goog.editor.plugins.FirstStrong.isBlock_(start)) {
start = start.parentNode;
}
return /** @type {Element} */ (start);
};
/**
* @return {boolean} Whether the paragraph where the next character will be
* entered contains only non-Strong characters.
* @private
*/
goog.editor.plugins.FirstStrong.prototype.isNeutralBlock_ = function() {
'use strict';
var root = this.getBlockAncestor_();
// The exact node with the cursor location. Simply calling getStartNode() on
// the range only returns the containing block node.
var cursor =
goog.editor.range.getDeepEndPoint(this.getFieldObject().getRange(), false)
.node;
// In FireFox the BR tag also represents a change in paragraph if not inside a
// list. So we need special handling to only look at the sub-block between
// BR elements.
var blockFunction = (goog.userAgent.GECKO && !this.isList_(root)) ?
goog.editor.plugins.FirstStrong.isGeckoBlock_ :
goog.editor.plugins.FirstStrong.isBlock_;
var paragraph = this.getTextAround_(root, cursor, blockFunction);
// Not using `goog.i18n.bidi.isNeutralText` as it contains additional,
// unwanted checks to the content.
return !goog.i18n.bidi.hasAnyLtr(paragraph) &&
!goog.i18n.bidi.hasAnyRtl(paragraph);
};
/**
* Checks if an element is a list element ('UL' or 'OL').
*
* @param {Element} element The element to test.
* @return {boolean} Whether the element is a list element ('UL' or 'OL').
* @private
*/
goog.editor.plugins.FirstStrong.prototype.isList_ = function(element) {
'use strict';
if (!element) {
return false;
}
var tagName = element.tagName;
return tagName == goog.dom.TagName.UL || tagName == goog.dom.TagName.OL;
};
/**
* Returns the text within the local paragraph around the cursor.
* Notice that for GECKO a BR represents a pargraph change despite not being a
* block element.
*
* @param {Element} root The first block element ancestor of the node the cursor
* is in.
* @param {Node} cursorLocation Node where the cursor currently is, marking the
* paragraph whose text we will return.
* @param {function(Node): boolean} isParagraphBoundary The function to
* determine if a node represents the start or end of the paragraph.
* @return {string} the text in the paragraph around the cursor location.
* @private
*/
goog.editor.plugins.FirstStrong.prototype.getTextAround_ = function(
root, cursorLocation, isParagraphBoundary) {
'use strict';
// The buffer where we're collecting the text.
var buffer = [];
// Have we reached the cursor yet, or are we still before it?
var pastCursorLocation = false;
if (root && cursorLocation) {
goog.iter.some(new goog.dom.TagIterator(root), function(node) {
'use strict';
if (node == cursorLocation) {
pastCursorLocation = true;
} else if (isParagraphBoundary(node)) {
if (pastCursorLocation) {
// This is the end of the paragraph containing the cursor. We're done.
return true;
} else {
// All we collected so far does not count; it was in a previous
// paragraph that did not contain the cursor.
buffer = [];
}
}
if (node.nodeType == goog.dom.NodeType.TEXT) {
buffer.push(node.nodeValue);
}
return false; // Keep going.
});
}
return buffer.join('');
};
/**
* @param {Node} node Node to check.
* @return {boolean} Does the given node represent a Block element? Notice we do
* not consider list items as Block elements in the algorithm.
* @private
*/
goog.editor.plugins.FirstStrong.isBlock_ = function(node) {
'use strict';
return !!node && goog.editor.node.isBlockTag(node) &&
/** @type {!Element} */ (node).tagName != goog.dom.TagName.LI;
};
/**
* @param {Node} node Node to check.
* @return {boolean} Does the given node represent a Block element from the
* point of view of FireFox? Notice we do not consider list items as Block
* elements in the algorithm.
* @private
*/
goog.editor.plugins.FirstStrong.isGeckoBlock_ = function(node) {
'use strict';
return !!node &&
(/** @type {!Element} */ (node).tagName == goog.dom.TagName.BR ||
goog.editor.plugins.FirstStrong.isBlock_(node));
};
Codebase Browser
chromium