diff options
Diffstat (limited to 'ext/js/dom/dom-text-scanner.js')
| -rw-r--r-- | ext/js/dom/dom-text-scanner.js | 142 |
1 files changed, 69 insertions, 73 deletions
diff --git a/ext/js/dom/dom-text-scanner.js b/ext/js/dom/dom-text-scanner.js index a81d6b4f..fff08825 100644 --- a/ext/js/dom/dom-text-scanner.js +++ b/ext/js/dom/dom-text-scanner.js @@ -44,7 +44,7 @@ class DOMTextScanner { /** * Gets the current node being scanned. - * @returns A DOM Node. + * @type {Node} */ get node() { return this._node; @@ -53,7 +53,7 @@ class DOMTextScanner { /** * Gets the current offset corresponding to the node being scanned. * This value is only applicable for text nodes. - * @returns An integer. + * @type {number} */ get offset() { return this._offset; @@ -62,7 +62,7 @@ class DOMTextScanner { /** * Gets the remaining number of characters that weren't scanned in the last seek() call. * This value is usually 0 unless the end of the document was reached. - * @returns An integer. + * @type {number} */ get remainder() { return this._remainder; @@ -70,7 +70,7 @@ class DOMTextScanner { /** * Gets the accumulated content string resulting from calls to seek(). - * @returns A string. + * @type {string} */ get content() { return this._content; @@ -78,11 +78,11 @@ class DOMTextScanner { /** * Seeks a given length in the document and accumulates the text content. - * @param length A positive or negative integer corresponding to how many characters + * @param {number} length A positive or negative integer corresponding to how many characters * should be added to content. Content is only added to the accumulation string, * never removed, so mixing seek calls with differently signed length values * may give unexpected results. - * @returns this + * @returns {DOMTextScanner} this */ seek(length) { const forward = (length >= 0); @@ -114,7 +114,7 @@ class DOMTextScanner { } else if (nodeType === ELEMENT_NODE) { lastNode = node; this._offset = 0; - [enterable, newlines] = DOMTextScanner.getElementSeekInfo(node); + ({enterable, newlines} = DOMTextScanner.getElementSeekInfo(node)); if (newlines > this._newlines && generateLayoutContent) { this._newlines = newlines; } @@ -125,7 +125,7 @@ class DOMTextScanner { for (const exitedNode of exitedNodes) { if (exitedNode.nodeType !== ELEMENT_NODE) { continue; } - newlines = DOMTextScanner.getElementSeekInfo(exitedNode)[1]; + ({newlines} = DOMTextScanner.getElementSeekInfo(exitedNode)); if (newlines > this._newlines && generateLayoutContent) { this._newlines = newlines; } @@ -144,18 +144,14 @@ class DOMTextScanner { /** * Seeks forward in a text node. - * @param textNode The text node to use. - * @param resetOffset Whether or not the text offset should be reset. - * @returns true if scanning should continue, or false if the scan length has been reached. + * @param {Text} textNode The text node to use. + * @param {boolean} resetOffset Whether or not the text offset should be reset. + * @returns {boolean} `true` if scanning should continue, or `false` if the scan length has been reached. */ _seekTextNodeForward(textNode, resetOffset) { const nodeValue = textNode.nodeValue; const nodeValueLength = nodeValue.length; - const [preserveNewlines, preserveWhitespace] = ( - this._forcePreserveWhitespace ? - [true, true] : - DOMTextScanner.getWhitespaceSettings(textNode) - ); + const {preserveNewlines, preserveWhitespace} = this._getWhitespaceSettings(textNode); let lineHasWhitespace = this._lineHasWhitespace; let lineHasContent = this._lineHasContent; @@ -234,18 +230,14 @@ class DOMTextScanner { * - offset is decremented before getting the character. * - offset is reverted by incrementing instead of decrementing. * - content string is prepended instead of appended. - * @param textNode The text node to use. - * @param resetOffset Whether or not the text offset should be reset. - * @returns true if scanning should continue, or false if the scan length has been reached. + * @param {Text} textNode The text node to use. + * @param {boolean} resetOffset Whether or not the text offset should be reset. + * @returns {boolean} `true` if scanning should continue, or `false` if the scan length has been reached. */ _seekTextNodeBackward(textNode, resetOffset) { const nodeValue = textNode.nodeValue; const nodeValueLength = nodeValue.length; - const [preserveNewlines, preserveWhitespace] = ( - this._forcePreserveWhitespace ? - [true, true] : - DOMTextScanner.getWhitespaceSettings(textNode) - ); + const {preserveNewlines, preserveWhitespace} = this._getWhitespaceSettings(textNode); let lineHasWhitespace = this._lineHasWhitespace; let lineHasContent = this._lineHasContent; @@ -315,15 +307,41 @@ class DOMTextScanner { return (remainder > 0); } + /** + * Gets information about how whitespace characters are treated. + * @param {Text} textNode The text node to check. + * @returns {{preserveNewlines: boolean, preserveWhitespace: boolean}} Information about the whitespace. + * The value of `preserveNewlines` indicates whether or not newline characters are treated as line breaks. + * The value of `preserveWhitespace` indicates whether or not sequences of whitespace characters are collapsed. + */ + _getWhitespaceSettings(textNode) { + if (this._forcePreserveWhitespace) { + return {preserveNewlines: true, preserveWhitespace: true}; + } + const element = DOMTextScanner.getParentElement(textNode); + if (element !== null) { + const style = window.getComputedStyle(element); + switch (style.whiteSpace) { + case 'pre': + case 'pre-wrap': + case 'break-spaces': + return {preserveNewlines: true, preserveWhitespace: true}; + case 'pre-line': + return {preserveNewlines: true, preserveWhitespace: false}; + } + } + return {preserveNewlines: false, preserveWhitespace: false}; + } + // Static helpers /** * Gets the next node in the document for a specified scanning direction. - * @param node The current DOM Node. - * @param forward Whether to scan forward in the document or backward. - * @param visitChildren Whether the children of the current node should be visited. - * @param exitedNodes An array which stores nodes which were exited. - * @returns The next node in the document, or null if there is no next node. + * @param {Node} node The current DOM Node. + * @param {boolean} forward Whether to scan forward in the document or backward. + * @param {boolean} visitChildren Whether the children of the current node should be visited. + * @param {Node[]} exitedNodes An array which stores nodes which were exited. + * @returns {?Node} The next node in the document, or `null` if there is no next node. */ static getNextNode(node, forward, visitChildren, exitedNodes) { let next = visitChildren ? (forward ? node.firstChild : node.lastChild) : null; @@ -345,8 +363,8 @@ class DOMTextScanner { /** * Gets the parent element of a given Node. - * @param node The node to check. - * @returns The parent element if one exists, otherwise null. + * @param {Node} node The node to check. + * @returns {?Node} The parent element if one exists, otherwise `null`. */ static getParentElement(node) { while (node !== null && node.nodeType !== Node.ELEMENT_NODE) { @@ -359,8 +377,8 @@ class DOMTextScanner { * Gets the parent <ruby> element of a given node, if one exists. For efficiency purposes, * this only checks the immediate parent elements and does not check all ancestors, so * there are cases where the node may be in a ruby element but it is not returned. - * @param node The node to check. - * @returns A <ruby> node if the input node is contained in one, otherwise null. + * @param {Node} node The node to check. + * @returns {?HTMLElement} A <ruby> node if the input node is contained in one, otherwise `null`. */ static getParentRubyElement(node) { node = DOMTextScanner.getParentElement(node); @@ -374,9 +392,10 @@ class DOMTextScanner { } /** - * @returns [enterable: boolean, newlines: integer] - * The enterable value indicates whether the content of this node should be entered. - * The newlines value corresponds to the number of newline characters that should be added. + * Gets seek information about an element. + * @returns {{enterable: boolean, newlines: number}} The seek information. + * The `enterable` value indicates whether the content of this node should be entered. + * The `newlines` value corresponds to the number of newline characters that should be added. * 1 newline corresponds to a simple new line in the layout. * 2 newlines corresponds to a significant visual distinction since the previous content. */ @@ -387,9 +406,9 @@ class DOMTextScanner { case 'RT': case 'SCRIPT': case 'STYLE': - return [false, 0]; + return {enterable: false, newlines: 0}; case 'BR': - return [false, 1]; + return {enterable: false, newlines: 1}; case 'TEXTAREA': case 'INPUT': case 'BUTTON': @@ -418,36 +437,13 @@ class DOMTextScanner { } } - return [enterable, newlines]; - } - - /** - * Gets information about how whitespace characters are treated. - * @param textNode The Text node to check. - * @returns [preserveNewlines: boolean, preserveWhitespace: boolean] - * The value of preserveNewlines indicates whether or not newline characters are treated as line breaks. - * The value of preserveWhitespace indicates whether or not sequences of whitespace characters are collapsed. - */ - static getWhitespaceSettings(textNode) { - const element = DOMTextScanner.getParentElement(textNode); - if (element !== null) { - const style = window.getComputedStyle(element); - switch (style.whiteSpace) { - case 'pre': - case 'pre-wrap': - case 'break-spaces': - return [true, true]; - case 'pre-line': - return [true, false]; - } - } - return [false, false]; + return {enterable, newlines}; } /** * Gets attributes for the specified character. - * @param character A string containing a single character. - * @returns An integer representing the attributes of the character. + * @param {string} character A string containing a single character. + * @returns {number} An integer representing the attributes of the character. * 0: Character should be ignored. * 1: Character is collapsible whitespace. * 2: Character should be added to the content. @@ -472,9 +468,9 @@ class DOMTextScanner { /** * Checks whether a given style is visible or not. - * This function does not check style.display === 'none'. - * @param style An object implementing the CSSStyleDeclaration interface. - * @returns true if the style should result in an element being visible, otherwise false. + * This function does not check `style.display === 'none'`. + * @param {CSSStyleDeclaration} style An object implementing the CSSStyleDeclaration interface. + * @returns {boolean} `true` if the style should result in an element being visible, otherwise `false`. */ static isStyleVisible(style) { return !( @@ -493,8 +489,8 @@ class DOMTextScanner { /** * Checks whether a given style is selectable or not. - * @param style An object implementing the CSSStyleDeclaration interface. - * @returns true if the style is selectable, otherwise false. + * @param {CSSStyleDeclaration} style An object implementing the CSSStyleDeclaration interface. + * @returns {boolean} `true` if the style is selectable, otherwise `false`. */ static isStyleSelectable(style) { return !( @@ -507,8 +503,8 @@ class DOMTextScanner { /** * Checks whether a CSS color is transparent or not. - * @param cssColor A CSS color string, expected to be encoded in rgb(a) form. - * @returns true if the color is transparent, otherwise false. + * @param {string} cssColor A CSS color string, expected to be encoded in rgb(a) form. + * @returns {false} `true` if the color is transparent, otherwise `false`. */ static isCSSColorTransparent(cssColor) { return ( @@ -520,8 +516,8 @@ class DOMTextScanner { /** * Checks whether a CSS display value will cause a layout change for text. - * @param cssDisplay A CSS string corresponding to the value of the display property. - * @returns true if the layout is changed by this value, otherwise false. + * @param {string} cssDisplay A CSS string corresponding to the value of the display property. + * @returns {boolean} `true` if the layout is changed by this value, otherwise `false`. */ static doesCSSDisplayChangeLayout(cssDisplay) { let pos = cssDisplay.indexOf(' '); |