qutebrowser/qutebrowser/javascript/caret.js

1410 lines
49 KiB
JavaScript

/* eslint-disable max-len, max-statements, complexity,
default-case, valid-jsdoc */
// Copyright 2014 The Chromium Authors. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
/**
* Copyright 2018 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
*
* This file is part of qutebrowser.
*
* qutebrowser is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* qutebrowser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with qutebrowser. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Ported chrome-caretbrowsing extension.
* https://cs.chromium.org/chromium/src/ui/accessibility/extensions/caretbrowsing/
*
* The behavior is based on Mozilla's spec whenever possible:
* http://www.mozilla.org/access/keyboard/proposal
*
* The one exception is that Esc is used to escape out of a form control,
* rather than their proposed key (which doesn't seem to work in the
* latest Firefox anyway).
*
* Some details about how Chrome selection works, which will help in
* understanding the code:
*
* The Selection object (window.getSelection()) has four components that
* completely describe the state of the caret or selection:
*
* base and anchor: this is the start of the selection, the fixed point.
* extent and focus: this is the end of the selection, the part that
* moves when you hold down shift and press the left or right arrows.
*
* When the selection is a cursor, the base, anchor, extent, and focus are
* all the same.
*
* There's only one time when the base and anchor are not the same, or the
* extent and focus are not the same, and that's when the selection is in
* an ambiguous state - i.e. it's not clear which edge is the focus and which
* is the anchor. As an example, if you double-click to select a word, then
* the behavior is dependent on your next action. If you press Shift+Right,
* the right edge becomes the focus. But if you press Shift+Left, the left
* edge becomes the focus.
*
* When the selection is in an ambiguous state, the base and extent are set
* to the position where the mouse clicked, and the anchor and focus are set
* to the boundaries of the selection.
*
* The only way to set the selection and give it direction is to use
* the non-standard Selection.setBaseAndExtent method. If you try to use
* Selection.addRange(), the anchor will always be on the left and the focus
* will always be on the right, making it impossible to manipulate
* selections that move from right to left.
*
* Finally, Chrome will throw an exception if you try to set an invalid
* selection - a selection where the left and right edges are not the same,
* but it doesn't span any visible characters. A common example is that
* there are often many whitespace characters in the DOM that are not
* visible on the page; trying to select them will fail. Another example is
* any node that's invisible or not displayed.
*
* While there are probably many possible methods to determine what is
* selectable, this code uses the method of determining if there's a valid
* bounding box for the range or not - keep moving the cursor forwards until
* the range from the previous position and candidate next position has a
* valid bounding box.
*/
"use strict";
window._qutebrowser.caret = (function() {
function isElementInViewport(node) {
let i;
let boundingRect = (node.getClientRects()[0] ||
node.getBoundingClientRect());
if (boundingRect.width <= 1 && boundingRect.height <= 1) {
const rects = node.getClientRects();
for (i = 0; i < rects.length; i++) {
if (rects[i].width > rects[0].height &&
rects[i].height > rects[0].height) {
boundingRect = rects[i];
}
}
}
if (boundingRect === undefined) {
return null;
}
if (boundingRect.top > innerHeight || boundingRect.left > innerWidth) {
return null;
}
if (boundingRect.width <= 1 || boundingRect.height <= 1) {
const children = node.children;
let visibleChildNode = false;
for (i = 0; i < children.length; ++i) {
boundingRect = (children[i].getClientRects()[0] ||
children[i].getBoundingClientRect());
if (boundingRect.width > 1 && boundingRect.height > 1) {
visibleChildNode = true;
break;
}
}
if (visibleChildNode === false) {
return null;
}
}
if (boundingRect.top + boundingRect.height < 10 ||
boundingRect.left + boundingRect.width < -10) {
return null;
}
const computedStyle = window.getComputedStyle(node, null);
if (computedStyle.visibility !== "visible" ||
computedStyle.display === "none" ||
node.hasAttribute("disabled") ||
parseInt(computedStyle.width, 10) === 0 ||
parseInt(computedStyle.height, 10) === 0) {
return null;
}
return boundingRect.top >= -20;
}
function positionCaret() {
const walker = document.createTreeWalker(document.body, -1);
let node;
const textNodes = [];
let el;
while ((node = walker.nextNode())) {
if (node.nodeType === 3 && node.nodeValue.trim() !== "") {
textNodes.push(node);
}
}
for (let i = 0; i < textNodes.length; i++) {
const element = textNodes[i].parentElement;
if (isElementInViewport(element)) {
el = element;
break;
}
}
if (el !== undefined) {
/* eslint-disable no-use-before-define */
const start = new Cursor(el, 0, "");
const end = new Cursor(el, 0, "");
const nodesCrossed = [];
const result = TraverseUtil.getNextChar(
start, end, nodesCrossed, true);
if (result === null) {
return;
}
CaretBrowsing.setAndValidateSelection(start, start);
/* eslint-enable no-use-before-define */
}
}
/**
* Return whether a node is focusable. This includes nodes whose tabindex
* attribute is set to "-1" explicitly - these nodes are not in the tab
* order, but they should still be focused if the user navigates to them
* using linear or smart DOM navigation.
*
* Note that when the tabIndex property of an Element is -1, that doesn't
* tell us whether the tabIndex attribute is missing or set to "-1" explicitly,
* so we have to check the attribute.
*
* @param {Object} targetNode The node to check if it's focusable.
* @return {boolean} True if the node is focusable.
*/
function isFocusable(targetNode) {
if (!targetNode || typeof (targetNode.tabIndex) !== "number") {
return false;
}
if (targetNode.tabIndex >= 0) {
return true;
}
if (targetNode.hasAttribute &&
targetNode.hasAttribute("tabindex") &&
targetNode.getAttribute("tabindex") === "-1") {
return true;
}
return false;
}
const axs = {};
axs.dom = {};
axs.color = {};
axs.utils = {};
axs.dom.parentElement = function(node) {
if (!node) {
return null;
}
const composedNode = axs.dom.composedParentNode(node);
if (!composedNode) {
return null;
}
switch (composedNode.nodeType) {
case Node.ELEMENT_NODE:
return composedNode;
default:
return axs.dom.parentElement(composedNode);
}
};
axs.dom.shadowHost = function(node) {
if ("host" in node) {
return node.host;
}
return null;
};
axs.dom.composedParentNode = function(node) {
if (!node) {
return null;
}
if (node.nodeType === Node.DOCUMENT_FRAGMENT_NODE) {
return axs.dom.shadowHost(node);
}
const parentNode = node.parentNode;
if (!parentNode) {
return null;
}
if (parentNode.nodeType === Node.DOCUMENT_FRAGMENT_NODE) {
return axs.dom.shadowHost(parentNode);
}
if (!parentNode.shadowRoot) {
return parentNode;
}
const points = node.getDestinationInsertionPoints();
if (points.length > 0) {
return axs.dom.composedParentNode(points[points.length - 1]);
}
return null;
};
axs.color.Color = function(red, green, blue, alpha) {
this.red = red;
this.green = green;
this.blue = blue;
this.alpha = alpha;
};
axs.color.parseColor = function(colorText) {
if (colorText === "transparent") {
return new axs.color.Color(0, 0, 0, 0);
}
let match = colorText.match(/^rgb\((\d+), (\d+), (\d+)\)$/);
if (match) {
const blue = parseInt(match[3], 10);
const green = parseInt(match[2], 10);
const red = parseInt(match[1], 10);
return new axs.color.Color(red, green, blue, 1);
}
match = colorText.match(/^rgba\((\d+), (\d+), (\d+), (\d*(\.\d+)?)\)/);
if (match) {
const red = parseInt(match[1], 10);
const green = parseInt(match[2], 10);
const blue = parseInt(match[3], 10);
const alpha = parseFloat(match[4]);
return new axs.color.Color(red, green, blue, alpha);
}
return null;
};
axs.color.flattenColors = function(color1, color2) {
const colorAlpha = color1.alpha;
return new axs.color.Color(
((1 - colorAlpha) * color2.red) + (colorAlpha * color1.red),
((1 - colorAlpha) * color2.green) + (colorAlpha * color1.green),
((1 - colorAlpha) * color2.blue) + (colorAlpha * color2.blue),
color1.alpha + (color2.alpha * (1 - color1.alpha)));
};
axs.utils.getParentBgColor = function(_el) {
let el = _el;
let el2 = el;
let iter = null;
el = [];
for (iter = null; (el2 = axs.dom.parentElement(el2));) {
const style = window.getComputedStyle(el2, null);
if (style) {
const color = axs.color.parseColor(style.backgroundColor);
if (color &&
(style.opacity < 1 &&
(color.alpha *= style.opacity), color.alpha !== 0 &&
(el.push(color), color.alpha === 1))) {
iter = !0;
break;
}
}
}
if (!iter) {
el.push(new axs.color.Color(255, 255, 255, 1));
}
for (el2 = el.pop(); el.length;) {
iter = el.pop();
el2 = axs.color.flattenColors(iter, el2);
}
return el2;
};
axs.utils.getFgColor = function(el, el2, color) {
let color2 = axs.color.parseColor(el.color);
if (!color2) {
return null;
}
if (color2.alpha < 1) {
color2 = axs.color.flattenColors(color2, color);
}
if (el.opacity < 1) {
const el3 = axs.utils.getParentBgColor(el2);
color2.alpha *= el.opacity;
color2 = axs.color.flattenColors(color2, el3);
}
return color2;
};
axs.utils.getBgColor = function(el, elParent) {
let color = axs.color.parseColor(el.backgroundColor);
if (!color) {
return null;
}
if (el.opacity < 1) {
color.alpha *= el.opacity;
}
if (color.alpha < 1) {
const bgColor = axs.utils.getParentBgColor(elParent);
if (bgColor === null) {
return null;
}
color = axs.color.flattenColors(color, bgColor);
}
return color;
};
axs.color.colorChannelToString = function(_color) {
const color = Math.round(_color);
if (color < 15) {
return `0${color.toString(16)}`;
}
return color.toString(16);
};
axs.color.colorToString = function(color) {
if (color.alpha === 1) {
const red = axs.color.colorChannelToString(color.red);
const green = axs.color.colorChannelToString(color.green);
const blue = axs.color.colorChannelToString(color.blue);
return `#${red}${green}${blue}`;
}
const arr = [color.red, color.green, color.blue, color.alpha].join();
return `rgba(${arr})`;
};
/**
* A class to represent a cursor location in the document,
* like the start position or end position of a selection range.
*
* Later this may be extended to support "virtual text" for an object,
* like the ALT text for an image.
*
* Note: we cache the text of a particular node at the time we
* traverse into it. Later we should add support for dynamically
* reloading it.
* @param {Node} node The DOM node.
* @param {number} index The index of the character within the node.
* @param {string} text The cached text contents of the node.
* @constructor
*/
// eslint-disable-next-line func-style
const Cursor = function(node, index, text) {
this.node = node;
this.index = index;
this.text = text;
};
/**
* @return {Cursor} A new cursor pointing to the same location.
*/
Cursor.prototype.clone = function() {
return new Cursor(this.node, this.index, this.text);
};
/**
* Modify this cursor to point to the location that another cursor points to.
* @param {Cursor} otherCursor The cursor to copy from.
*/
Cursor.prototype.copyFrom = function(otherCursor) {
this.node = otherCursor.node;
this.index = otherCursor.index;
this.text = otherCursor.text;
};
/**
* Utility functions for stateless DOM traversal.
* @constructor
*/
const TraverseUtil = {};
/**
* Gets the text representation of a node. This allows us to substitute
* alt text, names, or titles for html elements that provide them.
* @param {Node} node A DOM node.
* @return {string} A text string representation of the node.
*/
TraverseUtil.getNodeText = function(node) {
if (node.constructor === Text) {
return node.data;
}
return "";
};
/**
* Return true if a node should be treated as a leaf node, because
* its children are properties of the object that shouldn't be traversed.
*
* TODO(dmazzoni): replace this with a predicate that detects nodes with
* ARIA roles and other objects that have their own description.
* For now we just detect a couple of common cases.
*
* @param {Node} node A DOM node.
* @return {boolean} True if the node should be treated as a leaf node.
*/
TraverseUtil.treatAsLeafNode = function(node) {
return node.childNodes.length === 0 ||
node.nodeName === "SELECT" ||
node.nodeName === "OBJECT";
};
/**
* Return true only if a single character is whitespace.
* From https://developer.mozilla.org/en/Whitespace_in_the_DOM,
* whitespace is defined as one of the characters
* "\t" TAB \u0009
* "\n" LF \u000A
* "\r" CR \u000D
* " " SPC \u0020.
*
* @param {string} c A string containing a single character.
* @return {boolean} True if the character is whitespace, otherwise false.
*/
TraverseUtil.isWhitespace = function(ch) {
return (ch === " " || ch === "\n" || ch === "\r" || ch === "\t");
};
/**
* Use the computed CSS style to figure out if this DOM node is currently
* visible.
* @param {Node} node A HTML DOM node.
* @return {boolean} Whether or not the html node is visible.
*/
TraverseUtil.isVisible = function(node) {
if (!node.style) {
return true;
}
const style = window.getComputedStyle(node, null);
return (Boolean(style) &&
style.display !== "none" &&
style.visibility !== "hidden");
};
/**
* Use the class name to figure out if this DOM node should be traversed.
* @param {Node} node A HTML DOM node.
* @return {boolean} Whether or not the html node should be traversed.
*/
TraverseUtil.isSkipped = function(_node) {
let node = _node;
if (node.constructor === Text) {
node = node.parentElement;
}
if (node.className === "CaretBrowsing_Caret") {
return true;
}
return false;
};
/**
* Moves the cursor forwards until it has crossed exactly one character.
* @param {Cursor} cursor The cursor location where the search should start.
* On exit, the cursor will be immediately to the right of the
* character returned.
* @param {Array<Node>} nodesCrossed Any HTML nodes crossed between the
* initial and final cursor position will be pushed onto this array.
* @return {?string} The character found, or null if the bottom of the
* document has been reached.
*/
TraverseUtil.forwardsChar = function(cursor, nodesCrossed) {
for (;;) {
let childNode = null;
if (!TraverseUtil.treatAsLeafNode(cursor.node)) {
for (let i = cursor.index;
i < cursor.node.childNodes.length;
i++) {
const node = cursor.node.childNodes[i];
if (TraverseUtil.isSkipped(node)) {
nodesCrossed.push(node);
} else if (TraverseUtil.isVisible(node)) {
childNode = node;
break;
}
}
}
if (childNode) {
cursor.node = childNode;
cursor.index = 0;
cursor.text = TraverseUtil.getNodeText(cursor.node);
if (cursor.node.constructor !== Text) {
nodesCrossed.push(cursor.node);
}
} else {
// Return the next character from this leaf node.
if (cursor.index < cursor.text.length) {
return cursor.text[cursor.index++];
}
// Move to the next sibling, going up the tree as necessary.
while (cursor.node !== null) {
// Try to move to the next sibling.
let siblingNode = null;
for (let node = cursor.node.nextSibling;
node !== null;
node = node.nextSibling) {
if (TraverseUtil.isSkipped(node)) {
nodesCrossed.push(node);
} else if (TraverseUtil.isVisible(node)) {
siblingNode = node;
break;
}
}
if (siblingNode) {
cursor.node = siblingNode;
cursor.text = TraverseUtil.getNodeText(siblingNode);
cursor.index = 0;
if (cursor.node.constructor !== Text) {
nodesCrossed.push(cursor.node);
}
break;
}
// Otherwise, move to the parent.
const parentNode = cursor.node.parentNode;
if (parentNode &&
parentNode.constructor !== HTMLBodyElement) {
cursor.node = cursor.node.parentNode;
cursor.text = null;
cursor.index = 0;
} else {
return null;
}
}
}
}
};
/**
* Finds the next character, starting from endCursor. Upon exit, startCursor
* and endCursor will surround the next character. If skipWhitespace is
* true, will skip until a real character is found. Otherwise, it will
* attempt to select all of the whitespace between the initial position
* of endCursor and the next non-whitespace character.
* @param {Cursor} startCursor On exit, points to the position before
* the char.
* @param {Cursor} endCursor The position to start searching for the next
* char. On exit, will point to the position past the char.
* @param {Array<Node>} nodesCrossed Any HTML nodes crossed between the
* initial and final cursor position will be pushed onto this array.
* @param {boolean} skipWhitespace If true, will keep scanning until a
* non-whitespace character is found.
* @return {?string} The next char, or null if the bottom of the
* document has been reached.
*/
TraverseUtil.getNextChar = function(
startCursor, endCursor, nodesCrossed, skipWhitespace) {
// Save the starting position and get the first character.
startCursor.copyFrom(endCursor);
let fChar = TraverseUtil.forwardsChar(endCursor, nodesCrossed);
if (fChar === null) {
return null;
}
// Keep track of whether the first character was whitespace.
const initialWhitespace = TraverseUtil.isWhitespace(fChar);
// Keep scanning until we find a non-whitespace or non-skipped character.
while ((TraverseUtil.isWhitespace(fChar)) ||
(TraverseUtil.isSkipped(endCursor.node))) {
fChar = TraverseUtil.forwardsChar(endCursor, nodesCrossed);
if (fChar === null) {
return null;
}
}
if (skipWhitespace || !initialWhitespace) {
// If skipWhitepace is true, or if the first character we encountered
// was not whitespace, return that non-whitespace character.
startCursor.copyFrom(endCursor);
startCursor.index--;
return fChar;
}
for (let i = 0; i < nodesCrossed.length; i++) {
if (TraverseUtil.isSkipped(nodesCrossed[i])) {
// We need to make sure that startCursor and endCursor aren't
// surrounding a skippable node.
endCursor.index--;
startCursor.copyFrom(endCursor);
startCursor.index--;
return " ";
}
}
// Otherwise, return all of the whitespace before that last character.
endCursor.index--;
return " ";
};
/**
* The class handling the Caret Browsing implementation in the page.
* Sets up communication with the background page, and then when caret
* browsing is enabled, response to various key events to move the caret
* or selection within the text content of the document.
* @constructor
*/
const CaretBrowsing = {};
/**
* Is caret browsing enabled?
* @type {boolean}
*/
CaretBrowsing.isEnabled = false;
/**
* Keep it enabled even when flipped off (for the options page)?
* @type {boolean}
*/
CaretBrowsing.forceEnabled = false;
/**
* What to do when the caret appears?
* @type {string}
*/
CaretBrowsing.onEnable = undefined;
/**
* What to do when the caret jumps?
* @type {string}
*/
CaretBrowsing.onJump = undefined;
/**
* Is this window / iframe focused? We won't show the caret if not,
* especially so that carets aren't shown in two iframes of the same
* tab.
* @type {boolean}
*/
CaretBrowsing.isWindowFocused = false;
/**
* Is the caret actually visible? This is true only if isEnabled and
* isWindowFocused are both true.
* @type {boolean}
*/
CaretBrowsing.isCaretVisible = false;
/**
* The actual caret element, an absolute-positioned flashing line.
* @type {Element}
*/
CaretBrowsing.caretElement = undefined;
/**
* The x-position of the caret, in absolute pixels.
* @type {number}
*/
CaretBrowsing.caretX = 0;
/**
* The y-position of the caret, in absolute pixels.
* @type {number}
*/
CaretBrowsing.caretY = 0;
/**
* The width of the caret in pixels.
* @type {number}
*/
CaretBrowsing.caretWidth = 0;
/**
* The height of the caret in pixels.
* @type {number}
*/
CaretBrowsing.caretHeight = 0;
/**
* The foregroundc color.
* @type {string}
*/
CaretBrowsing.caretForeground = "#000";
/**
* The backgroundc color.
* @type {string}
*/
CaretBrowsing.caretBackground = "#fff";
/**
* Is the selection collapsed, i.e. are the start and end locations
* the same? If so, our blinking caret image is shown; otherwise
* the Chrome selection is shown.
* @type {boolean}
*/
CaretBrowsing.isSelectionCollapsed = false;
/**
* The id returned by window.setInterval for our blink function, so
* we can cancel it when caret browsing is disabled.
* @type {number?}
*/
CaretBrowsing.blinkFunctionId = null;
/**
* The desired x-coordinate to match when moving the caret up and down.
* To match the behavior as documented in Mozilla's caret browsing spec
* (http://www.mozilla.org/access/keyboard/proposal), we keep track of the
* initial x position when the user starts moving the caret up and down,
* so that the x position doesn't drift as you move throughout lines, but
* stays as close as possible to the initial position. This is reset when
* moving left or right or clicking.
* @type {number?}
*/
CaretBrowsing.targetX = null;
/**
* A flag that flips on or off as the caret blinks.
* @type {boolean}
*/
CaretBrowsing.blinkFlag = true;
/**
* Whether we're running on Windows.
* @type {boolean}
*/
CaretBrowsing.isWindows = null;
/**
* Whether we're running on on old Qt 5.7.1.
* @type {boolean}
*/
CaretBrowsing.isOldQt = null;
/**
* Check if a node is a control that normally allows the user to interact
* with it using arrow keys. We won't override the arrow keys when such a
* control has focus, the user must press Escape to do caret browsing outside
* that control.
* @param {Node} node A node to check.
* @return {boolean} True if this node is a control that the user can
* interact with using arrow keys.
*/
CaretBrowsing.isControlThatNeedsArrowKeys = function(node) {
if (!node) {
return false;
}
if (node === document.body || node !== document.activeElement) {
return false;
}
if (node.constructor === HTMLSelectElement) {
return true;
}
if (node.constructor === HTMLInputElement) {
switch (node.type) {
case "email":
case "number":
case "password":
case "search":
case "text":
case "tel":
case "url":
case "":
return true; // All of these are text boxes.
case "datetime":
case "datetime-local":
case "date":
case "month":
case "radio":
case "range":
case "week":
return true; // These are other input elements that use arrows.
}
}
// Handle focusable ARIA controls.
if (node.getAttribute && isFocusable(node)) {
const role = node.getAttribute("role");
switch (role) {
case "combobox":
case "grid":
case "gridcell":
case "listbox":
case "menu":
case "menubar":
case "menuitem":
case "menuitemcheckbox":
case "menuitemradio":
case "option":
case "radiogroup":
case "scrollbar":
case "slider":
case "spinbutton":
case "tab":
case "tablist":
case "textbox":
case "tree":
case "treegrid":
case "treeitem":
return true;
}
}
return false;
};
CaretBrowsing.injectCaretStyles = function() {
const prefix = CaretBrowsing.isOldQt ? "-webkit-" : "";
const style = `
.CaretBrowsing_Caret {
position: absolute;
z-index: 2147483647;
min-height: 1em;
min-width: 0.2em;
animation: blink 1s step-end infinite;
--inherited-color: inherit;
background-color: var(--inherited-color, #000);
color: var(--inherited-color, #000);
mix-blend-mode: difference;
${prefix}filter: invert(85%);
}
@keyframes blink {
50% { visibility: hidden; }
}
`;
const node = document.createElement("style");
node.innerHTML = style;
document.body.appendChild(node);
};
/**
* If there's no initial selection, set the cursor just before the
* first text character in the document.
*/
CaretBrowsing.setInitialCursor = function() {
const selectionRange = window.getSelection().toString().length;
if (selectionRange === 0) {
positionCaret();
}
CaretBrowsing.injectCaretStyles();
CaretBrowsing.toggle();
CaretBrowsing.initiated = true;
CaretBrowsing.selectionEnabled = selectionRange > 0;
};
/**
* Try to set the window's selection to be between the given start and end
* cursors, and return whether or not it was successful.
* @param {Cursor} start The start position.
* @param {Cursor} end The end position.
* @return {boolean} True if the selection was successfully set.
*/
CaretBrowsing.setAndValidateSelection = function(start, end) {
const sel = window.getSelection();
sel.setBaseAndExtent(start.node, start.index, end.node, end.index);
if (sel.rangeCount !== 1) {
return false;
}
return (sel.anchorNode === start.node &&
sel.anchorOffset === start.index &&
sel.focusNode === end.node &&
sel.focusOffset === end.index);
};
/**
* Set focus to a node if it's focusable. If it's an input element,
* select the text, otherwise it doesn't appear focused to the user.
* Every other control behaves normally if you just call focus() on it.
* @param {Node} node The node to focus.
* @return {boolean} True if the node was focused.
*/
CaretBrowsing.setFocusToNode = function(nodeArg) {
let node = nodeArg;
while (node && node !== document.body) {
if (isFocusable(node) && node.constructor !== HTMLIFrameElement) {
node.focus();
if (node.constructor === HTMLInputElement && node.select) {
node.select();
}
return true;
}
node = node.parentNode;
}
return false;
};
/**
* Set the caret element's normal style, i.e. not when animating.
*/
CaretBrowsing.setCaretElementNormalStyle = function() {
const element = CaretBrowsing.caretElement;
element.className = "CaretBrowsing_Caret";
if (CaretBrowsing.isSelectionCollapsed) {
element.style.opacity = "1.0";
} else {
element.style.opacity = "0.0";
}
element.style.left = `${CaretBrowsing.caretX}px`;
element.style.top = `${CaretBrowsing.caretY}px`;
element.style.width = `${CaretBrowsing.caretWidth}px`;
element.style.height = `${CaretBrowsing.caretHeight}px`;
element.style.color = CaretBrowsing.caretForeground;
};
/**
* Create the caret element. This assumes that caretX, caretY,
* caretWidth, and caretHeight have all been set. The caret is
* animated in so the user can find it when it first appears.
*/
CaretBrowsing.createCaretElement = function() {
const element = document.createElement("div");
element.className = "CaretBrowsing_Caret";
document.body.appendChild(element);
CaretBrowsing.caretElement = element;
CaretBrowsing.setCaretElementNormalStyle();
};
/**
* Recreate the caret element, triggering any intro animation.
*/
CaretBrowsing.recreateCaretElement = function() {
if (CaretBrowsing.caretElement) {
window.clearInterval(CaretBrowsing.blinkFunctionId);
CaretBrowsing.caretElement.parentElement.removeChild(
CaretBrowsing.caretElement);
CaretBrowsing.caretElement = null;
CaretBrowsing.updateIsCaretVisible();
}
};
/**
* Get the rectangle for a cursor position. This is tricky because
* you can't get the bounding rectangle of an empty range, so this function
* computes the rect by trying a range including one character earlier or
* later than the cursor position.
* @param {Cursor} cursor A single cursor position.
* @return {{left: number, top: number, width: number, height: number}}
* The bounding rectangle of the cursor.
*/
CaretBrowsing.getCursorRect = function(cursor) {
let node = cursor.node;
const index = cursor.index;
const rect = {
"left": 0,
"top": 0,
"width": 1,
"height": 0,
};
if (node.constructor === Text) {
let left = index;
let right = index;
const max = node.data.length;
const newRange = document.createRange();
while (left > 0 || right < max) {
if (left > 0) {
left--;
newRange.setStart(node, left);
newRange.setEnd(node, index);
const rangeRect = newRange.getBoundingClientRect();
if (rangeRect && rangeRect.width && rangeRect.height) {
rect.left = rangeRect.right;
rect.top = rangeRect.top;
rect.height = rangeRect.height;
break;
}
}
if (right < max) {
right++;
newRange.setStart(node, index);
newRange.setEnd(node, right);
const rangeRect = newRange.getBoundingClientRect();
if (rangeRect && rangeRect.width && rangeRect.height) {
rect.left = rangeRect.left;
rect.top = rangeRect.top;
rect.height = rangeRect.height;
break;
}
}
}
} else {
rect.height = node.offsetHeight;
while (node !== null) {
rect.left += node.offsetLeft;
rect.top += node.offsetTop;
node = node.offsetParent;
}
}
rect.left += window.pageXOffset;
rect.top += window.pageYOffset;
return rect;
};
/**
* Compute the new location of the caret or selection and update
* the element as needed.
* @param {boolean} scrollToSelection If true, will also scroll the page
* to the caret / selection location.
*/
CaretBrowsing.updateCaretOrSelection =
function(scrollToSelection) {
const sel = window.getSelection();
if (sel.rangeCount === 0) {
if (CaretBrowsing.caretElement) {
CaretBrowsing.isSelectionCollapsed = false;
CaretBrowsing.caretElement.style.opacity = "0.0";
}
return;
}
const range = sel.getRangeAt(0);
if (!range) {
if (CaretBrowsing.caretElement) {
CaretBrowsing.isSelectionCollapsed = false;
CaretBrowsing.caretElement.style.opacity = "0.0";
}
return;
}
if (CaretBrowsing.isControlThatNeedsArrowKeys(
document.activeElement)) {
let node = document.activeElement;
CaretBrowsing.caretWidth = node.offsetWidth;
CaretBrowsing.caretHeight = node.offsetHeight;
CaretBrowsing.caretX = 0;
CaretBrowsing.caretY = 0;
while (node.offsetParent) {
CaretBrowsing.caretX += node.offsetLeft;
CaretBrowsing.caretY += node.offsetTop;
node = node.offsetParent;
}
CaretBrowsing.isSelectionCollapsed = false;
} else if (range.startOffset !== range.endOffset ||
range.startContainer !== range.endContainer) {
const rect = range.getBoundingClientRect();
if (!rect) {
return;
}
CaretBrowsing.caretX = rect.left + window.pageXOffset;
CaretBrowsing.caretY = rect.top + window.pageYOffset;
CaretBrowsing.caretWidth = rect.width;
CaretBrowsing.caretHeight = rect.height;
CaretBrowsing.isSelectionCollapsed = false;
} else {
const rect = CaretBrowsing.getCursorRect(
new Cursor(range.startContainer,
range.startOffset,
TraverseUtil.getNodeText(range.startContainer)));
CaretBrowsing.caretX = rect.left;
CaretBrowsing.caretY = rect.top;
CaretBrowsing.caretWidth = rect.width;
CaretBrowsing.caretHeight = rect.height;
CaretBrowsing.isSelectionCollapsed = true;
}
if (CaretBrowsing.caretElement) {
const element = CaretBrowsing.caretElement;
if (CaretBrowsing.isSelectionCollapsed) {
element.style.opacity = "1.0";
element.style.left = `${CaretBrowsing.caretX}px`;
element.style.top = `${CaretBrowsing.caretY}px`;
element.style.width = `${CaretBrowsing.caretWidth}px`;
element.style.height = `${CaretBrowsing.caretHeight}px`;
} else {
element.style.opacity = "0.0";
}
} else {
CaretBrowsing.createCaretElement();
}
let elem = range.startContainer;
if (elem.constructor === Text) {
elem = elem.parentElement;
}
const style = window.getComputedStyle(elem);
const bg = axs.utils.getBgColor(style, elem);
const fg = axs.utils.getFgColor(style, elem, bg);
CaretBrowsing.caretBackground = axs.color.colorToString(bg);
CaretBrowsing.caretForeground = axs.color.colorToString(fg);
if (scrollToSelection) {
// Scroll just to the "focus" position of the selection,
// the part the user is manipulating.
const rect = CaretBrowsing.getCursorRect(
new Cursor(sel.focusNode, sel.focusOffset,
TraverseUtil.getNodeText(sel.focusNode)));
const yscroll = window.pageYOffset;
const pageHeight = window.innerHeight;
const caretY = rect.top;
const caretHeight = Math.min(rect.height, 30);
if (yscroll + pageHeight < caretY + caretHeight) {
window.scroll(0, (caretY + caretHeight - pageHeight + 100));
} else if (caretY < yscroll) {
window.scroll(0, (caretY - 100));
}
}
};
CaretBrowsing.move = function(direction, granularity) {
let action = "move";
if (CaretBrowsing.selectionEnabled) {
action = "extend";
}
window.
getSelection().
modify(action, direction, granularity);
if (CaretBrowsing.isWindows &&
(direction === "forward" ||
direction === "right") &&
granularity === "word") {
CaretBrowsing.move("left", "character");
} else {
window.setTimeout(() => {
CaretBrowsing.updateCaretOrSelection(true);
}, 0);
}
CaretBrowsing.stopAnimation();
};
CaretBrowsing.moveToBlock = function(paragraph, boundary) {
let action = "move";
if (CaretBrowsing.selectionEnabled) {
action = "extend";
}
window.
getSelection().
modify(action, paragraph, "paragraph");
window.
getSelection().
modify(action, boundary, "paragraphboundary");
window.setTimeout(() => {
CaretBrowsing.updateCaretOrSelection(true);
}, 0);
CaretBrowsing.stopAnimation();
};
CaretBrowsing.toggle = function(value) {
if (CaretBrowsing.forceEnabled) {
CaretBrowsing.recreateCaretElement();
return;
}
if (value === undefined) {
CaretBrowsing.isEnabled = !CaretBrowsing.isEnabled;
} else {
CaretBrowsing.isEnabled = value;
}
CaretBrowsing.updateIsCaretVisible();
};
/**
* Event handler, called when the mouse is clicked. Chrome already
* sets the selection when the mouse is clicked, all we need to do is
* update our cursor.
* @param {Event} evt The DOM event.
* @return {boolean} True if the default action should be performed.
*/
CaretBrowsing.onClick = function() {
if (!CaretBrowsing.isEnabled) {
return true;
}
window.setTimeout(() => {
CaretBrowsing.targetX = null;
CaretBrowsing.updateCaretOrSelection(false);
}, 0);
return true;
};
/**
* Update whether or not the caret is visible, based on whether caret browsing
* is enabled and whether this window / iframe has focus.
*/
CaretBrowsing.updateIsCaretVisible = function() {
CaretBrowsing.isCaretVisible =
(CaretBrowsing.isEnabled && CaretBrowsing.isWindowFocused);
if (CaretBrowsing.isCaretVisible && !CaretBrowsing.caretElement) {
CaretBrowsing.setInitialCursor();
CaretBrowsing.updateCaretOrSelection(true);
} else if (!CaretBrowsing.isCaretVisible &&
CaretBrowsing.caretElement) {
window.clearInterval(CaretBrowsing.blinkFunctionId);
if (CaretBrowsing.caretElement) {
CaretBrowsing.isSelectionCollapsed = false;
CaretBrowsing.caretElement.parentElement.removeChild(
CaretBrowsing.caretElement);
CaretBrowsing.caretElement = null;
}
}
};
CaretBrowsing.onWindowFocus = function() {
CaretBrowsing.isWindowFocused = true;
CaretBrowsing.updateIsCaretVisible();
};
CaretBrowsing.onWindowBlur = function() {
CaretBrowsing.isWindowFocused = false;
CaretBrowsing.updateIsCaretVisible();
};
CaretBrowsing.startAnimation = function() {
CaretBrowsing.caretElement.style.animationIterationCount = "infinite";
};
CaretBrowsing.stopAnimation = function() {
CaretBrowsing.caretElement.style.animationIterationCount = 0;
window.setTimeout(() => {
CaretBrowsing.startAnimation();
}, 1000);
};
CaretBrowsing.init = function() {
CaretBrowsing.isWindowFocused = document.hasFocus();
document.addEventListener("click", CaretBrowsing.onClick, false);
window.addEventListener("focus", CaretBrowsing.onWindowFocus, false);
window.addEventListener("blur", CaretBrowsing.onWindowBlur, false);
};
window.setTimeout(() => {
if (!window.caretBrowsingLoaded) {
window.caretBrowsingLoaded = true;
CaretBrowsing.init();
if (document.body &&
document.body.getAttribute("caretbrowsing") === "on") {
CaretBrowsing.forceEnabled = true;
CaretBrowsing.isEnabled = true;
CaretBrowsing.updateIsCaretVisible();
}
}
}, 0);
const funcs = {};
funcs.setInitialCursor = () => {
if (!CaretBrowsing.initiated) {
CaretBrowsing.setInitialCursor();
return CaretBrowsing.selectionEnabled;
}
if (window.getSelection().toString().length === 0) {
positionCaret();
}
CaretBrowsing.toggle();
return CaretBrowsing.selectionEnabled;
};
funcs.setPlatform = (platform, qtVersion) => {
CaretBrowsing.isWindows = platform.startsWith("win");
CaretBrowsing.isOldQt = qtVersion === "5.7.1";
};
funcs.disableCaret = () => {
CaretBrowsing.toggle(false);
};
funcs.toggle = () => {
CaretBrowsing.toggle();
};
funcs.moveRight = () => {
CaretBrowsing.move("right", "character");
};
funcs.moveLeft = () => {
CaretBrowsing.move("left", "character");
};
funcs.moveDown = () => {
CaretBrowsing.move("forward", "line");
};
funcs.moveUp = () => {
CaretBrowsing.move("backward", "line");
};
funcs.moveToEndOfWord = () => {
funcs.moveToNextWord();
funcs.moveLeft();
};
funcs.moveToNextWord = () => {
CaretBrowsing.move("forward", "word");
funcs.moveRight();
};
funcs.moveToPreviousWord = () => {
CaretBrowsing.move("backward", "word");
};
funcs.moveToStartOfLine = () => {
CaretBrowsing.move("left", "lineboundary");
};
funcs.moveToEndOfLine = () => {
CaretBrowsing.move("right", "lineboundary");
};
funcs.moveToStartOfNextBlock = () => {
CaretBrowsing.moveToBlock("forward", "backward");
};
funcs.moveToStartOfPrevBlock = () => {
CaretBrowsing.moveToBlock("backward", "backward");
};
funcs.moveToEndOfNextBlock = () => {
CaretBrowsing.moveToBlock("forward", "forward");
};
funcs.moveToEndOfPrevBlock = () => {
CaretBrowsing.moveToBlock("backward", "forward");
};
funcs.moveToStartOfDocument = () => {
CaretBrowsing.move("backward", "documentboundary");
};
funcs.moveToEndOfDocument = () => {
CaretBrowsing.move("forward", "documentboundary");
funcs.moveLeft();
};
funcs.dropSelection = () => {
window.getSelection().removeAllRanges();
};
funcs.getSelection = () => window.getSelection().toString();
funcs.toggleSelection = () => {
CaretBrowsing.selectionEnabled = !CaretBrowsing.selectionEnabled;
return CaretBrowsing.selectionEnabled;
};
return funcs;
})();