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/*
* Copyright (C) 2012 Google Inc. 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.
*/
(function(mod) {
})(function(CodeMirror) {
// CodeMirror uses an offscreen <textarea> to detect input.
// Due to inconsistencies in the many browsers it supports, it simplifies things by
// regularly checking if something is in the textarea, adding those characters to the
// document, and then clearing the textarea.
// This breaks assistive technology that wants to read from CodeMirror, because the
// <textarea> that they interact with is constantly empty.
// Because we target up-to-date Firefox, we can guarantee consistent input events.
// This lets us leave the current line from the editor in our <textarea>.
// CodeMirror still expects a mostly empty <textarea>, so we pass CodeMirror a fake
// <textarea> that only contains the users input.
CodeMirror.inputStyles.accessibleTextArea = class extends CodeMirror.inputStyles.textarea {
/**
* @override
* @param {!Object} display
*/
init(display) {
super.init(display);
this.textarea.addEventListener("compositionstart",
this._onCompositionStart.bind(this));
}
_onCompositionStart() {
if (this.textarea.selectionEnd === this.textarea.value.length) {
return;
}
// CodeMirror always expects the caret to be at the end of the textarea
// When in IME composition mode, clip the textarea to how CodeMirror expects it,
// and then let CodeMirror do its thing.
this.textarea.value = this.textarea.value.substring(0, this.textarea.selectionEnd);
const length = this.textarea.value.length;
this.textarea.setSelectionRange(length, length);
this.prevInput = this.textarea.value;
}
/**
* @override
* @param {Boolean} typing
*/
reset(typing) {
if (
typing ||
this.contextMenuPending ||
this.composing ||
this.cm.somethingSelected()
) {
super.reset(typing);
return;
}
// When navigating around the document, keep the current visual line in the textarea.
const cursor = this.cm.getCursor();
let start, end;
if (this.cm.options.lineWrapping) {
// To get the visual line, compute the leftmost and rightmost character positions.
const top = this.cm.charCoords(cursor, "page").top;
start = this.cm.coordsChar({left: -Infinity, top});
end = this.cm.coordsChar({left: Infinity, top});
} else {
// Limit the line to 1000 characters to prevent lag.
const offset = Math.floor(cursor.ch / 1000) * 1000;
start = {ch: offset, line: cursor.line};
end = {ch: offset + 1000, line: cursor.line};
}
this.textarea.value = this.cm.getRange(start, end);
const caretPosition = cursor.ch - start.ch;
this.textarea.setSelectionRange(caretPosition, caretPosition);
this.prevInput = this.textarea.value;
}
/**
* @override
* @return {boolean}
*/
poll() {
if (this.contextMenuPending || this.composing) {
return super.poll();
}
const text = this.textarea.value;
let start = 0;
const length = Math.min(this.prevInput.length, text.length);
while (start < length && this.prevInput[start] === text[start]) {
++start;
}
let end = 0;
while (
end < length - start &&
this.prevInput[this.prevInput.length - end - 1] === text[text.length - end - 1]
) {
++end;
}
// CodeMirror expects the user to be typing into a blank <textarea>.
// Pass a fake textarea into super.poll that only contains the users input.
const placeholder = this.textarea;
this.textarea = document.createElement("textarea");
this.textarea.value = text.substring(start, text.length - end);
this.textarea.setSelectionRange(
placeholder.selectionStart - start,
placeholder.selectionEnd - start
);
this.prevInput = "";
const result = super.poll();
this.prevInput = text;
this.textarea = placeholder;
return result;
}
};
});