1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/*
* Copyright (C) 2020-2022 Yomichan Authors
*
* This program 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.
*
* This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
*/
/* global
* MediaUtil
*/
/**
* Class which can read text and images from the clipboard.
*/
class ClipboardReader {
/**
* Creates a new instances of a clipboard reader.
* @param document The Document object to be used, or null for no support.
* @param pasteTargetSelector The selector for the paste target element.
* @param imagePasteTargetSelector The selector for the image paste target element.
*/
constructor({document=null, pasteTargetSelector=null, imagePasteTargetSelector=null}) {
this._document = document;
this._browser = null;
this._pasteTarget = null;
this._pasteTargetSelector = pasteTargetSelector;
this._imagePasteTarget = null;
this._imagePasteTargetSelector = imagePasteTargetSelector;
}
/**
* Gets the browser being used.
*/
get browser() {
return this._browser;
}
/**
* Assigns the browser being used.
*/
set browser(value) {
this._browser = value;
}
/**
* Gets the text in the clipboard.
* @returns A string containing the clipboard text.
* @throws Error if not supported.
*/
async getText() {
/*
Notes:
document.execCommand('paste') doesn't work on Firefox.
See: https://bugzilla.mozilla.org/show_bug.cgi?id=1603985
Therefore, navigator.clipboard.readText() is used on Firefox.
navigator.clipboard.readText() can't be used in Chrome for two reasons:
* Requires page to be focused, else it rejects with an exception.
* When the page is focused, Chrome will request clipboard permission, despite already
being an extension with clipboard permissions. It effectively asks for the
non-extension permission for clipboard access.
*/
if (this._isFirefox()) {
try {
return await navigator.clipboard.readText();
} catch (e) {
// Error is undefined, due to permissions
throw new Error('Cannot read clipboard text; check extension permissions');
}
}
const document = this._document;
if (document === null) {
throw new Error('Clipboard reading not supported in this context');
}
let target = this._pasteTarget;
if (target === null) {
target = document.querySelector(this._pasteTargetSelector);
if (target === null) {
throw new Error('Clipboard paste target does not exist');
}
this._pasteTarget = target;
}
target.value = '';
target.focus();
document.execCommand('paste');
const result = target.value;
target.value = '';
return (typeof result === 'string' ? result : '');
}
/**
* Gets the first image in the clipboard.
* @returns A string containing a data URL of the image file, or null if no image was found.
* @throws Error if not supported.
*/
async getImage() {
// See browser-specific notes in getText
if (
this._isFirefox() &&
typeof navigator.clipboard !== 'undefined' &&
typeof navigator.clipboard.read === 'function'
) {
// This function is behind the Firefox flag: dom.events.asyncClipboard.dataTransfer
let files;
try {
({files} = await navigator.clipboard.read());
} catch (e) {
return null;
}
for (const file of files) {
if (MediaUtil.getFileExtensionFromImageMediaType(file.type) !== null) {
return await this._readFileAsDataURL(file);
}
}
return null;
}
const document = this._document;
if (document === null) {
throw new Error('Clipboard reading not supported in this context');
}
let target = this._imagePasteTarget;
if (target === null) {
target = document.querySelector(this._imagePasteTargetSelector);
if (target === null) {
throw new Error('Clipboard paste target does not exist');
}
this._imagePasteTarget = target;
}
target.focus();
document.execCommand('paste');
const image = target.querySelector('img[src^="data:"]');
const result = (image !== null ? image.getAttribute('src') : null);
for (const image2 of target.querySelectorAll('img')) {
image2.removeAttribute('src');
}
target.textContent = '';
return result;
}
// Private
_isFirefox() {
return (this._browser === 'firefox' || this._browser === 'firefox-mobile');
}
_readFileAsDataURL(file) {
return new Promise((resolve, reject) => {
const reader = new FileReader();
reader.onload = () => resolve(reader.result);
reader.onerror = () => reject(reader.error);
reader.readAsDataURL(file);
});
}
}
|