1 files changed, 114 insertions, 0 deletions
diff --git a/ext/mixed/js/environment.js b/ext/mixed/js/environment.js
new file mode 100644
index 00000000..e5bc20a7
--- /dev/null
+++ b/ext/mixed/js/environment.js
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2020  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/>.
+ */
+
+
+class Environment {
+    constructor() {
+        this._cachedEnvironmentInfo = null;
+    }
+
+    async prepare() {
+        this._cachedEnvironmentInfo = await this._loadEnvironmentInfo();
+    }
+
+    getInfo() {
+        if (this._cachedEnvironmentInfo === null) { throw new Error('Not prepared'); }
+        return this._cachedEnvironmentInfo;
+    }
+
+    async _loadEnvironmentInfo() {
+        const browser = await this._getBrowser();
+        const platform = await new Promise((resolve) => chrome.runtime.getPlatformInfo(resolve));
+        const modifierInfo = this._getModifierInfo(browser, platform.os);
+        return {
+            browser,
+            platform: {
+                os: platform.os
+            },
+            modifiers: modifierInfo
+        };
+    }
+
+    async _getBrowser() {
+        if (EXTENSION_IS_BROWSER_EDGE) {
+            return 'edge';
+        }
+        if (typeof browser !== 'undefined') {
+            try {
+                const info = await browser.runtime.getBrowserInfo();
+                if (info.name === 'Fennec') {
+                    return 'firefox-mobile';
+                }
+            } catch (e) {
+                // NOP
+            }
+            return 'firefox';
+        } else {
+            return 'chrome';
+        }
+    }
+
+    _getModifierInfo(browser, os) {
+        let osKeys;
+        let separator;
+        switch (os) {
+            case 'win':
+                separator = ' + ';
+                osKeys = [
+                    ['alt', 'Alt'],
+                    ['ctrl', 'Ctrl'],
+                    ['shift', 'Shift'],
+                    ['meta', 'Windows']
+                ];
+                break;
+            case 'mac':
+                separator = '';
+                osKeys = [
+                    ['alt', '⌥'],
+                    ['ctrl', '⌃'],
+                    ['shift', '⇧'],
+                    ['meta', '⌘']
+                ];
+                break;
+            case 'linux':
+            case 'openbsd':
+            case 'cros':
+            case 'android':
+                separator = ' + ';
+                osKeys = [
+                    ['alt', 'Alt'],
+                    ['ctrl', 'Ctrl'],
+                    ['shift', 'Shift'],
+                    ['meta', 'Super']
+                ];
+                break;
+            default:
+                throw new Error(`Invalid OS: ${os}`);
+        }
+
+        const isFirefox = (browser === 'firefox' || browser === 'firefox-mobile');
+        const keys = [];
+
+        for (const [value, name] of osKeys) {
+            // Firefox doesn't support event.metaKey on platforms other than macOS
+            if (value === 'meta' && isFirefox && os !== 'mac') { continue; }
+            keys.push({value, name});
+        }
+
+        return {keys, separator};
+    }
+}