Yomichan object separation (#627)

* Move "yomichan" object setup to a separate file

* Update script imports

* Align message handlers

* Rename Yomichan.prepare to Yomichan.ready

* Add new prepare function

* Improve isExtensionUrl

1 files changed, 208 insertions, 0 deletions

diff --git a/ext/mixed/js/yomichan.js b/ext/mixed/js/yomichan.js
new file mode 100644
index 00000000..5fa504ef
--- /dev/null
+++ b/ext/mixed/js/yomichan.js
@@ -0,0 +1,208 @@
+/*
+ * 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/>.
+ */
+
+const yomichan = (() => {
+    class Yomichan extends EventDispatcher {
+        constructor() {
+            super();
+
+            const {promise, resolve} = deferPromise();
+            this._isBackendPreparedPromise = promise;
+            this._isBackendPreparedPromiseResolve = resolve;
+
+            this._messageHandlers = new Map([
+                ['backendPrepared', this._onMessageBackendPrepared.bind(this)],
+                ['getUrl',          this._onMessageGetUrl.bind(this)],
+                ['optionsUpdated',  this._onMessageOptionsUpdated.bind(this)],
+                ['zoomChanged',     this._onMessageZoomChanged.bind(this)]
+            ]);
+        }
+
+        // Public
+
+        prepare() {
+            chrome.runtime.onMessage.addListener(this._onMessage.bind(this));
+        }
+
+        ready() {
+            chrome.runtime.sendMessage({action: 'yomichanCoreReady'});
+            return this._isBackendPreparedPromise;
+        }
+
+        generateId(length) {
+            const array = new Uint8Array(length);
+            crypto.getRandomValues(array);
+            let id = '';
+            for (const value of array) {
+                id += value.toString(16).padStart(2, '0');
+            }
+            return id;
+        }
+
+        triggerOrphaned(error) {
+            this.trigger('orphaned', {error});
+        }
+
+        isExtensionUrl(url) {
+            try {
+                return url.startsWith(chrome.runtime.getURL('/'));
+            } catch (e) {
+                return false;
+            }
+        }
+
+        getTemporaryListenerResult(eventHandler, userCallback, timeout=null) {
+            if (!(
+                typeof eventHandler.addListener === 'function' &&
+                typeof eventHandler.removeListener === 'function'
+            )) {
+                throw new Error('Event handler type not supported');
+            }
+
+            return new Promise((resolve, reject) => {
+                const runtimeMessageCallback = ({action, params}, sender, sendResponse) => {
+                    let timeoutId = null;
+                    if (timeout !== null) {
+                        timeoutId = setTimeout(() => {
+                            timeoutId = null;
+                            eventHandler.removeListener(runtimeMessageCallback);
+                            reject(new Error(`Listener timed out in ${timeout} ms`));
+                        }, timeout);
+                    }
+
+                    const cleanupResolve = (value) => {
+                        if (timeoutId !== null) {
+                            clearTimeout(timeoutId);
+                            timeoutId = null;
+                        }
+                        eventHandler.removeListener(runtimeMessageCallback);
+                        sendResponse();
+                        resolve(value);
+                    };
+
+                    userCallback({action, params}, {resolve: cleanupResolve, sender});
+                };
+
+                eventHandler.addListener(runtimeMessageCallback);
+            });
+        }
+
+        logWarning(error) {
+            this.log(error, 'warn');
+        }
+
+        logError(error) {
+            this.log(error, 'error');
+        }
+
+        log(error, level, context=null) {
+            if (!isObject(context)) {
+                context = this._getLogContext();
+            }
+
+            let errorString;
+            try {
+                errorString = error.toString();
+                if (/^\[object \w+\]$/.test(errorString)) {
+                    errorString = JSON.stringify(error);
+                }
+            } catch (e) {
+                errorString = `${error}`;
+            }
+
+            let errorStack;
+            try {
+                errorStack = (typeof error.stack === 'string' ? error.stack.trimRight() : '');
+            } catch (e) {
+                errorStack = '';
+            }
+
+            let errorData;
+            try {
+                errorData = error.data;
+            } catch (e) {
+                // NOP
+            }
+
+            if (errorStack.startsWith(errorString)) {
+                errorString = errorStack;
+            } else if (errorStack.length > 0) {
+                errorString += `\n${errorStack}`;
+            }
+
+            const manifest = chrome.runtime.getManifest();
+            let message = `${manifest.name} v${manifest.version} has encountered a problem.`;
+            message += `\nOriginating URL: ${context.url}\n`;
+            message += errorString;
+            if (typeof errorData !== 'undefined') {
+                message += `\nData: ${JSON.stringify(errorData, null, 4)}`;
+            }
+            message += '\n\nIssues can be reported at https://github.com/FooSoft/yomichan/issues';
+
+            switch (level) {
+                case 'info': console.info(message); break;
+                case 'debug': console.debug(message); break;
+                case 'warn': console.warn(message); break;
+                case 'error': console.error(message); break;
+                default: console.log(message); break;
+            }
+
+            this.trigger('log', {error, level, context});
+        }
+
+        // Private
+
+        _getUrl() {
+            return (typeof window === 'object' && window !== null ? window.location.href : '');
+        }
+
+        _getLogContext() {
+            return {url: this._getUrl()};
+        }
+
+        _onMessage({action, params}, sender, callback) {
+            const handler = this._messageHandlers.get(action);
+            if (typeof handler !== 'function') { return false; }
+
+            const result = handler(params, sender);
+            callback(result);
+            return false;
+        }
+
+        _onMessageBackendPrepared() {
+            if (this._isBackendPreparedPromiseResolve === null) { return; }
+            this._isBackendPreparedPromiseResolve();
+            this._isBackendPreparedPromiseResolve = null;
+        }
+
+        _onMessageGetUrl() {
+            return {url: this._getUrl()};
+        }
+
+        _onMessageOptionsUpdated({source}) {
+            this.trigger('optionsUpdated', {source});
+        }
+
+        _onMessageZoomChanged({oldZoomFactor, newZoomFactor}) {
+            this.trigger('zoomChanged', {oldZoomFactor, newZoomFactor});
+        }
+    }
+
+    return new Yomichan();
+})();
+
+yomichan.prepare();