1 files changed, 160 insertions, 0 deletions
diff --git a/ext/js/background/script-manager.js b/ext/js/background/script-manager.js
new file mode 100644
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+++ b/ext/js/background/script-manager.js
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+/*
+ * Copyright (C) 2021  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/>.
+ */
+
+/**
+ * This class is used to manage script injection into content tabs.
+ */
+class ScriptManager {
+    /**
+     * Injects a stylesheet into a specific tab and frame.
+     * @param {string} type The type of content to inject; either 'file' or 'code'.
+     * @param {string} content The content to inject.
+     *   If type is 'file', this argument should be a path to a file.
+     *   If type is 'code', this argument should be the CSS content.
+     * @param {number} tabId The id of the tab to inject into.
+     * @param {number} frameId The id of the frame to inject into.
+     * @returns {Promise<void>}
+     */
+    injectStylesheet(type, content, tabId, frameId) {
+        if (isObject(chrome.tabs) && typeof chrome.tabs.insertCSS === 'function') {
+            return this._injectStylesheetMV2(type, content, tabId, frameId);
+        } else if (isObject(chrome.scripting) && typeof chrome.scripting.insertCSS === 'function') {
+            return this._injectStylesheetMV3(type, content, tabId, frameId);
+        } else {
+            return Promise.reject(new Error('Stylesheet injection not supported'));
+        }
+    }
+    /**
+     * Injects a script into a specific tab and frame.
+     * @param {string} file The path to a file to inject.
+     * @param {number} tabId The id of the tab to inject into.
+     * @param {number} frameId The id of the frame to inject into.
+     * @returns {Promise<{frameId: number, result: object}>} The id of the frame and the result of the script injection.
+     */
+    injectScript(file, tabId, frameId) {
+        if (isObject(chrome.tabs) && typeof chrome.tabs.executeScript === 'function') {
+            return this._injectScriptMV2(file, tabId, frameId);
+        } else if (isObject(chrome.scripting) && typeof chrome.scripting.executeScript === 'function') {
+            return this._injectScriptMV3(file, tabId, frameId);
+        } else {
+            return Promise.reject(new Error('Script injection not supported'));
+        }
+    }
+
+    // Private
+
+    _injectStylesheetMV2(type, content, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = (
+                type === 'file' ?
+                {
+                    file: content,
+                    runAt: 'document_start',
+                    cssOrigin: 'author',
+                    allFrames: false,
+                    matchAboutBlank: true
+                } :
+                {
+                    code: content,
+                    runAt: 'document_start',
+                    cssOrigin: 'user',
+                    allFrames: false,
+                    matchAboutBlank: true
+                }
+            );
+            if (typeof frameId === 'number') {
+                details.frameId = frameId;
+            }
+            chrome.tabs.insertCSS(tabId, details, () => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    resolve();
+                }
+            });
+        });
+    }
+
+    _injectStylesheetMV3(type, content, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = (
+                type === 'file' ?
+                {origin: chrome.scripting.StyleOrigin.AUTHOR, files: [content]} :
+                {origin: chrome.scripting.StyleOrigin.USER,   css: content}
+            );
+            details.target = {
+                tabId,
+                allFrames: false
+            };
+            if (typeof frameId === 'number') {
+                details.target.frameIds = [frameId];
+            }
+            chrome.scripting.insertCSS(details, () => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    resolve();
+                }
+            });
+        });
+    }
+
+    _injectScriptMV2(file, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = {
+                allFrames: false,
+                frameId,
+                file,
+                matchAboutBlank: true,
+                runAt: 'document_start'
+            };
+            chrome.tabs.executeScript(tabId, details, (results) => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    const result = results[0];
+                    resolve({frameId, result});
+                }
+            });
+        });
+    }
+
+    _injectScriptMV3(file, tabId, frameId) {
+        return new Promise((resolve, reject) => {
+            const details = {
+                files: [file],
+                target: {
+                    allFrames: false,
+                    frameIds: [frameId],
+                    tabId
+                }
+            };
+            chrome.scripting.executeScript(details, (results) => {
+                const e = chrome.runtime.lastError;
+                if (e) {
+                    reject(new Error(e.message));
+                } else {
+                    const {frameId: frameId2, result} = results[0];
+                    resolve({frameId: frameId2, result});
+                }
+            });
+        });
+    }
+}