give plugins the ability to make custom key shortcuts

README.md

@@ -312,7 +312,7 @@ Make `package.json` manually or by `$ npm init` in the directory.
 }
 ```
 
-Finally make `index.js` as below:
+And make `index.js` as below:
 
 ```javascript
 module.exports = {
@@ -324,7 +324,31 @@ module.exports = {
 
 Package must export one object.
 If the object has a function as a value of `preload` key, it will be called at page being loaded.
-The function which receives two parameters `config` and `account`.
+The function receives two parameters `config` and `account`.
+
+By defining `keymaps` key you can define plugin-defined key shortcut action.
+
+```javascript
+module.exports = {
+    preload(config, account) {
+        console.log('Hello from plugin!', config, account);
+    },
+    keymaps: {
+        'alert-hello'(event, config, account) {
+            event.preventDefault();
+            alert('Hello, ' + account.name);
+        }
+    }
+};
+```
+
+The object of `keymaps` has keymap action name (key) and its handler (value). Here 'alert-hello'
+key shortcut action is defined. Key shortcut handler takes 3 arguments. `config` and `account`
+is the same as `preload`'s. `event` is a `KeyboardEvent` browser event on the key shortcut
+being called. You can cancel default event behavior by `.preventDefault()` method.
+
+User can specify the key shortcut as `plugin:{plugin name}:{action name}`. In above example,
+`plugin:hello:alert-hello` is available in `keymaps` section in config.json.
 
 Note that you can use below APIs in the script.
 
@@ -354,6 +378,8 @@ $ npm install mstdn-plugin-hello
 
 And then write what plugin should be loaded to `"plugins"` section of your account in `config.json`.
 `"hello"` should be added to the list.
+If listed plugin defines some keymaps, you can specify it in `keymaps` section with
+`plugin:{name}:{action}` format.
 
 ```json
 {
@@ -368,12 +394,17 @@ And then write what plugin should be loaded to `"plugins"` section of your accou
             ]
         }
     ],
+    "keymaps": {
+        ...
+
+        "ctrl+h": "plugin:hello:alert-hello"
+    },
 
     ...
 }
 ```
 
-You can enable different plugin for each your accounts.
+Note that you can enable different plugin for each your accounts.
 
 Finally open Mstdn.app and see DevTools via [Menu] -> [View] -> [Developper Tools] -> console.
 If window is too small to see DevTools, please make window size bigger.

renderer/index.ts

@@ -6,6 +6,6 @@ import PluginsLoader from './plugins';
 Ipc.on('mstdn:config', (c: Config, a: Account) => {
     const loader = new PluginsLoader(c, a);
     loader.loadAfterAppPrepared();
-    setupKeymaps(c, a);
+    setupKeymaps(c, a, loader);
     document.title = `${document.title} @${a.name}@${a.host}`;
 });

renderer/key_handler.ts

@@ -3,6 +3,7 @@ import {remote} from 'electron';
 import * as Mousetrap from 'mousetrap';
 import * as Ipc from './ipc';
 import log from './log';
+import PluginsLoader from './plugins';
 import {Config, Account} from '../main/config';
 
 function scrollable() {
@@ -58,6 +59,7 @@ const ShortcutActions = {
 export default function setupKeymaps(
     config: Config,
     account: Account,
+    loader: PluginsLoader,
 ) {
     const dataDir = config.__DATA_DIR || '/';
     for (const key in config.keymaps) {
@@ -85,6 +87,16 @@ export default function setupKeymaps(
                     log.error('Failed to run shortcut script ' + script, e);
                 }
             });
+        } else if (action.startsWith('plugin:')) {
+            // Format is 'plugin:{name}:{action}'
+            const split = action.split(':').slice(1);
+            if (split.length <= 1) {
+                log.error('Invalid format keymap. Plugin-defined action should be "plugin:{name}:{action}":', action);
+                continue;
+            }
+            Mousetrap.bind(key, e => {
+                loader.runKeyShortcut(e, split[0], split[1]);
+            });
         } else if (action.startsWith('/')) {
             Mousetrap.bind(key, e => {
                 e.preventDefault();

renderer/plugins.ts

@@ -3,7 +3,10 @@ import {Config, Account} from '../main/config';
 import log from './log';
 
 interface Plugin {
-    preload(c: Config, a: Account): void;
+    preload?(c: Config, a: Account): void;
+    keymaps?: {
+        [action: string]: (e: KeyboardEvent, c: Config, a: Account) => void;
+    };
 }
 interface Plugins {
     [module_path: string]: Plugin;
@@ -83,4 +86,34 @@ export default class PluginsLoader {
         log.info('Plugins were loaded:', this.preloads);
         return true;
     }
+
+    findPluginByName(name: string): Plugin | null {
+        const pluginName = `mstdn-plugin-${name}`;
+        for (const p in this.preloads) {
+            if (p.endsWith(pluginName)) {
+                return this.preloads[p];
+            }
+        }
+        return null;
+    }
+
+    runKeyShortcut(event: KeyboardEvent, name: string, action: string) {
+        const plugin = this.findPluginByName(name);
+        if (plugin === null) {
+            log.error(`While trying to execute key shortcut '${action}', plugin for '${name}' not found:`, this.preloads);
+            return;
+        }
+
+        const f = (plugin.keymaps || {})[action];
+        if (!f) {
+            log.error(`There is no key shortcut action '${action}' in plugin '${name}'`, plugin);
+            return;
+        }
+
+        try {
+            f(event, this.config, this.account);
+        } catch (e) {
+            log.error(`Error while executing plugin-defined key short action: ${action} with plugin '${name}'`, e);
+        }
+    }
 }