add site-specific behaviors for twitter, instagram, and expand lib wi…

…th xpath selector functions

- autoplay + autofetch, if enabled, start on load
- autoscroll used if no site-specific behaviors
- build to 'behaviors.js', include dist build for package

.eslintrc.js

@@ -0,0 +1,29 @@
+module.exports = {
+    "env": {
+        "browser": true,
+        "es2021": true
+    },
+    "extends": "eslint:recommended",
+    "parserOptions": {
+        "ecmaVersion": 12,
+        "sourceType": "module"
+    },
+    "rules": {
+        "indent": [
+            "error",
+            2
+        ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
+        "quotes": [
+            "error",
+            "double"
+        ],
+        "semi": [
+            "error",
+            "always"
+        ]
+    }
+}

.gitignore

@@ -0,0 +1 @@
+node_modules/

src/autofetcher.js

@@ -3,6 +3,8 @@
 // also extract any urls from media query stylesheets that have not necessarily been loaded
 // (May not work for cross-origin stylesheets)
 
+import { runOnload } from "./lib/utils";
+
 const SRC_SET_SELECTOR = "img[srcset], img[data-srcset], img[data-src], " +  
 "video[srcset], video[data-srcset], video[data-src], audio[srcset], audio[data-srcset], audio[data-src], " +
 "picture > source[srcset], picture > source[data-srcset], picture > source[data-src], " +
@@ -22,17 +24,14 @@ export class AutoFetcher
     this.urlSet = new Set();
     this.urlqueue = [];
     this.numPending = 0;
+    this.start();
   }
 
-  init() {
-    console.log("init autofetch");
-    this.run();
-    this.initObserver();
-  }
-
-  done() {
-    //todo:
-    return Promise.resolve();
+  start() {
+    runOnload(() => {
+      this.run();
+      this.initObserver();
+    });
   }
 
   async run() {

src/autoplay.js

@@ -1,4 +1,4 @@
-import { sleep } from "./lib/utils";
+import { sleep, runOnload } from "./lib/utils";
 
 
 const domainSpecificRedirect = [
@@ -36,6 +36,8 @@ export class Autoplay {
     this.mediaSet = new Set();
 
     this.promises = [];
+
+    this.start();
   }
 
   async checkAutoPlayRedirect() {   
@@ -54,9 +56,11 @@ export class Autoplay {
     }
   }
 
-  init() {
-    this.checkAutoPlayRedirect();
-    this.initObserver();
+  start() {
+    runOnload(() => {
+      this.checkAutoPlayRedirect();
+      this.initObserver();
+    });
   }
 
   initObserver() {

src/autoscroll.js

@@ -1,14 +1,10 @@
-import { sleep } from "./lib/utils";
+import { sleep, Behavior } from "./lib/utils";
 
 
 // ===========================================================================
-export class AutoScroll
+export class AutoScroll extends Behavior
 {
-  init() {
-    this.running = this.run();
-  }
-
-  async run() {
+  async* [Symbol.asyncIterator]() {
     const canScrollMore = () =>
       self.scrollY + self.innerHeight <
       Math.max(
@@ -23,11 +19,8 @@ export class AutoScroll
 
     while (canScrollMore()) {
       self.scrollBy(scrollOpts);
+      yield {"msg": "Scrolling by " + scrollOpts.top};
       await sleep(500);
     }
   }
-
-  done() {
-    return Promise.race([this.running, sleep(30000)]);
-  }
 }

src/index.js

@@ -1,15 +1,20 @@
 import { AutoFetcher } from "./autofetcher";
 import { Autoplay } from "./autoplay";
 import { AutoScroll } from "./autoscroll";
-import { runOnload } from "./lib/utils";
+import { runOnload, sleep } from "./lib/utils";
 
+import siteBehaviors from "./site";
+
+
+// ===========================================================================
 export class BehaviorManager
 {
   constructor() {
     this.behaviors = [];
+    this.mainBehavior = null;
   }
 
-  run(opts = {}) {
+  init(opts = {}) {
     if (opts.autofetch) {
       this.behaviors.push(new AutoFetcher());
     }
@@ -18,19 +23,60 @@ export class BehaviorManager
       this.behaviors.push(new Autoplay());
     }
 
-    if (opts.autoscroll) {
-      this.behaviors.push(new AutoScroll());
+    let siteMatch = false;
+
+    if (opts.siteSpecific) {
+      for (const siteBehaviorClass of siteBehaviors) {
+        if (siteBehaviorClass.isMatch()) {
+          console.log("Starting Site-Specific Behavior: " + siteBehaviorClass.name);
+          this.mainBehavior = new siteBehaviorClass();
+          siteMatch = true;
+          break;
+        }
+      }
+    } 
+
+    if (!siteMatch && opts.autoscroll) {
+      this.mainBehavior = new AutoScroll();
     }
 
+    if (this.mainBehavior)  {
+      this.behaviors.push(this.mainBehavior);
+    }
+
+    this.timeout = opts.timeout;
+  }
+
+  start() {
     runOnload(() => {
-      for (const behavior of this.behaviors) {
-        behavior.init();
+      if (this.mainBehavior) {
+        this.mainBehavior.start();
       }
     });
   }
 
   done() {
-    return Promise.all(this.behaviors.map(x => x.done()));
+    const allBehaviors = Promise.all(this.behaviors.map(x => x.done()));
+
+    if (this.timeout) {
+      return Promise.race([allBehaviors, sleep(this.timeout)]);
+    } else {
+      return allBehaviors;
+    }
+  }
+
+  pause() {
+    console.log("pausing");
+    if (this.mainBehavior) {
+      this.mainBehavior.pause();
+    }
+  }
+
+  unpause() {
+    console.log("unpausing");
+    if (this.mainBehavior) {
+      this.mainBehavior.unpause();
+    }
   }
 }