feat: #470 use a router for navigation, support backwards/forwards navigation

removed fork's back button support

common/App.svelte

@@ -14,7 +14,34 @@
     page.set('schedule')
   })
 
+  let ignoreNext = false
+  function addPage (value, type) {
+    if (ignoreNext) {
+      ignoreNext = false
+      return
+    }
+    history.pushState({ type, value }, '', './?id=' + Math.trunc(Math.random() * Number.MAX_SAFE_INTEGER).toString())
+  }
+  page.subscribe((value) => {
+    addPage(value, 'page')
+  })
+  view.subscribe((value) => {
+    addPage(value, 'view')
+  })
 
+  addPage('home', 'page')
+
+  window.addEventListener('popstate', e => {
+    const { state } = e
+    if (!state) return
+    ignoreNext = true
+    view.set(null)
+    if (state.type === 'page') {
+      page.set(state.value)
+    } else {
+      view.set(state.value)
+    }
+  })
 </script>
 
 <script>

common/Router.svelte

@@ -33,34 +33,8 @@
   $: maxwidth = $isMobile ? '200px' : '60rem'
 
   onMount(() => {
-    // Check update (ask if on Android, install if on PC)
+    // Check update
     if($settings.enableAutoUpdate && SUPPORTS.update) IPC.emit('update')
-    if (SUPPORTS.isAndroid) {
-      // Back button support
-      let backButtonPressTimeout;
-      window.Capacitor.Plugins.App.addListener("backButton", () => {
-        if (page === "home" && $view === null && $rss === null) {
-          if (backButtonPressTimeout) {
-            clearTimeout(backButtonPressTimeout);
-            window.Capacitor.Plugins.App.exitApp();
-          } else {
-            toast.warning("Press again to exit", { duration: 1000 });
-            backButtonPressTimeout = setTimeout(() => {
-              backButtonPressTimeout = null;
-            }, 1000);
-          }
-        } else {
-          if (document.fullscreenElement) document.exitFullscreen();
-          page = "home";
-          $rss = null;
-          $view = null;
-        }
-      });
-    }
-  });
-
-  onDestroy(() => {
-    if (SUPPORTS.isAndroid) window.Capacitor.Plugins.App.removeAllListeners();
   });
 
   function closeMiniplayer() {