feat: add torch plugin for iOS and Android (#3551)

* feat(barcode-scanner): add torch toggle

* feat: torch plugin

* fix

---------

Co-authored-by: Lucas Nogueira <lucas@tauri.app>

examples/api/src/App.svelte

@@ -32,6 +32,7 @@
   import Biometric from './views/Biometric.svelte'
   import Geolocation from './views/Geolocation.svelte'
   import Haptics from './views/Haptics.svelte'
+  import Torch from './views/Torch.svelte'
   import Nfc from './views/Nfc.svelte'
   import Autostart from './views/Autostart.svelte'
   import DeepLink from './views/DeepLink.svelte'
@@ -185,6 +186,11 @@
       label: 'Haptics',
       component: Haptics,
       icon: 'i-ph-vibrate'
+    },
+    isMobile && {
+      label: 'Torch',
+      component: Torch,
+      icon: 'i-ph-flashlight'
     }
   ].filter(Boolean) as {
     label: string

examples/api/src/views/Scanner.svelte

@@ -6,6 +6,7 @@
     Format,
     cancel
   } from '@tauri-apps/plugin-barcode-scanner'
+  import { toggle as toggleTorch } from '@tauri-apps/plugin-torch'
 
   export let onMessage
 
@@ -35,6 +36,12 @@
     }
   }
 
+  async function toggleScanTorch() {
+    toggleTorch()
+      .then((on) => onMessage(`torch ${on ? 'on' : 'off'}`))
+      .catch(onMessage)
+  }
+
   async function cancelScan() {
     await cancel()
     scanning = false
@@ -67,6 +74,9 @@
           <p>Aim your camera at a QR code</p>
           <button class="btn" type="button" on:click={cancelScan}>Cancel</button
           >
+          <button class="btn" type="button" on:click={toggleScanTorch}
+            >Torch</button
+          >
         </div>
         <div class="square surround-cover">
           <div class="barcode-scanner--area--outer surround-cover">

examples/api/src/views/Torch.svelte

@@ -0,0 +1,56 @@
+<script>
+  import { onMount } from 'svelte'
+  import {
+    enable,
+    disable,
+    toggle,
+    isAvailable,
+    isEnabled
+  } from '@tauri-apps/plugin-torch'
+
+  export let onMessage
+
+  let available = null
+  let enabled = null
+
+  async function refresh() {
+    try {
+      available = await isAvailable()
+      enabled = await isEnabled()
+    } catch (e) {
+      onMessage(e)
+    }
+  }
+
+  function run(action) {
+    return () =>
+      action()
+        .then((res) => onMessage(res ?? 'ok'))
+        .catch(onMessage)
+        .finally(refresh)
+  }
+
+  onMount(refresh)
+</script>
+
+<div>
+  <p>
+    Available: <b>{available ?? '...'}</b> / Enabled:
+    <b>{enabled ?? '...'}</b>
+  </p>
+
+  <button class="btn" id="torch-enable" on:click={run(enable)}>enable</button>
+  <button class="btn" id="torch-disable" on:click={run(disable)}
+    >disable</button
+  >
+  <button class="btn" id="torch-toggle" on:click={run(toggle)}>toggle</button>
+  <button class="btn" id="torch-refresh" on:click={refresh}>refresh state</button
+  >
+</div>
+
+<br />
+
+<p>
+  The torch can also be toggled while scanning from the Scanner page, which on
+  Android goes through the barcode scanner's camera.
+</p>