Update preview on change in image and audio inputs (#1807)

assets/js/hooks/audio_input.js

@@ -32,14 +32,21 @@ const AudioInput = {
 
     this.mediaRecorder = null;
 
-    // Render initial value
+    // Render updated value
-    this.handleEvent(`audio_input_init:${this.props.id}`, (audioInfo) => {
+    this.handleEvent(
-      this.updatePreview({
+      `audio_input_change:${this.props.id}`,
-        data: this.decodeAudio(base64ToBuffer(audioInfo.data)),
+      ({ audio_info: audioInfo }) => {
-        numChannels: audioInfo.num_channels,
+        if (audioInfo) {
-        samplingRate: audioInfo.sampling_rate,
+          this.updatePreview({
-      });
+            data: this.decodeAudio(base64ToBuffer(audioInfo.data)),
-    });
+            numChannels: audioInfo.num_channels,
+            samplingRate: audioInfo.sampling_rate,
+          });
+        } else {
+          this.clearPreview();
+        }
+      }
+    );
 
     // File selection
 
@@ -173,7 +180,6 @@ const AudioInput = {
 
     context.decodeAudioData(buffer, (audioBuffer) => {
       const audioInfo = audioBufferToAudioInfo(audioBuffer);
-      this.updatePreview(audioInfo);
       this.pushAudio(audioInfo);
     });
   },
@@ -185,6 +191,12 @@ const AudioInput = {
     oldUrl && URL.revokeObjectURL(oldUrl);
   },
 
+  clearPreview() {
+    const oldUrl = this.audioEl.src;
+    this.audioEl.src = "";
+    oldUrl && URL.revokeObjectURL(oldUrl);
+  },
+
   pushAudio(audioInfo) {
     this.pushEventTo(this.props.phxTarget, "change", {
       data: bufferToBase64(this.encodeAudio(audioInfo)),

assets/js/hooks/image_input.js

@@ -32,6 +32,8 @@ const ImageInput = {
     this.inputEl = this.el.querySelector(`[data-input]`);
     this.previewEl = this.el.querySelector(`[data-preview]`);
 
+    this.initialPreviewContentEl = this.previewEl.firstElementChild;
+
     this.cameraPreviewEl = this.el.querySelector(`[data-camera-preview]`);
     this.cameraListEl = this.el.querySelector(`[data-camera-list]`);
     this.cameraItemTemplateEl = this.cameraListEl.firstElementChild;
@@ -48,11 +50,18 @@ const ImageInput = {
     this.cameraVideoEl = null;
     this.cameraStream = null;
 
-    // Render initial value
+    // Render updated value
-    this.handleEvent(`image_input_init:${this.props.id}`, (imageInfo) => {
+    this.handleEvent(
-      const canvas = imageInfoToElement(imageInfo, this.props.format);
+      `image_input_change:${this.props.id}`,
-      this.setPreview(canvas);
+      ({ image_info: imageInfo }) => {
-    });
+        if (imageInfo) {
+          const canvas = imageInfoToElement(imageInfo, this.props.format);
+          this.setPreview(canvas);
+        } else {
+          this.setPreview(this.initialPreviewContentEl);
+        }
+      }
+    );
 
     // File selection
 
@@ -119,7 +128,6 @@ const ImageInput = {
         this.cameraVideoEl.videoWidth,
         this.cameraVideoEl.videoHeight
       );
-      this.setPreview(canvas);
       this.pushImage(canvas);
       this.closeCameraView();
     });
@@ -152,7 +160,6 @@ const ImageInput = {
 
       imgEl.addEventListener("load", (loadEvent) => {
         const canvas = this.toCanvas(imgEl, imgEl.width, imgEl.height);
-        this.setPreview(canvas);
         this.pushImage(canvas);
       });
 
@@ -379,11 +386,13 @@ const ImageInput = {
 
   setPreview(element) {
     element.style.maxHeight = "300px";
+    element.style.maxWidth = "100%";
     this.previewEl.replaceChildren(element);
   },
 
   setCameraPreview(element) {
     element.style.maxHeight = "300px";
+    element.style.maxWidth = "100%";
     this.cameraPreviewEl.replaceChildren(element);
   },
 };

lib/livebook_web/live/output/audio_input_component.ex

@@ -3,7 +3,7 @@ defmodule LivebookWeb.Output.AudioInputComponent do
 
   @impl true
   def mount(socket) do
-    {:ok, assign(socket, endianness: System.endianness(), initialized: false)}
+    {:ok, assign(socket, endianness: System.endianness(), value: nil)}
   end
 
   @impl true
@@ -13,24 +13,22 @@ defmodule LivebookWeb.Output.AudioInputComponent do
     socket = assign(socket, assigns)
 
     socket =
-      if socket.assigns.initialized do
+      if value == socket.assigns.value do
         socket
       else
-        socket =
+        audio_info =
           if value do
-            push_event(socket, "audio_input_init:#{socket.assigns.id}", %{
+            %{
               data: Base.encode64(value.data),
               num_channels: value.num_channels,
               sampling_rate: value.sampling_rate
-            })
+            }
-          else
-            socket
           end
 
-        assign(socket, initialized: true)
+        push_event(socket, "audio_input_change:#{socket.assigns.id}", %{audio_info: audio_info})
       end
 
-    {:ok, socket}
+    {:ok, assign(socket, value: value)}
   end
 
   @impl true

lib/livebook_web/live/output/image_input_component.ex

@@ -3,7 +3,7 @@ defmodule LivebookWeb.Output.ImageInputComponent do
 
   @impl true
   def mount(socket) do
-    {:ok, assign(socket, initialized: false)}
+    {:ok, assign(socket, value: nil)}
   end
 
   @impl true
@@ -13,24 +13,18 @@ defmodule LivebookWeb.Output.ImageInputComponent do
     socket = assign(socket, assigns)
 
     socket =
-      if socket.assigns.initialized do
+      if value == socket.assigns.value do
         socket
       else
-        socket =
+        image_info =
           if value do
-            push_event(socket, "image_input_init:#{socket.assigns.id}", %{
+            %{data: Base.encode64(value.data), height: value.height, width: value.width}
-              data: Base.encode64(value.data),
-              height: value.height,
-              width: value.width
-            })
-          else
-            socket
           end
 
-        assign(socket, initialized: true)
+        push_event(socket, "image_input_change:#{socket.assigns.id}", %{image_info: image_info})
       end
 
-    {:ok, socket}
+    {:ok, assign(socket, value: value)}
   end
 
   @impl true