From 715b66bc9b60eb49b6305aed971cc3c1fce77336 Mon Sep 17 00:00:00 2001
From: Francisco De La Hoz <39561227+franciscodelahoz@users.noreply.github.com>
Date: Sat, 9 Nov 2024 15:44:54 -0500
Subject: [PATCH] feat: implement file picker for loading ROM files and update
 UI for better user interaction

---
 src/html/index.html                 |  2 +-
 src/scripts/ui/controls/emulator.ts | 97 +++++++++++++++++++++++------
 src/styles/style.css                | 32 ++--------
 3 files changed, 84 insertions(+), 47 deletions(-)

diff --git a/src/html/index.html b/src/html/index.html
index 3f0e484..4aa3f52 100644
--- a/src/html/index.html
+++ b/src/html/index.html
@@ -22,7 +22,7 @@
       <section class="emulator-view">
         <canvas id="canvas" width="768" height="384"></canvas>
         <div class="rom-controller">
-          <input type="file" name="file" id="file" accept=".ch8,.sc8,.xo8" aria-label="Chip8 file selector">
+          <div id="file">Click to Load ROM File</div>
           <button id="reset-rom-btn" class="default-button">Reset ROM</button>
         </div>
       </section>
diff --git a/src/scripts/ui/controls/emulator.ts b/src/scripts/ui/controls/emulator.ts
index ee7e835..b3803f2 100644
--- a/src/scripts/ui/controls/emulator.ts
+++ b/src/scripts/ui/controls/emulator.ts
@@ -1,17 +1,89 @@
 import { Chip8Emulator } from '../../emulator/emulator';
 
-const input = document.getElementById('file') as HTMLInputElement | null;
+const input = document.getElementById('file') as HTMLElement | null;
 const resetRomBtn = document.getElementById('reset-rom-btn') as HTMLElement | null;
 
+async function getFileFromHandle(fileHandle: File | FileSystemFileHandle): Promise<File> {
+  if (fileHandle instanceof FileSystemFileHandle) {
+    return await fileHandle.getFile();
+  } else {
+    return fileHandle;
+  }
+}
+
+async function handleFileInput(files: FileList | FileSystemFileHandle[], emulatorInstance: Chip8Emulator) {
+  let fileData = await getFileFromHandle(files[0]);
+
+  try {
+    const arrayBuffer = await fileData.arrayBuffer();
+    const romData = new Uint8Array(arrayBuffer);
+
+    emulatorInstance.loadRomFromData(romData);
+
+  } catch(error) {
+    return alert(`Error loading the ROM file.`);
+  }
+}
+
+function setNowPlayingRomName(romName: string) {
+  if (!input) return;
+  input.innerText = `Loaded ROM: ${romName}`;
+}
+
+async function handleFilePickerEvent(emulatorInstance: Chip8Emulator) {
+  const filePickerOptions: OpenFilePickerOptions = {
+    types: [
+      {
+        description: 'Chip-8 ROM files',
+        accept: {
+          'application/octet-stream': ['.ch8', '.sc8', '.xo8'],
+        },
+      },
+    ],
+    multiple: false,
+  };
+
+  const fileHandle = await window.showOpenFilePicker(filePickerOptions);
+  await handleFileInput(fileHandle, emulatorInstance);
+
+  setNowPlayingRomName(fileHandle[0].name);
+}
+
+async function handleFilePickerEventFallback(emulatorInstance: Chip8Emulator) {
+  const fileInput = document.createElement('input');
+
+  fileInput.type = 'file';
+  fileInput.accept = '.ch8,.sc8,.xo8';
+  fileInput.style.display = 'none';
+
+  fileInput.addEventListener('change', async (event) => {
+    const target = event.target as HTMLInputElement;
+
+    if (target.files && target.files.length > 0) {
+      await handleFileInput(target.files, emulatorInstance);
+      setNowPlayingRomName(target.files[0].name);
+    }
+  });
+
+  document.body.appendChild(fileInput);
+  fileInput.click();
+  document.body.removeChild(fileInput);
+}
+
 function initializeRomFileInputEventHandlers(emulatorInstance: Chip8Emulator) {
   if (!input) return;
 
-  input.addEventListener('change', async (event) => {
+  input.addEventListener('click', async () => {
     try {
-      await emulatorInstance.startEmulation(event as GenericEvent<HTMLInputElement>);
-      input.blur();
+      if ('showOpenFilePicker' in window) {
+        await handleFilePickerEvent(emulatorInstance);
+      } else {
+        await handleFilePickerEventFallback(emulatorInstance);
+      }
     } catch(error) {
-      console.error(error);
+      if ((error as Error)?.name !== 'AbortError') {
+        return alert(`Error loading the ROM file.`);
+      }
     }
   });
 }
@@ -28,21 +100,6 @@ function initializeResetRomButtonEventHandlers(emulatorInstance: Chip8Emulator)
   });
 }
 
-async function handleFileInput(files: Array<FileSystemFileHandle>, emulatorInstance: Chip8Emulator) {
-  const fileHandle = files[0];
-
-  try {
-    const fileData = await fileHandle.getFile();
-    const arrayBuffer = await fileData.arrayBuffer();
-
-    const romData = new Uint8Array(arrayBuffer);
-    emulatorInstance.loadRomFromData(romData);
-
-  } catch(error) {
-    return alert(`Error loading the ROM file.`);
-  }
-}
-
 function registerFileHandlerLoadRom(emulatorInstance: Chip8Emulator) {
   window.launchQueue?.setConsumer(async (launchParams) => {
     if (launchParams.files.length) {
diff --git a/src/styles/style.css b/src/styles/style.css
index f3fcf8a..b5c12e1 100644
--- a/src/styles/style.css
+++ b/src/styles/style.css
@@ -82,16 +82,16 @@ body {
   width: 100%;
 }
 
-.rom-controller input {
-  content: 'Upload rom file';
-  border: 2px solid #34ff66;
-  padding: 5px;
-  border-radius: 5px;
+#file {
   user-select: none;
   cursor: pointer;
-  flex-grow: 10;
   font-family: Verdana;
   font-size: 0.83rem;
+  flex-grow: 9;
+  border: 2px solid #34ff66;
+  padding: 5px;
+  border-radius: 5px;
+  text-overflow: ellipsis;
 }
 
 .default-button {
@@ -161,26 +161,6 @@ body {
   height: 1.9rem;
 }
 
-input[type="file"]::-webkit-file-upload-button {
-  display: none;
-}
-
-input[type="file"]::-moz-file-upload-button {
-  display: none;
-}
-
-input[type="file"]::-ms-file-upload-button {
-  display: none;
-}
-
-input[type="file"]::-o-file-upload-button {
-  display: none;
-}
-
-input[type="file"]::file-upload-button {
-  display: none;
-}
-
 .keyboard-container {
   padding: 0.6rem;
 }