Add drag & drop, smart presets, and keyboard shortcuts

frontend/src/App.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { onMount } from 'svelte';
   import { transformImage } from "./lib/api";
   import {
     generateClientPreview,
@@ -9,6 +10,7 @@
     type TransformOptions
   } from "./lib/preview";
   import { theme } from "./lib/theme";
+  import { PRESETS, applyPreset, type Preset } from "./lib/presets";
 
   let file: File | null = null;
   let filePreviewUrl: string | null = null;
@@ -22,6 +24,10 @@
   let processing = false;
   let error: string | null = null;
   
+  // Drag & drop state
+  let isDragging = false;
+  let showShortcuts = false;
+  
   // Preview state
   let previewUrl: string | null = null;
   let previewSize = 0;
@@ -93,13 +99,93 @@
     }
   }
 
+  function handleFile(selectedFile: File) {
+    if (!selectedFile.type.startsWith('image/')) {
+      error = 'Please select an image file';
+      return;
+    }
+    file = selectedFile;
+    filePreviewUrl = URL.createObjectURL(selectedFile);
+    error = null;
+  }
+
   function onFileChange(e: Event) {
     const target = e.target as HTMLInputElement;
-    file = target.files?.[0] || null;
-    if (file) {
-      filePreviewUrl = URL.createObjectURL(file);
-    } else {
-      filePreviewUrl = null;
+    const selectedFile = target.files?.[0];
+    if (selectedFile) {
+      handleFile(selectedFile);
+    }
+  }
+
+  // Drag & Drop handlers
+  function onDragOver(e: DragEvent) {
+    e.preventDefault();
+    isDragging = true;
+  }
+
+  function onDragLeave(e: DragEvent) {
+    e.preventDefault();
+    isDragging = false;
+  }
+
+  function onDrop(e: DragEvent) {
+    e.preventDefault();
+    isDragging = false;
+    
+    const droppedFile = e.dataTransfer?.files?.[0];
+    if (droppedFile) {
+      handleFile(droppedFile);
+    }
+  }
+
+  // Paste handler
+  function onPaste(e: ClipboardEvent) {
+    const items = e.clipboardData?.items;
+    if (!items) return;
+
+    for (let i = 0; i < items.length; i++) {
+      if (items[i].type.indexOf('image') !== -1) {
+        const pastedFile = items[i].getAsFile();
+        if (pastedFile) {
+          handleFile(pastedFile);
+        }
+        break;
+      }
+    }
+  }
+
+  // Keyboard shortcuts
+  function onKeyDown(e: KeyboardEvent) {
+    // Show shortcuts help
+    if (e.key === '?') {
+      e.preventDefault();
+      showShortcuts = !showShortcuts;
+      return;
+    }
+
+    // Close shortcuts dialog
+    if (e.key === 'Escape' && showShortcuts) {
+      showShortcuts = false;
+      return;
+    }
+
+    // Ctrl/Cmd + V - Paste (handled by paste event)
+    // Ctrl/Cmd + Enter - Transform & Download
+    if ((e.ctrlKey || e.metaKey) && e.key === 'Enter' && file && !processing) {
+      e.preventDefault();
+      onSubmit();
+      return;
+    }
+
+    // Enter alone - Transform & Download (if input not focused)
+    const activeElement = document.activeElement;
+    const isInputFocused = activeElement?.tagName === 'INPUT' || 
+                           activeElement?.tagName === 'SELECT' ||
+                           activeElement?.tagName === 'TEXTAREA';
+    
+    if (e.key === 'Enter' && !isInputFocused && file && !processing) {
+      e.preventDefault();
+      onSubmit();
     }
   }
 
@@ -112,6 +198,27 @@
     previewSize = 0;
   }
 
+  // Apply preset
+  function selectPreset(preset: Preset) {
+    const settings = applyPreset(preset, width, height);
+    width = settings.width;
+    height = settings.height;
+    quality = settings.quality;
+    format = settings.format;
+    fit = settings.fit;
+  }
+
+  // Setup event listeners
+  onMount(() => {
+    document.addEventListener('paste', onPaste);
+    document.addEventListener('keydown', onKeyDown);
+    
+    return () => {
+      document.removeEventListener('paste', onPaste);
+      document.removeEventListener('keydown', onKeyDown);
+    };
+  });
+
   const savings = showPreview ? calculateSavings(originalSize, previewSize) : null;
 </script>
 
@@ -122,6 +229,10 @@
       <h1 class="mb-0">PNGer</h1>
       <p class="text-sm mb-0">Modern PNG Editor & Resizer</p>
     </div>
+    <div class="flex gap-sm">
+      <button class="btn-outline" on:click={() => showShortcuts = !showShortcuts} title="Keyboard shortcuts (?)">
+        ⌨️
+      </button>
       <button class="btn-outline" on:click={() => theme.toggle()}>
         {#if $theme === 'dark'}
           ☀️ Light
@@ -129,8 +240,43 @@
           🌙 Dark
         {/if}
       </button>
+    </div>
   </header>
 
+  <!-- Shortcuts Modal -->
+  {#if showShortcuts}
+    <div class="modal-overlay" on:click={() => showShortcuts = false}>
+      <div class="modal-content" on:click|stopPropagation>
+        <h2>Keyboard Shortcuts</h2>
+        <div class="shortcuts-list">
+          <div class="shortcut-item">
+            <kbd>Ctrl</kbd> + <kbd>V</kbd>
+            <span>Paste image from clipboard</span>
+          </div>
+          <div class="shortcut-item">
+            <kbd>Enter</kbd>
+            <span>Transform & Download</span>
+          </div>
+          <div class="shortcut-item">
+            <kbd>Ctrl</kbd> + <kbd>Enter</kbd>
+            <span>Transform & Download (anywhere)</span>
+          </div>
+          <div class="shortcut-item">
+            <kbd>?</kbd>
+            <span>Show/hide this help</span>
+          </div>
+          <div class="shortcut-item">
+            <kbd>Esc</kbd>
+            <span>Close this dialog</span>
+          </div>
+        </div>
+        <button style="margin-top: var(--space-lg);" on:click={() => showShortcuts = false}>
+          Close
+        </button>
+      </div>
+    </div>
+  {/if}
+
   <!-- Controls Section -->
   <div class="card fade-in" style="margin-bottom: var(--space-xl);">
     <div class="grid grid-cols-2 gap-lg">
@@ -138,30 +284,74 @@
       <div>
         <h2>Upload & Settings</h2>
 
-        <!-- File Upload -->
+        <!-- Drag & Drop / File Upload -->
         <div style="margin-bottom: var(--space-lg);">
           <label style="display: block; margin-bottom: var(--space-sm); font-weight: 500;">
-            Select Image
+            Select or Drop Image
           </label>
+          
+          <!-- Drop Zone -->
+          <div 
+            class="drop-zone {isDragging ? 'dragging' : ''}"
+            on:dragover={onDragOver}
+            on:dragleave={onDragLeave}
+            on:drop={onDrop}
+          >
             <input 
               type="file" 
               accept="image/*" 
               on:change={onFileChange}
-            style="margin-bottom: var(--space-sm);"
+              id="file-input"
+              style="display: none;"
             />
+            <label for="file-input" class="drop-zone-label">
               {#if file}
-            <div class="flex gap-sm items-center" style="margin-top: var(--space-sm);">
+                <div class="flex gap-sm items-center" style="flex-direction: column;">
+                  <span style="font-size: 2rem;">✅</span>
                   <span class="text-sm">{file.name}</span>
                   <span class="text-xs" style="color: var(--color-text-secondary);">
                     ({formatFileSize(file.size)})
                   </span>
-              <button class="btn-secondary" style="padding: var(--space-xs) var(--space-sm); font-size: 0.875rem;" on:click={clearFile}>
-                Clear
-              </button>
+                </div>
+              {:else}
+                <div style="text-align: center;">
+                  <p style="font-size: 3rem; margin-bottom: var(--space-sm);">🖼️</p>
+                  <p style="margin-bottom: var(--space-xs);">Drag & drop image here</p>
+                  <p class="text-sm" style="color: var(--color-text-secondary); margin-bottom: var(--space-sm);">or click to browse</p>
+                  <p class="text-xs" style="color: var(--color-text-secondary);">Paste with Ctrl+V</p>
                 </div>
               {/if}
+            </label>
           </div>
 
+          {#if file}
+            <button class="btn-secondary" style="width: 100%; margin-top: var(--space-sm);" on:click={clearFile}>
+              Clear File
+            </button>
+          {/if}
+        </div>
+
+        <!-- Smart Presets -->
+        {#if file}
+          <div style="margin-bottom: var(--space-lg);" class="fade-in">
+            <label style="display: block; margin-bottom: var(--space-sm); font-weight: 500;">
+              Quick Presets
+            </label>
+            <div class="presets-grid">
+              {#each PRESETS as preset}
+                <button 
+                  class="preset-btn"
+                  on:click={() => selectPreset(preset)}
+                  title={preset.description}
+                >
+                  <span class="preset-icon">{preset.icon}</span>
+                  <span class="preset-name">{preset.name}</span>
+                </button>
+              {/each}
+            </div>
+          </div>
+        {/if}
+
         <!-- Dimensions -->
         <div style="margin-bottom: var(--space-lg);">
           <h3>Dimensions</h3>
@@ -258,6 +448,12 @@
             ⬇️ Transform & Download
           {/if}
         </button>
+        
+        {#if file}
+          <p class="text-xs" style="color: var(--color-text-secondary); text-align: center; margin-top: var(--space-sm); margin-bottom: 0;">
+            Press <kbd style="font-size: 0.75rem; padding: 2px 4px;">Enter</kbd> to download
+          </p>
+        {/if}
       </div>
     </div>
   </div>
@@ -271,6 +467,7 @@
         <div>
           <p style="font-size: 3rem; margin-bottom: var(--space-md)">🖼️</p>
           <p class="mb-0">Upload an image to see live preview</p>
+          <p class="text-sm" style="color: var(--color-text-secondary); margin-top: var(--space-sm);">Drag & drop, click to browse, or paste with Ctrl+V</p>
         </div>
       </div>
     {:else if showPreview}
@@ -337,3 +534,130 @@
     {/if}
   </div>
 </div>
+
+<style>
+  /* Drop zone styles */
+  .drop-zone {
+    border: 2px dashed var(--color-border);
+    border-radius: var(--radius-md);
+    padding: var(--space-xl);
+    text-align: center;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    background: var(--color-bg-secondary);
+  }
+
+  .drop-zone:hover {
+    border-color: var(--color-accent);
+    background: var(--color-bg-tertiary);
+  }
+
+  .drop-zone.dragging {
+    border-color: var(--color-accent);
+    background: var(--color-accent)15;
+    border-style: solid;
+  }
+
+  .drop-zone-label {
+    display: block;
+    cursor: pointer;
+  }
+
+  /* Presets grid */
+  .presets-grid {
+    display: grid;
+    grid-template-columns: repeat(4, 1fr);
+    gap: var(--space-sm);
+  }
+
+  .preset-btn {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: var(--space-xs);
+    padding: var(--space-sm);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-sm);
+    background: var(--color-bg-secondary);
+    cursor: pointer;
+    transition: all 0.2s ease;
+    font-size: 0.75rem;
+  }
+
+  .preset-btn:hover {
+    border-color: var(--color-accent);
+    background: var(--color-bg-tertiary);
+    transform: translateY(-2px);
+  }
+
+  .preset-icon {
+    font-size: 1.5rem;
+  }
+
+  .preset-name {
+    font-size: 0.7rem;
+    text-align: center;
+    line-height: 1.2;
+  }
+
+  /* Modal styles */
+  .modal-overlay {
+    position: fixed;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    background: rgba(0, 0, 0, 0.5);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 1000;
+    animation: fadeIn 0.2s ease;
+  }
+
+  .modal-content {
+    background: var(--color-bg-primary);
+    border-radius: var(--radius-lg);
+    padding: var(--space-2xl);
+    max-width: 500px;
+    width: 90%;
+    box-shadow: var(--shadow-2xl);
+  }
+
+  .shortcuts-list {
+    display: flex;
+    flex-direction: column;
+    gap: var(--space-md);
+    margin-top: var(--space-lg);
+  }
+
+  .shortcut-item {
+    display: flex;
+    align-items: center;
+    gap: var(--space-md);
+    padding: var(--space-sm);
+    background: var(--color-bg-secondary);
+    border-radius: var(--radius-sm);
+  }
+
+  .shortcut-item span {
+    flex: 1;
+    color: var(--color-text-secondary);
+  }
+
+  kbd {
+    display: inline-block;
+    padding: 4px 8px;
+    font-size: 0.875rem;
+    font-family: monospace;
+    background: var(--color-bg-tertiary);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-sm);
+    box-shadow: 0 2px 0 var(--color-border);
+  }
+
+  @keyframes fadeIn {
+    from { opacity: 0; }
+    to { opacity: 1; }
+  }
+</style>