feat: rebuild UI with sidebar and tabbed Single/Batch layout

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -170,42 +170,66 @@ def _build_demo() -> gr.Blocks:
             "[Paper](https://arxiv.org/pdf/2309.04662)"
         )
 
-        target_language = gr.Dropdown(
-            choices=language_names,
-            value="French",
-            label="Target language",
-        )
-
         with gr.Row():
-            input_text = gr.Textbox(
-                label="English",
-                placeholder="Enter English text here",
-                lines=4,
-            )
-            output_text = gr.Textbox(
-                label="Translation",
-                lines=4,
-                buttons=["copy"],
-                interactive=False,
-            )
-
-        translate_btn = gr.Button("Translate", variant="primary")
-
-        translate_btn.click(
-            fn=translate,
-            inputs=[input_text, target_language],
-            outputs=output_text,
-        )
-
-        gr.Examples(
-            examples=[
-                ["Hello, how are you today?", "French"],
-                ["The weather is beautiful.", "Spanish"],
-                ["Thank you very much.", "German"],
-                ["Where is the train station?", "Portuguese"],
-            ],
-            inputs=[input_text, target_language],
-        )
+            # --- Sidebar ---
+            with gr.Column(scale=1, min_width=250):
+                gr.Markdown("### Settings")
+
+                target_language = gr.Dropdown(
+                    choices=language_names,
+                    value="French",
+                    label="Target language",
+                )
+                max_new_tokens = gr.Slider(minimum=1, maximum=1024, value=512, step=1, label="Max new tokens")
+                num_beams = gr.Slider(minimum=1, maximum=10, value=1, step=1, label="Num beams")
+                temperature = gr.Slider(minimum=0.1, maximum=2.0, value=1.0, step=0.1, label="Temperature")
+
+            # --- Main area ---
+            with gr.Column(scale=3):
+                with gr.Tab("Single"):
+                    with gr.Row():
+                        input_text = gr.Textbox(
+                            label="English",
+                            placeholder="Enter English text here",
+                            lines=4,
+                        )
+                        output_text = gr.Textbox(
+                            label="Translation",
+                            lines=4,
+                            buttons=["copy"],
+                            interactive=False,
+                        )
+
+                    single_btn = gr.Button("Translate", variant="primary")
+
+                    single_btn.click(
+                        fn=translate,
+                        inputs=[input_text, target_language, max_new_tokens, num_beams, temperature],
+                        outputs=output_text,
+                    )
+
+                    gr.Examples(
+                        examples=[
+                            ["Hello, how are you today?", "French"],
+                            ["The weather is beautiful.", "Spanish"],
+                            ["Thank you very much.", "German"],
+                            ["Where is the train station?", "Portuguese"],
+                        ],
+                        inputs=[input_text, target_language],
+                    )
+
+                with gr.Tab("Batch"):
+                    gr.Markdown("Upload a `.txt` file (one sentence per line) or a `.csv` file with a `text` column.")
+                    batch_input = gr.File(label="Upload file", file_types=[".txt", ".csv"])
+                    batch_output = gr.File(label="Download translations", interactive=False)
+
+                    batch_btn = gr.Button("Translate", variant="primary")
+
+                    batch_btn.click(
+                        fn=translate_batch,
+                        inputs=[batch_input, target_language, max_new_tokens, num_beams, temperature],
+                        outputs=batch_output,
+                    )
 
     return demo
 

tests/test_app.py

@@ -122,6 +122,39 @@ def test_translate_batch_exists():
     assert callable(app.translate_batch)
 
 
+def test_demo_has_sidebar_and_tabs():
+    """Verify the demo contains the expected layout components."""
+    import app
+
+    demo = app._build_demo()
+    # Flatten all blocks in the demo
+    blocks = demo.blocks
+
+    # Check for key component types by looking at block values
+    component_types = {type(b).__name__ for b in blocks.values()}
+    assert "Tab" in component_types, f"Expected Tab component, found: {component_types}"
+    assert "Slider" in component_types, f"Expected Slider component, found: {component_types}"
+    assert "Dropdown" in component_types, f"Expected Dropdown component, found: {component_types}"
+
+
+def test_demo_has_three_sliders():
+    """Three sliders: max_new_tokens, num_beams, temperature."""
+    import app
+
+    demo = app._build_demo()
+    sliders = [b for b in demo.blocks.values() if type(b).__name__ == "Slider"]
+    assert len(sliders) == 3, f"Expected 3 sliders, found {len(sliders)}"
+
+
+def test_demo_has_two_tabs():
+    """Two tabs: Single and Batch."""
+    import app
+
+    demo = app._build_demo()
+    tabs = [b for b in demo.blocks.values() if type(b).__name__ == "Tab"]
+    assert len(tabs) == 2, f"Expected 2 tabs, found {len(tabs)}"
+
+
 # --- Slow tests (require CUDA + model download) ---
 
 gpu_available = torch.cuda.is_available()