Add processing preview with progress tracking to the main application

- Implemented a new feature to show a processing preview for clips.
- Added a progress bar, elapsed time, and remaining time indicators.
- Utilized threading to keep the main application responsive during processing.
- Included buttons for previewing clips, opening videos, and exiting the application.

Main.py

@@ -0,0 +1,52 @@
+import tkinter as tk
+from tkinter import ttk, filedialog
+import threading
+import time
+
+# Example function that simulates clip processing with time tracking
+def process_clips(progress_var, progress_bar, status_label, time_label, total_steps=10):
+    start_time = time.time()
+    for i in range(total_steps):
+        time.sleep(0.5)  # Simulate processing time
+        elapsed = time.time() - start_time
+        remaining = (elapsed / (i+1)) * (total_steps - (i+1))
+        progress_var.set((i+1) * 100 / total_steps)
+        status_label.config(text=f"Processing... {i+1}/{total_steps}")
+        time_label.config(text=f"Elapsed: {elapsed:.1f}s | Remaining: {remaining:.1f}s")
+    status_label.config(text="Done!")
+    time_label.config(text=f"Total Time: {time.time() - start_time:.1f}s")
+
+def start_preview_with_progress():
+    progress_window = tk.Toplevel(root)
+    progress_window.title("Processing Preview")
+    progress_window.geometry("320x130")
+    progress_window.resizable(False, False)
+
+    status_label = tk.Label(progress_window, text="Initializing...", anchor="w")
+    status_label.pack(fill="x", padx=10, pady=(10,0))
+
+    time_label = tk.Label(progress_window, text="Elapsed: 0.0s | Remaining: --s", anchor="w")
+    time_label.pack(fill="x", padx=10)
+
+    progress_var = tk.DoubleVar()
+    progress_bar = ttk.Progressbar(progress_window, variable=progress_var, maximum=100)
+    progress_bar.pack(fill="x", padx=10, pady=10)
+
+    threading.Thread(target=process_clips, args=(progress_var, progress_bar, status_label, time_label), daemon=True).start()
+
+# Main Tkinter app remains responsive with all buttons available
+root = tk.Tk()
+root.title("Shorts Generator 2")
+root.geometry("400x200")
+
+preview_button = tk.Button(root, text="Preview Clips", command=start_preview_with_progress)
+preview_button.pack(pady=10)
+
+# Example of other functional buttons remaining available
+open_button = tk.Button(root, text="Open Video", command=lambda: filedialog.askopenfilename())
+open_button.pack(pady=10)
+
+exit_button = tk.Button(root, text="Exit", command=root.quit)
+exit_button.pack(pady=10)
+
+root.mainloop()