#6 File Dialog: Building Modern GUIs using Python | Full Course | 2025

Key Concepts

File uploaders, file dialogues, drag and drop functionality, file filters, open file, save file, select folder, UI events, path retrieval, image processing.

Project Setup and Initial Design

The video begins with creating a new project named "file dialogue" in PyCharm. A folder with the same name is created, and its path is used to enable autosync in PyCharm. The presenter then navigates to the "inputs" section to find file dialogue options. The video highlights the availability of pre-designed file uploader components that can be directly used.

File Dialogue Types and Options

The video emphasizes three main types of file dialogues:

1. Open File: Allows selecting files from the system. By default, it allows all file types, but file filters can be applied to restrict the selection to specific types (e.g., PNG images).
   • Example: Setting the file filter to "PNG" will only display PNG images in the file selection dialogue.
2. Save File: Provides a dialogue to save a file to a specified location. It prompts the user to choose a folder and filename.
   • Functionality: When selected, it prompts the user to "save as" and choose a file location.
3. Select Folder: Enables the user to select a folder, returning the path to that folder.
   • Functionality: When selected, it prompts the user to "select folder" and returns the path of the selected folder.

Customization Options

The video details various customization options for the file dialogue component:

• Size and Position: Width and height can be adjusted by dragging.
• Drag and Drop: Enables or disables drag-and-drop functionality.
  • Example: Disabling drag and drop forces the user to click the component to open the file browser.
• Text and Font: The "Drop a file here" text, color, font family, and font size can be modified.
• Background: Background color and opacity can be adjusted.
• Border: Corner radius, padding, border thickness, border color, and dashed/dotted border styles can be customized. The dashed/dotted border is noted as experimental.
  • Note: The dashed/dotted border style may not render correctly with small border thicknesses.
• Icons: Different icons can be selected, scaled, and positioned within the component.

Code Implementation and Event Handling

The video explains how to retrieve the selected file path using event handling:

1. Attaching Events: The attach_events function is used to link the file dialogue component to a Python function that will be executed when a file is selected.
2. UI Access: The file dialogue component is accessed using its name (e.g., file_dialog_zero) through the UI object (UI).
3. on_file_selected Event: The on_file_selected event is triggered when a file is selected. A custom function (e.g., do_something) is assigned to this event.
4. Path Retrieval: The selected file path is passed as an argument to the custom function.
5. Path Processing: The path can then be used to access, process, or manipulate the selected file.
   • Example: The video demonstrates printing the file path to the console.

Code Snippet:

UI.page_0.file_dialog_zero.on_file_selected = do_something

def do_something(path):
    print(path)

Drag and Drop Example

The video demonstrates dragging an image file ("drone programming.jpg") onto the file dialogue component. When drag and drop is enabled, the file path is displayed after the file is dropped.

Conclusion

The video provides a comprehensive guide on using file uploaders in the software, covering different file dialogue types, customization options, and code implementation for retrieving file paths. It emphasizes the ease of integrating file selection functionality and the flexibility in processing the selected files. The key takeaway is that the file uploader component provides a path to the selected file or folder, which can then be used for further processing within the application.