SimpleFileReader

This is a simple Android app to read and display PDF, DOCX, and XLSX files from internal and external storage.

Features

• PDF reading:

  • Uses Android's built-in PdfRenderer to render and display PDF files.

  • Optimized with cache to make PDF rendering smoother and faster, especially when switching pages.

• DOCX and XLSX reading (see feature branches):

  • Supports reading DOCX and XLSX files using third-party libraries like:

    • Apache POI

    • docx4j

    • Other similar libraries

  • Note: These libraries only help read the data.
    You must manually visualize the content in your app.

    Example for XLSX files:

    • Use Apache POI to access specific cell positions.

    • Extract the raw data.

    • Build your own UI.

    For manual visualization, you can:

    • Render content as custom HTML inside a WebView.

    • Or draw directly on a Canvas and render to a Bitmap.

How It Works

• PDF files:

  • Open using Android's PdfRenderer.

  • Render each page as a bitmap image.

  • Cache pages smartly to reduce loading time and memory usage.

• DOCX files:

  • Read paragraphs, tables, and document structures via library APIs.

  • Visualize manually using HTML rendering or custom Bitmap drawing.

• XLSX files:

  • Read sheets, rows, and cells via library APIs.

  • Extract and map data manually to display in your own UI components.

Tech Stack

• Kotlin

• Android Jetpack

• MVVM architecture (ViewModel, Repository)

• Hilt for Dependency Injection

• Flow for reactive streams

• Storage Access Framework (SAF) for Android 13+ support

• MediaStore for Android 12 and below

• Caching for improving PDF rendering performance

Screenshot

Note

• This project focuses on file reading and basic data handling.

• PDF rendering is optimized using caching techniques for better UX.

• DOCX/XLSX visualization must be custom-built:

  • You can either render via HTML inside a WebView,

  • Or draw manually on Bitmap/Canvas for full control.

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