Design and Implementation of a Custom Flutter Photo Album Component

When developing image and video features, accessing the system photo album is common but limited; advanced needs such as custom UI and multi‑selection require a dedicated component.

The component provides a simple yet flexible API. The UI layer is built with Flutter, while data is supplied by native platforms via a MethodChannel, following an MVC pattern where Widgets act as Views, Models hold state, and Controllers trigger native calls.

Native side modules include UIAdapter (device adaptation), Permission (media access), Cache (GPU texture caching), Decoder (Bitmap decoding), and OpenGL (texture conversion).

Key challenges:

Pagination loading : Use

GridView.builder({ ... List<Widget> children = const <Widget>[], ... })

for lazy widget creation.

Resource recycling : Delete GPU textures when images go off‑screen; a state machine (None, Loading, Loaded, Wait_Dispose, Disposed) manages image lifecycle to avoid memory spikes.

Large‑image preview : Decode Bitmaps with scaling (max 1080p) and rotate via OpenGL texture coordinates for performance.

PageView preloading : Set PageController(viewportFraction=0.9999) to keep adjacent pages ready, or preload neighboring textures on the native side.

Memory usage is greatly reduced because most images are kept as GPU textures rather than Java heap objects, but GPU memory must be released on the GPU thread to prevent leaks.

The component is highly customizable, independent of the system album, and ready for future extensions such as 4K image support and open‑source release.