New custom insta delegate

[LeGoffMael]

As we discussed previously #399.
Introduce InstaAssetPickerBuilder based on insta_assets_picker which reproduces instagram layout.

This custom delegate show how to:

• setup a complete different: layout, select and view logic
• use keepScrollOffset when set to true to restore scroll and preview
• customize DefaultAssetPickerViewerBuilderDelegate (currently there is no example for it)

Tested on both iOS and Android.

Changes needed outside of example folder

• Fixed an issue in AssetPickerViewer, when not used in a new pushed route, initStateAndTicker would be omitted.

Record

RPReplay_Final1672293966-3.mov

[AlexV525]

I run the example with the new delegate and delete the didUpdateWidget in the state, nothing happened as I observed. So what's the first issue with the builder exactly?

[LeGoffMael]

I run the example with the new delegate and delete the didUpdateWidget in the state, nothing happened as I observed. So what's the first issue with the builder exactly?

Here i recorded my screen while reproducing the error. Basically when the InstaAssetPickerViewerBuilder is updated to show a different asset or from a scroll action for example, the error occur.

Screen.Recording.2022-12-30.at.2.26.45.PM.mov

[AlexV525]

I've split the initAnimations for the delegate, please try again to see if exceptions were thrown. 😄

[LeGoffMael]

I've split the initAnimations for the delegate, please try again to see if exceptions were thrown. 😄

The exception seems to be gone! Thank you

[AlexV525]

LGTM. Although I do found some strange behavior when scrolling the picker, but I think I'll try to update them and submit issues to your picker if possible.

[LeGoffMael]

LGTM. Although I do found some strange behavior when scrolling the picker, but I think I'll try to update them and submit issues to your picker if possible.

Great! Sure, if you find any issue let me know via the insta_assets_picker repository, i will try to fix it there and apply it in the delegate example as well.