DApp browser: slow/unresponsive tap handling on Android (QubicTrade)

[sallymoc]

Bug Report

User reports being unable to tap into coins in QubicTrade dApp within the Android wallet. Rows highlight but navigation doesn't occur.

Reported Behavior

• Tapping a row highlights it, but second tap does nothing
• Same dApp works correctly in mobile browser
• After phone restart, briefly worked (2 clicks) then showed "page not available"
• Issue persists after closing/reopening app

Investigation

Testing Results

• Android: Initially appeared reproducible, but seems to be a performance/latency issue rather than a complete failure. Taps are slow to respond compared to regular browser.
• iOS: QubicTrade performs well, issue not present.

Potential Causes

1. Gesture recognizer interference (webview_screen.dart:165-169)

   • Custom OnTapGestureRecognizer overrides rejectGesture() to always accept
   • May be intercepting/delaying taps intended for WebView content

2. WebView cache corruption

   • System WebView cache persists across app restarts
   • No way for user to clear cache currently

3. Android WebView performance

   • General performance difference between Android WebView and iOS WKWebView

Possible Improvements to evaluate

• Review gesture recognizer implementation - consider removing or making less aggressive
• Add "Clear browser cache" option in settings or DApp browser menu
• Investigate Android-specific WebView optimizations
• Add explicit WebView settings: javaScriptEnabled, domStorageEnabled

Related Code

• lib/pages/main/tab_dapps/webview_screen.dart
• lib/helpers/dapp_helpers.dart