feat: stagger cell fetches 8s apart; apply same stagger on connectivity restored

Author: bpmct

src/com/bpmct/trmnl_nook_simple_touch/ShowcaseActivity.java

@@ -373,7 +373,7 @@ private boolean anyCacheExists() {
     private static final long WIFI_WARMUP_MS = 15 * 1000;
     private final android.os.Handler handler = new android.os.Handler();
 
-    private static final long CELL_FETCH_STAGGER_MS = 1500;
+    private static final long CELL_FETCH_STAGGER_MS = 8000;
 
     private void startFetchAll() {
         if (isConnected()) {
@@ -521,7 +521,14 @@ public void onReceive(android.content.Context context, Intent intent) {
                 handler.post(new Runnable() {
                     public void run() {
                         hideNoWifiScreen();
-                        for (int i = 0; i < NUM_CELLS; i++) fetchCell(i);
+                        for (int i = 0; i < NUM_CELLS; i++) {
+                            final int cellIdx = i;
+                            handler.postDelayed(new Runnable() {
+                                public void run() {
+                                    if (isCellConfigured(ShowcaseActivity.this, cellIdx)) fetchCell(cellIdx);
+                                }
+                            }, cellIdx * CELL_FETCH_STAGGER_MS);
+                        }
                     }
                 });
             }