Ticket #4628: ScreenSaverRunnerFix_4628.diff

src/kits/screensaver/ScreenSaverRunner.cpp

@@ -172 +172 @@
 void
 ScreenSaverRunner::_Run() 
 {
-    const uint32 kTickBase = 50000;
+static const uint32 kInitialTickRate = 50000;
+
     if (fWindow->Lock()) {
         fView->SetViewColor(0, 0, 0);
         fView->SetLowColor(0, 0, 0);
@@ -181 +182 @@
         fWindow->Unlock();
     }
     
+    uint32 TickBase = kInitialTickRate;
     int32 snoozeCount = 0;
     int32 frame = 0;
     bigtime_t lastTickTime = 0;
-    bigtime_t tick = fSaver ? fSaver->TickSize() : kTickBase;
+    bigtime_t tick = fSaver ? fSaver->TickSize() : TickBase;
 
     while (!fQuitting) {
         // break the idle time up into ticks so that we can evaluate
@@ -192 +194 @@
         // otherwise a screen saver that sets, say, a 30 second tick
         // will result in the screen saver not responding to deactivation
         // for that length of time
-        snooze(kTickBase);
-        if (system_time() - lastTickTime < tick)
+        snooze(TickBase);
+        if (system_time() - lastTickTime < tick) {
             continue;
-        else { 
+        } else {
             // re-evaluate the tick time after each successful wakeup - 
-            // screensavers can adjust it on the fly and we must be
+            // screensavers can adjust it on the fly, and we must be
             // prepared to accomodate that
-            tick = fSaver ? fSaver->TickSize() : kTickBase;
+            tick = fSaver ? fSaver->TickSize() : TickBase;
+            
+            if (tick < TickBase) {
+                if (tick < 0) tick = 0;
+                TickBase = tick;
+            }
+            else if (TickBase < kInitialTickRate && tick >= kInitialTickRate) {
+                TickBase = kInitialTickRate;
+            }
+            
             lastTickTime = system_time();
         }