refactoring: make periodic handler use weak references

PeriodicHandler now uses weak references to keep a link to the looper
that requested it. This way, it will not prevent the source from being
garbage collected even though a delayed message may be queued in the
handler.

Also, at the next iteration, the periodic handler will notice that its
starter looper has been garbage collected and will stop itself if it has
not been already.

1 files changed, 13 insertions, 20 deletions

diff --git a/main/src/cgeo/geocaching/ui/CompassView.java b/main/src/cgeo/geocaching/ui/CompassView.java
index 0ef3a43..c926057 100644
--- a/main/src/cgeo/geocaching/ui/CompassView.java
+++ b/main/src/cgeo/geocaching/ui/CompassView.java
@@ -3,6 +3,7 @@ package cgeo.geocaching.ui;
 import cgeo.geocaching.R;
 import cgeo.geocaching.utils.AngleUtils;
 import cgeo.geocaching.utils.PeriodicHandler;
+import cgeo.geocaching.utils.PeriodicHandler.PeriodicHandlerListener;
 
 import android.content.Context;
 import android.graphics.Bitmap;
@@ -14,7 +15,7 @@ import android.util.AttributeSet;
 import android.util.FloatMath;
 import android.view.View;
 
-public class CompassView extends View {
+public class CompassView extends View implements PeriodicHandlerListener {
 
     private Context context = null;
     private Bitmap compassUnderlay = null;
@@ -48,7 +49,7 @@ public class CompassView extends View {
     private int compassOverlayWidth = 0;
     private int compassOverlayHeight = 0;
     private boolean initialDisplay;
-    private final RedrawHandler redrawHandler = new RedrawHandler();
+    private final PeriodicHandler redrawHandler = new PeriodicHandler(40, this);
 
     public CompassView(Context contextIn) {
         super(contextIn);
@@ -145,26 +146,18 @@ public class CompassView extends View {
         return AngleUtils.normalize(actual + offset);
     }
 
-    private class RedrawHandler extends PeriodicHandler {
-
-        public RedrawHandler() {
-            super(40);
-        }
-
-        @Override
-        public void act() {
-            final float newAzimuthShown = smoothUpdate(northMeasured, azimuthShown);
-            final float newCacheHeadingShown = smoothUpdate(cacheHeadingMeasured, cacheHeadingShown);
-            if (Math.abs(AngleUtils.difference(azimuthShown, newAzimuthShown)) >= 2 ||
-                    Math.abs(AngleUtils.difference(cacheHeadingShown, newCacheHeadingShown)) >= 2) {
-                synchronized(CompassView.this) {
-                    azimuthShown = newAzimuthShown;
-                    cacheHeadingShown = newCacheHeadingShown;
-                }
-                invalidate();
+    @Override
+    public void onPeriodic() {
+        final float newAzimuthShown = smoothUpdate(northMeasured, azimuthShown);
+        final float newCacheHeadingShown = smoothUpdate(cacheHeadingMeasured, cacheHeadingShown);
+        if (Math.abs(AngleUtils.difference(azimuthShown, newAzimuthShown)) >= 2 ||
+                Math.abs(AngleUtils.difference(cacheHeadingShown, newCacheHeadingShown)) >= 2) {
+            synchronized(this) {
+                azimuthShown = newAzimuthShown;
+                cacheHeadingShown = newCacheHeadingShown;
             }
+            invalidate();
         }
-
     }
 
     @Override