Rewrite: Widget preview loader logic

> Widget previews are saved in data dir instead of cache dir
> Expiring widget previews similar to IconCache
> Removed support for setting thread priorities

Bug: 19865031
Change-Id: Ib6033c2b1ff8ae61bba8762ca994ccd8217d3c75
diff --git a/src/com/android/launcher3/LauncherAppState.java b/src/com/android/launcher3/LauncherAppState.java
index 9082276..555b1cc 100644
--- a/src/com/android/launcher3/LauncherAppState.java
+++ b/src/com/android/launcher3/LauncherAppState.java
@@ -32,7 +32,6 @@
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.Display;
-import android.view.View.AccessibilityDelegate;
 import android.view.WindowManager;
 
 import com.android.launcher3.compat.LauncherAppsCompat;
@@ -49,12 +48,12 @@
     private final BuildInfo mBuildInfo;
     @Thunk final LauncherModel mModel;
     private final IconCache mIconCache;
+    private final WidgetPreviewLoader mWidgetCache;
 
     private final boolean mIsScreenLarge;
     private final float mScreenDensity;
     private final int mLongPressTimeout = 300;
 
-    private WidgetPreviewLoader.CacheDb mWidgetPreviewCacheDb;
     private boolean mWallpaperChangedSinceLastCheck;
 
     private static WeakReference<LauncherProvider> sLauncherProvider;
@@ -101,9 +100,8 @@
         // set sIsScreenXLarge and mScreenDensity *before* creating icon cache
         mIsScreenLarge = isScreenLarge(sContext.getResources());
         mScreenDensity = sContext.getResources().getDisplayMetrics().density;
-
-        recreateWidgetPreviewDb();
         mIconCache = new IconCache(sContext);
+        mWidgetCache = new WidgetPreviewLoader(sContext, mIconCache);
 
         mAppFilter = AppFilter.loadByName(sContext.getString(R.string.app_filter_class));
         mBuildInfo = BuildInfo.loadByName(sContext.getString(R.string.build_info_class));
@@ -125,13 +123,6 @@
                 mFavoritesObserver);
     }
 
-    public void recreateWidgetPreviewDb() {
-        if (mWidgetPreviewCacheDb != null) {
-            mWidgetPreviewCacheDb.close();
-        }
-        mWidgetPreviewCacheDb = new WidgetPreviewLoader.CacheDb(sContext);
-    }
-
     /**
      * Call from Application.onTerminate(), which is not guaranteed to ever be called.
      */
@@ -181,10 +172,6 @@
         return mAppFilter == null || mAppFilter.shouldShowApp(componentName);
     }
 
-    WidgetPreviewLoader.CacheDb getWidgetPreviewCacheDb() {
-        return mWidgetPreviewCacheDb;
-    }
-
     static void setLauncherProvider(LauncherProvider provider) {
         sLauncherProvider = new WeakReference<LauncherProvider>(provider);
     }
@@ -240,6 +227,10 @@
         return mDynamicGrid;
     }
 
+    public WidgetPreviewLoader getWidgetCache() {
+        return mWidgetCache;
+    }
+
     public boolean isScreenLarge() {
         return mIsScreenLarge;
     }