Android: Use system cache directory as cache directory

This lets Android automatically delete data in the cache
directory when the device is running low on space or
when Dolphin is uninstalled.

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/NativeLibrary.java

@@ -366,6 +366,8 @@ public final class NativeLibrary
    */
   public static native String GetUserDirectory();
 
+  public static native void SetCacheDirectory(String directory);
+
   public static native int DefaultCPUCore();
 
   public static native void ReloadConfig();

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/model/GameFile.java

@@ -1,5 +1,6 @@
 package org.dolphinemu.dolphinemu.model;
 
+import android.content.Context;
 import android.os.Environment;
 
 public class GameFile
@@ -54,10 +55,9 @@ public class GameFile
 
   public native int getBannerHeight();
 
-  public String getCoverPath()
+  public String getCoverPath(Context context)
   {
-    return Environment.getExternalStorageDirectory().getPath() +
+    return context.getExternalCacheDir().getPath() + "/GameCovers/" + getGameTdbId() + ".png";
-            "/dolphin-emu/Cache/GameCovers/" + getGameTdbId() + ".png";
   }
 
   public String getCustomCoverPath()

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/DirectoryInitialization.java

@@ -64,7 +64,7 @@ public final class DirectoryInitialization
     {
       if (PermissionsHandler.hasWriteAccess(context))
       {
-        if (setDolphinUserDirectory())
+        if (setDolphinUserDirectory(context))
         {
           initializeInternalStorage(context);
           initializeExternalStorage(context);
@@ -88,22 +88,27 @@ public final class DirectoryInitialization
     sendBroadcastState(directoryState, context);
   }
 
-  private static boolean setDolphinUserDirectory()
+  private static boolean setDolphinUserDirectory(Context context)
-  {
-    if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
   {
+    if (!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
+      return false;
+
     File externalPath = Environment.getExternalStorageDirectory();
-      if (externalPath != null)
+    if (externalPath == null)
-      {
+      return false;
+
     userPath = externalPath.getAbsolutePath() + "/dolphin-emu";
     Log.debug("[DirectoryInitialization] User Dir: " + userPath);
     NativeLibrary.SetUserDirectory(userPath);
-        return true;
-      }
-
-    }
 
+    File cacheDir = context.getExternalCacheDir();
+    if (cacheDir == null)
       return false;
+
+    Log.debug("[DirectoryInitialization] Cache Dir: " + cacheDir.getPath());
+    NativeLibrary.SetCacheDirectory(cacheDir.getPath());
+
+    return true;
   }
 
   private static void initializeInternalStorage(Context context)

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/PicassoUtils.java

@@ -1,5 +1,6 @@
 package org.dolphinemu.dolphinemu.utils;
 
+import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.drawable.BitmapDrawable;
 import android.net.Uri;
@@ -33,6 +34,7 @@ public class PicassoUtils
 
   public static void loadGameCover(ImageView imageView, GameFile gameFile)
   {
+    Context context = imageView.getContext();
     File cover = new File(gameFile.getCustomCoverPath());
     if (cover.exists())
     {
@@ -46,7 +48,7 @@ public class PicassoUtils
               .error(R.drawable.no_banner)
               .into(imageView);
     }
-    else if ((cover = new File(gameFile.getCoverPath())).exists())
+    else if ((cover = new File(gameFile.getCoverPath(context))).exists())
     {
       Picasso.get()
               .load(cover)
@@ -76,7 +78,7 @@ public class PicassoUtils
                 public void onSuccess()
                 {
                   CoverHelper.saveCover(((BitmapDrawable) imageView.getDrawable()).getBitmap(),
-                          gameFile.getCoverPath());
+                          gameFile.getCoverPath(context));
                 }
 
                 @Override
@@ -98,7 +100,7 @@ public class PicassoUtils
                             {
                               CoverHelper.saveCover(
                                       ((BitmapDrawable) imageView.getDrawable()).getBitmap(),
-                                      gameFile.getCoverPath());
+                                      gameFile.getCoverPath(context));
                             }
 
                             @Override
@@ -121,7 +123,7 @@ public class PicassoUtils
                                           CoverHelper.saveCover(
                                                   ((BitmapDrawable) imageView.getDrawable())
                                                           .getBitmap(),
-                                                  gameFile.getCoverPath());
+                                                  gameFile.getCoverPath(context));
                                         }
 
                                         @Override

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/TvUtil.java

@@ -168,7 +168,7 @@ public class TvUtil
       {
         contentUri = getUriForFile(context, getFileProvider(context), cover);
       }
-      else if ((cover = new File(game.getCoverPath())).exists())
+      else if ((cover = new File(game.getCoverPath(context))).exists())
       {
         contentUri = getUriForFile(context, getFileProvider(context), cover);
       }

Source/Android/jni/MainAndroid.cpp

@@ -240,6 +240,8 @@ JNIEXPORT void JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_SetUserDirec
     JNIEnv* env, jobject obj, jstring jDirectory);
 JNIEXPORT jstring JNICALL
 Java_org_dolphinemu_dolphinemu_NativeLibrary_GetUserDirectory(JNIEnv* env, jobject obj);
+JNIEXPORT void JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_SetCacheDirectory(
+    JNIEnv* env, jobject obj, jstring jDirectory);
 JNIEXPORT jint JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_DefaultCPUCore(JNIEnv* env,
                                                                                    jobject obj);
 JNIEXPORT void JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_SetProfiling(JNIEnv* env,
@@ -534,6 +536,13 @@ JNIEXPORT jstring JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_GetUserDi
   return ToJString(env, File::GetUserPath(D_USER_IDX).c_str());
 }
 
+JNIEXPORT void JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_SetCacheDirectory(
+    JNIEnv* env, jobject obj, jstring jDirectory)
+{
+  std::lock_guard<std::mutex> guard(s_host_identity_lock);
+  File::SetUserPath(D_CACHE_IDX, GetJString(env, jDirectory) + DIR_SEP);
+}
+
 JNIEXPORT jint JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_DefaultCPUCore(JNIEnv* env,
                                                                                    jobject obj)
 {