v1.2.0: improved how the game handles being interrupted while saving

SPD-classes/src/main/java/com/watabou/utils/FileUtils.java

@@ -68,6 +68,50 @@ public class FileUtils {
 	}
 	
 	// Files
+
+	//looks to see if there is any evidence of interrupted saving
+	public static boolean cleanTempFiles(){
+		return cleanTempFiles("");
+	}
+
+	public static boolean cleanTempFiles( String dirName ){
+		FileHandle dir = getFileHandle(dirName);
+		boolean foundTemp = false;
+		for (FileHandle file : dir.list()){
+			if (file.isDirectory()){
+				foundTemp = cleanTempFiles(dirName + file.name()) || foundTemp;
+			} else {
+				if (file.name().endsWith(".tmp")){
+					FileHandle temp = file;
+					FileHandle original = getFileHandle( defaultFileType, "", temp.path().replace(".tmp", "") );
+
+					//replace the base file with the temp one if base is invalid or temp is valid and newer
+					try {
+						bundleFromStream(temp.read());
+
+						try {
+							bundleFromStream(original.read());
+
+							if (temp.lastModified() > original.lastModified()) {
+								temp.moveTo(original);
+							} else {
+								temp.delete();
+							}
+
+						} catch (Exception e) {
+							temp.moveTo(original);
+						}
+
+					} catch (Exception e) {
+						temp.delete();
+					}
+
+					foundTemp = true;
+				}
+			}
+		}
+		return foundTemp;
+	}
 	
 	public static boolean fileExists( String name ){
 		FileHandle file = getFileHandle( name );
@@ -119,7 +163,19 @@ public class FileUtils {
 	//only works for base path
 	public static void bundleToFile( String fileName, Bundle bundle ) throws IOException{
 		try {
-			bundleToStream(getFileHandle( fileName ).write(false), bundle);
+			FileHandle file = getFileHandle(fileName);
+
+			//write to a temp file, then move the files.
+			// This helps prevent save corruption if writing is interrupted
+			if (file.exists()){
+				FileHandle temp = getFileHandle(fileName + ".tmp");
+				bundleToStream(temp.write(false), bundle);
+				file.delete();
+				temp.moveTo(file);
+			} else {
+				bundleToStream(file.write(false), bundle);
+			}
+
 		} catch (GdxRuntimeException e){
 			//game classes expect an IO exception, so wrap the GDX exception in that
 			throw new IOException(e);

core/src/main/assets/messages/scenes/scenes.properties

@@ -110,3 +110,4 @@ scenes.welcomescene.lang_warning_title=Incomplete Translation
 scenes.welcomescene.lang_warning_msg=Some of the new content from this update has not yet been translated.\n\nSome phrases may be written in English.\n\nThe translation teams are working to resolve this and a full translation should be patched in soon.\n\nThank you for your patience.
 scenes.welcomescene.continue=Continue
 scenes.welcomescene.changelist=Changelist
+scenes.welcomescene.save_warning=Shattered Pixel Dungeon was interrupted while trying to save your game data recently.\n\nShattered has built-in protections against this, so your game data is probably fine. You may want to check to be sure.\n\nThis usually happens when your device suddenly loses power, or if it terminates Shattered without letting it close properly. Battery saver features can often cause this on mobile devices.

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/scenes/WelcomeScene.java

@@ -38,6 +38,9 @@ import com.shatteredpixel.shatteredpixeldungeon.ui.Archs;
 import com.shatteredpixel.shatteredpixeldungeon.ui.Icons;
 import com.shatteredpixel.shatteredpixeldungeon.ui.RenderedTextBlock;
 import com.shatteredpixel.shatteredpixeldungeon.ui.StyledButton;
+import com.shatteredpixel.shatteredpixeldungeon.windows.WndError;
+import com.shatteredpixel.shatteredpixeldungeon.windows.WndHardNotification;
+import com.shatteredpixel.shatteredpixeldungeon.windows.WndMessage;
 import com.watabou.glwrap.Blending;
 import com.watabou.noosa.Camera;
 import com.watabou.noosa.ColorBlock;
@@ -58,6 +61,21 @@ public class WelcomeScene extends PixelScene {
 
 		final int previousVersion = SPDSettings.version();
 
+		if (FileUtils.cleanTempFiles()){
+			add(new WndHardNotification(Icons.get(Icons.WARNING),
+					Messages.get(WndError.class, "title"),
+					Messages.get(this, "save_warning"),
+					Messages.get(this, "continue"),
+					5){
+				@Override
+				public void hide() {
+					super.hide();
+					ShatteredPixelDungeon.resetScene();
+				}
+			});
+			return;
+		}
+
 		if (ShatteredPixelDungeon.versionCode == previousVersion && !SPDSettings.intro()) {
 			ShatteredPixelDungeon.switchNoFade(TitleScene.class);
 			return;