Add java-side prefix filtering for ContentUri directory listing

Common/File/AndroidStorage.cpp

@@ -39,7 +39,7 @@ void Android_RegisterStorageCallbacks(JNIEnv * env, jobject obj) {
 
 	openContentUri = env->GetStaticMethodID(localClass, "openContentUri", "(Landroid/app/Activity;Ljava/lang/String;Ljava/lang/String;)I");
 	_dbg_assert_(openContentUri);
-	listContentUriDir = env->GetStaticMethodID(localClass, "listContentUriDir", "(Landroid/app/Activity;Ljava/lang/String;)[Ljava/lang/String;");
+	listContentUriDir = env->GetStaticMethodID(localClass, "listContentUriDir", "(Landroid/app/Activity;Ljava/lang/String;Ljava/lang/String;)[Ljava/lang/String;");
 	_dbg_assert_(listContentUriDir);
 	contentUriCreateDirectory = env->GetStaticMethodID(localClass, "contentUriCreateDirectory", "(Landroid/app/Activity;Ljava/lang/String;Ljava/lang/String;)I");
 	_dbg_assert_(contentUriCreateDirectory);
@@ -265,7 +265,8 @@ std::vector<File::FileInfo> Android_ListContentUri(const std::string &uri, const
 	double start = time_now_d();
 
 	jstring param = env->NewStringUTF(uri.c_str());
-	jobject retval = env->CallStaticObjectMethod(g_classContentUri, listContentUriDir, g_nativeActivity, param);
+	jstring filenamePrefix = prefix.empty() ? nullptr : env->NewStringUTF(prefix.c_str());
+	jobject retval = env->CallStaticObjectMethod(g_classContentUri, listContentUriDir, g_nativeActivity, param, filenamePrefix);
 
 	jobjectArray fileList = (jobjectArray)retval;
 	std::vector<File::FileInfo> items;

Core/SaveState.cpp

@@ -26,6 +26,7 @@
 #include "Common/System/System.h"
 
 #include "Common/File/FileUtil.h"
+#include "Common/File/DirListing.h"
 #include "Common/Serialize/Serializer.h"
 #include "Common/Serialize/SerializeFuncs.h"
 #include "Common/StringUtils.h"
@@ -68,7 +69,9 @@ static const char * const LOAD_UNDO_NAME = "load_undo.ppst";
 
 namespace SaveState {
 
+// Used for "confirm exit if you haven't saved in a while"
 double g_lastSaveTime = -1.0;
+
 static bool needsProcess = false;
 static bool needsRestart = false;
 static std::mutex mutex;

Core/SaveState.h

@@ -41,6 +41,8 @@ namespace SaveState {
 	// Cycle through the 5 savestate slots
 	void PrevSlot();
 	void NextSlot();
+
+	// Run the various actions directly.
 	void SaveSlot(const Path &gameFilename, int slot, Callback callback);
 	void LoadSlot(const Path &gameFilename, int slot, Callback callback);
 	bool UndoSaveSlot(const Path &gameFilename, int slot);
@@ -55,6 +57,7 @@ namespace SaveState {
 	bool HasUndoLoad(const Path &gameFilename);
 	bool HasScreenshotInSlot(const Path &gameFilename, int slot);
 
+	// Just returns the current slot from config.
 	int GetCurrentSlot();
 
 	// Returns -1 if there's no oldest/newest slot.
@@ -62,7 +65,6 @@ namespace SaveState {
 	int GetOldestSlot(const Path &gameFilename);
 	
 	std::string GetSlotDateAsString(const Path &gameFilename, int slot);
-	std::string GenerateFullDiscId(const Path &gameFilename);
 	Path GenerateSaveSlotFilename(const Path &gameFilename, int slot, const char *extension);
 
 	std::string GetTitle(const Path &filename);

android/src/org/ppsspp/ppsspp/ContentUri.java

@@ -19,6 +19,7 @@ import androidx.documentfile.provider.DocumentFile;
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Locale;
 import java.util.UUID;
 
 public class ContentUri {
@@ -65,7 +66,7 @@ public class ContentUri {
 		DocumentsContract.Document.COLUMN_LAST_MODIFIED
 	};
 
-	private static String cursorToString(Cursor c) {
+	private static String cursorToString(Cursor c, String prefixLowercase) {
 		final int flags = c.getInt(2);
 		// Filter out any virtual or partial nonsense.
 		// There's a bunch of potentially-interesting flags here btw,
@@ -74,9 +75,16 @@ public class ContentUri {
 		if ((flags & (DocumentsContract.Document.FLAG_PARTIAL | DocumentsContract.Document.FLAG_VIRTUAL_DOCUMENT)) != 0) {
 			return null;
 		}
+		final String documentName = c.getString(0);
+		if (prefixLowercase != null && !prefixLowercase.isEmpty()) {
+			// Filter by prefix, case insensitive.
+			if (!documentName.toLowerCase(Locale.ROOT).startsWith(prefixLowercase)) {
+				return null;
+			}
+		}
+
 		final String mimeType = c.getString(3);
 		final boolean isDirectory = mimeType.equals(DocumentsContract.Document.MIME_TYPE_DIR);
-		final String documentName = c.getString(0);
 		final long size = isDirectory ? 0 : c.getLong(1);
 		final long lastModified = c.getLong(4);
 
@@ -160,7 +168,7 @@ public class ContentUri {
 	// uestions/42186820/documentfile-is-very-slow
 	@Keep
 	@SuppressWarnings("unused")
-	public static String[] listContentUriDir(Activity activity, String uriString) {
+	public static String[] listContentUriDir(Activity activity, String uriString, String prefix) {
 		try {
 			Uri uri = Uri.parse(uriString);
 			final ContentResolver resolver = activity.getContentResolver();
@@ -176,12 +184,16 @@ public class ContentUri {
 				DocumentsContract.Document.COLUMN_LAST_MODIFIED   // index 4
 			};
 
+			if (prefix != null) {
+				prefix = prefix.toLowerCase(Locale.ROOT);
+			}
+
 			try (Cursor c = resolver.query(childrenUri, projection, null, null, null)) {
 				if (c == null) {
 					return new String[]{"X"};
 				}
 				while (c.moveToNext()) {
-					String str = cursorToString(c);
+					String str = cursorToString(c, prefix);
 					if (str != null) {
 						listing.add(str);
 					}
@@ -354,7 +366,7 @@ public class ContentUri {
 
 		try (Cursor c = activity.getContentResolver().query(Uri.parse(fileName), projection, null, null, null)) {
 			if (c != null && c.moveToFirst()) {
-				return cursorToString(c);
+				return cursorToString(c, null);
 			} else {
 				return null;
 			}