Assorted plumbing.

wip

Buildfix

CMakeLists.txt

@@ -1156,6 +1156,7 @@ list(APPEND NativeAppSource
 	UI/Store.cpp
 	UI/CwCheatScreen.cpp
 	UI/InstallZipScreen.cpp
+	UI/MemStickScreen.cpp
 	UI/ProfilerDraw.cpp
 	UI/TextureUtil.cpp
 	UI/ComboKeyMappingScreen.cpp

Common/File/FileUtil.cpp

@@ -24,6 +24,8 @@
 
 #include "ppsspp_config.h"
 
+#include "android/jni/app-android.h"
+
 #ifdef __MINGW32__
 #include <unistd.h>
 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
@@ -257,7 +259,9 @@ bool IsDirectory(const Path &filename) {
 	WIN32_FILE_ATTRIBUTE_DATA data{};
 	if (!GetFileAttributesEx(copy.c_str(), GetFileExInfoStandard, &data) || data.dwFileAttributes == INVALID_FILE_ATTRIBUTES) {
 		auto err = GetLastError();
-		WARN_LOG(COMMON, "GetFileAttributes failed on %s: %08x %s", fn.c_str(), (uint32_t)err, GetStringErrorMsg(err).c_str());
+		if (err != ERROR_FILE_NOT_FOUND) {
+			WARN_LOG(COMMON, "GetFileAttributes failed on %s: %08x %s", fn.c_str(), (uint32_t)err, GetStringErrorMsg(err).c_str());
+		}
 		return false;
 	}
 	DWORD result = data.dwFileAttributes;

Common/File/FileUtil.h

@@ -27,6 +27,8 @@
 #include "Common/Common.h"
 #include "Common/File/Path.h"
 
+// Some functions here support Android content URIs. These are marked as such.
+
 #ifdef _MSC_VER
 inline struct tm* localtime_r(const time_t *clock, struct tm *result) {
 	if (localtime_s(result, clock) == 0)

Core/FileSystems/AndroidStorageFileSystem.cpp

@@ -121,8 +121,12 @@ bool AndroidDirectoryFileHandle::Open(const std::string &basePath, std::string &
 		success = false;
 	}
 
-	// Seek to end if append mode.
-	Seek(0, FILEMOVE_END);
+	// TODO: Experiment with fstat to see if we can extract more info.
+
+	// Seek to end to simulate append mode, if requested.
+	if (access & FILEACCESS_APPEND) {
+		Seek(0, FILEMOVE_END);
+	}
 
 	// Try to detect reads/writes to PSP/GAME to avoid them in replays.
 	if (basePath.find("/PSP/GAME/") != std::string::npos) {
@@ -439,10 +443,11 @@ std::vector<PSPFileInfo> AndroidStorageFileSystem::GetDirListing(std::string pat
 	bool hideISOFiles = PSP_CoreParameter().compat.flags().HideISOFiles;
 	for (auto &info : fileInfo) {
 		PSPFileInfo entry;
-		if (info.isDirectory)
+		if (info.isDirectory) {
 			entry.type = FILETYPE_DIRECTORY;
-		else
+		} else {
 			entry.type = FILETYPE_NORMAL;
+		}
 		entry.access = info.isWritable ? 0777 : 0666;
 		entry.name = info.name;
 		if (Flags() & FileSystemFlags::SIMULATE_FAT32) {
@@ -466,8 +471,9 @@ std::vector<PSPFileInfo> AndroidStorageFileSystem::GetDirListing(std::string pat
 		localtime_r((time_t*)&atime, &entry.atime);
 		localtime_r((time_t*)&ctime, &entry.ctime);
 		localtime_r((time_t*)&mtime, &entry.mtime);
-		if (!hideFile && (!listingRoot || (strcmp(info.name.c_str(), "..") && strcmp(info.name.c_str(), "."))))
+		if (!hideFile && (!listingRoot || (strcmp(info.name.c_str(), "..") && strcmp(info.name.c_str(), ".")))) {
 			myVector.push_back(entry);
+		}
 	}
 
 	return ReplayApplyDiskListing(myVector, CoreTiming::GetGlobalTimeUs());

Core/FileSystems/VirtualDiscFileSystem.cpp

@@ -285,8 +285,7 @@ int VirtualDiscFileSystem::getFileListIndex(std::string &fileName)
 #endif
 	}
 
-	FileType type = File::IsDirectory(fullName) ? FILETYPE_DIRECTORY : FILETYPE_NORMAL;
-	if (type == FILETYPE_DIRECTORY)
+	if (File::IsDirectory(fullName))
 		return -1;
 
 	FileListEntry entry = {""};

UI/GameSettingsScreen.cpp

@@ -51,6 +51,7 @@
 #include "UI/TiltEventProcessor.h"
 #include "UI/ComboKeyMappingScreen.h"
 #include "UI/GPUDriverTestScreen.h"
+#include "UI/MemStickScreen.h"
 
 #include "Common/File/FileUtil.h"
 #include "Common/OSVersion.h"
@@ -931,6 +932,7 @@ void GameSettingsScreen::CreateViews() {
 #if defined(USING_WIN_UI) || defined(USING_QT_UI) || PPSSPP_PLATFORM(ANDROID)
 	systemSettings->Add(new CheckBox(&g_Config.bBypassOSKWithKeyboard, sy->T("Use system native keyboard")));
 #endif
+
 #if PPSSPP_PLATFORM(ANDROID)
 	memstickDisplay_ = g_Config.memStickDirectory.ToVisualString();
 	auto memstickPath = systemSettings->Add(new ChoiceWithValueDisplay(&memstickDisplay_, sy->T("Change Memory Stick folder"), (const char *)nullptr));
@@ -1098,40 +1100,12 @@ UI::EventReturn GameSettingsScreen::OnJitAffectingSetting(UI::EventParams &e) {
 	return UI::EVENT_DONE;
 }
 
-#if PPSSPP_PLATFORM(ANDROID)
-
 UI::EventReturn GameSettingsScreen::OnChangeMemStickDir(UI::EventParams &e) {
-	auto sy = GetI18NCategory("System");
-	System_InputBoxGetString(sy->T("Memory Stick Folder"), g_Config.memStickDirectory.ToString(), [&](bool result, const std::string &value) {
-		auto sy = GetI18NCategory("System");
-		auto di = GetI18NCategory("Dialog");
-
-		if (result) {
-			std::string newPath = value;
-			size_t pos = newPath.find_last_not_of("/");
-			// Gotta have at least something but a /, and also needs to start with a /.
-			if (newPath.empty() || pos == newPath.npos || newPath[0] != '/') {
-				settingInfo_->Show(sy->T("ChangingMemstickPathInvalid", "That path couldn't be used to save Memory Stick files."), nullptr);
-				return;
-			}
-			if (pos != newPath.size() - 1) {
-				newPath = newPath.substr(0, pos + 1);
-			}
-
-			pendingMemstickFolder_ = newPath;
-			std::string promptMessage = sy->T("ChangingMemstickPath", "Save games, save states, and other data will not be copied to this folder.\n\nChange the Memory Stick folder?");
-			if (!File::Exists(Path(newPath))) {
-				promptMessage = sy->T("ChangingMemstickPathNotExists", "That folder doesn't exist yet.\n\nSave games, save states, and other data will not be copied to this folder.\n\nCreate a new Memory Stick folder?");
-			}
-			// Add the path for clarity and proper confirmation.
-			promptMessage += "\n\n" + newPath + "/";
-			screenManager()->push(new PromptScreen(promptMessage, di->T("Yes"), di->T("No"), std::bind(&GameSettingsScreen::CallbackMemstickFolder, this, std::placeholders::_1)));
-		}
-	});
+	screenManager()->push(new MemStickScreen());
 	return UI::EVENT_DONE;
 }
 
-#elif defined(_WIN32) && !PPSSPP_PLATFORM(UWP)
+#if defined(_WIN32) && !PPSSPP_PLATFORM(UWP)
 
 UI::EventReturn GameSettingsScreen::OnSavePathMydoc(UI::EventParams &e) {
 	const Path &PPSSPPpath = File::GetExeDirectory();
@@ -2006,52 +1980,3 @@ void HostnameSelectScreen::OnCompleted(DialogResult result) {
 	if (result == DR_OK)
 		*value_ = StripSpaces(addrView_->GetText());
 }
-
-SettingInfoMessage::SettingInfoMessage(int align, UI::AnchorLayoutParams *lp)
-	: UI::LinearLayout(UI::ORIENT_HORIZONTAL, lp) {
-	using namespace UI;
-	SetSpacing(0.0f);
-	Add(new UI::Spacer(10.0f));
-	text_ = Add(new UI::TextView("", align, false, new LinearLayoutParams(1.0, Margins(0, 10))));
-	Add(new UI::Spacer(10.0f));
-}
-
-void SettingInfoMessage::Show(const std::string &text, UI::View *refView) {
-	if (refView) {
-		Bounds b = refView->GetBounds();
-		const UI::AnchorLayoutParams *lp = GetLayoutParams()->As<UI::AnchorLayoutParams>();
-		if (b.y >= cutOffY_) {
-			ReplaceLayoutParams(new UI::AnchorLayoutParams(lp->width, lp->height, lp->left, 80.0f, lp->right, lp->bottom, lp->center));
-		} else {
-			ReplaceLayoutParams(new UI::AnchorLayoutParams(lp->width, lp->height, lp->left, dp_yres - 80.0f - 40.0f, lp->right, lp->bottom, lp->center));
-		}
-	}
-	text_->SetText(text);
-	timeShown_ = time_now_d();
-}
-
-void SettingInfoMessage::Draw(UIContext &dc) {
-	static const double FADE_TIME = 1.0;
-	static const float MAX_ALPHA = 0.9f;
-
-	// Let's show longer messages for more time (guesstimate at reading speed.)
-	// Note: this will give multibyte characters more time, but they often have shorter words anyway.
-	double timeToShow = std::max(1.5, text_->GetText().size() * 0.05);
-
-	double sinceShow = time_now_d() - timeShown_;
-	float alpha = MAX_ALPHA;
-	if (timeShown_ == 0.0 || sinceShow > timeToShow + FADE_TIME) {
-		alpha = 0.0f;
-	} else if (sinceShow > timeToShow) {
-		alpha = MAX_ALPHA - MAX_ALPHA * (float)((sinceShow - timeToShow) / FADE_TIME);
-	}
-
-	if (alpha >= 0.1f) {
-		UI::Style style = dc.theme->popupTitle;
-		style.background.color = colorAlpha(style.background.color, alpha - 0.1f);
-		dc.FillRect(style.background, bounds_);
-	}
-
-	text_->SetTextColor(whiteAlpha(alpha));
-	ViewGroup::Draw(dc);
-}

UI/GameSettingsScreen.h

@@ -24,8 +24,6 @@
 #include "Common/UI/UIScreen.h"
 #include "UI/MiscScreens.h"
 
-class SettingInfoMessage;
-
 // Per-game settings screen - enables you to configure graphic options, control options, etc
 // per game.
 class GameSettingsScreen : public UIDialogScreenWithGameBackground {
@@ -108,9 +106,8 @@ private:
 	UI::EventReturn OnMicDeviceChange(UI::EventParams& e);
 	UI::EventReturn OnAudioDevice(UI::EventParams &e);
 	UI::EventReturn OnJitAffectingSetting(UI::EventParams &e);
-#if PPSSPP_PLATFORM(ANDROID)
 	UI::EventReturn OnChangeMemStickDir(UI::EventParams &e);
-#elif defined(_WIN32) && !PPSSPP_PLATFORM(UWP)
+#if defined(_WIN32) && !PPSSPP_PLATFORM(UWP)
 	UI::EventReturn OnSavePathMydoc(UI::EventParams &e);
 	UI::EventReturn OnSavePathOther(UI::EventParams &e);
 #endif
@@ -141,23 +138,6 @@ private:
 	std::string pendingMemstickFolder_;
 };
 
-class SettingInfoMessage : public UI::LinearLayout {
-public:
-	SettingInfoMessage(int align, UI::AnchorLayoutParams *lp);
-
-	void SetBottomCutoff(float y) {
-		cutOffY_ = y;
-	}
-	void Show(const std::string &text, UI::View *refView = nullptr);
-
-	void Draw(UIContext &dc);
-
-private:
-	UI::TextView *text_ = nullptr;
-	double timeShown_ = 0.0;
-	float cutOffY_;
-};
-
 class DeveloperToolsScreen : public UIDialogScreenWithBackground {
 public:
 	DeveloperToolsScreen() {}

UI/MiscScreens.cpp

@@ -948,3 +948,52 @@ void CreditsScreen::render() {
 
 	dc.Flush();
 }
+
+SettingInfoMessage::SettingInfoMessage(int align, UI::AnchorLayoutParams *lp)
+	: UI::LinearLayout(UI::ORIENT_HORIZONTAL, lp) {
+	using namespace UI;
+	SetSpacing(0.0f);
+	Add(new UI::Spacer(10.0f));
+	text_ = Add(new UI::TextView("", align, false, new LinearLayoutParams(1.0, Margins(0, 10))));
+	Add(new UI::Spacer(10.0f));
+}
+
+void SettingInfoMessage::Show(const std::string &text, UI::View *refView) {
+	if (refView) {
+		Bounds b = refView->GetBounds();
+		const UI::AnchorLayoutParams *lp = GetLayoutParams()->As<UI::AnchorLayoutParams>();
+		if (b.y >= cutOffY_) {
+			ReplaceLayoutParams(new UI::AnchorLayoutParams(lp->width, lp->height, lp->left, 80.0f, lp->right, lp->bottom, lp->center));
+		} else {
+			ReplaceLayoutParams(new UI::AnchorLayoutParams(lp->width, lp->height, lp->left, dp_yres - 80.0f - 40.0f, lp->right, lp->bottom, lp->center));
+		}
+	}
+	text_->SetText(text);
+	timeShown_ = time_now_d();
+}
+
+void SettingInfoMessage::Draw(UIContext &dc) {
+	static const double FADE_TIME = 1.0;
+	static const float MAX_ALPHA = 0.9f;
+
+	// Let's show longer messages for more time (guesstimate at reading speed.)
+	// Note: this will give multibyte characters more time, but they often have shorter words anyway.
+	double timeToShow = std::max(1.5, text_->GetText().size() * 0.05);
+
+	double sinceShow = time_now_d() - timeShown_;
+	float alpha = MAX_ALPHA;
+	if (timeShown_ == 0.0 || sinceShow > timeToShow + FADE_TIME) {
+		alpha = 0.0f;
+	} else if (sinceShow > timeToShow) {
+		alpha = MAX_ALPHA - MAX_ALPHA * (float)((sinceShow - timeToShow) / FADE_TIME);
+	}
+
+	if (alpha >= 0.1f) {
+		UI::Style style = dc.theme->popupTitle;
+		style.background.color = colorAlpha(style.background.color, alpha - 0.1f);
+		dc.FillRect(style.background, bounds_);
+	}
+
+	text_->SetTextColor(whiteAlpha(alpha));
+	ViewGroup::Draw(dc);
+}

UI/MiscScreens.h

@@ -164,3 +164,20 @@ private:
 
 	double startTime_ = 0.0;
 };
+
+class SettingInfoMessage : public UI::LinearLayout {
+public:
+	SettingInfoMessage(int align, UI::AnchorLayoutParams *lp);
+
+	void SetBottomCutoff(float y) {
+		cutOffY_ = y;
+	}
+	void Show(const std::string &text, UI::View *refView = nullptr);
+
+	void Draw(UIContext &dc);
+
+private:
+	UI::TextView *text_ = nullptr;
+	double timeShown_ = 0.0;
+	float cutOffY_;
+};

UI/NativeApp.cpp

@@ -511,10 +511,12 @@ void NativeInit(int argc, const char *argv[], const char *savegame_dir, const ch
 		Path memstickPath(memstickDir);
 		if (!memstickPath.empty() && File::Exists(memstickPath)) {
 			g_Config.memStickDirectory = memstickPath;
+			INFO_LOG(SYSTEM, "Memstick Directory from memstick_dir.txt: %s", g_Config.memStickDirectory.c_str());
 		} else {
-		    ERROR_LOG(SYSTEM, "Couldn't read directory '%s' specified by memstick_dir.txt.", memstickDir.c_str());
+			ERROR_LOG(SYSTEM, "Couldn't read directory '%s' specified by memstick_dir.txt.", memstickDir.c_str());
 		}
 	}
+
 #elif PPSSPP_PLATFORM(IOS)
 	g_Config.defaultCurrentDirectory = g_Config.internalDataDirectory;
 	g_Config.memStickDirectory = Path(user_data_path);

UI/UI.vcxproj

@@ -51,6 +51,7 @@
     <ClCompile Include="GameSettingsScreen.cpp" />
     <ClCompile Include="GPUDriverTestScreen.cpp" />
     <ClCompile Include="MainScreen.cpp" />
+    <ClCompile Include="MemStickScreen.cpp" />
     <ClCompile Include="MiscScreens.cpp" />
     <ClCompile Include="NativeApp.cpp" />
     <ClCompile Include="OnScreenDisplay.cpp" />
@@ -85,6 +86,7 @@
     <ClInclude Include="GPUDriverTestScreen.h" />
     <ClInclude Include="HostTypes.h" />
     <ClInclude Include="MainScreen.h" />
+    <ClInclude Include="MemStickScreen.h" />
     <ClInclude Include="MiscScreens.h" />
     <ClInclude Include="OnScreenDisplay.h" />
     <ClInclude Include="PauseScreen.h" />
@@ -394,4 +396,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>

UI/UI.vcxproj.filters

@@ -78,6 +78,9 @@
     <ClCompile Include="Store.cpp">
       <Filter>Screens</Filter>
     </ClCompile>
+    <ClCompile Include="MemStickScreen.cpp">
+      <Filter>Screens</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="GameInfoCache.h" />
@@ -157,6 +160,9 @@
     <ClInclude Include="Store.h">
       <Filter>Screens</Filter>
     </ClInclude>
+    <ClInclude Include="MemStickScreen.h">
+      <Filter>Screens</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Screens">

android/jni/AndroidContentURI.h

@@ -9,9 +9,12 @@
 // content://com.android.externalstorage.documents/tree/primary%3APSP%20ISO
 // content://com.android.externalstorage.documents/tree/primary%3APSP%20ISO/document/primary%3APSP%20ISO
 
+// This file compiles on all platforms, to reduce the need for ifdefs.
+
 // I am not 100% sure it's OK to rely on the internal format of file content URIs.
 // On the other hand, I'm sure tons of apps would break if these changed, so I think we can
-// consider them pretty stable.
+// consider them pretty stable. Additionally, the official Document library just manipulates the URIs
+// in similar ways...
 class AndroidStorageContentURI {
 private:
 	std::string provider;

android/jni/app-android.cpp

@@ -177,6 +177,8 @@ static jmethodID contentUriCreateFile;
 static jmethodID contentUriCreateDirectory;
 static jmethodID contentUriRemoveFile;
 static jmethodID contentUriGetFileInfo;
+static jmethodID contentUriGetFreeStorageSpace;
+static jmethodID filePathGetFreeStorageSpace;
 
 static jobject nativeActivity;
 static volatile bool exitRenderLoop;
@@ -342,6 +344,21 @@ std::vector<File::FileInfo> Android_ListContentUri(const std::string &path) {
 	return items;
 }
 
+int64_t Android_GetFreeSpaceByContentUri(const std::string &uri) {
+    auto env = getEnv();
+
+    jstring param = env->NewStringUTF(uri.c_str());
+	return env->CallLongMethod(nativeActivity, contentUriGetFreeStorageSpace, param);
+}
+
+int64_t Android_GetFreeSpaceByFilePath(const std::string &filePath) {
+	auto env = getEnv();
+
+	jstring param = env->NewStringUTF(filePath.c_str());
+	return env->CallLongMethod(nativeActivity, filePathGetFreeStorageSpace, param);
+}
+
+
 class ContentURIFileLoader : public ProxiedFileLoader {
 public:
 	ContentURIFileLoader(const Path &filename)
@@ -627,6 +644,10 @@ extern "C" void Java_org_ppsspp_ppsspp_NativeActivity_registerCallbacks(JNIEnv *
 	_dbg_assert_(contentUriRemoveFile);
 	contentUriGetFileInfo = env->GetMethodID(env->GetObjectClass(obj), "contentUriGetFileInfo", "(Ljava/lang/String;)Ljava/lang/String;");
 	_dbg_assert_(contentUriGetFileInfo);
+	contentUriGetFreeStorageSpace = env->GetMethodID(env->GetObjectClass(obj), "contentUriGetFreeStorageSpace", "(Ljava/lang/String;)J");
+	_dbg_assert_(contentUriGetFreeStorageSpace);
+	filePathGetFreeStorageSpace = env->GetMethodID(env->GetObjectClass(obj), "filePathGetFreeStorageSpace", "(Ljava/lang/String;)J");
+	_dbg_assert_(filePathGetFreeStorageSpace);
 }
 
 extern "C" void Java_org_ppsspp_ppsspp_NativeActivity_unregisterCallbacks(JNIEnv *env, jobject obj) {

android/jni/app-android.h

@@ -4,10 +4,19 @@
 
 #include <string>
 #include <vector>
+#include <cstdint>
 
 #include "Common/LogManager.h"
 #include "Common/File/DirListing.h"
 
+// To emphasize that Android storage mode strings are different, let's just use
+// an enum.
+enum class Android_OpenContentUriMode {
+	READ = 0,  // "r"
+	READ_WRITE = 1,  // "rw"
+	READ_WRITE_TRUNCATE = 2,  // "rwt"
+};
+
 #if PPSSPP_PLATFORM(ANDROID)
 
 #include <jni.h>
@@ -25,21 +34,30 @@ extern std::string g_extFilesDir;
 // Called from PathBrowser for example.
 
 bool Android_IsContentUri(const std::string &uri);
-
-// To emphasize that Android storage mode strings are different, let's just use
-// an enum.
-enum class Android_OpenContentUriMode {
-	READ = 0,  // "r"
-	READ_WRITE = 1,  // "rw"
-	READ_WRITE_TRUNCATE = 2,  // "rwt"
-};
-
 int Android_OpenContentUriFd(const std::string &uri, const Android_OpenContentUriMode mode);
 bool Android_CreateDirectory(const std::string &parentTreeUri, const std::string &dirName);
 bool Android_CreateFile(const std::string &parentTreeUri, const std::string &fileName);
 bool Android_RemoveFile(const std::string &fileUri);
 bool Android_GetFileInfo(const std::string &fileUri, File::FileInfo *info);
+int64_t Android_GetFreeSpaceByContentUri(const std::string &uri);
+int64_t Android_GetFreeSpaceByFilePath(const std::string &filePath);
 
 std::vector<File::FileInfo> Android_ListContentUri(const std::string &uri);
 
+#else
+
+// Stub out the Android Storage wrappers, so that we can avoid ifdefs everywhere.
+
+inline bool Android_IsContentUri(const std::string &uri) { return false; }
+inline int Android_OpenContentUriFd(const std::string &uri, const Android_OpenContentUriMode mode) { return -1; }
+inline bool Android_CreateDirectory(const std::string &parentTreeUri, const std::string &dirName) { return false; }
+inline bool Android_CreateFile(const std::string &parentTreeUri, const std::string &fileName) { return false; }
+inline bool Android_RemoveFile(const std::string &fileUri) { return false; }
+inline bool Android_GetFileInfo(const std::string &fileUri, File::FileInfo *info) { return false; }
+inline int64_t Android_GetFreeSpaceByContentUri(const std::string &uri) { return -1; }
+inline int64_t Android_GetFreeSpaceByFilePath(const std::string &filePath) { return -1; }
+inline std::vector<File::FileInfo> Android_ListContentUri(const std::string &uri) {
+	return std::vector<File::FileInfo>();
+}
+
 #endif

android/src/org/ppsspp/ppsspp/PpssppActivity.java

@@ -8,8 +8,11 @@ import android.os.Bundle;
 import android.os.Looper;
 import android.os.ParcelFileDescriptor;
 import android.util.Log;
+import android.os.storage.StorageManager;
 import androidx.documentfile.provider.DocumentFile;
 import java.util.ArrayList;
+import java.util.UUID;
+import java.io.File;
 
 public class PpssppActivity extends NativeActivity {
 	private static final String TAG = "PpssppActivity";
@@ -223,4 +226,41 @@ public class PpssppActivity extends NativeActivity {
 			return null;
 		}
 	}
+
+	// The example in Android documentation uses this.getFilesDir for path.
+	// There's also a way to beg the OS for more space, which might clear caches, but
+	// let's just not bother with that for now.
+	public long contentUriGetFreeStorageSpace(String uriString) {
+		try {
+			StorageManager storageManager = getApplicationContext().getSystemService(StorageManager.class);
+
+			// In 29 and later, we can directly get the UUID for the storage volume
+			// through the URI.
+			UUID volumeUUID;
+			if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+				Uri uri = Uri.parse(uriString);
+				volumeUUID = UUID.fromString(storageManager.getStorageVolume(uri).getUuid());
+			} else {
+				volumeUUID = storageManager.getUuidForPath(this.getFilesDir());
+			}
+			long availableBytes = storageManager.getAllocatableBytes(volumeUUID);
+			return availableBytes;
+		}  catch (Exception e) {
+			Log.e(TAG, "Exception checking free space: " + e.toString());
+			return -1;
+		}
+	}
+
+	public long filePathGetFreeStorageSpace(String filePath) {
+		try {
+			StorageManager storageManager = getApplicationContext().getSystemService(StorageManager.class);
+			File file = new File(filePath);
+			UUID volumeUUID = storageManager.getUuidForPath(file);
+			long availableBytes = storageManager.getAllocatableBytes(volumeUUID);
+			return availableBytes;
+		}  catch (Exception e) {
+			Log.e(TAG, "Exception checking free space: " + e.toString());
+			return -1;
+		}
+	}
 }