@@ -28,6 +28,7 @@ file(GLOB GBA_SRC ${CMAKE_SOURCE_DIR}/src/gba/*.c)
 file(GLOB GBA_CHEATS_SRC ${CMAKE_SOURCE_DIR}/src/gba/cheats/*.c)
 file(GLOB GBA_RR_SRC ${CMAKE_SOURCE_DIR}/src/gba/rr/*.c)
 file(GLOB GBA_SV_SRC ${CMAKE_SOURCE_DIR}/src/gba/supervisor/*.c)
+file(GLOB GUI_SRC ${CMAKE_SOURCE_DIR}/src/gui/*.c)
 file(GLOB UTIL_SRC ${CMAKE_SOURCE_DIR}/src/util/*.[cSs])
 file(GLOB RENDERER_SRC ${CMAKE_SOURCE_DIR}/src/gba/renderers/*.c)
 file(GLOB SIO_SRC ${CMAKE_SOURCE_DIR}/src/gba/sio/lockstep.c)

@@ -0,0 +1,35 @@
+/* Copyright (c) 2013-2015 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef GUI_H
+#define GUI_H
+
+#include "util/common.h"
+
+struct GUIFont;
+
+enum GUIInput {
+	GUI_INPUT_NONE = -1,
+	GUI_INPUT_SELECT = 0,
+	GUI_INPUT_BACK,
+	GUI_INPUT_CANCEL,
+
+	GUI_INPUT_UP,
+	GUI_INPUT_DOWN,
+	GUI_INPUT_LEFT,
+	GUI_INPUT_RIGHT,
+};
+
+struct GUIParams {
+	int width;
+	int height;
+	const struct GUIFont* font;
+
+	void (*drawStart)(void);
+	void (*drawEnd)(void);
+	int (*pollInput)(void);
+};
+
+#endif

@@ -0,0 +1,128 @@
+/* Copyright (c) 2013-2015 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "file-select.h"
+
+#include "util/gui/font.h"
+#include "util/vector.h"
+#include "util/vfs.h"
+
+DECLARE_VECTOR(FileList, char*);
+DEFINE_VECTOR(FileList, char*);
+
+void _cleanFiles(struct FileList* currentFiles) {
+	size_t size = FileListSize(currentFiles);
+	size_t i;
+	for (i = 0; i < size; ++i) {
+		free(*FileListGetPointer(currentFiles, i));
+	}
+	FileListClear(currentFiles);
+}
+
+void _upDirectory(char* currentPath) {
+	char* end = strrchr(currentPath, '/');
+	if (!end) {
+		return;
+	}
+	end[0] = '\0';
+	if (end[1]) {
+		return;
+	}
+	// TODO: What if there was a trailing slash?
+}
+
+bool _refreshDirectory(const char* currentPath, struct FileList* currentFiles) {
+	_cleanFiles(currentFiles);
+
+	struct VDir* dir = VDirOpen(currentPath);
+	if (!dir) {
+		return false;
+	}
+	struct VDirEntry* de;
+	while ((de = dir->listNext(dir))) {
+		if (de->name(de)[0] == '.') {
+			continue;
+		}
+		*FileListAppend(currentFiles) = strdup(de->name(de));
+	}
+	dir->close(dir);
+	return true;
+}
+
+bool selectFile(const struct GUIParams* params, const char* basePath, char* outPath, size_t outLen, const char* suffix) {
+	char currentPath[256];
+	strncpy(currentPath, basePath, sizeof(currentPath));
+	int oldInput = -1;
+	size_t fileIndex = 0;
+	size_t start = 0;
+
+	struct FileList currentFiles;
+	FileListInit(&currentFiles, 0);
+	_refreshDirectory(currentPath, &currentFiles);
+
+	while (true) {
+		int input = params->pollInput();
+		int newInput = input & (oldInput ^ input);
+		oldInput = input;
+
+		if (newInput & (1 << GUI_INPUT_UP) && fileIndex > 0) {
+			--fileIndex;
+		}
+		if (newInput & (1 << GUI_INPUT_DOWN) && fileIndex < FileListSize(&currentFiles) - 1) {
+			++fileIndex;
+		}
+		if (fileIndex < start) {
+			start = fileIndex;
+		}
+		while ((fileIndex - start + 4) * GUIFontHeight(params->font) > params->height) {
+			++start;
+		}
+		if (newInput & (1 << GUI_INPUT_CANCEL)) {
+			_cleanFiles(&currentFiles);
+			FileListDeinit(&currentFiles);
+			return false;
+		}
+		if (newInput & (1 << GUI_INPUT_SELECT)) {
+			snprintf(currentPath, sizeof(currentPath), "%s%c%s", currentPath, '/', *FileListGetPointer(&currentFiles, fileIndex));
+			if (!_refreshDirectory(currentPath, &currentFiles)) {
+				strncpy(outPath, currentPath, outLen);
+				return true;
+			}
+			fileIndex = 0;
+		}
+		if (newInput & (1 << GUI_INPUT_BACK)) {
+			if (strncmp(currentPath, basePath, sizeof(currentPath)) == 0) {
+				_cleanFiles(&currentFiles);
+				FileListDeinit(&currentFiles);
+				return false;
+			}
+			_upDirectory(currentPath);
+			_refreshDirectory(currentPath, &currentFiles);
+			fileIndex = 0;
+		}
+
+		params->drawStart();
+		int y = GUIFontHeight(params->font);
+		GUIFontPrintf(params->font, 0, y, GUI_TEXT_LEFT, 0xFFFFFFFF, "Current directory: %s", currentPath);
+		y += 2 * GUIFontHeight(params->font);
+		size_t i;
+		for (i = start; i < FileListSize(&currentFiles); ++i) {
+			int color = 0xE0A0A0A0;
+			char bullet = ' ';
+			if (i == fileIndex) {
+				color = 0xFFFFFFFF;
+				bullet = '>';
+			}
+			GUIFontPrintf(params->font, 0, y, GUI_TEXT_LEFT, color, "%c %s", bullet, *FileListGetPointer(&currentFiles, i));
+			y += GUIFontHeight(params->font);
+			if (y + GUIFontHeight(params->font) > params->height) {
+				break;
+			}
+		}
+		y += GUIFontHeight(params->font) * 2;
+
+		params->drawEnd();
+	}
+}

@@ -0,0 +1,13 @@
+/* Copyright (c) 2013-2015 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef GUI_FILE_CHOOSER_H
+#define GUI_FILE_CHOOSER_H
+
+#include "util/gui.h"
+
+bool selectFile(const struct GUIParams*, const char* basePath, char* outPath, size_t outLen, const char* suffix);
+
+#endif

@@ -0,0 +1,25 @@
+/* Copyright (c) 2013-2015 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef GUI_FONT_H
+#define GUI_FONT_H
+
+#include "util/common.h"
+
+struct GUIFont;
+struct GUIFont* GUIFontCreate(void);
+void GUIFontDestroy(struct GUIFont*);
+
+enum GUITextAlignment {
+	GUI_TEXT_LEFT = 0,
+	GUI_TEXT_CENTER,
+	GUI_TEXT_RIGHT
+};
+
+int GUIFontHeight(const struct GUIFont*);
+
+void GUIFontPrintf(const struct GUIFont*, int x, int y, enum GUITextAlignment, uint32_t color, const char* text, ...);
+
+#endif