Add README

Author: AirGuanZ

README.md

@@ -0,0 +1,52 @@
+# imgui-filebrowser
+
+[imgui-filebrowser](https://github.com/AirGuanZ/imgui-filebrowser) is a simple file browser implementation for [dear-imgui](https://github.com/ocornut/imgui).
+
+![IMG](./screenshots/0.png)
+
+## Getting Started
+
+imgui-filebrowser is header-only and must be included after imgui.h:
+
+```cpp
+#include <imgui.h>
+#include <imfilebrowser.h>
+```
+
+It's hard for me to design interface for a stateless file browser. Thus, instead of creating a file dialog by a immediate function call, user needs to create a `ImGui::FileBrowser` instance, open it with member function `Open()`, and calls `Display()` in each rendering frame. Here is a simple example:
+
+```cpp
+#include <imgui.h>
+#include <imfilebrowser.h>
+
+int main()
+{
+    //...initialize rendering window and imgui
+    
+    // create a file browser instance
+    ImGui::FileBrowser fileDialog(ImGuiFileBrowserFlags_EnterNewFilename);
+    
+    // mainloop
+    while(continueRendering)
+    {
+        //...do other stuff like ImGui::NewFrame();
+        
+        // open file dialog when user clicks this button
+        if(ImGui::Button("open file dialog"))
+            fileDialog.Open();
+        
+        fileDialog.Display();
+        
+        if(fileDialog.HasSelected())
+        {
+            std::cout << "Selected filename" << fileDialog.GetSelected() << std::endl;
+            fileDialog.ClearSelected();
+        }
+        
+        //...do other stuff like ImGui::Render();
+    }
+    
+    //...shutdown
+}
+```
+

imfilebrowser.h

@@ -116,13 +116,15 @@ inline void ImGui::FileBrowser::SetTitle(std::string title)
 inline void ImGui::FileBrowser::Open()
 {
     ClearSelected();
+	statusStr_ = std::string();
     openFlag_ = true;
     closeFlag_ = false;
 }
 
 inline void ImGui::FileBrowser::Close()
 {
     ClearSelected();
+	statusStr_ = std::string();
     closeFlag_ = true;
     openFlag_ = false;
 }