IO: added io.PlatformOpenInShellFn handler to open a link/folder/file…

… in OS shell, added IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS. (ocornut#7660)

docs/CHANGELOG.txt

@@ -43,6 +43,9 @@ Breaking changes:
 
 Other changes:
 
+- IO: added io.PlatformOpenInShellFn handler to open a link/folder/file in OS shell. (#7660)
+  Default to use ShellExecute() under Windows, and system("") under Mac/Linux/etc.
+  Added IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS to disable default implementation.
 - Debug Tools: Added IMGUI_DEBUG_LOG(), ImGui::DebugLog() in public API. (#5855)
   Debug log entries add a imgui frame counter prefix + are redirected to ShowDebugLogWindow() and
   other configurable locations. Always call IMGUI_DEBUG_LOG() for maximum stripping in caller code.

imconfig.h

@@ -42,6 +42,7 @@
 //#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS         // [Win32] [Default with non-Visual Studio compilers] Don't implement default IME handler (won't require imm32.lib/.a)
 //#define IMGUI_DISABLE_WIN32_FUNCTIONS                     // [Win32] Won't use and link with any Win32 function (clipboard, IME).
 //#define IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS      // [OSX] Implement default OSX clipboard handler (need to link with '-framework ApplicationServices', this is why this is not the default).
+//#define IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS             // Don't implement default io.PlatformOpenInShellFn() handler (Win32: ShellExecute(), require shell32.lib/.a, Mac/Linux: use system("")).
 //#define IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS            // Don't implement ImFormatString/ImFormatStringV so you can implement them yourself (e.g. if you don't want to link with vsnprintf)
 //#define IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS              // Don't implement ImFabs/ImSqrt/ImPow/ImFmod/ImCos/ImSin/ImAcos/ImAtan2 so you can implement them yourself.
 //#define IMGUI_DISABLE_FILE_FUNCTIONS                      // Don't implement ImFileOpen/ImFileClose/ImFileRead/ImFileWrite and ImFileHandle at all (replace them with dummies)

imgui.cpp

@@ -1015,7 +1015,7 @@ CODE
 #endif
 
 // [Windows] OS specific includes (optional)
-#if defined(_WIN32) && defined(IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS) && defined(IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS) && defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)
+#if defined(_WIN32) && defined(IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS) && defined(IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS) && defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS) && defined(IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)
 #define IMGUI_DISABLE_WIN32_FUNCTIONS
 #endif
 #if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)
@@ -1034,6 +1034,7 @@ CODE
 // The UWP and GDK Win32 API subsets don't support clipboard nor IME functions
 #define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS
 #define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS
+#define IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS
 #endif
 #endif
 
@@ -1124,6 +1125,7 @@ static void             WindowSettingsHandler_WriteAll(ImGuiContext*, ImGuiSetti
 static const char*      GetClipboardTextFn_DefaultImpl(void* user_data_ctx);
 static void             SetClipboardTextFn_DefaultImpl(void* user_data_ctx, const char* text);
 static void             SetPlatformImeDataFn_DefaultImpl(ImGuiViewport* viewport, ImGuiPlatformImeData* data);
+static void             PlatformOpenInShellFn_DefaultImpl(ImGuiContext* ctx, const char* path);
 
 namespace ImGui
 {
@@ -1369,6 +1371,7 @@ ImGuiIO::ImGuiIO()
     // Note: Initialize() will setup default clipboard/ime handlers.
     BackendPlatformName = BackendRendererName = NULL;
     BackendPlatformUserData = BackendRendererUserData = BackendLanguageUserData = NULL;
+    PlatformOpenInShellUserData = NULL;
     PlatformLocaleDecimalPoint = '.';
 
     // Input (NB: we already have memset zero the entire structure!)
@@ -3712,6 +3715,7 @@ void ImGui::Initialize()
     g.IO.GetClipboardTextFn = GetClipboardTextFn_DefaultImpl;    // Platform dependent default implementations
     g.IO.SetClipboardTextFn = SetClipboardTextFn_DefaultImpl;
     g.IO.ClipboardUserData = (void*)&g;                          // Default implementation use the ImGuiContext as user data (ideally those would be arguments to the function)
+    g.IO.PlatformOpenInShellFn = PlatformOpenInShellFn_DefaultImpl;
     g.IO.SetPlatformImeDataFn = SetPlatformImeDataFn_DefaultImpl;
 
     // Create default viewport
@@ -14200,6 +14204,10 @@ static void ImGui::UpdateViewportsNewFrame()
 //-----------------------------------------------------------------------------
 // [SECTION] PLATFORM DEPENDENT HELPERS
 //-----------------------------------------------------------------------------
+// - Default clipboard handlers
+// - Default shell function handlers
+// - Default IME handlers
+//-----------------------------------------------------------------------------
 
 #if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS)
 
@@ -14325,7 +14333,36 @@ static void SetClipboardTextFn_DefaultImpl(void* user_data_ctx, const char* text
     g.ClipboardHandlerData[(int)(text_end - text)] = 0;
 }
 
+#endif // Default clipboard handlers
+
+//-----------------------------------------------------------------------------
+
+#if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS)
+#include <shellapi.h>   // ShellExecuteA()
+#ifdef _MSC_VER
+#pragma comment(lib, "shell32")
 #endif
+static void PlatformOpenInShellFn_DefaultImpl(ImGuiContext*, const char* path)
+{
+    ::ShellExecuteA(NULL, "open", path, NULL, NULL, SW_SHOWDEFAULT);
+}
+#elif !defined(IMGUI_DISABLE_DEFAULT_SHELL_FUNCTIONS))
+static void PlatformOpenInShellFn_DefaultImpl(ImGuiContext*, const char* path)
+{
+#if __APPLE__
+    const char* open_executable = "open";
+#else
+    const char* open_executable = "xdg-open";
+#endif
+    ImGuiTextBuffer buf;
+    buf.appendf("%s \"%s\"", open_executable, path);
+    system(buf.c_str());
+}
+#else
+static void PlatformOpenInShellFn_DefaultImpl(ImGuiContext*, const char*) {}
+#endif // Default shell handlers
+
+//-----------------------------------------------------------------------------
 
 // Win32 API IME support (for Asian languages, etc.)
 #if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)