Update changelog, comments, made empty/no-text clipboard return NULL as with other implementation. Minor style tweaks. (#2546)

Fixed IMGUI_DISABLE_WIN32_FUNCTIONS not disabling IME code.

docs/CHANGELOG.txt

@@ -49,6 +49,8 @@ Other Changes:
 - Scrollbar: Very minor bounding box adjustment to cope with various border size.
 - ImFontAtlas: FreeType: Added RasterizerFlags::Monochrome flag to disable font anti-aliasing. (#2545)
   Combine with RasterizerFlags::MonoHinting for best results.
+- Add native Mac clipboard copy/paste default implementation in core library to match what we are
+  dealing with Win32, and to facilitate integration in custom engines. (#2546) [@andrewwillmott]
 - Examples/Backends: Don't filter characters under 0x10000 before calling io.AddInputCharacter(),
   the filtering is done in io.AddInputCharacter() itself. This is in prevision for fuller Unicode
   support. (#2538, #2541)

examples/imgui_impl_osx.mm

@@ -12,6 +12,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2019-05-18: Misc: Removed clipboard handlers as they are now supported by core imgui.cpp.
 //  2019-05-11: Inputs: Don't filter character values before calling AddInputCharacter() apart from 0xF700..0xFFFF range.
 //  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
 //  2018-07-07: Initial version.
@@ -55,6 +56,9 @@ bool ImGui_ImplOSX_Init()
     io.KeyMap[ImGuiKey_Y]           = 'Y';
     io.KeyMap[ImGuiKey_Z]           = 'Z';
 
+    // We don't set the io.SetClipboardTextFn/io.GetClipboardTextFn handlers,
+    // because imgui.cpp has a default for them that works with OSX.
+
     return true;
 }
 

imconfig.h

@@ -31,7 +31,8 @@
 //---- Don't implement some functions to reduce linkage requirements.
 //#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // [Win32] Don't implement default clipboard handler. Won't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc.
 //#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS         // [Win32] Don't implement default IME handler. Won't use and link with ImmGetContext/ImmSetCompositionWindow.
-//#define IMGUI_DISABLE_WIN32_FUNCTIONS                     // [Win32] Won't use and link with any Win32 function.
+//#define IMGUI_DISABLE_WIN32_FUNCTIONS                     // [Win32] Won't use and link with any Win32 function (clipboard, ime).
+//#define IMGUI_DISABLE_OSX_FUNCTIONS                       // [OSX] Won't use and link with any OSX function (clipboard).
 //#define IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS             // Don't implement ImFormatString/ImFormatStringV so you can implement them yourself if you don't want to link with vsnprintf.
 //#define IMGUI_DISABLE_MATH_FUNCTIONS                      // Don't implement ImFabs/ImSqrt/ImPow/ImFmod/ImCos/ImSin/ImAcos/ImAtan2 wrapper so you can implement them yourself. Declare your prototypes in imconfig.h.
 //#define IMGUI_DISABLE_DEFAULT_ALLOCATORS                  // Don't implement default allocators calling malloc()/free() to avoid linking with them. You will need to call ImGui::SetAllocatorFunctions().

imgui.cpp

@@ -9528,13 +9528,13 @@ static void SettingsHandlerWindow_WriteAll(ImGuiContext* ctx, ImGuiSettingsHandl
 #include <TargetConditionals.h>
 #endif
 
-// Win32 API clipboard implementation
 #if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS)
 
 #ifdef _MSC_VER
 #pragma comment(lib, "user32")
 #endif
 
+// Win32 clipboard implementation
 static const char* GetClipboardTextFn_DefaultImpl(void*)
 {
     static ImVector<char> buf_local;
@@ -9579,18 +9579,20 @@ static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 }
 
 #elif defined(__APPLE__) && TARGET_OS_OSX && !defined(IMGUI_DISABLE_OSX_FUNCTIONS)
-#include <Carbon/Carbon.h>  // use ye olde worlde API to avoid need for separate .mm file
+
+#include <Carbon/Carbon.h>  // Use old API to avoid need for separate .mm file
 static PasteboardRef main_clipboard = 0;
 
+// OSX clipboard implementation
 static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 {
     if (!main_clipboard)
         PasteboardCreate(kPasteboardClipboard, &main_clipboard);
     PasteboardClear(main_clipboard);
-    CFDataRef cf_data = CFDataCreate(kCFAllocatorDefault, (const UInt8*) text, strlen(text));
+    CFDataRef cf_data = CFDataCreate(kCFAllocatorDefault, (const UInt8*)text, strlen(text));
     if (cf_data)
     {
-        PasteboardPutItemFlavor(main_clipboard, (PasteboardItemID) 1, CFSTR("public.utf8-plain-text"), cf_data, 0);
+        PasteboardPutItemFlavor(main_clipboard, (PasteboardItemID)1, CFSTR("public.utf8-plain-text"), cf_data, 0);
         CFRelease(cf_data);
     }
 }
@@ -9603,7 +9605,6 @@ static const char* GetClipboardTextFn_DefaultImpl(void*)
 
     ItemCount item_count = 0;
     PasteboardGetItemCount(main_clipboard, &item_count);
-
     for (int i = 0; i < item_count; i++)
     {
         PasteboardItemID item_id = 0;
@@ -9616,30 +9617,27 @@ static const char* GetClipboardTextFn_DefaultImpl(void*)
             if (PasteboardCopyItemFlavorData(main_clipboard, item_id, CFSTR("public.utf8-plain-text"), &cf_data) == noErr)
             {
                 static ImVector<char> clipboard_text;
-
-                int length = (int) CFDataGetLength(cf_data);
+                int length = (int)CFDataGetLength(cf_data);
                 clipboard_text.resize(length + 1);
-                CFDataGetBytes(cf_data, CFRangeMake(0, length), (UInt8*) clipboard_text.Data);
+                CFDataGetBytes(cf_data, CFRangeMake(0, length), (UInt8*)clipboard_text.Data);
                 clipboard_text[length] = 0;
-
                 CFRelease(cf_data);
                 return clipboard_text.Data;
             }
         }
     }
-    return "";
+    return NULL;
 }
 
 #else
 
-// Local ImGui-only clipboard implementation, if user hasn't defined better clipboard handlers
+// Local Dear ImGui-only clipboard implementation, if user hasn't defined better clipboard handlers.
 static const char* GetClipboardTextFn_DefaultImpl(void*)
 {
     ImGuiContext& g = *GImGui;
     return g.PrivateClipboard.empty() ? NULL : g.PrivateClipboard.begin();
 }
 
-// Local ImGui-only clipboard implementation, if user hasn't defined better clipboard handlers
 static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 {
     ImGuiContext& g = *GImGui;
@@ -9653,7 +9651,7 @@ static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 #endif
 
 // Win32 API IME support (for Asian languages, etc.)
-#if defined(_WIN32) && !defined(__GNUC__) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)
+#if defined(_WIN32) && !defined(__GNUC__) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)
 
 #include <imm.h>
 #ifdef _MSC_VER