"writeImage" method support for windows (#145)

* fix js version dependance

* writeImage method support for windows

---------

Co-authored-by: alexkmbk <[email protected]>

Author: alexkmbk

packages/pasteboard/lib/pasteboard.dart

@@ -10,7 +10,7 @@ class Pasteboard {
   /// available on iOS, desktop and the web.
   static Future<Uint8List?> get image => pasteboard.image;
 
-  /// only available on Windows
+  /// only available on Windows and the web.
   /// Get "HTML format" from system pasteboard.
   /// HTML format: https://docs.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/platform-apis/aa767917(v=vs.85)
   static Future<String?> get html => pasteboard.html;

packages/pasteboard/lib/src/pasteboard_platform_io.dart

@@ -1,5 +1,7 @@
 import 'dart:io';
 import 'dart:typed_data';
+import 'package:path/path.dart' as Path;
+import 'package:uuid/uuid.dart';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
@@ -63,6 +65,12 @@ class PasteboardPlatformIO implements PasteboardPlatform {
     }
     if (Platform.isIOS || Platform.isMacOS) {
       await _channel.invokeMethod<void>('writeImage', image);
+    } else if (Platform.isWindows) {
+      final file = await File(GetTempFileName()).create();
+      file.writeAsBytesSync(image);
+      await _channel
+          .invokeMethod<Object>('writeImage', {'fileName': file.path});
+      file.delete();
     }
   }
 
@@ -77,3 +85,19 @@ class PasteboardPlatformIO implements PasteboardPlatform {
     Clipboard.setData(ClipboardData(text: value));
   }
 }
+
+String GetTempFileName() {
+  final dir = Directory.systemTemp;
+  String tempFileName;
+
+  var uuid = Uuid();
+
+  while (true) {
+    tempFileName = Path.join(dir.path, uuid.v1().toString());
+    if (!File(tempFileName).existsSync()) {
+      break;
+    }
+  }
+
+  return tempFileName;
+}

packages/pasteboard/windows/CMakeLists.txt

@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.14)
 set(PROJECT_NAME "pasteboard")
 project(${PROJECT_NAME} LANGUAGES CXX)
 
+
 # This value is used when generating builds using this plugin, so it must
 # not be changed
 set(PLUGIN_NAME "pasteboard_plugin")
@@ -17,6 +18,11 @@ target_include_directories(${PLUGIN_NAME} INTERFACE
         "${CMAKE_CURRENT_SOURCE_DIR}/include")
 target_link_libraries(${PLUGIN_NAME} PRIVATE flutter flutter_wrapper_plugin)
 
+# GdiPlus doesn't compile with /W4 warning level
+target_compile_options(${PLUGIN_NAME} PRIVATE
+  $<$<CXX_COMPILER_ID:MSVC>:/W3 /WX>
+  $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wall -Wextra -Wpedantic -Werror>
+)
 
 
 # List of absolute paths to libraries that should be bundled with the plugin

packages/pasteboard/windows/pasteboard_plugin.cpp

@@ -4,14 +4,18 @@
 #include <flutter/plugin_registrar_windows.h>
 #include <flutter/standard_method_codec.h>
 
+
 #include <Windows.h>
 #include <ShlObj.h>
+#include <gdiplus.h>
 
 #include <map>
 #include <memory>
 
 #include "strconv.h"
 
+#pragma comment(lib, "GdiPlus")
+
 namespace {
 
 constexpr STGMEDIUM kNullStorageMedium = {TYMED_NULL, nullptr, nullptr};
@@ -131,6 +135,49 @@ PBITMAPINFO CreateBitmapInfoStruct(HBITMAP hBmp) {
   return pbmi;
 }
 
+// The code was taken from this answer: https://stackoverflow.com/a/39201008/2134488
+//
+bool CopyImageToClipboard(const wchar_t* filename)
+{
+	//initialize Gdiplus once:
+	Gdiplus::GdiplusStartupInput gdiplusStartupInput;
+	ULONG_PTR gdiplusToken;
+	Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
+
+	bool result = false;
+	Gdiplus::Bitmap *gdibmp = Gdiplus::Bitmap::FromFile(filename);
+	if (gdibmp)
+	{
+		HBITMAP hbitmap;
+		gdibmp->GetHBITMAP(0, &hbitmap);
+		if (OpenClipboard(NULL))
+		{
+			EmptyClipboard();
+			DIBSECTION ds;
+			if (GetObject(hbitmap, sizeof(DIBSECTION), &ds))
+			{
+				HDC hdc = GetDC(HWND_DESKTOP);
+				//create compatible bitmap (get DDB from DIB)
+				HBITMAP hbitmap_ddb = CreateDIBitmap(hdc, &ds.dsBmih, CBM_INIT,
+					ds.dsBm.bmBits, (BITMAPINFO*)&ds.dsBmih, DIB_RGB_COLORS);
+				ReleaseDC(HWND_DESKTOP, hdc);
+				SetClipboardData(CF_BITMAP, hbitmap_ddb);
+				DeleteObject(hbitmap_ddb);
+				result = true;
+			}
+			CloseClipboard();
+		}
+
+		//cleanup:
+		DeleteObject(hbitmap);
+		delete gdibmp;
+	}
+
+	Gdiplus::GdiplusShutdown(gdiplusToken);
+
+	return result;
+}
+
 void CreateBMPFile(LPCTSTR pszFile, HBITMAP hBMP) {
   HANDLE hf;               // file handle
   BITMAPFILEHEADER hdr;    // bitmap file-header
@@ -431,6 +478,34 @@ void PasteboardPlugin::HandleMethodCall(
     SetClipboardData(CF_HDROP, storage.hGlobal);
 	result->Success();
   }
+  else if (method_call.method_name() == "writeImage") {
+
+
+  const auto* arguments = std::get_if<flutter::EncodableMap>(method_call.arguments());
+
+  std::string fileName;
+  if (arguments) {
+	  auto it = arguments->find(flutter::EncodableValue("fileName"));
+	  if (it != arguments->end()) {
+		  if (std::holds_alternative<std::string>(it->second)) {
+			  fileName = std::get<std::string>(it->second);
+		  }
+	  }
+  }
+
+  if (fileName.size() == 0) {
+	  result->Error("0", "File name is empty");
+	  return;
+  }
+  std::wstring wsFileName = cp_to_wide(fileName, CP_UTF8);
+
+  if (!CopyImageToClipboard(wsFileName.c_str())) {
+	  result->Error("0", "Failed to copy image to clipboard");
+	  return;
+  }
+
+  result->Success();
+}
   else if (method_call.method_name() == "html") {
 
   UINT CF_HTML = RegisterClipboardFormatA("HTML Format");