Very controlled GDIplus startup and shutdown #635 (#679)

Fall back to GDI if GDIplus is not available

4 files changed, 44 insertions, 5 deletions

diff --git a/.gitignore b/.gitignore
index 51e1e9951..764ca6526 100644
--- a/.gitignore
+++ b/.gitignore
@@ -90,3 +90,7 @@ src/xdg-shell-protocol.c
 
 # libdecor/build/demo
 # libdecor/build/egl
+/out/build/x64-Debug/.cmake/api/v1/query/client-MicrosoftVS/query.json
+/out/build/x64-Debug
+/CMakeSettings.json
+/CppProperties.json
diff --git a/src/drivers/GDI/Fl_GDI_Graphics_Driver.H b/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
index 6fa6840c8..941ac4db1 100644
--- a/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
+++ b/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
@@ -182,7 +182,16 @@ private:
   Gdiplus::Color gdiplus_color_;
   Gdiplus::Pen *pen_;
   Gdiplus::SolidBrush *brush_;
-  static ULONG_PTR gdiplusToken;
+  // The code below ensures the a connection to GDIplus is only made once, and that the
+  // matching connection shutdown is also done exactly once.
+  enum {
+	  STATE_CLOSED = 0,					// no connection, token is invalid
+	  STATE_STARTUP,					// attempt to start up, avoid recursions for whatever reason
+	  STATE_OPEN,						// connection was successful and the token is valid
+	  STATE_SHUTDOWN					// shutting down the gdi connection, avoid possible recursion
+  };
+  static int gdiplus_state_;			// reflect the state of the GDIplus driver connection
+  static ULONG_PTR gdiplus_token_;		// the token that GDIplus gives to us
 public:
   Fl_GDIplus_Graphics_Driver();
   virtual ~Fl_GDIplus_Graphics_Driver();
diff --git a/src/drivers/GDI/Fl_GDI_Graphics_Driver.cxx b/src/drivers/GDI/Fl_GDI_Graphics_Driver.cxx
index 188bd1d2d..7897dce53 100644
--- a/src/drivers/GDI/Fl_GDI_Graphics_Driver.cxx
+++ b/src/drivers/GDI/Fl_GDI_Graphics_Driver.cxx
@@ -53,10 +53,22 @@ int Fl_GDIplus_Graphics_Driver::antialias() {
 
 #if USE_GDIPLUS
 
-ULONG_PTR Fl_GDIplus_Graphics_Driver::gdiplusToken = 0;
+int Fl_GDIplus_Graphics_Driver::gdiplus_state_ = Fl_GDIplus_Graphics_Driver::STATE_CLOSED;
+ULONG_PTR Fl_GDIplus_Graphics_Driver::gdiplus_token_ = 0;
 
 void Fl_GDIplus_Graphics_Driver::shutdown() {
-  Gdiplus::GdiplusShutdown(Fl_GDIplus_Graphics_Driver::gdiplusToken);
+  if (gdiplus_state_ == STATE_OPEN) {
+    gdiplus_state_ = STATE_SHUTDOWN;
+    Gdiplus::GdiplusShutdown(Fl_GDIplus_Graphics_Driver::gdiplus_token_);
+    gdiplus_token_ = 0;
+    gdiplus_state_ = STATE_CLOSED;
+  } else if (gdiplus_state_ == STATE_CLOSED) {
+//    Fl::warning("Fl_GDIplus_Graphics_Driver::shutdown() called, but driver is closed.");
+  } else if (gdiplus_state_ == STATE_SHUTDOWN) {
+//    Fl::warning("Fl_GDIplus_Graphics_Driver::shutdown() called recursively.");
+  } else if (gdiplus_state_ == STATE_STARTUP) {
+//    Fl::warning("Fl_GDIplus_Graphics_Driver::shutdown() called while driver is starting up.");
+  }
 }
 #endif
 
diff --git a/src/drivers/WinAPI/fl_WinAPI_platform_init.cxx b/src/drivers/WinAPI/fl_WinAPI_platform_init.cxx
index bf5e34d36..5f3ba4ec4 100644
--- a/src/drivers/WinAPI/fl_WinAPI_platform_init.cxx
+++ b/src/drivers/WinAPI/fl_WinAPI_platform_init.cxx
@@ -34,8 +34,22 @@ Fl_Graphics_Driver *Fl_Graphics_Driver::newMainGraphicsDriver()
 #if USE_GDIPLUS
   // Initialize GDI+.
   static Gdiplus::GdiplusStartupInput gdiplusStartupInput;
-  if (Fl_GDIplus_Graphics_Driver::gdiplusToken == 0) {
-    GdiplusStartup(&Fl_GDIplus_Graphics_Driver::gdiplusToken, &gdiplusStartupInput, NULL);
+  if (Fl_GDIplus_Graphics_Driver::gdiplus_state_ == Fl_GDIplus_Graphics_Driver::STATE_CLOSED) {
+    Fl_GDIplus_Graphics_Driver::gdiplus_state_ = Fl_GDIplus_Graphics_Driver::STATE_STARTUP;
+    Gdiplus::Status ret = GdiplusStartup(&Fl_GDIplus_Graphics_Driver::gdiplus_token_, &gdiplusStartupInput, NULL);
+    if (ret == Gdiplus::Status::Ok) {
+      Fl_GDIplus_Graphics_Driver::gdiplus_state_ = Fl_GDIplus_Graphics_Driver::STATE_OPEN;
+    } else {
+      Fl::warning("GdiplusStartup failed with error code %d.", ret);
+      Fl_GDIplus_Graphics_Driver::gdiplus_state_ = Fl_GDIplus_Graphics_Driver::STATE_CLOSED;
+      return new Fl_GDI_Graphics_Driver();
+    }
+  } else if (Fl_GDIplus_Graphics_Driver::gdiplus_state_ == Fl_GDIplus_Graphics_Driver::STATE_OPEN) {
+//    Fl::warning("GdiplusStartup() called, but driver is already open.");
+  } else if (Fl_GDIplus_Graphics_Driver::gdiplus_state_ == Fl_GDIplus_Graphics_Driver::STATE_SHUTDOWN) {
+//    Fl::warning("GdiplusStartup() called while driver is shutting down.");
+  } else if (Fl_GDIplus_Graphics_Driver::gdiplus_state_ == Fl_GDIplus_Graphics_Driver::STATE_STARTUP) {
+//    Fl::warning("GdiplusStartup() called recursively.");
   }
   Fl_Graphics_Driver *driver = new Fl_GDIplus_Graphics_Driver();
   return driver;