glfw: export Drop callback

backend.go

@@ -5,6 +5,7 @@ package imgui
 // extern void afterRender();
 // extern void afterCreateContext();
 // extern void beforeDestoryContext();
+// extern void dropCallback(void*, int, char**);
 import "C"
 
 import (
@@ -59,6 +60,20 @@ func beforeDestoryContext() {
 	}
 }
 
+type DropCallback func([]string)
+
+//export dropCallback
+func dropCallback(wnd unsafe.Pointer, count C.int, names **C.char) {
+	namesSlice := make([]string, int(count))
+	for i := 0; i < int(count); i++ {
+		var x *C.char
+		p := (**C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(names)) + uintptr(i)*unsafe.Sizeof(x)))
+		namesSlice[i] = C.GoString(*p)
+	}
+
+	currentBackend.dropCallback()(namesSlice)
+}
+
 // Backend is a special interface that implements all methods required
 // to render imgui application.
 type Backend interface {
@@ -80,6 +95,7 @@ type Backend interface {
 	CreateTexture(pixels unsafe.Pointer, width, Height int) TextureID
 	CreateTextureRgba(img *image.RGBA, width, height int) TextureID
 	DeleteTexture(id TextureID)
+	SetDropCallback(DropCallback)
 
 	// TODO: flags needs generic layer
 	CreateWindow(title string, width, height int, flags GLFWWindowFlags)
@@ -99,6 +115,7 @@ type Backend interface {
 	loopFunc() func()
 	afterRenderHook() func()
 	beforeDestroyHook() func()
+	dropCallback() DropCallback
 }
 
 func CreateBackend( /*TODO: backend type*/ ) Backend {

examples/main.go

@@ -128,5 +128,9 @@ func main() {
 
 	backend.CreateWindow("Hello from cimgui-go", 1200, 900, 0)
 
+	backend.SetDropCallback(func(p []string) {
+		fmt.Printf("drop triggered: %v", p)
+	})
+
 	backend.Run(loop)
 }

glfw_backend.cpp

@@ -285,4 +285,8 @@ void igGLFWWindow_SetShouldClose(GLFWwindow *window, int value){
   glfwSetWindowShouldClose(window, value);
 }
 
+void igGLFWWindow_SetDropCallbackCB(GLFWwindow *wnd){
+ glfwSetDropCallback(wnd, (GLFWdropfun)dropCallback);
+}
+
 #endif

glfw_backend.go

@@ -44,6 +44,7 @@ type GLFWBackend struct {
 	beforeRender         voidCallbackFunc
 	afterRender          voidCallbackFunc
 	beforeDestoryContext voidCallbackFunc
+	dropCB               DropCallback
 	window               uintptr
 }
 
@@ -96,6 +97,10 @@ func (b *GLFWBackend) loopFunc() func() {
 	return b.loop
 }
 
+func (b *GLFWBackend) dropCallback() DropCallback {
+	return b.dropCB
+}
+
 func (b *GLFWBackend) SetWindowPos(x, y int) {
 	C.igGLFWWindow_SetWindowPos(b.handle(), C.int(x), C.int(y))
 }
@@ -152,3 +157,10 @@ func (b *GLFWBackend) CreateTextureRgba(img *image.RGBA, width, height int) Text
 func (b *GLFWBackend) DeleteTexture(id TextureID) {
 	C.igDeleteTexture(C.ImTextureID(id))
 }
+
+// SetDropCallback sets the drop callback which is called when an object
+// is dropped over the window.
+func (b *GLFWBackend) SetDropCallback(cbfun DropCallback) {
+	b.dropCB = cbfun
+	C.igGLFWWindow_SetDropCallbackCB(b.handle())
+}

glfw_backend.h

@@ -32,10 +32,13 @@ extern void igRunLoop(GLFWwindow *window, VoidCallback loop, VoidCallback before
 extern void igGLFWWindow_GetDisplaySize(GLFWwindow *window, int *width, int *height);
 extern void igGLFWWindow_SetWindowPos(GLFWwindow *window, int x, int y);
 extern void igGLFWWindow_SetShouldClose(GLFWwindow *window, int value);
+extern void igGLFWWindow_SetDropCallbackCB(GLFWwindow *window);
 extern void igRefresh();
 extern ImTextureID igCreateTexture(unsigned char *pixels, int width, int height);
 extern void igDeleteTexture(ImTextureID id);
 
+extern void dropCallback(int, char**);
+
 #ifdef __cplusplus
 }
 #endif