implemented get window title for win32

include/GLFW/glfw3.h

@@ -2895,6 +2895,26 @@ GLFWAPI int glfwWindowShouldClose(GLFWwindow* window);
  */
 GLFWAPI void glfwSetWindowShouldClose(GLFWwindow* window, int value);
 
+/*! @brief Retrieves the title of the specified window.
+ *
+ *  This function gets the window title, encoded as UTF-8, of the specified
+ *  window.
+ *
+ *  @param[in] window The window to query.
+ *  @return A copy of the UTF-8 encoded window title, or NULL if an error has occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref window_title
+ *  @sa @ref glfwSetWindowTitle
+ *
+ *  @ingroup window
+ */
+GLFWAPI char* glfwGetWindowTitle(GLFWwindow* window);
+
 /*! @brief Sets the title of the specified window.
  *
  *  This function sets the window title, encoded as UTF-8, of the specified
@@ -2912,7 +2932,8 @@ GLFWAPI void glfwSetWindowShouldClose(GLFWwindow* window, int value);
  *  @thread_safety This function must only be called from the main thread.
  *
  *  @sa @ref window_title
- *
+ *  @sa @ref glfwGetWindowTitle
+ * 
  *  @since Added in version 1.0.
  *  @glfw3 Added window handle parameter.
  *

src/internal.h

@@ -650,6 +650,7 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
                               const _GLFWctxconfig* ctxconfig,
                               const _GLFWfbconfig* fbconfig);
 void _glfwPlatformDestroyWindow(_GLFWwindow* window);
+char* _glfwPlatformGetWindowTitle(_GLFWwindow* window);
 void _glfwPlatformSetWindowTitle(_GLFWwindow* window, const char* title);
 void _glfwPlatformSetWindowIcon(_GLFWwindow* window,
                                 int count, const GLFWimage* images);

src/win32_window.c

@@ -1462,6 +1462,37 @@ void _glfwPlatformDestroyWindow(_GLFWwindow* window)
         DestroyIcon(window->win32.smallIcon);
 }
 
+char* _glfwPlatformGetWindowTitle(_GLFWwindow* window)
+{
+    int count = GetWindowTextLengthW(window->win32.handle);
+    if(count == 0)
+    {
+        SetLastError(0);
+        int error = GetLastError();
+
+        if(error != 0)
+        {
+            _glfwInputErrorWin32(GLFW_PLATFORM_ERROR, "Win32: Querying window title failed");
+            return NULL;
+        }
+        else
+            return calloc(1, sizeof(char)); // single \0
+        
+    }
+    else
+    {
+        count += 1; // the \0
+        WCHAR* wideTitle = calloc(count, sizeof(WCHAR));
+        GetWindowTextW(window->win32.handle, wideTitle, count);
+        
+        char* title = _glfwCreateUTF8FromWideStringWin32(wideTitle);
+        if(!title)
+            return calloc(1, sizeof(char)); // single \0
+            
+        return title;
+    }
+}
+
 void _glfwPlatformSetWindowTitle(_GLFWwindow* window, const char* title)
 {
     WCHAR* wideTitle = _glfwCreateWideStringFromUTF8Win32(title);

src/window.c

@@ -501,6 +501,15 @@ GLFWAPI void glfwSetWindowShouldClose(GLFWwindow* handle, int value)
     window->shouldClose = value;
 }
 
+GLFWAPI char* glfwGetWindowTitle(GLFWwindow* handle)
+{
+    _GLFWwindow* window = (_GLFWwindow*) handle;
+    assert(window != NULL);
+
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+    return _glfwPlatformGetWindowTitle(window);
+}
+
 GLFWAPI void glfwSetWindowTitle(GLFWwindow* handle, const char* title)
 {
     _GLFWwindow* window = (_GLFWwindow*) handle;