From d2e9a9aa23fe843257ac6826d38d9fbb8b9f6e5f Mon Sep 17 00:00:00 2001
From: Diederick Niehorster <dcnieho@gmail.com>
Date: Sat, 17 Nov 2012 01:02:30 +0000
Subject: [PATCH] menus attached to child windows did not appear in the right
 place. Fixed in fghActivateMenu, whose logic is now simpler
 and commented as well

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@1398 7f0cb862-5218-0410-a997-914c9d46530a
---
 progs/demos/One/one.c |   16 +++++++++++++---
 src/fg_menu.c         |   21 +++++++++++++++------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/progs/demos/One/one.c b/progs/demos/One/one.c
index b5d9732..464c2bf 100644
--- a/progs/demos/One/one.c
+++ b/progs/demos/One/one.c
@@ -277,13 +277,18 @@ void SampleSpecial( int nSpecial, int nMouseX, int nMouseY )
  */
 void SampleMenu( int menuID )
 {
-    /*
-     * Just print something funny
-     */
     printf( "SampleMenu() callback executed, menuID is %i\n", menuID );
 }
 
 /*
+ * A sample menu status callback
+ */
+void SampleMenuStatus( int status, int x, int y )
+{
+    printf ( "SampleMenu() callback executed, MenuStatus is %i at (%i,%i)\n", status, x, y );
+}
+
+/*
  * The sample's entry point
  */
 int main( int argc, char** argv )
@@ -325,6 +330,7 @@ int main( int argc, char** argv )
     glutSpecialFunc( SampleSpecial );
     glutIdleFunc( SampleIdle );
     glutEntryFunc( SampleEntry );
+    glutMenuStatusFunc( SampleMenuStatus );
     glutAttachMenu( GLUT_LEFT_BUTTON );
 
     glutInitWindowPosition( 200, 200 );
@@ -334,6 +340,8 @@ int main( int argc, char** argv )
     glutKeyboardFunc( SampleKeyboard );
     glutSpecialFunc( SampleSpecial );
     glutIdleFunc( SampleIdle );
+    glutEntryFunc( SampleEntry );
+    glutMenuStatusFunc( SampleMenuStatus );
     glutAttachMenu( GLUT_LEFT_BUTTON );
     glutSetMenu(subMenuA);
     glutAttachMenu( GLUT_RIGHT_BUTTON );
@@ -367,6 +375,8 @@ int main( int argc, char** argv )
     glutReshapeFunc( SampleReshape );
     glutKeyboardFunc( SampleGameModeKeyboard );
     glutIdleFunc( SampleIdle );
+    glutEntryFunc( SampleEntry );
+    glutMenuStatusFunc( SampleMenuStatus );
     glutSetMenu(menuID);
     glutAttachMenu( GLUT_LEFT_BUTTON );
 
diff --git a/src/fg_menu.c b/src/fg_menu.c
index 6a7d96d..9b40bfe 100644
--- a/src/fg_menu.c
+++ b/src/fg_menu.c
@@ -509,6 +509,7 @@ void fgDisplayMenu( void )
 static void fghActivateMenu( SFG_Window* window, int button )
 {
     int max_x, max_y;
+    SFG_XYUse mouse_pos;
 
     /* We'll be referencing this menu a lot, so remember its address: */
     SFG_Menu* menu = window->Menu[ button ];
@@ -527,9 +528,17 @@ static void fghActivateMenu( SFG_Window* window, int button )
     /* Set up the initial menu position now: */
     fghGetVMaxExtent(menu->ParentWindow, &max_x, &max_y);
     fgSetWindow( window );
-    menu->X = window->State.MouseX + glutGet( GLUT_WINDOW_X );
-    menu->Y = window->State.MouseY + glutGet( GLUT_WINDOW_Y );
+    /* get mouse position on screen (window->State.MouseX and window->State.MouseY
+     * are relative to client area origin), and not easy to correct given that
+     * glutGet( GLUT_WINDOW_X ) and glutGet( GLUT_WINDOW_Y ) return relative to parent
+     * origin when looking at a child window
+     * for parent windows: window->State.MouseX + glutGet( GLUT_WINDOW_X ) == mouse_pos.X
+     */
+    fghPlatformGetCursorPos(&mouse_pos);
+    menu->X = mouse_pos.X;
+    menu->Y = mouse_pos.Y;
 
+    /* Make sure the whole menu is on the screen */
     if( menu->X + menu->Width > max_x )
         menu->X -=menu->Width;
 
@@ -540,10 +549,9 @@ static void fghActivateMenu( SFG_Window* window, int button )
             menu->Y = 0;
     }
 
-    menu->Window->State.MouseX =
-        window->State.MouseX + glutGet( GLUT_WINDOW_X ) - menu->X;
-    menu->Window->State.MouseY =
-        window->State.MouseY + glutGet( GLUT_WINDOW_Y ) - menu->Y;
+    /* Set position of mouse relative to top-left menu in menu's window state (could as well set 0 at creation time...) */
+    menu->Window->State.MouseX = mouse_pos.X - menu->X;
+    menu->Window->State.MouseY = mouse_pos.Y - menu->Y;
 
     /* Menu status callback */
     if (fgState.MenuStateCallback || fgState.MenuStatusCallback)
@@ -553,6 +561,7 @@ static void fghActivateMenu( SFG_Window* window, int button )
         if (fgState.MenuStateCallback)
             fgState.MenuStateCallback(GLUT_MENU_IN_USE);
         if (fgState.MenuStatusCallback)
+            /* window->State.MouseX and window->State.MouseY are relative to client area origin, as needed */
             fgState.MenuStatusCallback(GLUT_MENU_IN_USE, window->State.MouseX, window->State.MouseY);
     }
 
-- 
1.7.10.4