Value | Symbolic name | Description | 
|   0 | GDK_SHIFT_MASK | 
   Denotes that a shift modifier is in place.  A dedicated key or
   mouse-button will not become active until the Shift 
   key is pressed down.
   | 
|   1 | GDK_LOCK_MASK | 
   Denotes that a Caps Lock modifier is in place.  Note
   that this modifier is illegal for use with accelerator keys, and will not
   work there.
   | 
|   2 | GDK_CONTROL_MASK | 
   Denotes that a control modifier is in place.  A dedicated key or
   mouse-button will not become active until the Control 
   key is pressed down.
   | 
|   3 | GDK_MOD1_MASK | 
   Denotes that an alt modifier is in place.  A dedicated key or
   mouse-button will not become active until the Alt 
   key is pressed down.
   | 
|   4 | GDK_MOD2_MASK | 
   | 
|   5 | GDK_MOD3_MASK | 
   | 
|   6 | GDK_MOD4_MASK | 
   | 
|   7 | GDK_MOD5_MASK | 
   | 
|   8 | GDK_BUTTON1_MASK | 
   The first (mostly left) mouse button.
   | 
|   9 | GDK_BUTTON2_MASK | 
   The second (middle) mouse button.
   | 
|   10 | GDK_BUTTON3_MASK | 
   The third (mostly right) mouse button.
   | 
|   11 | GDK_BUTTON4_MASK | 
   Mouse wheel up.
   | 
|   12 | GDK_BUTTON5_MASK | 
   Mouse wheel down.
   | 
|   13 | GDK_RELEASE_MASK | 
   Denotes that the act of releasing the button is a modifier.
   | 
|   14 | GDK_MODIFIER_MASK | 
   Returns all the modifiers that are possible in the current context.
   |