TGDoubleSlider

Class Description

                                                                      
 TGDoubleSlider, TGDoubleVSlider and TGDoubleHSlider                  
                                                                      
 DoubleSlider widgets allow easy selection of a min and a max value   
 out of a range.                                                      
 DoubleSliders can be either horizontal or vertical oriented and      
 there is a choice of three different types of tick marks.            
                                                                      
 To change the min value press the mouse near to the left / bottom    
 edge of the slider.                                                  
 To change the max value press the mouse near to the right / top      
 edge of the slider.                                                  
 To change both values simultaneously press the mouse near to the     
 center of the slider.                                                
                                                                      
 TGDoubleSlider is an abstract base class. Use the concrete           
 TGDoubleVSlider and TGDoubleHSlider.                                 
                                                                      
 Dragging the slider will generate the event:                         
 kC_VSLIDER, kSL_POS, slider id, 0  (for vertical slider)             
 kC_HSLIDER, kSL_POS, slider id, 0  (for horizontal slider)           
                                                                      
 Pressing the mouse will generate the event:                          
 kC_VSLIDER, kSL_PRESS, slider id, 0  (for vertical slider)           
 kC_HSLIDER, kSL_PRESS, slider id, 0  (for horizontal slider)         
                                                                      
 Releasing the mouse will generate the event:                         
 kC_VSLIDER, kSL_RELEASE, slider id, 0  (for vertical slider)         
 kC_HSLIDER, kSL_RELEASE, slider id, 0  (for horizontal slider)       
                                                                      
 Use the functions GetMinPosition(), GetMaxPosition() and             
 GetPosition() to retrieve the position of the slider.