Using a PanWindow
The Pan Window is a small window which will display a scaled view of a bitmap, which is also being displayed in another main window at a size that would require scrolling. The Pan Window will maintain the image’s aspect ratio. In the Pan Window, a colored Pan Rect will be displayed to indicate the portion of the image currently being displayed in the main window.
When a user clicks inside the Pan Window and moves the mouse, while holding down the button, the Pan Rect will move with the mouse pointer. The Pan Window Callback function will notify the user that the main window should be updated. The Pan Window Callback function will be called after the Pan Window processes a WM_PAINT message, to allow the user to do custom painting or to be notified of interactive Pan Window updates.
The functions provided for working with a PanWindow are: