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|Home GeoPack GeoMap Class TGeoMap Methods ZoomHistory|
|See also: MaxZoomStack, ClearZoomHistory, ZoomStack|
The method ZoomHistory allows to revert to a previous zoom state of the map. Any changes of the map range (either due to mouse actions or to programmatical changes) are recorded and stored in a circular stack of 16 (MAXGMZOOMSTACK) elements. Therefore, the last 16 different setups are available by accessing this stack using the method ZoomHistory. The parameter Index may take any value between -15 and 0, referring to the oldest setup (Index = -15) up to the most recent one (Index = 0).
Note that setting the chart ranges by means of ZoomHistory does not (re)enter these settings into the zoom stack.