To get a professional Zoom Control for WPF check out the ZoomPanel.
It is not free, but is very easy to use and has many features - animated zooming and panning, support for ScrollViewer, mouse wheel support, included ZoomController (with move, zoom in, zoom out, rectangle zoom, reset buttons). It also comes with many code samples.
You should have a look at this article by Mitsu Furuta (don't worry about the funny title !). I'm not sure whether it meets your requirements exactly, but it could give you some ideas...
Maybe you could try out the Zoom Control which is part of WPF Extensions available on Codeplex:
alt text http://i3.codeplex.com/Project/Download/FileDownload.aspx?ProjectName=wpfextensions&DownloadId=66810
To get a professional Zoom Control for WPF check out the ZoomPanel.
It is not free, but is very easy to use and has many features - animated zooming and panning, support for ScrollViewer, mouse wheel support, included ZoomController (with move, zoom in, zoom out, rectangle zoom, reset buttons). It also comes with many code samples.
You should have a look at this article by Mitsu Furuta (don't worry about the funny title !). I'm not sure whether it meets your requirements exactly, but it could give you some ideas...
Put your stuff into a grid, bind the grid's scale render transformation to a slider (slider should have min value of 1):