Zooming gives you the ability to expand or contract the viewport around a particular point or area in a graph control. When you zoom in, the logical area contained in the viewport gets smaller, showing the area with more resolution. When you zoom out, the viewport shows a wider area. You can also use panning, which is the ability to shift the viewport.
By default, zooming and panning are disabled. To enable zooming and panning in a graph control, set the graph control to a mode other than indicator. You should then set one of the following available zooming modes through the Edit Graph dialog box or programmatically:
To pan, press <Ctrl-Shift>, click and hold the left mouse button, and drag the mouse to a new point. The graph viewport scrolls so that a new portion of the graph is visible. You can drag the mouse anywhere on the screen, even beyond the viewport. Panning is available whenever you enable zooming.
To zoom out, press <Ctrl> and click and hold the right mouse button. In Zoom Around Point mode, the resolution in the viewport decreases dynamically until you release the mouse. In all other modes, the resolution incrementally decreases by 10% along the zoomed axes.
Note: You also can undo up to 25 of the most recent pans or zooms by pressing <Ctrl-Space> to reverse each successive change.
To programmatically enable zooming and panning, use the SetCtrlAttribute function with the control attribute ATTR_ENABLE_ZOOM_AND_PAN set to true.
Note If you enable autoscaling for the graph, autoscaling is disabled while you zoom or pan. If you plot additional data during zooming or panning, LabWindows/CVI completes the zooming or panning and then displays the new data with autoscaling.
Note The above zoom modes were introduced in LabWindows/CVI 8.5. The Zoom Around Point style matches the zooming functionality in previous versions of LabWindows/CVI.
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