I just realized, that Zoom-in and Zoom-out (with the mousewheel) works different from graphical editors I know (as soon as drawing is larger than full screen).
Graphical editor (PSP X2 (and other too I think)):
Will make the position of the cursor the center of the drawing area. Thus allowing very fast to reposition the viewable area without changing into a move mode (Hand icon) and without the rulers on the left or down of the drawing area. The reposition is very handsome!
But this solution is only half way practical: If you use the wheel twice to zoom twice in sequence without moving the cursor, it will reposition the image twice - this double reposition is not practical at all, as the second reposition is rather random!
QCAD:
Lets the center unchanged and just zooms-in or Zooms-out.
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My proposal:
- Zoom-in or Zoom-out around the current position of the cursor
- move this current position to the center of the screen
- move the cursor itself to the center of the screen (thus avoiding to shift the image again with a subsequent zoom-operation
if the user uses a second zoom-op the new center remains mostly fixed. This would allow best of both solutions:
but the user is free to make an other area of the drawing the new center if he actively moves the cursor again.
I think this would be very simple, intuitive and efficient to handle, reducing the need to reposition the drawing manually a lot.
Actually I think earlier version of graphical editors I used worked with were implemented that way.
Caveat:
I’m not an extensive CAD user. Maybe there are special requests for this type of work that are in contradiction to my idea. Maybe it would be practical to activate this type of zooming when used along with <ALT>. Hmmm - no: Allow original QCAD-zooming with <ALT>!
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By the way:
Mouse right-click seems never assigned in QCAD. In Windows a user usually expects ‘Properties’ to be activated with right-click. But I think with the clever way you implemented this, there is no real need to change this. As the standard is already broken: Why not assign permanently a ‘Move’ (Hand icon) to ‘right-click’...
QCAD actually zooms in and out 'around' the mouse cursor. This means that the detail under the cursor remains positioned under the mouse cursor. Zooming in / out without considering the cursor position can also be achieved using the + / - keys (zooms in / out around the center of the viewport).
This should be the case (if not, it would be a bug).
Personally I don't think that programmatically moving the mouse cursor is a good option. The user expects the mouse cursor to be there where it has just been moved to.
For graphic tablets which use absolute positioning the mouse cursor would even jump back immediately.
A configuration remains of course an option.
Right-clicks are used in QCAD to go back one step while using a tool or cancel the tool.
Example for drawing two unconnected lines:
- start line tool
- set start point of first line with left mouse button
- set end point of first line with left mouse button
- click right mouse button
- set start point of second line with left mouse button
- set end point of second line with left mouse button
- click right mouse button twice