Picking in a graphics system

• US 4,847,605 A
• Filed: 04/27/1987
• Issued: 07/11/1989
• Est. Priority Date: 04/27/1987
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Whistance, Bruce E., Flickinger, Edward C., Callahan, Robert M., Hempel, Bruce C., Fiore, Anthony M.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/043,019
• Time in Patent Office: 806 Days
• Field of Search: 364/521, 340/707, 340/708, 340/709, 340/710, 340/706
• US Class Current: 715/856
• CPC Class Codes: G06F 3/04842 Selection of displayed objects or displayed text elements G06F3/0482 takes precedence

Abstract

A method is described for improving the responsiveness and accuracy of a graphics system to user-initiated picking actions. In this method, the visual cueing and pick window positioning components of the graphics system tracking/picking function are temporarily separated at the time the user attempts to pick. By handling these two components of the tracking/picking function independently, both type 1 (failure to pick the desired item) and type 2 (picking an undesired item) errors are prevented. This translates into greater productivity for the graphics system user.

Claims

1. A method of selecting or picking objects in response to an operator generated pick request, on a graphics workstation display having both a pick window and a cursor, where the cursor and pick window positions are both modified in response to the movement of a cursor tracking device, and where selecting or picking occurs at a rate slower than the rate of updating cursor position, said method comprising the steps of:

determining a position of said cursor tracking device;

testing for the existence of an operator generated pick request;

updating said pick request status indicator, if a pick request is detected;

repositioning said cursor to said position of said tracking device;

testing said pick request status indicator to determine whether outstanding pick requests exist;

maintaining said pick window position whenever outstanding pick requests exist;

repositioning said pick window to said position of said tracking device whenever there are no outstanding pick requests; and

periodically re-executing a display program, testing each object against the pick window to determine whether a pick occurred, indicating a picked object, if a pick occurred, and updating said pick request status indicator.

2. The method of claim 1, wherein said step of updating said pick request status indicator comprises the steps of:

setting said pick request status indicator to indicate an outstanding pick request if a pick request is found and there are no outstanding pick requests;

declaring a pick request overrun condition if a pick request is found and outstanding pick requests exist.

3. The method of claim 2, wherein said declaring step comprises:

signalling a user if a pick request is found and outstanding pick requests exist.

4. The method of claim 2, wherein said declaring step comprises:

storing said position of said cursor tracking device and said pick request;

updating said pick request status indicator to reflect said stored request.

5. The method of claim 1, wherein the step of periodically re-executing a display program, indicating a picked object, if a pick occurred, and updating said pick request status indicator comprises the steps of:

testing for a third condition indicator;

resetting said pick request status indicator, a second pick request indicator, and said third condition indicator, if said third condition indicator is set;

testing said pick request status indicator to determine whether outstanding pick requests exist, if said third condition indicator is not set;

setting said third condition indicator and said second pick request indicator to indicate picking should occur during display program re-execution if outstanding pick requests exist;

resetting said second pick request indicator if there are no outstanding pick requests, and executing graphics orders necessary to create a frame and indicating a picked object if a pick occurred.

6. The method of claim 5, wherein said second pick request indicator is a latched function of said first pick request indicator.