Display with enhanced scrolling capabilities

• US 5,237,312 A
• Filed: 03/01/1991
• Issued: 08/17/1993
• Est. Priority Date: 04/17/1989
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Busboom, Leah J. H., Maitland, William J. Jr., Akiyama, Alex A.
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): WU, XIAO MIN
• Application Number:
  US07/665,197
• Time in Patent Office: 900 Days
• Field of Search: 340/724, 340/726, 340/721, 340/723, 340/709, 340/799
• US Class Current: 345/10
• CPC Class Codes: G09G 5/14 Display of multiple viewports

Abstract

A computer display has a display processor connected to a presentation space buffer and a screen buffer. The presentation space buffer is larger than the screen buffer, and is divided into a plurality of partitions. Each partition has a partition window which maps into the screen buffer. If a partition is active, its associated partition window is written into the screen buffer at the mapped location. The screen buffer periodically refreshes the display screen, so a plurality of partition windows are displayed to the computer user. One or more scroll groups can be defined, and one or more partitions can be assigned to each scroll group. Each defined scroll group has a vertical scroll trigger and a horizontal scroll trigger. The display monitors the movement of the cursor within a partition window. When the cursor gets close enough to a boundary of a partition window, to trigger a scroll trigger, the display shifts the partition window within its partition and writes this updated partition window into the screen buffer. Updated partition windows are written into the screen buffer for the other partitions in the scroll group.

Claims

1. A computer display having a display screen and a cursor, comprising:

a display processor;

a screen buffer, connected to said display processor;

a presentation space buffer, connected to said display processor, said presentation space buffer being larger than said screen buffer;

means for defining a first partition and a second partition in said presentation space buffer;

first mapping means for mapping a first partition window from said first partition to said screen buffer;

first activating means for activating said first partition;

first writing means for writing said first partition window to said screen buffer responsive to said first activating means;

second mapping means for mapping a second partition window from said second partition to said screen buffer;

means for defining a first scroll group containing a first scroll trigger, said first scroll group comprising said first and second partitions;

means for shifting said first and second partition windows simultaneously in response to said first scroll trigger; and

means for displaying said screen buffer on said display screen, wherein only partition windows that have been mapped and activated are displayed.

2. The computer display of claim 1, further comprising:

second activating means for activating said second partition; and

second writing means for writing said second partition window to said screen buffer responsive to said second activating means.

3. The computer display of claim 2, wherein a portion of said screen buffer containing said first partition window is overlaid by said second partition window.

4. The computer display of claim 2, wherein said second activating means further comprises:

means for deactivating said second partition, wherein said second partition window is erased from said screen buffer, but without disturbing said mapping of said second partition to said screen buffer performed by said second mapping means.

5. A method for activating and deactivating windows on a computer display having a display processor, a screen buffer, a presentation space buffer larger than said screen buffer, a display screen and a cursor, the method comprising the steps of:

defining a first partition, and a second partition in said presentation space buffer;

mapping a first partition window from said first partition to said screen buffer;

activating said first partition;

writing said first partition window to said screen buffer responsive to said activating said first partition step;

mapping a second partition window from said second partition to said screen buffer;

defining a first scroll group containing a first scroll trigger, said first scroll group comprising said first and second partitions;

shifting said first and second partition windows simultaneously in response to said first scroll trigger; and

displaying said screen buffer on said display screen, wherein only partition windows that have been mapped and activated are displayed.

6. The method of claim 5, further comprising the steps of:

activating said second partition; and

writing said second partition window to said screen buffer responsive to said activating said second partition step.

7. The method of claim 6, further comprising the step of;

deactivating said second partition, wherein said second partition window is erased from said screen buffer, but without disturbing said mapping of said second partition to said screen buffer performed by said mapping a second partition window step.