# Patent

## Title
Table column spanning

## Abstract

Disclosed are a method and system for grouping columns of data into different levels for subsequent multiple level operations. The method comprises the steps of providing sub-columns within a single table column, said table columns and each of the sub-columns having an associated header; and using multiple dummy tables and displaying them separately on different locations, one of the dummy tables including one or more of the associated headers. The preferred embodiment of the invention uses a tool, referred to as the Jtable class, which is used to display and edit regular two-dimensional tables of cells. The present invention is able to support multilevel headers and column spanning by using multiple tables and displaying them separately. Preferably, this is done using another tool, GridBagLayout, which is associated with Jpanel tool.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to the display of data tables, and more specifically, the invention relates to the display of tables having plural or multi-level headers.
2. Background Art
It is often useful to represent data in the form of a data table. Conventionally, data tables include a plurality of cells arranged in horizontal rows and vertical columns. Each of the columns and/or rows typically contain a cell describing the content of the cells of the column and/or row, such as a parameter in a spreadsheet table, a time period, or geographical area in a table of a text or a presentation document.
The cells describing the content of each of the columns of the data table are often arranged in one row located in the first row of the data table, although they can also be located at the last row of the data table or at some other position within each of the columns. The description of the content of each of the columns is termed the header inscription.
A header inscription can take any of a variety of forms, such as alphabetic, numeric, alphanumeric, symbolic, or of some other form representative of the column contents. A header inscription can be of varying length, and is frequently of a different length from that of the contents of the cells within the column.
One specific, common type of table found in a variety of hardware/software computer systems and applied in a variety of different contexts is the categorization table. A categorization table organizes data under successive and expandable levels of categorized headings. Such headings give relevant information to the user as to the nature of the underlying subheadings and/or data grouped under particular headings at a given level.
With many conventional database management programs, it is difficult or time consuming to manage the data in data tables having multiple levels of headers. In part this is because the top, or first level, headers may have different numbers of columns beneath them.
BRIEF SUMMARY OF THE INVENTION
An object of this invention is to provide an improved method and system for displaying a table having plural or multi-levels of headers.
Another object of the invention is to display multiple tables together so that they appear as one table.
These and other objectives are attained with a method and system for grouping columns of data into different levels for subsequent multiple level operations. The method comprises the steps of providing sub-columns within a single table column, said table columns and each of the sub-columns having an associated header; and using multiple dummy tables and displaying them separately on different locations, one of the dummy tables including one or more of the associated headers.
The preferred embodiment of the invention uses a tool, referred to as the Jtable class, which is used to display and edit regular two-dimensional tables of cells. The present invention is able to support multilevel headers and column spanning by using multiple tables and displaying them separately. Preferably, this is done using another tool, GridBagLayout, which is associated with Jpanel tool.
Generally, in accordance with the preferred embodiment of this invention, a dummy table is created, which does not have data cells, to show only the header and the dummy table is placed in a location (x,y) on GridBagLayout. Then, a number of dummy tables are created and arranged in a required manner. Another table is created with the number of required cells which does not have header, and this table is located just below all of the headers. Then, the dummy header columns are mapped to the corresponding cell's columns, so the dummy table header will have the association to the table that has data. The sorting and other needed operations will preferably be done with this mapping.
Further benefits and advantages of the invention will become apparent from a consideration of the following detailed description, given with reference to the accompanying drawings, which specify and show preferred embodiments of the invention.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer that provides an exemplary operating environment for the present invention.
FIG. 2 illustrates a sample table which has multilevel headers.
FIG. 3 is another example of plural header levels for a data table.
FIG. 4 is a flow chart showing a procedure for presenting the table, having the headers of FIG. 3, as a group of tables displayed separately.
FIG. 5 is a table display formed using the procedure of FIG. 4.
FIG. 6 shows the table of FIG. 5 and also includes indexes showing where the data in the table is stored.
FIG. 7 shows the table of FIG. 6 after re-ordering of the second header level.
FIG. 8 shows the table of FIG. 7 after re-ordering of the first header level.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 and the following discussion are intended to provide a brief, general description of a suitable computing environment in which the invention may be implemented. While the invention will be described in the general context of an application program that runs on an operating system in conjunction with a personal computer, those skilled in the art will recognize that the invention also may be implemented in combination with other program modules.
Generally, program modules include routines, programs, components, data structures, etc, that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like.
The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
With reference to FIG. 1, an exemplary system for implementing the invention includes a conventional personal computer 12, including a processing unit 14, a system memory 16, and a system bus 18 that couples the system memory to the processing unit. The system memory 16 includes read only memory (ROM) 20 and random access memory 22. A basic input/output system 24 (BIOS), containing the basic routines that help to transfer information between elements within the personal computer 12, such as during start-up, is stored in ROM 20. The personal computer 12 further includes a hard disk drive 26, a magnetic disk drive 30 to read from or write to a removable disk 32, and an optical disk drive 36, e.g., for reading a CD-ROM disk 38 or to read from or write to other optical media.
The hard disk drive, magnetic disk drive, and optical disk drive are connected to the system bus 18 by a hard disk drive interface 40, a magnetic disk drive interface 42 and an optical drive interface 44, respectively. The drives and their associated computer-readable media provide nonvolatile storage for the personal computer 12. Although the description of computer-readable media above refers to a hard disk, a removable magnetic disk and a CD-ROM disk, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as magnetic cassettes, flash memory cards, digital video disks, and the like, may also be used in the exemplary operating environment.
A number of program modules may be stored in the drives and RAM, including an operating system, one or more application programs, a word processor program module, program data, and other program modules (not shown). The word processor program module may also include a table drawing tool and a table erasing tool program module 46 for adding tables to an electronic document and editing tables in an electronic document.
A user may enter commands and information into the personal computer 12 through a keyboard 48 and pointing device, such as a mouse 50. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 14 through a serial port interface 52 that is coupled to the system bus, but may be connected by other interfaces, such as a game port or a universal serial bus (USB). A monitor 54 or other type of display device is also connected to the system bus via an interface, such as a video adapter. In addition to the monitor 54, personal computers typically include other peripheral output devices (not shown), such as speakers or printers.
The personal computer 12 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 56. The remote computer 56 may be a server, a router, a peer device or other common network node, and typically includes many or all of the elements described relative to the personal computer 12, although only a memory storage device 58 has been illustrated in FIG. 1. The logical connections depicted in FIG. 1 include a local area network (LAN) and a wide area network (WAN). Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
Having described an exemplary operating environment for the present invention, embodiments of this invention will be described below. In brief, the invention provides a method and system for presenting or re-presenting a table having plural or multiple header levels as a series of tables displayed separately.
FIG. 2 represents a sample table 60 which has multilevel headers. Header Level 1 (Hlevel1) has five columns. The H1COL4 and H1COL5 columns split into sub columns. Header Level 2 (Hlevel2) has 4 columns which are sub columns of H1COL4 and H1COL5. The HiCOL4 column splits into three sub columns H2COL1, H2COL2 and H2COL3. The H1COL5 column splits into only one sub column H2COL4.
The table row data will be associated with the columns: {H1COL1, H1COL2, H1COL3, H1COL4, H1COL5}, {H2COL1, H2COL2, H2COL3} and {H2COL4}.
The preferred embodiment of the invention uses a tool, referred to as the Jtable class, which is used to display and edit regular two-dimensional tables of cells, and which has many facilities that allow customized rendering and editing. The Jtable class will display a header followed by its two dimensional cells, but this tool does not support multilevel headers and column spanning.
The present invention is able to support multilevel headers and column spanning by using multiple tables and displaying them separately. Preferably, this is done using another tool, GridBagLayout, which is associated with Jpanel tool. Jtable, it may be noted, allows headers and cells to be separated and to be displayed separately.
Generally, in accordance with this invention, a dummy table is created, which does not have data cells, to show only the header and the dummy table is placed in a location (x,y) on GridBagLayout. Then, a number of dummy tables are created and arranged in a required manner. Another table is created with the number of required cells which does not have header, and this table is located just below all of the headers. Then, the dummy header columns are mapped to the corresponding cell's columns, so the dummy table header will have the association to the table that has data. The sorting and other needed operations will preferably be done with this mapping.
FIGS. 3 through 5 illustrate in greater detail a preferred method for implementing this invention. In particular, FIG. 3 shows a header area 62 of a table, FIG. 4 is a flow chart 64 for transferring this table (header and data) into a multitude of separate, dummy tables, and FIG. 5 shows the resultant table display 66.
With reference to FIGS. 3 through 5, at step 70, a dummy table is created with the columns “Grains,” “Fruit” and “Vegetables,” and the header is placed in GridBagLayut on the location (x:0,y:0). At step 72, another dummy table is created with a single column “Meat,” and the header is placed on the location (x:1,y:0). At step 74, another dummy table is created with a single column “Dairy,” and the header is placed on the location (x:2,y:0). These three dummy tables represent the Header Level 1 (Hlevel1).
At step 76 another dummy table is created with the columns “Pork,” “Chicken” and “Beef,” and the header is placed on the location (x:1,y:1) of GridBagLayout. This header represents the sub columns of “Meat.” At step 80, another dummy table is created with the single column “Cheese,” and the header is placed on the location (x:2,y:1) of GridBagLayout. This header represents the sub column of “Dairy.” These two dummy tables represent the Header Level2 (Hlevel2) that shows the sub columns of “Meat” and “Dairy.” At step 82, one more table is created with all number of columns that will display the row data. This will be placed without its header on the location (x:0,y:2) of GridBagLayout. This table represents all the table cells for data.
The multiple level headers provide the grouping that is desired to be maintained. The ability to re-order columns in a multi-column table is desirable when large amounts of data are displayed where the width of the columns may cause part of the table to go out of view. It also provides the ability to place columns near each other for easier comparisons.
The reordering of columns is supported at two levels. The columns within a group—“pork,” “chicken,” “beef” under “meat” (in the above example)—can be reordered to be: “chicken,” “pork,” “beef,” as shown in FIG. 7. The reordering can be accomplished by mouse drag-and-drop or with keyboard support. Additionally, the user or customer can drag the header “Meat” and move it to the left of “Dairy,” dragging with the “Meat” header all three sub columns underneath it, as shown in FIG. 8.
Preferably, normal or standard sorting and filtering of the rows is also supported. This function may be provided in any suitable way, such as by a multi-column, sortable, filterable table (MCSFT).
When a column is moved from one location to another, software code determines the columns affected by determining the original location of the header selected. The code then determines if a single column is affected or multiple columns. If multiple columns are affected, the code also moves the headings in header level 2 that are affected.
Next, the code determines the new location of the header and calculates the new column numbers for the columns in the data table. To improve performance, preferably, the data within the table is never moved around. Each column in the table has an index field, as shown at 84 in FIGS. 6-8, to indicate which column it should be displayed in. A column can also be hidden by specifying that it should not be displayed. The same algorithm applies to the rows when doing sorting and filtering.
The preferred embodiment of the invention, as described above in detail, provides a number of important advantages. For example, the invention provides improved usability to the customer by allowing the table to be manipulated within the boundaries established by the multiple header levels. This allows each user to customize their view of the data in the way that best suits their needs. Also, the invention achieves improved performance without actually manipulating the stored data table in any way. Instead, the improved performance is accomplished in how the data is displayed, not how it is stored.
While it is apparent that the invention herein disclosed is well calculated to fulfill the objects previously stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.

## Claims

1. A method of re-displaying a display table having a grid of columns and rows, at least one of the columns having a plurality of sub-columns, each of the columns having a main header, and each of the sub-columns having a sub-header, said headers and said sub-headers forming first and second levels of headers, and wherein each of the columns and sub-columns includes a plurality of data cells aligned with a respective one of the main headers or sub-headers of the display table, the method comprising the steps of:
dividing the entire display table into a multitude of separately moveable dummy tables, including the steps of:
i) forming a first of the dummy tables including all of the main headers, wherein said main headers are separately moveable within the first dummy table,
ii) forming a second of the dummy tables including all of said sub-headers, wherein the sub-headers are separately moveable within the second dummy table, and
iii) forming a third of the dummy tables including all of the columns of the display table, wherein the columns are separately moveable within the third dummy table;

positioning the first dummy table at a first location on a display screen, and moving the main headers within the first dummy table;
moving the second dummy table to a second location on the display screen adjacent to the first dummy table, with the sub-headers of the second dummy table aligned with the main header of the colunm that includes the sub-columns having said sub-headers; and
moving the third dummy table to a third location on the display screen adjacent the second dummy table, including the step of moving each of the columns of the third dummy table to a position aligned with the main header or sub-header of said each column of the third dummy table;
wherein said first, second and third dummy tables are displayed together at the same time and side-by-side at different locations on the same display screen and form a single composite table on said display screen.

2. A method according to claim 1, wherein:
each of the columns and sub-columns of the display table has an identifying display index number;
each of the columns of the third dummy table has a respective one data location index number; and
the step of moving the third dummy table includes the steps of:
i) assigning each of the data location index numbers to one of the display index numbers, and
ii) putting each of the columns of the third dummy table into the column or sub column of the display table having the display index number to which the data location index number of said each column of the third dummy table has been assigned.

3. A method according to claim 2, wherein the displaying step includes the step of contiguously displaying the first, second and third dummy tables.

4. A method according to claim 2, wherein:
the first dummy table includes only the main headers of the table columns: and
the second dummy table includes only the sub-headers of the sub-columns.

5. A method according to claim 4, wherein the third dummy table includes only said multitude of data cells.