JPH05324555A - Already executed operation canceller - Google Patents

Abstract

PURPOSE:To restore data by retracting an arbitrary past operation even after plural operations are executed. CONSTITUTION:An element data base 3 is provided with an undo stack and a redo stack, and the former is provided to save information before the change of elements changed by execution of an operation, and the latter is provided to save information of elements changed by the just preceding operation at the time of undo execution, and information corresponding to plural operations can be stored in both of them. A write/read control part 12 successively saves information before the change of elements to be changed in the undo stack at each time of executing the operation. The write/read control part 12 restores elements based on information from the undo stack after saving information of elements as the restore object in the redo stack at each time of execution of undo and restores elements based on information from the redo stack after saving information of elements as the restore object in the undo stack at each time of executing redo.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for canceling an executed operation in a CAD system or the like, which executes an undo process for canceling an executed operation and restoring the data before the operation is executed, and particularly to a continuous undo operation. The present invention relates to a device for canceling an already-executed operation that realizes processing.

[0002]

2. Description of the Related Art In a CAD system or the like, if a drawing is accidentally erased or a portion to be copied is moved, an undo process for canceling the immediately preceding operation and restoring the previous screen is required. Are known. In the conventional undo process, when the element data that makes up the drawing is changed, the information before the change of the element data is copied and saved,
When the undo is executed, the data is restored by restoring the saved previous information.

[0003]

However, in the above-mentioned conventional canceling method for executed operations, since the cancelable operation is limited to the immediately preceding operation, the operation is continuously executed without noticing the operation error. If it happens, there is a problem that past data can no longer be restored.

The present invention has been made in view of the above problems, and provides a canceling device for an already-executed operation that can restore data to any past operation even after executing a plurality of operations. The purpose is to In addition, the present invention can execute a plurality of operations and then trace back to a desired operation or return to the previous operation, which can greatly improve the operability of the system. It is another object to provide an operation canceling device.

[0005]

An apparatus for canceling an already-executed operation according to the present invention is for saving the information before the change of the element changed by the execution of the operation, and the information for a plurality of operations. And an undo stack capable of storing the elements, and each time an operation is executed, the information before the change of the changed element is sequentially saved, and each time the undo is executed, the element is changed based on the information from the undo stack. And means for restoring.

Further, another undoing device for an already-executed operation according to the present invention is for saving the information before the change of the element changed by the execution of the operation, and storing the information for a plurality of operations. A possible undo stack, a redo stack for saving the information of the element changed by the previous operation at the time of undo execution, and a redo stack capable of storing the information for a plurality of operations, and The information before the change of the changed element is sequentially saved to the undo stack, and the information of the element to be restored is saved to the redo stack each time undo is executed, and then based on the information from the undo stack. The information of the element to be restored is restored each time the element is restored and redo is executed. After saving the down de stack, characterized by comprising a means for restoring the element based on information from the redo stack.

[0007]

According to the cancel device for an already-executed operation according to the present invention, the information before the change of the changed element is stored in the undo stack every time the operation is executed. The undo stack has a capacity capable of storing the information for a plurality of operations. Then, each time the undo is executed, information is sequentially read from the undo stack, and the element is restored based on this information. Therefore, according to the present invention, even after a plurality of operations have been executed, it is possible to restore elements to any operation.

Further, according to another undoing device for an already executed operation according to the present invention, a redo stack is provided in addition to the undo stack, and at the time of undo execution, the information of the element changed by the immediately preceding operation is added to the redo stack. Are evacuated to. This redo stack also has a capacity capable of storing information for a plurality of operations. Then, at the time of executing the undo, the information of the element to be restored is saved in the redo stack. Therefore, by continuously executing the undo, the data is restored until the arbitrary operation is executed, and then by executing the redo, it is possible to return to the data after the immediately previous operation is executed again. Therefore, according to the present invention, after executing a plurality of operations, it is possible to perform operations such as going back to an arbitrary operation and returning to the original operation, which improves the operability of the system and improves work efficiency.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A CAD system according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a functional block diagram of a CAD system according to this embodiment. This system includes an input device 1, a CAD processing unit 2, an element database 3, a display device 4, and a drawing output device 5.

The input device 1 is composed of a keyboard, a mouse, etc., and specifies a necessary command from a command menu displayed on the display device 4, or the display device 4
It is intended to specify points, graphic elements, areas, etc. when the above drawing and editing work is performed. Further, the input device 1 is provided with an undo key for instructing execution of undo processing and a redo key for instructing execution of redo processing.

The CAD processing unit 2 is a drawing / editing processing unit 1.
1, a writing / reading control unit 12, a display control unit 13, and a drawing output control unit 14. The drawing / editing processing unit 11 interprets a command instructed by the input device 1 to generate necessary graphic element data at a position instructed by the input device 1, or specifies specified element data or input additional information. Edit processing such as deleting, copying, moving, etc. The writing / reading control unit 12 writes the element data and the additional information created and edited by the drawing / editing processing unit 11 into the element database 3, and the drawing / editing processing unit 11
Under the control of 1), it has a function of reading necessary element data and additional information from the element database 3. The writing / reading control unit 12 saves necessary information in an undo stack 24 described later each time an operation is executed, and is necessary in the undo stack 24 and a redo stack 25 described later during undo execution or redo execution. It has a function of saving information and retrieving data by taking out necessary information from these stacks 24 and 25. The display control unit 13 performs display control for displaying the graphic element data, the additional information, the command menu, etc. generated / edited by the drawing / editing processing unit 11 on the display device 4 such as a CRT display. The drawing output control unit 14 performs output control when drawing the graphic element data generated and edited by the drawing / editing processing unit 11 to the drawing output device 5 such as a pen plotter.

The element database 3 is a database for registering element data constituting the created drawing. For example, as shown in FIG.
2, point database 23, undo stack 24
And a redo stack 25. The element number, the segment address, the element type, the selection flag, and the like are stored in the ent node 21. Segment 2
2 stores data (straight lines) indicating both end points, data indicating a center point, a major axis vector, a minor axis vector (circle and ellipse), and the like. Indexes to the point database 23 are stored in the point and vector data, and the coordinate values themselves are stored in the point database 23. The undo stack 24 stores information on elements that change each time the operation is executed, specifically, the element number (No.) of the ent node 21, the address (AD) to the segment 22 and the element type (TYP). Element information is stored. The undo stack 24 has a capacity capable of storing element information for 20 operations, for example. The redo stack 25 also has a structure similar to that of the undo stack 24, and the information of the element to be restored when the undo is executed, that is, the element number (No.) of the ent node 21,
Address (AD) to segment 22 and element type (TY
Information of elements such as P) is stored.

Next, the operation of the present system configured as described above will be described. First, the processing when a new element is added will be described with reference to FIGS. FIG. 3 shows a state in which no element data is stored in the element database 3. The "NULL" code is stored in the address to the segment of the ent node 21 and the element type, and the flag is set to "0". Also, undo stack 2
The stack pointer ASP of No. 4 and the stack pointer RSP of the redo stack 25 both point to the 0th stack 24, 25. In this state, using the mouse or the like of the input device 1, as shown in FIG.
When 2 is newly drawn, first, data is newly written in the area of the element number “1” of the ent node 21. Therefore, prior to this writing, as shown in FIG. The data is advanced by one, and the data (element number “1”, address “NULL” to segment 22 and element type “NULL”) in the area of the element number “1” of the ent node 21 is saved in the undo stack 24. Next, the coordinate values of the points P1 and P2 are written in the point database 23, and the index to the storage location of the points P1 and P2 of the point database 23 is registered in the segment 22. Then, in the area of the element number "1" of the ent node 21, the address "AD1" to the segment 22 storing the indexes of the points P1 and P2 is stored, and "Line" is written as the element type.

Then, as shown in FIG. 5A, a straight line P
When 1-P3 is drawn, as shown in FIG.
After P is advanced by 1 and the data (element number “1”, address “NULL” to segment 22 and element type “NULL”) in the area of element number “2” is saved in the undo stack 24, point P3 Coordinate values of point database 2
3 and the indexes to the points P1 and P3 are registered in the segment 22. Then, in the area of the element number "2" of the ent node 21, the address "AD2" to the segment 22 storing the indexes of the points P1 and P3 is stored, and "Line" is stored as the element type.

Next, the processing when the undo key is pressed twice in this state will be described with reference to FIGS. 6 and 7. When the undo key is pressed, as shown in FIG.
Since it is known from the contents of SP currently indicated (dotted line) that the undo target is the element of the element number "2", the flag of the element number "2" of the ent node 21 is set to "1". Next, the RSP is advanced by one and the element number “2” of the element having the flag of the ent node 21 of “1”, the address “AD2” to the segment and the element type “Line” are saved in the redo stack 25. Then, the contents pointed by the ASP of the undo stack 24 (element number “2”, address “NULL” to segment 22 and element type “NULL”) are restored in the ent node 21, and one ASP is returned. As a result, the address to segment 22 becomes "NULL",
The straight line P1-P3 shown by the dotted line in FIG. 6B is deleted.
That is, it returns to the state before the second straight line was drawn.

Further, when the undo key is pressed again, as shown in FIG. 7A, it can be understood from the contents of the ASP currently indicated (dotted line) that the undo target is the element having the element number "1". Therefore, the flag of the element number "1" of the ent node 21 is set to "1". Next, the RSP is advanced by one, and the element number “1” of the element having the flag of the ent node 21 of “1”, the address “AD1” to the segment and the element type “Line” are saved in the redo stack 25. Then, the contents indicated by the ASP of the undo stack 24 (element number "1", address "NUL to segment 22"
L "and element type" NULL ") are restored to the ent node 21, and one ASP is returned.
Address becomes "NULL", and the straight line P1-P2 shown by the dotted line in FIG. 7B is erased. That is, it returns to the state before the first straight line was drawn.

Next, the processing when the redo key is pressed in this state will be described with reference to FIG. When the redo key is pressed, as shown in FIG. 8, it can be known from the contents of the RSP currently indicated (dotted line) that the redo target is the element with the element number “1”, and therefore the element number “1” of the enent node 21. The "flag" is set to "1". Next, the ASP is advanced by one, and the element number “1” of the element having the flag “1” of the ent node 21, the address “NULL” to the segment, and the element type “NULL” are saved in the undo stack 24. Then, the contents pointed to by the RSP of the redo stack 25 (element number “1”, address “AD1 to segment 22
, And the element type “Line”) are restored to the ent node 21 and one RSP is returned. As a result, the segment 22
Address becomes "AD1", and the straight line P1-P2 shown in FIG. 4A is restored. That is, it returns to the state after the first straight line is drawn.

The above-mentioned processing is basically performed in the same manner at the time of copying and deleting operations, and the description thereof will be omitted.

Next, as shown in FIG. 9A, a straight line P1
The processing when -P2 is moved to the position of the straight line P1'-P2 'will be described. In this case, since the straight line itself remains and only the coordinates of the end points are changed, the contents of the point database 23 are rewritten. Therefore, prior to this rewriting, as shown in FIG. 9B, the contents of the segment 22 registered at the address AD1 are copied to the position of the address AD1 '. 1 ASP
Then, the data in the area of the element number “1” is saved. At this time, as the address of the segment 22, the copy destination address “AD1 ′” is stored in the undo stack 24. Next, the coordinate values of the points P1 'and P2' are written in the point database 23, and the index of the segment of the address AD1 into the point database 23 is "P.
1 ', P2'". The contents of the area of the element number" 1 "of the ent node 21 do not change.

Also in this case, when the undo key is pressed, the data of the original point coordinates will be restored.
You can return to the state before moving. In addition, this process is
Since the same operation is performed when the position of one end point is changed or when the figure is rotated, the description thereof will be omitted.

In the above, the processing in a single operation such as drawing one straight line has been described. For example, in the case of including a multi-operation in which a plurality of elements are moved at a time or a rectangle is drawn by one operation. For example, the structures of the undo stack 24 and the redo stack 25 may be set as follows. FIG. 10 is a diagram showing a main structure of the undo stack 24 in this case. The redo stack 25 has the same structure as this. That is, assuming that the unit pointed to by each ASP of the undo stack 24 is the undo stack element 31, this undo stack element 31 includes a pointer BP to the previous undo stack element 31 and a pointer AP to the next undo stack element 31. Has been. These pointers BP and AP are
Used to give the next address of the ASP when updating the stack when the addresses of the undo stack element 31 are discontinuous.

The undo stack element 31 also includes a pointer NP to the undo node 32 for storing its actual content. The undo node 32 contains information on the above-mentioned evacuation element, that is, the element number No. , The address AD to the segment, the element type TYP, and the pointer NP to the next undo node 32 are also stored. By connecting a plurality of undo nodes 32 in a chain via the pointer NP as shown in the figure, it is possible to cope with a change in a plurality of elements during execution of multi-operation.

11 to 13 are flow charts for explaining the processing of the part of the write / read controller 12 including the above points, which is relevant to the present invention. FIG. 11 shows the processing when the drawing / editing operation is executed. During drawing / editing operations, first Redo Stack 2
The contents of 5 are cleared (S1). Specifically, RSP
Should be returned to the 0th position. Then, it is determined whether the operation is multi-operation (S2). In the case of a single operation, the ASP is advanced by one (S3), and in the case of multi-operation, the ASP remains fixed during a series of operations. That is, the pointer N of the undo node 32 in FIG.
Associate each operation with a join through P. If the operation is other than "change" and "move" (S
4) PUS the predetermined information of the ent node 21 to the undo node 32 pointed to by the pointer NP of the undo stack 24.
After H (P5), the information of the ent node 21 is rewritten (S6). When the operation is “change” or “move” (S4), the information of the segment 22 is copied (S7), and the predetermined information of the ennode node 21 is stored in the undo node 32 pointed to by the pointer NP of the undo stack 24. PUSH. However, the address to the segment 22 is the copy destination address (S8). Then, the information of the segment 22 is rewritten.

FIG. 12 shows the processing at the time of executing undo. When executing undo, advance RSP by one (S1
1) Extract the element number to be undone from the contents indicated by the ASP of the undo stack 24, and
A flag is set to the corresponding element of 1 (S12). Next, the predetermined information of the flagged element of the ent node 21 is PUSHed to the redo stack 25 (S13). Then, the contents of the undo stack 24 are POP'd to the ent node 21 (S14), and one ASP is returned (S15).

FIG. 13 shows a process at the time of executing redo. When executing redo, advance ASP by 1 (S21),
The element number to be redoed is extracted from the content indicated by the RSP of the redo stack 25, and a flag is set to the corresponding element of the ent node 21 (S22). Next, ent node 2
The predetermined information of the element for which the flag of 1 is set is pushed to the undo stack 24 (S23). Then, the contents of the redo stack 25 are popped to the ent node 21 (S2
4) Return one RSP (S25).

[0026]

As described above, according to the present invention, even after a plurality of operations are executed, it is possible to restore the elements by tracing back to an arbitrary operation.
The operability of the system is improved and the work efficiency is improved.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a main part of a CAD system according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the contents of an element database in the system.

FIG. 3 is a diagram for explaining a process at the time of element writing in the system.

FIG. 4 is a diagram for explaining a process at the time of element writing in the system.

FIG. 5 is a diagram for explaining a process at the time of element writing in the same system.

FIG. 6 is a diagram for explaining processing at the time of executing undo in the system.

FIG. 7 is a diagram for explaining a process during undo execution in the system.

FIG. 8 is a diagram for explaining a process at the time of executing redo in the system.

FIG. 9 is a diagram for explaining a process when moving an element in the system.

FIG. 10 is a diagram showing a main structure of an undo stack capable of supporting multiple operations in the system.

FIG. 11 is a flowchart for explaining a process of a writing / reading control unit when executing a drawing / editing operation in the system.

FIG. 12 is a flowchart for explaining processing of a writing / reading control unit at the time of executing undo in the system.

[Fig. 13] Writing at the time of redo execution in the system
7 is a flowchart for explaining the processing of the read control unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input device, 2 ... CAD processing part, 3 ... Element database, 4 ... Display device, 5 ... Drawing output device, 11 ... Drawing / editing processing part, 12 ... Write / read control part, 13 ... Display control part, 14 ... Drawing output control unit.

Claims (2)

[Claims] 1. An undo stack capable of storing information before change of an element changed by execution of an operation, the undo stack capable of storing the information for a plurality of operations, and the undo stack each time an operation is executed. A previously executed operation, comprising means for sequentially saving information before change of the element to be changed to a stack and restoring the element based on the information from the undo stack each time undo is executed. Cancellation device. 2. An undo stack capable of storing information before change of an element changed by execution of an operation, the undo stack capable of storing the information for a plurality of operations, and a change by an operation immediately before undo execution. And a redo stack capable of storing the information of a plurality of operations, and information before the change of the changed element to the undo stack each time an operation is executed. After sequentially saving and saving the information of the element to be restored each time undo is performed to the redo stack, restore the element based on the information from the undo stack, and restore each time redo is performed. After saving the information of the target element to the undo stack, from the redo stack Cancellation device already executing operations, characterized in that a means for restoring the element based on the information.