JPH05324556A - Already executed operation canceller - Google Patents

Abstract

PURPOSE:To restore plural elements by one operation at the time or execution of undoing in the case that plural elements are changed by one operation. CONSTITUTION:An element data base 3 is provided with an undo stack and a redo stack. The undo stack is provided to save information before the change of elements changed by execution of an operation, and information before the change of plural changed elements are related like a chain and are stored in the case of multiple operations. A write/read control part 12 relates information before the change of elements changed by execution of multiple operations like a chain and saves these information in the undo stack, and this part 12 relates information of elements as the restore object like a chain and saves these information in the redo stack and restores plural elements based on information from the undo stack when undo to cancel multiple operations is executed.

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 execution of the operation, and particularly to a single operation. The present invention relates to a device for canceling an already-executed operation, which realizes undo processing after executing an operation in which a plurality of elements are changed by.

[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. Therefore, it is possible to restore the state up to multiple steps by sequentially storing the elements that change each operation in the stack and restoring the previous element data from the stack when undoing. What was made by the applicant,
is suggesting. However, in a normal stack structure, it is necessary to restore each element one by one.
If you perform a multi-operation that you draw every time,
At the time of restoration, straight lines must be restored one by one, which not only complicates the operation, but also has a problem that the operation at the time of undo does not correspond to the operation at the time of drawing one to one.

The present invention has been made in view of the above problems, and even after executing a plurality of operations, it is possible to restore data to any past operation and restore a plurality of data in one operation. It is an object of the present invention to provide a canceling device for an already-executed operation that can restore a plurality of elements at once even when an undo is executed when the element is changed.

[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. When the elements of are changed, the undo stack that stores the information before the changes of these elements in a chain-like manner and the undo stack when the operation of changing a plurality of elements by one operation is executed. The information before the change of the plurality of elements to be changed is associated with each other in a chain form and saved, and when the undo is executed, the plurality of elements are restored at one time based on the information from the undo stack. It is characterized by

Another device 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. When the undo is changed, the undo stack stores the information before the change of these elements in a chain-like manner and the information of the element changed by the previous operation at the time of executing the undo. When multiple elements are restored by undoing once, a redo stack that stores the pre-restoration information of these elements in a chained manner and when an operation that changes multiple elements by one operation is performed In the undo stack, the information before the change of the changed element is associated with the chain and saved. A plurality of elements are restored by the undo of the above. When the undo is executed, the information of the plurality of elements to be restored is saved in the redo stack in a chained manner, and then based on the information from the undo stack. After restoring a plurality of elements and performing a redo in which a plurality of elements are restored by one redo, the information of the plurality of elements to be restored is saved in the undo stack in a chained manner, and then, Means for restoring the plurality of elements 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. When a plurality of elements are changed in one operation, the changed plurality of elements are stored in the undo stack in a chained manner, and when the undo is executed, the information of the plurality of related elements is stored. Restored at once.
Therefore, according to the present invention, even after a plurality of operations have been executed, it is possible to restore an element dating back to an arbitrary operation, and in the case where a plurality of elements are changed at one time by executing a multi-operation. Also in the undo processing, it is possible to restore the plurality of elements at once.

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. When a plurality of elements are changed in one operation, the changed plurality of elements are stored in the undo stack in a chained manner, and when the undo is executed, the information of the plurality of related elements is stored. The information of a plurality of elements before being restored at the same time is stored in the redo stack in a chained manner. .. Therefore, according to the present invention,
After execution of multiple operations, operations such as going back to any operation and undoing are possible, and when multiple elements are changed at once by execution of multi-operation, undo processing and redo processing Can restore the above multiple elements at once. Therefore, the operability of the system is improved,
Work efficiency is also improved.

[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 have been executed, it is possible to restore elements up to an arbitrary operation, and by executing multiple operations, a plurality of elements can be restored. When is changed at once, the plurality of elements can be restored at the same time even in the undo process, so that the operability of the system is improved and the working 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. A method for saving information before change of an element changed by execution of an operation, and when a plurality of elements are changed by one operation, information before change of these elements is stored. An undo stack that is stored in association with a chain shape, and a chain of information before the change of the plurality of elements that are changed to the undo stack when an operation that changes a plurality of elements by one operation is executed And a unit for restoring the plurality of elements at a time based on information from the undo stack when the associated undo is performed and the undo is executed. 2. The information for saving the information before the change of the element changed by the execution of the operation, and when the plurality of elements are changed by one operation, the information before the change of these elements is stored. An undo stack that is stored in association with a chain, and for saving the information of the elements changed by the previous operation at the time of undo execution. If multiple elements are restored by one undo, these A redo stack that stores the information before the restoration of the elements in association with each other in a chain form, and a redo stack that stores the changed elements to the undo stack when a plurality of elements are changed by one operation. Saves information by linking it in a chain and recovers multiple elements with a single undo. When the information of the plurality of elements to be restored is saved in the redo stack in a chained manner, the plurality of elements are restored based on the information from the undo stack, and the plurality of elements are restored by one redo. When the redo that restores the element of is executed, the information of the plurality of elements to be restored is associated with the undo stack in a chain form and saved, and then the plurality of elements are saved based on the information from the redo stack. An apparatus for canceling an already-executed operation, comprising: means for restoring.