Window management apparatus for a document creating apparatus

A document creating apparatus for creating and editing a document in which a plurality of different types of descriptive element data, such as text data, graph data, pattern data, image data and other data, coexist. Plural types of edit sections are provided in correspondence with the types of data to be handled. Various types of data are edited under coordination by selecting edit sections corresponding to the types of data, respectively, while maintaining the editing function of the editing section once selected and activated so that the editing section can be selected again without losing its editing function.

BACKGROUND OF THE INVENTION 
The present invention relates to a document creation apparatus which is 
advantageously suited for creating and editing documents in which there 
coexist plural types or species of descriptive element data, such as text 
data, graph data, pattern data, image data and other data. 
In recent years, the document creating apparatus exemplified by a word 
processor tends to be imposed with such a requirement that the apparatus 
should be capable of coping with various species of descriptive element 
data such as graph, pattern and the like data in addition to the text 
(character) data. Since these descriptive elements of different types are 
edited with data formats differing from one to another data, creation and 
editing of a document in which a plurality of different type data coexist 
mixedly are conducted in such a manner in which a page layout for the 
document to be created is first displayed, wherein fields containing data 
to be edited on the layout are subsequently designated and the descriptive 
elements for the designated field are created and edited while displaying 
the elements on an area separated from that for the page layout, as is 
disclosed in JP-A-61-18036. 
The hitherto known apparatus is however disadvantageous in that editing for 
one field can not be performed in parallel with editing for other field 
and the layout of other pages can not be referred to in the course of 
editing for a field on a certain page. Accordingly, when edit processing 
should be started for one field in the course of edit processing for 
another field, the later processing must be terminated previously. When 
the layout of the other page is to be referred to, the edit processing to 
this end has to be executed. Upon returning to the editing for the 
original field, a similar procedure must be followed. For these reasons, 
the document creating apparatus of the prior art involves a very 
troublesome procedure and manipulation in creating and editing the 
documents. 
SUMMARY OF THE INVENTION 
It is an ultimate object of the present invention to provide a document 
creating apparatus which can create and edit documents containing 
coexistently a plurality of different types of descriptive element through 
a much facilitated and simplified procedure. 
For accomplishing the ultimate object mentioned above, the following 
objects are also contemplated by the invention. 
Accordingly, another object of the invention is to simplify the procedure 
for editing selectively different species or types of descriptive element 
data. 
Still another object of the present invention is to facilitate 
discriminative identification of relationships existing between a 
plurality of documents to be processed and descriptive element fields 
thereof. 
A further object of the present invention is to simplify the procedure and 
manipulation for activating and ending data processing programs suited for 
the species or types of the descriptive elements to be created and edited. 
A still further object of the invention is to facilitate recognition of 
descriptive element fields which are in the course of being created and 
edited. 
A further object of the invention is to facilitate recognition of the 
descriptive element data field which can not be processed. 
In view of the above objects, there is provided according to a general 
aspect of the present invention a document creating apparatus which 
includes input means for inputting on a field-by-field basis descriptive 
element data to be entered in a document in which a plurality of various 
species of the descriptive element data such as text data, graph data, 
pattern data, image data and other data coexist, storage means for storing 
the descriptive element data inputted through the input means and display 
means for displaying dot patterns on the basis of the various species of 
descriptive element data stored in the storage means, and which apparatus 
further comprises document edit means for causing the display means to 
display a page layout of a document to be created thereon and performing 
editing of the fields on the displayed layout in accordance with input 
information supplied from the input means, field edit means composed of a 
plurality of edit divisions provided in correspondence with the species of 
the descriptive element data, respectively, for creating and editing the 
descriptive element data within respective fields in accordance with input 
information supplied from the input means, activate means for activating 
relevant field edit means in accordance with the species of the 
description element data which are commanded for creation and renewal by 
the document edit means, and edit switching means for changing over the 
document edit means and the field edit means activated by the activate 
means without terminating the functions of both means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the following, the present invention will be described in detail in 
conjunction with an exemplary embodiment thereof on the assumption that 
the invention is applied to a word processor. 
FIG. 1 shows schematically in a block diagram a general arrangement of a 
word processor to which the present invention can be applied. In the 
figure, a reference numeral 1 denotes an input unit which includes a 
keyboard for inputting information such as characters or the like and a 
pointing device such as a mouse serving as a means for designating objects 
or targets to be processed, names of functions and others. A reference 
numeral 2 denotes a display unit constituted by a CRT display device for 
displaying characters, graphics and others, a numeral 3 denotes a storage 
unit constituted by a semiconductor memory, magnetic storage device or the 
like for storing contents or data of the created documents, descriptive 
element data, information (data) used for window management or 
manipulation described hereinafter and others, and a numeral 4 denotes a 
printer unit which may be constituted by a wire-dot printer or the like. A 
reference numeral 5 denotes generally a control unit constituted by a 
microprocessor or the like for controlling and supervising operations of 
the various units mentioned above. The control unit 5 includes an input 
control section 51, a window management section 52, a system control 
section 53, a print control section 54, a display control section 55, an 
edit section 56, a system management section 57 and a file edit section 
58. In the case of the illustrative embodiment, processings for creation 
and edition of the documents are carried out by the edit section 56 which 
is composed of a document edit section 561 and field edit sections 562. 
FIG. 2 shows, by way of example, a screen image produced visibly on the 
display unit 2. The image generally denoted by a numeral 21 includes a 
menu area 22, an edition area 23 and an iconographic area 24. Each of the 
edit sections displays relevant data in the form of dot patterns within 
its own rectangular frame 25 (hereinafter referred to as a window) and 
performs edit processing of document data within the window separately 
from the others. In the menu area 22, the edit function 
classification/identification names (hereinafter referred to as pull-down 
menu names) 26 are displayed. When an operator designates a given 
pull-down menu name 26 with the aid of the mouse, a window associated with 
the designated function is established (which will hereinafter be termed 
as the opening of a window), and a detailed list 28 containing function 
items (hereinafter referred to as pull-down menu 28) is displayed. More 
specifically, the pull-down menu names 26 such as, for example, "edition", 
"print" and so forth are displayed on the menu area 22. When an operator 
selects or designates "edition" by means of the mouse, the pull-down menu 
28 makes an appearance, whereby function items such as "create", "update", 
"delete" and others are displayed within the menu 28. In this state, an 
operator can select the desired function by designating the function item 
by means of the mouse, and the designated function is executed. A window 
denoted by a numeral 25 may include, for example, a caption area 251 
destined for displaying the window name, a data area 252 for displaying 
data, and a control area 253 utilized by the operator for commanding an 
operation such as closing, moving, alteration of size or the like 
manipulation of the window. In an iconographic area 24, there are 
displayed iconographic characters (hereinafter referred to as icons for 
simplification) 27 which represent the programs for editing and other 
purposes. When an icon is selected under designation by the operator, the 
corresponding program is activated. 
Referring to FIG. 3, the mouse 31 is equipped with an execution button 311 
for selecting the target or item to be subjected to the processing or 
manipulation, the function to be executed and others and a canceling 
button 312 for canceling the item or target selected for the processing or 
manipulation. Of course, the mouse 31 incorporates switches interlocked 
with the buttons mentioned above, although not shown. A mouse cursor 30 as 
displayed can move on the image screen by following the operator's 
manipulation to move the mouse 31 and is used for designating the 
displayed item or target for the processing. 
Now, description will be turned to various parts or sections which 
constitute the control unit 5. 
The system management section 57 activates programs such as, for example, 
the program for the file edit section 58, the document edit section 561 or 
others in correspondence to the icon information furnished from the input 
control section 51. Correspondence relation existing between the icons and 
the programs are managed with the aid of an icon management table 571 in 
which icon numbers (No.) and corresponding program numbers (No.) are 
stored, as illustrated in FIG. 4. The program numbers are program 
identification numbers assigned to the individual programs, respectively. 
Each of the programs is managed by means of a program control table 572 
shown in FIG. 5. As will be seen in FIG. 5, the program control table 572 
stores therein program control blocks (hereinafter also referred to as PCB 
in abbreviation) 573 which are arrayed in a sequence coinciding with the 
order of the program numbers. Each of the program control blocks or PCB 
573 stores therein program start address information 5731 of the 
corresponding program, a stack address 5732, priority level information 
5733, a parent program number 5734, data species (or type) information 
5735 and other program attribute information 5736. The parent program 
number 5734 designates an origin program by which the associated program 
is activated. The data species (or type) information 5735 indicates the 
species of data such as text, graphics, pattern or the like which the 
associated program is destined to handle and each contains a data number 
(No.). On the other hand, names corresponding to the data numbers are 
stored in a data name definition table (hereinafter also referred to as 
DNDT in abbreviation) 574 in a manner illustrated in FIG. 6. 
Turning back to FIG. 1, the file edit section 58 operates to display within 
the associated window a list of documents stored in the storage unit 3 and 
performs edition of a document designated by an operator. With the phrase 
"edition of document", it is intended to encompass alteration or update, 
deletion, printing and other operations in general. 
The document edit section 561 displays within the window the layout of a 
page of a document which is commanded to be created or altered (updated) 
by the file edit section 58 and performs edition of fields on the 
displayed page. With the phrase "edition of field", "field edition" or 
"field based edition" it is intended to cover in more general terms the 
creation, alteration (update), deletion, movement, copying and others of 
elementary data within a field. 
The field edit section 562 displays within a window the content of the 
field for which creation, alteration (update) or the like operation is 
commanded by the document edit section 561 and performs creation and 
edition on the data located within the designated field. The field edit 
section 562 includes a variety of edit subsections in correspondence to 
the data species, respectively. By way of example, there can be mentioned 
a text data edit subsection (also referred to simply as the section), 
graph data edit subsection and graphics (pattern) data edit subsection. 
Once creation of document has been initiated, the one of the edit sections 
mentioned above which can participate in the creation of document is 
always indicated in the topmost one of the windows displayed on the 
screen. For indexing a window at the topmost position, i.e. for the 
exchange of the edit sections, the mouse cursor 30 is moved onto the 
desired window as displayed and the execution button 311 is pressed. 
Alteration of the overlapping sequence of the window as commanded by the 
operator is performed by the window management section 52. 
In addition to the alteration of the overlapping sequence of the windows, 
the window management section 52 serves to open or close the window on the 
screen in accordance with the request issued by the edit section. The 
window opened on the display screen is managed with the aid of a window 
management table 521 shown in FIG. 7. The window management table 521 
stores window management or control blocks (hereinafter also referred to 
as WCB in abbreviation) 522 arrayed in the order of the window numbers. 
Further, each of the window management blocks or WCBs 522 stores 
information mentioned below. 
WINDOW LOCATION AND SIZE INFORMATION 5221 
This information consists of an upper left x-coordinate, an upper left 
y-coordinate, a lower right x-coordinate and a lower right y-coordinate of 
a window on the assumption that the origin of the coordinate system is 
located at the topmost and leftmost point. 
WINDOW OVERLAP SEQUENCE INFORMATION 5222 
When a plurality of windows are opened on the image screen, this 
information indicates in what order the windows are sequenced. 
WINDOW NAME INFORMATION 5223 
This information represents the window name to be displayed in a caption 
area 251 of the window 25. 
TASK NUMBER INFORMATION 5224 
This information represents the identification number of the task which has 
set the window of concern. Each of the edit sections is created through a 
task, wherein the task number is allocated by the system control section 
53 described hereinafter whenever the edit section is created as the task. 
STORAGE LOCATION INFORMATION 5225 FOR THE IMAGE TO BE DISPLAYED IN WINDOW 
A window display buffer is provided for each of the windows to store the 
image data to be displayed in the associated window. More specifically, 
the storage location information 5225 of the image data to be displayed 
within a window represents the location of the associated window display 
buffer. This information is utilized for recovering a portion of the image 
which is hidden underneath a window at the time when the window 
overlapping sequence is to be altered. 
MENU DATA STORAGE LOCATION INFORMATION 5226 
This information represents the storage address of menu data to be 
displayed in the menu area 22 and the pull-down menu area 28. 
IN-SERVICE FLAG INFORMATION 5227 
This information represents whether the WCB 522 is in service or not. 
On the basis of the information mentioned above, the window management 
section 52 performs operations such as alteration of overlapping sequence 
of the windows as well as opening and closing thereof. When the 
overlapping sequence is to be altered, the window management section 52 
requests the system control section 53 to interrupt the edit operation 
performed until then and reinitiate the edition for the designated window 
by making use of the aforementioned task number 5224. Additionally, the 
window management section 52 requests the input control section 51 to 
display the menu corresponding to the window located at the topmost 
position through the window operation described above in accordance with 
the aforementioned menu data storage position information 5226. 
The system control section 53 performs the control operation such as 
interruption and reinitiation (or restart) of the corresponding tasks in 
response to the request issued by the window management section 52. 
Additionally, the system control section 53 serves to create as the task 
an edit section in accordance with the request issued by a certain edit 
section, activate the task corresponding to an edit section requested by 
the certain edit section and performs a task end processing corresponding 
for the edit section requested by the certain edit section. Furthermore, 
the system control section 53 performs processing for sending messages to 
an edit section of concern in accordance with the request issued by a 
certain edit section for thereby allowing information transfer among the 
tasks as well as reception of the message transmitted from the edit 
section of concern. Each task is managed with the aid of a table referred 
to as the task control table 531 and shown in FIG. 8. The task control 
table 531 contains task control blocks (hereinafter referred to as TCB in 
abbreviation) 532 arrayed in the order of the task numbers, wherein one 
task is assigned with one TCB 532, which contains all information 
necessary for initiation and reinitiation or restart of the task, as 
mentioned below. 
LINK FIELD INFORMATION 5321 
This information is utilized for connecting or linking the TCB 532 to the 
list. 
TASK PRIORITY LEVEL INFORMATION 5322 
This information represents the priority level of the task upon execution 
thereof. 
PROGRAM NUMBER INFORMATION 5323 
This information represents the number of the program by which a relevant 
task was created. 
TASK STATUS INFORMATION 5324 
This information indicates the status the task assumes currently. 
INTERRUPT FLAG INFORMATION 5325 
This information indicates the presence of request for interruption of 
task. 
TASK START/RESTART ADDRESS INFORMATION 5326 
This information represents the addresses at which execution of task was 
started or interrupted. 
STACK STATUS INFORMATION 5327 
This information represents the position of the stack at which task is 
interrupted. 
CPU STATUS INFORMATION 5328 
This information includes all register contents at the time point when task 
is interrupted. 
As the task status indicating information, the following can be mentioned. 
NONEXISTENT (NONEXISTENT) STATE 
This information indicates the state in which no program exists as a task. 
In that case, the task number corresponding to the associated TCB is in 
the non-used state. 
DORMANT (DORMANT) STATE 
This information indicates the state in which a program exists as a task 
but remains inhibited from execution. 
READY (READY) STATE 
Assigning of a CPU to a task indicates a state capable of excuting a 
program. A portion which assign the task to the CPU is referred to as the 
task dispatcher. 
RUNNING (RUNNING) STATE 
This information indicates the state in which a program for a task is being 
executed. 
WAITING (WAITING) STATE 
This information indicates the interrupted status in which execution of a 
task is held pending until a certain event occurs. By way of example, 
there can be mentioned a message reception waiting state in which the 
execution of a task is held pending until a message is furnished and an 
input/output completion waiting state in which the execution of a task is 
held pending until input/output operation has been completed. 
The tasks in the READY state are managed, for example, by linking the 
corresponding TCB to one list in the order of priority levels allocated to 
these tasks, as is shown in FIG. 9. This list is referred to as READY 
queue. The READY quene has a header 5333 in which a pointer to the TCB 
corresponding to the task in the READY state and allotted with the highest 
priority level is stored, while in a link field 5321 of the aforementioned 
TCB, there is stored a pointer to the TCB corresponding to the task of the 
next high priority level. In this manner, the TCBs are linked together by 
the pointers in the order of the allotted priority levels, wherein the 
link field of the final TCB contains information indicating that the 
corresponding task is located at the trail or end. The task dispatcher 
allocates to the CPU the task corresponding to the TCB having the highest 
priority level from those linked to the READY queue. 
The tasks in the WAITING state are managed by linking them to respective 
lists prepared for each of the factors which set the corresponding TCB in 
the WAITING state, wherein the TCB is released from the associated list 
upon releasing of the WAITING state in response to occurrence of a certain 
event and linked to the READY queue, whereupon the execution of the task 
is reinitiated by the task dispatcher, starting from the interrupted 
position. 
The messages are managed by a message control table 534, as shown in FIG. 
10. The message control table 534 is constituted by an array of message 
control blocks (hereinafter referred to as MCB in abbreviation) 535, 
wherein one MCB 535 is allocated to one message. The MCB 535 includes, for 
example, status information 5351 indicating whether the associated MCB 535 
is being used or not, a sender task number 5352, a receiver task number 
5353, message size information 5354 and a message buffer 5355 for holding 
temporarily the incoming message. On the other hand, when it is found from 
the parameters intervening in the issue of the message reception request 
that no message is yet sent from the task to which the message reception 
request has been issued, the TCB 532 corresponding to the addresser task 
issuing the message reception request is decoupled from the READY queue 
and linked to a message reception waiting queue 536 shown in FIG. 11, to 
thereby place the task of concern in the WAITING state until the message 
is received. Alternatively, instead of placing the message reception 
requesting task in the WAITING state, information to the effect that the 
message is not sent out may be transmitted to that task. 
Now, the processing flow taking place in the system control section 53 will 
be described by referring to FIG. 12. When a processing request is issued 
by a task to the system control section 53, environments for execution 
existing at that time point are saved in the TCB 532 (steps 1001). 
Subsequently, functions as requested are discriminatively identified (step 
1002), being followed by activation of processing programs corresponding 
to the individual functions, respectively, (steps 1003 to 1008). After 
completion of the processings corresponding to the individual functions, 
it is decided on the basis of the state, for example, of the READY queue 
whether the task is to be exchanged with another (step 1011). If the 
answer of the decision step 1011 is affirmative (Y), the task dispatcher 
is activated (step 1013). Otherwise, the environments of execution saved 
at the step 1001 are recovered from the TCB 532 (step 1012), whereupon 
execution of the task issued the processing request is re-started (step 
1012). On the other hand, upon issuing of input/output completion 
interrupt from the input/output unit, environments of execution at that 
time point are saved in the TCB 532 (step 1009). Subsequently, 
input/output completion processing such as, for example, transfer of input 
character or text codes or the like to an input requesting task is 
performed to thereby release the latter from the input waiting state (step 
1010), being then followed by activation of the task dispatcher (step 
1013). The task dispatcher makes a decision as to whether the TCB is 
linked to the READY queue or not (step 1191), as is shown in FIG. 12K. 
Unless the TCB is linked to the TCB, an endless loop is established until 
an interrupt is issued (step 1197). Otherwise, the TCB of the highest 
priority level is derived by referring to the pointer stored in the header 
533 of the READY queue, and it is decided from the TCB interrupt flag 
information 5325 whether interrupt request to the task has been issued or 
not (step 1192). If the interrupt request is issued, the pointer is 
updated to decouple the TCB of concern from the READY queue (step 1193), 
and the processing is again executed starting from the step 1191 to 
thereby set the TCB of concern to the active (ACTIVE) state (step 1194), 
whereupon the environments of execution are restored from that TCB (step 
1195), being followed by the restart of execution of the corresponding 
task (step 1196). 
As the functions required for the system control division 53, there may be 
mentioned, for example, task creation/deletion processing (step 1003), 
task activation/termination processing (step 1004), forcible task 
termination processing (step 1005), task interrupt/restart processing 
(step 1006), inter-task message transmission/reception processing (step 
1007) and input/output request processing (step 1008), as shown in FIG. 
12A. In the input/output request processing 1008, the input/output request 
issued by a task to the keyboard, the display unit or other is accepted, 
to thereby set the request issuing task in the WAITING state until the 
input/output processing has been completed while restoring the task of the 
WAITING state to the READY state upon completion of the input/output 
processing. Description in detail of the other processings shown in FIGS. 
12B to 12J will be made later on. 
The input control section 51 performs various functions such as transfer of 
character codes inputted through the keyboard and the coordinate values 
inputted from the mouse to the task, information of the designated icon to 
the system management section 57 in accordance with the area on the 
display screen 21 as designated by the mouse, information of the 
designated menu to the task, indication of the designated window 
change-over request to the window management section 52 and others. 
Referring to FIG. 13, the input data from the input unit 1 is first 
analyzed at a step 1301 to decide whether the input data originates in the 
mouse. Unless the input data is from the mouse, this means that the input 
data originates in the keyboard, whereupon the character codes 
corresponding to the actuated or pressed keys are fetched or acquired 
(step 1311) and transferred to the input requesting task (step 1312). 
Assuming, for example, a character key labeled " " (a Japanese alphabetic 
character) in the keyboard is pressed by operator, then the character code 
corresponding to " " is transferred to the input requesting task. On the 
other hand, when the decision step 1301 shows that the input data 
originates in the mouse, coordinate indexing operation is performed to 
determine the location on the display screen that the operator has 
designated (step 1302), whereby the mouse cursor 30 is displayed at the 
position to which the mouse is moved (step 1303) When the decision step 
1302 shows that the location designated by operator lies within other 
window than the topmost one, it is decided that the window change-over is 
commanded (step 1304), whereupon a window change-over request is issued to 
the window management section 52 (step 1305). In case the operator 
designation is directed to the icon field 24 (step 1305), it is decided 
which of the icons is designated (step 1305) to acquire the corresponding 
icon number (step 1313), which is then indicated to the system management 
section 57 (step 1314). Further, in order to allow the system management 
section 57 to retrieve the program corresponding to the icon as indicated 
from the icon management table 571 to thereby create the retrieved program 
as a task and activate the created task, a request for creation and 
activation of that task is issued to the system control section 53. When 
an item located within the topmost window is designated by the operator 
(step 1306), the coordinate value thereof on the display screen is 
translated into a relative coordinate value within the topmost window 
(step 1317), followed by a step 1318 where the coordinate value resulting 
from the translation is transferred to the input requesting task (step 
1318). In case the item designated by the operator is found to lie within 
the menu area 22 (step 1307), a request is issued to the window management 
section 52 to open the pull-down menu (step 1315). When the item 
designated by the operator is located within the pull-down menu area 28 
(step 1308), it is then determined which of the function items is 
designated, whereupon the number identifying the designated function item 
is transferred to the input requesting task together with the pull-down 
menu number (step 1319). When the item designated by the operator is 
located within the control area 253 or caption area 251 of a window (step 
1309), a code indicative of the window closing, scrolling or the like is 
furnished to the input requesting task (step 1310). If the other area is 
designated, nothing is down. It should be noted that when the code is 
transferred to the input requesting task, the state of the latter is 
changed to the READY state from the WAITING state by the system control 
section 53. 
The menu is placed under control or management of the menu management table 
523 and the pull-down menu management table 525, both being shown in FIG. 
14. The menu management table 523 contains therein the information of the 
number of pull-down menus and in succession thereto menu management blocks 
524 arrayed in the order of the pull-down identification numbers (No.) in 
a number equal to that of the pull-down menus. Each of the menu management 
block 524 contains pull-down menu name 5241, a maximum character number of 
function item 5242, a function item number (No.) 5243 and a pointer 5244 
to the pull-down menu management table 525. On the other hand, the 
pull-down menu management table 525 contains pairs of a function item name 
5251 and a valid/invalid flag 5252 indicating whether the associated 
function item is valid or not, the pairs being arrayed in the order of the 
function item identification numbers (No.) in a number equal to that of 
the function items. 
On the basis of the information mentioned above, the input control section 
51 responds to the request issued by the window management section, if 
any, for displaying in the menu area the pull-down name of the window 
which occupies the topmost position upon opening or changing-over of the 
window. In case the pull-down name is designated by the mouse, the 
function item name is retrieved from the corresponding pull-down menu 
management table 525, whereby the retrieved function item is displayed in 
the pull-down menu area 28 with a normal brightness when it is valid, 
while being displayed with a half-brightness if the retrieved item is 
invalid. 
The print control section 54 serves to control the printer unit 4 in 
response to the request for document print-out issued by the edit section 
56. The display control section 55 responds to the display requests from 
the edit section 56 and the window management section 52 for writing the 
data only of a portion that can be displayed in the topmost window on the 
display unit 2 on the basis of the overlapping sequence information 
available from the window management block 522, said data being written on 
the dot basis in the memory dedicated for the display unit 2. 
Creation and editing of a document by the word processor according to the 
illustrated embodiment of the invention will now be described. 
At first, in the initial state, creation of a new document or editing of 
created documents is started, when operator designates the corresponding 
icon with the mouse. 
The input control section 51 responds to the designation or command thus 
inputted by operator to identify the icon of concern on the basis of the 
designated coordinate position on the display screen, whereupon the 
identified icon number (No.) is informed to the system management section 
57. On the other hand, referring to a flow chart shown in FIG. 18, the 
system management section 57 in its initial state first displays the icons 
(step 1701), issues a request for reception of message (step 1702), 
identifies the sender in which the received message, if any, originates 
(step 1703), acquires the program number (No.) corresponding to the 
designated icon with the aid of the icon management table 571 when the 
received message is from the aforementioned input control section 51 (step 
1704), and creates the relevant edit section as a task, being followed by 
activation of the task (step 1705). The task creation and activation are 
illustrated in the processing flow charts in FIGS. 12B and 12D. Referring 
to the figures, when the system management section 57 issues to the system 
control section a request for task creation in the form of the program 
number (No.), the system control section 53 responds to that request by 
acquiring the non-used task number from the task control table and 
creating a corresponding TCB (step 1101), whereupon the task is set to the 
DORMANT state (step 1102) and the acquired task number is sent back to the 
request issuer (step 1103). Subsequently, when the system management 
section 57 issues the request for activation of the task by designating 
its task number, the system control section 53 sets the TCB corresponding 
to the designated task number to the aforementioned READY state (step 
1121), whereupon the TCB is linked to the READY queue. Thus, the edit 
section assumes the state ready for execution (step 1122). 
The transaction of information mentioned above is carried out through 
transmission/reception of messages through the medium of the system 
control section 53. 
By way of example, in the case the message is transmitted from the input 
control section 51 to the system management section 57, the input control 
section 51 issues first to the system control section 53 a request for 
allowing the message to be transmitted to the system management section 57 
(step 1706). 
In response, the system control section 53 makes decision as to whether the 
reception request is issued by the system management section 57 by 
consulting the message control table, as is shown in FIG. 12I at a step 
1171. If the reception request is present, a transmission message is 
transferred to the message buffer of the corresponding MCB (step 1174) to 
perform the reception awaiting task, i.e. releasing of the TCB of the 
system management section 57 from the message awaiting queue and linking 
to the READY queue (step 1175). On the contrary, when no reception request 
is issued yet, the system control section 53 acquires a non-used MCB (step 
1172) and transfers the message to the message buffer of the MCB (step 
1173). 
On the other hand, when the system management section 57 issues the message 
request to the system control section 53, the latter makes a decision as 
to whether the message destined for the system management section 57 is 
present in the MCB, as shown in FIG. 12J at a step 1181. If present, the 
system control section 53 reads out the message from the MCB and transfers 
it to the system management section 57, the message request issuer (step 
1184). Unless the message is present in the MCB of concern, a decision is 
made as to whether the task which has issued the macro of concern 
indicates the WAITING (step 1182). Unless the WAITING is indicated, 
information that no message has been found for that task is sent back to 
thereby allow the processing to be completed (step 1185). Otherwise, the 
TCB of that task is disconnected from the READY queue shown in FIG. 9 
after acquisition of the non-used MCB and linked to the message reception 
awaiting queue 536, whereupon the control is transferred to the dispatcher 
(steps 1183 and 1186). In this manner, when the message is transferred to 
the MCB in response to the message transmission request, the task waiting 
for the message is linked to the READY queue. Thus, upon restating of the 
task of concern, execution is performed starting from the message 
reception processing, whereby the content (message) of the MCB can be 
received by the task. 
When the operator command resides in the creation of a new document, the 
system management section 57 activates the document edit section 56. And, 
in case the operator command resides in editing the previously created 
documents, the system management section 57 activates the file edit 
section 58 to indicate the next document which is to undergo the edit 
processing. 
Next, the processing performed by the file edit section 58 will be 
described by referring to the flow chart shown in FIG. 19. The file edit 
section first opens a window (step 2001) and displays a list of documents 
stored in the storage unit 3 within the opened window (step 2002). After 
the display, the file edit section 58 requests the input control section 
51 to input data or information, if any (step 2003). If the information is 
available, the content thereof is identified (step 2004). In this 
connection, when the information inputted by operator is of a document to 
be processed as designated by operation, a decision is made as to which of 
the documents is designated, whereupon the name of the designated document 
is registered in the relevant document table 581 (step 2005). The relevant 
document table 581 contains the numbers (No.) of designated documents 5811 
and the designated document names 5812. On the other hand, when the 
renewal/printing is commanded by the operator, information that the 
renewal/printing command has been inputted is sent to the system 
management section 57 together with the name of the document currently 
subjected to the processing and the data species number (No.) 
corresponding to that document (step 2006). Further, in the case of the 
edit command such as copying or deletion for a document, the processing 
for copying or deletion of the document as designated is executed (step 
2007). When the command is directed to the scrolling, a scrolling display 
for the list of documents is performed (step 2008). In the case of the 
task termination or end command, the window is closed (step 2009), and 
completion of the file edit processing is messaged to the system 
management section 57 (step 2010) while issuing the task end request (step 
2011). In response to the task end request, the system control section 53 
sets the TCB of the concerned task to the DOCUMENT state as shown in FIG. 
12E at step 1131, to thereby release the resource used by the task (step 
1132). The term "resource" is intended to encompass the memory and CPU. 
The open/close processing mentioned hereinbefore is performed in the window 
management section 52, which will be described below in detail by 
referring to the flow charts shown in FIGS. 15 and 16. 
In the first place, the window open processing will be described. The 
window management section 52 creates a WCB 522 in accordance with the 
information designated by a task (step 1501). At that time, it is also 
checked whether any window has been already opened (step 1502). If a 
window is present, the task which utilizes the window occupying the 
uppermost position currently is once interrupted (step 1503), and the 
displayed image within the uppermost window is saved in the display buffer 
(step 1504). Subsequently, a window is displayed in accordance with 
information of the position and size designated by the task of concern 
(step 1505). Further, the number (No.) of the created window management 
block is sent back to the request issuing task (step 1506). 
In the case of the window closing procedure, the image within the 
designated window is first erased (step 1511). Subsequently, the window 
hidden by one subjected to the close processing is retrieved from the 
window management table, the display image is read out from the 
aforementioned display buffer, the display image for the window of lower 
rank than the erased one is restored (step 1512), and the WCB 522 for the 
erased window is reset to the non-used state (step 1513). 
By the way, the task interruption processing mentioned above will be 
described in detail hereinafter. 
As will be appreciated from the foregoing, when the operator command is to 
create a new document, the system management section 57 creates the 
document edit section 561 as a task in accordance with the information 
from the input control section 51 (step 1705) and subsequently activates 
the new document creation mode (step 1707). In the case of renewal of a 
created document, the system management section 57 acquires the relevant 
program number (No.) from the program control table (FIG. 5) in accordance 
with the data species number supplied from the file edit section 58 (step 
1708), to thereby create the document edit section 561 as a task (step 
1709), and furnishes the parameters required for activating the document 
edit section 561 (step 1710), to thereby activate the document edit 
section 561 in the renewal mode (step 1711). 
Further, the system management section 57 executes deletion of the task 
upon reception of the end message from the very edit section that the 
system management section 57 has created and activated (step 1712). The 
task deletion processing is executed by the system control section 53 as 
in the case of the task creation request processing described above. As in 
the FIG. 12, the system control section 53 then sets the TCB corresponding 
to the designated task to the NONEXISTENT state (step 1111). In other 
words, the TCB is reset to the non-used state. 
Upon activation of the document edit section 561, the system management 
section 57 transmits the aforementioned mode and the created task number 
(No.) to the document edit section 561 as the parameters. In the case of 
the update mode, the name of the document to be updated which name is 
furnished from the file edit section 58 is also sent to the document edit 
section. 
Now, the processing performed by the activated document edit section 561 
will be described by referring to flow charts shown in FIGS. 21, 22A to 
22L. 
In the initialization processing (step 3001), the document edit section 561 
receives the activating parameters in the form of message (step 3101) and 
makes a decision on the basis of the contents of the parameters as to 
which of the new document creation activating mode or the document update 
activating mode is to be established (step 3102), as illustrated in detail 
in FIG. 22A. In the case the new document is to be created, the textual 
data is initialized (step 3103), while in the case of the document update, 
data for the update is read out from the storage unit 3 in accordance with 
the document name designated by the parameter mentioned above (step 3104). 
The structure of the textual data will be described hereinafter. 
Subsequently, by consulting the program control table (FIG. 5), a support 
field edit section management table (hereinafter referred to as SFMT in 
abbreviation) is prepared which table contains a list of field edit 
sections capable of performing creation/renewal of fields in the document. 
More specifically, the SFMT holds in pair the program number (No.) 5682 of 
the support field edit section and the data species number (No.) 5683 of 
the field edit sections, and further includes the field edit section (No.) 
5681, as is shown in FIG. 27. Additionally, in order to allow the operator 
to know the type of data for which the field can be created currently, the 
name of data for the aforementioned field edit section is set in the 
pull-down menu (step 3105). Subsequently, upon field edition described 
below, the designated field in a target field table indicating the field 
subjected to the processing (FIG. 28) is cleared (step 3106), being then 
followed by initialization of the pull-down menu data to the valid/invalid 
state (step 3107). The concerned field table holds the number of the 
fields (information denoted by 5684) designated currently as the targets 
for the processing, the types of the designated fields (5685) and the 
designated field numbers (No.) 5686, as shown in FIG. 28. Description 
concerning the types of the fields and change-over or switching of the 
pull-down menu between the valid/invalid states will be made hereinafter. 
Subsequently, the document edit section 561 opens a window (step 3108) and 
displays the layout of a first page of the document to be edited within 
the opened window in the manner illustrated in FIG. 31A (step 3109). In 
conjunction with the opening of the window, it should be mentioned that 
the window size is selected to be compatible with that of the printing 
sheet and the task number (No.) of the document edit section 561 is added 
as a part of the title of the window. 
Now, description will be turned to the processing involved in creating the 
SFMT and the menu data briefed above in conjunction with the step 3105 
shown in FIG. 22A. 
As will be seen in FIG. 27, the SFMT is a table containing a list of the 
program numbers (No.) 5682 and the data species numbers (No.) 5683 for the 
field edit sections which can be activated by the document edit section. 
The information is employed in making decision as to whether the relevant 
program exists upon creation, update or layout displaying of a field, or 
used as parameters for creating the program as a task. 
In preparation of the table SFMT, the program number P and the registration 
number E are first cleared to zero, as shown at steps 3111 and 3112 in 
FIG. 22B. Then, decision is made successively, starting from the leading 
or start block of the program control table (FIG. 5), as to whether the 
parent program number (No.) coincides with the program number of the 
document edit section itself (step 3114). When coincidence is found, the 
latter program is regarded as the PCB 573 for the field edit section which 
can be activated by the document edit section, whereupon the program 
number P and the data species number D.sub.p set in the PCB 573 are 
registered in the SFMT (step 3115). Further, a data name corresponding to 
the data species name (e.g. "graphic pattern", "graph" etc.) is read out 
from the DNDT (FIG. 6) and registered as the name of the pull-down menu 
data for creating a new field in the menu data (FIG. 23) possessed by the 
document edit section (step 3116), being followed by a step 3117 where the 
registration number E is incremented. The processing mentioned above is 
repeated a number of times corresponding to the number of the program 
management blocks (steps 3118, 3113). Finally, the registration number E 
is entered in the number of field edit sections 5681 (step 3119), whereby 
only the names of the field edit sections actually incorporated in the 
system currently can be displayed in the pull-down menu. 
Here, structure of the document data will be described by referring to FIG. 
24. 
The document data includes a chapter management table 5610, a page 
management table 5620, a page format table 5630, a field management table 
5640 and intra-field data 5660, wherein each table is composed of plural 
blocks. Details of these tables are as follows. 
CHAPTER MANAGEMENT TABLE 5610 
This table manages information about how many chapters are included in a 
whole document and contains page pointers 5611 and 5612 indicating the 
start/end pages of each chapter. Additionally, the chapter management 
table holds print information 5613 for displaying and/or printing header, 
footer or the like for each of the chapters. 
PAGE MANAGEMENT TABLE 5620 
This table contains field pointers 5623 and 5624 for indicating start/end 
fields of those included in the page and a page format pointer 5625 for 
indicating which of the format data is used on a particular page. The 
blocks are linked in the page ascending order by backward pointer 5621 and 
forward pointer 5622. The start and end pages are pointed by the 
aforementioned chapter management table. In the case of the illustrated 
document data, page is of such a structure as shown in FIG. 25. In the 
figure, a reference numeral 5671 indicates the page. It should be noted 
that the page size and the blanks (margins) are managed with the aid of 
the page format table mentioned below, while the base field 5672 and 
internal fields 5673 are managed by the field management table 5640. 
PAGE FORMAT MANAGEMENT TABLE 5630 
This table is used for managing document format data such as types of print 
sheets (A3, A4, etc.), paper direction (longitudinally or transversely), 
top, bottom, left and right blanks or margins. 
FIELD MANAGEMENT TABLE 5640 
This table manages the data to be contained in the document (or on page). 
More specifically, the table is used for determining intra-page positions 
and sizes for various data such as, for example, text data, pattern data, 
graph data etc. To this end, the field management table contains as the 
intra-page field location information the upper left x- and y-coordinates 
5643 and 5644, lower right x- and y-coordinates 5645 and 5646 for defining 
the field in the coordinate system having the origin located at the upper 
left corner of the page field exclusive of the blank portion. 
Additionally, the field management table 5640 contains data species 
information 5647 indicative of the species or type of the intra-field 
data, the field attributes of the field itself 5648 and a data pointer 
5650 for pointing the intra-field data 5660. As the attribute information 
of the field, there can be mentioned information indicating whether the 
field is transparent or opaque (the opaque page field covers invisibly the 
underlying field) and line species information for the field frame. 
Additionally, in order to manage the overlapping sequence of the fields 
within one and the same page, the fields are linked together by the 
backward pointer 5641 and the forward pointer 5642. This inter-field 
linkage is realized in the up-direction starting from the field having the 
lowest priority level to the field imparted with the highest priority 
level, i.e. from the bottom field to the topmost field in a page. Of the 
interlined fields, the start/end fields are pointed by the page management 
table mentioned above. Additionally, the field management table 5640 
contains status information 5649 indicating whether a concerned field is 
being edited and whether the field edit section corresponding to the field 
data species of concern exists or not in the currently working system. 
The intra-page fields may be globally classified into two groups mentioned 
below. 
(i) Internal fields 5673 
These fields exist in the base field mentioned below. Position and size of 
the internal field can be determined through manipulation by the operator. 
Each of the internal fields can contain one of various data such as text, 
pattern, graph, image and others. This internal field is susceptible to 
all the field editions such as new field creation, update, movement, copy, 
deletion and others. 
(ii) Base field 5672 
The base field corresponds to the whole field of a page exclusive of the 
top, bottom, left and right margins (blanks) thereof. Whenever a page is 
created through manipulation by operator, one base field 5672 is created. 
This field always assumes the leading position on the page (i.e. bottom 
field). This base field contains only the text data constituting the body 
of document and is susceptible only to the new field creation and update. 
Other sorts of editing such as move, copy, deletion, etc. for the base 
field are performed in terms of page editing such as move, copy and 
deletion of the associated page. 
INTRA-FIELD DATA 5660 
This data is placed in the fields and can include text data, pattern data, 
graph data, image data, etc. 
Now turning back to FIG. 21, the document edit section 561 issues an input 
request to the input control section 51 at a step 3002 in succession to 
the initialization step 3001. Next, at a step 3003, the result of input 
operation performed by operator is checked. If it is found that a field 
processing is commanded, the field as designated is identified on the 
basis of the page number, the designated intra-page location and the set 
position of the field included in the document data, whereupon the 
relevant field number (No.) is registered in the target field table (step 
3004). A decision method involved in this processing will be described 
below in more detail by referring to the flow chart shown in FIG. 22C. 
In the first place, a decision is made as to whether the designated 
location lies within the base field 5672 (step 3201). In case the 
designated location lies outside of the base field, it is determined that 
none of the fields corresponding to the designated location (position) 
exists, whereby a designation error message is issued. If the designated 
location is determined to lie within the base field, a decision is then 
made whether the designated location exists within any one of the internal 
fields 5673 by checking sequentially starting from the field of the 
highest rank (the intra-page end field) at steps 3202 to 3205. When the 
result of this decision shows that the designated location exists within 
an internal field, it is determined that the processing command of the 
operator is directed to the processing for the internal field, whereby the 
internal field designation flag is set to "1" (step 3206). On the other 
hand, when it is ultimately found that the designated location or position 
does not lie within any internal field on the page being currently 
displayed (i.e. when the internal field designation flag is "0"), it is 
decided that the operator designates the base field. When the designated 
position or location lies within an internal field 5673, it is then 
decided whether that field has already been registered in the target field 
table (step 3207). In case the field has been registered as the target, 
the succeeding field (i.e. the field of the document data indicated by the 
forward pointer 5642 of the field management block of the field now being 
subject to the decision) is checked. On the other hand, unless the number 
of the designated field has been registered in the target field table, the 
former is newly registered in the target field table. In this connection, 
it should be noted that when the relevant base field has been designated 
as the target field (step 3208), information 5684 about the number of the 
designated field contained in the target field table is once cleared to 
zero (i.e. target designation to the base field is once cleared) (step 
3209), and thereafter the above-mentioned internal field number and the 
field species or type are registered in the target field table, whereupon 
the number of the designated fields (denoted by 5681) is incremented by 
"1" (step 3210). The reason why the designation of the base field which 
has been already registered as the designated field is forcibly cleared 
can be explained by the fact that none of the field editing can cope with 
such situation where both the base field and the internal field are 
simultaneously designated. Further, when the internal field has not yet 
been registered in the processing mentioned above, it is checked whether 
the internal field designation flag is "0" or not (step 3212). If the flag 
is "0", it is then determined that none of the internal fields exists at 
the designated location and that the operator designation is directed to 
the base field. Accordingly, the base field number is registered in the 
table. In that case, however, it is again checked whether the base field 
has been designated as the target for the processing (step 3213). If not, 
it is then decided if an internal field has been designated (step 3214). 
If so, the target field table is once cleared (step 3215) and thereafter 
the base field number and the field type are registered in the target 
field table, with the number of the designated field being set to "1" 
(step 3216). 
Assuming that the operator command is to cancel a designated field in the 
course of target designation, it is determined which field is designated 
on the basis of the page number, the designated intra-page position and 
the field set position contained in the document data, which is then 
followed by canceling the relevant field number from the target field 
table (step 3005 in FIG. 21). This decision step will further be described 
by referring to the flow chart shown in FIG. 22D. 
At first, it is decided whether the designated location lies within the 
base field (step 3251). If the result of the decision is negative (N), the 
target field table is cleared unconditionally. In other words, all the 
designated fields registered in the target field table are canceled (step 
3258). On the other hand, when the result of the decision step (3251) is 
affirmative (i.e. when the designated location lies within the base 
field), the fields are sequentially checked starting from the field of the 
highest rank (i.e. the intra-page end field) as to the existence of the 
designated location in any one of the fields (steps 3252 and 3523). If the 
decision has proven that the designated location exists in a field, it is 
then checked whether that field has been registered in the target field 
table (step 3254). If so, the relevant field number is deleted from the 
target field table (step 3257). On the other hand, unless the designated 
location has been found in the checked fields at the step 3253 or 
alternatively unless the relevant field number has not been registered in 
the target field table at the step 3254, the similar decision procedure is 
taken for other succeeding fields through steps 3255 and 3256. 
In the course of the field designation/cancel operation mentioned above, 
the edit processing for the permissible fields may vary from one to 
another field. In this conjunction, the valid/invalid state of the 
pull-down menu participating in the field processing is also changed 
correspondingly. This processing (corresponding to the step 3014 shown in 
FIG. 21) will be described below in detail by referring to FIG. 22E. 
The edit operation for the fields may be classified into three groups in 
dependence on the number of the fields designated as the target for the 
processing, as shown in FIG. 26. More specifically, the number of the 
fields designated as the target for the processing is determined (step 
3301). When the number of the fields is found zero (0), only the pull-down 
menu for creating a new field is validated with all the remaining field 
edit processings being invalidated (step 3302). To the contrary, when the 
number of the fields designated as the target or object for the processing 
is "1 (one)", then the edition processing for all the other fields is 
validated (step 3303). Further, when the number of the fields designated 
as the target exceeds "2", only the field processing "move", "copy" and 
"delete" are validated with all the other edition processing being 
invalidated (step 3304). In case the number of the fields designated as 
the target is "1", it is additionally decided whether the designated field 
is the base one (step 3305). If so (Y), alteration of the attributes and 
size are inhibited (step 3306). Subsequently, it is checked whether the 
status of the designated field is other than "0" (step 3307). If so, this 
means that the field of concern is currently undergoing the edit 
processing or alternatively field edit section capable of renewing the 
field of concern does not exist in the system operating currently, and 
thus the renewal is also invalidated (step 3308). When the number of the 
fields designated as the target exceeds "1", it is then checked whether 
there exists the field whose status is "1" (i.e. the field currently 
undergoing the processing) among those designated (step 3309). If so, the 
deletion is also invalidated (step 3310). 
Next, description will be made by referring to the flow chart shown in FIG. 
22F on the assumption that operator command is to create a new field (step 
3006 in FIG. 21). 
In this case, the operator command for creating a new field is validated by 
designating a data name displayed within the pull-down menu. More 
specifically, the document edit section 561 acquires the relevant program 
number and data species number by consulting the aforementioned SFMT (FIG. 
27) with the aid of the pull-down menu number supplied from the input 
control section 51 (step 3401) to determine the data for which the field 
creation has been commanded (step 3402). When the data of concern is for 
the inner field, the area as well as attributes of that field are set 
(step 3403). Subsequently, in accordance with the information mentioned 
above, a field management block is created (step 3404) to thereby activate 
the field edit section (step 3405). This activation processing will be 
described hereinafter. 
Assuming that the operator command is to update the field created 
previously (the step 3007 in FIG. 21), the corresponding field number is 
retrieved from the target field table 5686 shown in FIG. 22G (step 3411). 
With the aid of this field number, the relevant program number is acquired 
from the SFMT by consulting the relevant field management block containing 
the data species (step 3412), whereupon the associated field edit section 
562 is activated as a task (step 3413). 
When the field edit section 562 is activated, the document edit section 561 
issues a task creating request to the system control section 53 (step 
3451), as shown in FIG. 22H. In response, corresponding task number and 
field number are fed back to the document edit section 561 and registered 
in an activated edition task management table (hereinafter referred to as 
ETMT in abbreviation) (step 3452). The table ETMT holds the 
above-mentioned task numbers (No.) 5688 and the field numbers (No.) 5689 
each in a pair and additionally contains an activated task number 
information 5687 indicating how many field edit sections are currently 
being activated, as shown in FIG. 29. Subsequently, the status of the 
field management block indicating that the field of concern is undergoing 
edition processing is changed from "0" to "1" (step 3453). In succession 
to the processing mentioned above, the document edit section 561 issues a 
task activation request to the system control section 53 (step 3454) and 
sends a corresponding message to the field edit section for activating the 
activation parameters (step 3455). In response, the document edit section 
transmits as the activation parameters the activation mode indicating 
either the new field creation or field update, the task number of the 
document edit section 561 and the task number of the field edit section to 
be activated, together with the field size information in the case of the 
new field creation. 
When other field editing such as, for example, movement, deletion, page 
insertion, addition or other is designated, the corresponding processing 
is performed (steps 3003 to 3011 in FIG. 21), and a next operator command 
is awaited (step 3002). 
Next, it is assumed that the operator command is to change or switch the 
displayed page (e.g. command for displaying the preceding or succeeding 
page) (step 3012 in FIG. 21). In this case, the layout of the designated 
page is displayed again within the window. The processing for layout 
display will be described below in detail by referring to FIG. 22I. 
In the layout display, the page frame, header, footer and the like are 
first displayed by retrieving the document data (steps 3501 and 3502). 
Subsequently, the fields created within the page are sequentially 
displayed, starting from the field of the lower priority (i.e. the 
intra-page leading field) (steps 3503 and 3514). In the field display, a 
field frame is first displayed (step 3504). Subsequently, it is decided 
whether there exists the edit program for the data for that field by 
checking the data species numbers contained in the associated field 
management block and consulting the SFMT (step 3505). If the edit program 
is absent, the status of the associated field management block is altered 
to "2" (step 3511), while the area of the field enclosed by the frame is 
displayed in black for informing operator of the unavailability of the 
edit program for the above field in the system (step 3512). On the other 
hand, when the edit program is present, decision is then made as to 
whether the attributes belonging to the field of concern are transparent 
(step 3506). If opaque, the inner area of the field is once cleared (step 
3507), being then followed by the display of the intra-field data (step 
3508). Further, in succession to the display, decision is made on the 
basis of the status information relevant to the field as to whether the 
field is being edited (i.e. if the status information is "1") at a step 
3509. If the result of this decision step is affirmative (Y), the field is 
displayed with cross-hatching to inform the operator of the field 
undergoing currently the edit processing (step 3510). Similar processing 
is performed on all the remaining fields existing on the page being 
displayed (steps 3513 and 3514). 
The processing of the activation inputs for the window switching 
(change-over) operation (step 3013 in FIG. 21) will be described 
hereinafter. When termination is commanded, the edition of the document 
comes to an end (step 3015 in FIG. 21). This processing will also be 
elucidated hereinafter. 
Now, consider the case where the field edit section 562, e.g. the pattern 
data editing section is to be activated by the document edit section 562 
in response to the command for creation or update of a field. In this 
case, the system control section 53 responds to this request by activating 
newly the pattern edit section as a task. 
The processing performed by the pattern data edit section is described 
below by referring to the processing flow chart shown in FIG. 30. 
At first, the pattern data edit section receives the activating parameters 
in the form of a message (step 4001), and decision is made as to whether 
the activation mode is for a new field creation or field update (step 
4002). If the decision results in the new field creation, initialization 
of data is first executed (step 4003). When the result of the decision 
shows the field update, the data to undergo the update processing are read 
out from the storage unit (step 4004). Subsequently, a window is opened 
(step 4005), and the pattern data is displayed within the opened window 
(step 4006). In this case, the size of the window is so opened as to 
correspond to that of the field. Additionally, the title attached to the 
window is added with the task number of the document edit section which 
activated the update mode. By virtue of this feature, it can be easily 
discriminated on the basis of the task number 254 displayed as a part of 
the window title which of the document the field of concern belongs. This 
is very convenient when a plurality of documents are simultaneously edited 
with some of the fields of these documents being displayed, as shown in 
FIG. 32. In this case, the state of display is such as shown in FIG. 31B. 
Subsequently, the pattern data edit section performs creation and editing 
of pattern data within the opened window in accordance with instructions 
inputted by operator (step 4007-4009). When the end of the intra-field 
editing is commanded by operator, the pattern data edit section stores the 
prepared pattern data in the storage unit 3 (step 4010), closes the window 
(step 4011), sends the field editing end message to the document editing 
section 561 which activated the field editing (step 4012) and terminates 
the task (step 4013). The field editing and termination message is affixed 
with an end code indicative of the completed intra-field editing and the 
task number of the pattern editing section itself so that the document 
editing section which has activated the field editing can know any 
particular field for which the edit processing has been completed. 
In this manner, the whole document as well as the intra-field contents can 
be created and edited. Next, description will be directed to the operation 
and processing for changing over (switching) the editing sections through 
window manipulation by referring to FIGS. 31A, 31B and 31C in combination 
with FIG. 17. 
First referring to FIGS. 31B and 31C, when editing of the document layout 
is to be done in the course of editing of the intra-field pattern data, 
the mouse cursor 30 is moved onto the window of the document edit section 
561 as in the case of the designation of target to be processed described 
hereinbefore and the execute button of the mouse is pressed. In response 
to this input command, the input control section 51 determines that the 
designated position is located outside of the window in which the pattern 
editing was being executed. Accordingly, the input control section 51 
transfers the input command to the window management section 52 instead of 
the pattern editing section. The window management section 52 determines 
on the basis of the mouse-designated position and the window management 
table that the window for the document editing section 561 is designated 
(step 1521) and interrupts once the task which has used the uppermost 
window until then, i.e. the pattern edit section (step 1522), while the 
displayed image data within the uppermost window is saved in the display 
buffer (step 1523). Subsequently, the window for the newly designated 
document edit section is displayed uppermost (step 1524), the overlapping 
sequence of the window management blocks is correspondingly updated (step 
1525), and an activate code is returned to the task using the window of 
concern for informing the document edit section ready for restarting new 
processing of the fact that the window has been switched (step 1526), 
whereupon the task using the window of concern, i.e. the document edit 
section, is restarted (step 1527). 
The interruption and restart of the editing described above are performed 
under the control of the system control section 53. Next, the interrupt 
and restart processing will be described by referring to FIGS. 12F and 
12G. 
When a task interrupt request is issued, the system control section 53 sets 
the interrupt flag of the TCB corresponding to the task designated (step 
1141), decides whether the task of concern is in the READY state (step 
1142), and releases the corresponding TCB from the READY queue when the 
task is in the READY state to thereby prevent the CPU from allocation by 
the dispatcher (step 1143). 
In response to the task restart request, the interrupt flag of the TCB 
corresponding to the designated task is reset (step 1151), and decision is 
made if the task of concern is in the READY state (step 1152). If so, the 
task is again linked to the READY queue (step 1153). In case the interrupt 
flag of TCB is set, the task dispatcher is inhibited from activating the 
task of concern, which released from the READY queue. 
When the update processing of the base field is performed starting from the 
state illustrated in FIG. 31C, the display on the screen is changed to the 
state shown in FIG. 31D. In this state, the switching or change-over of 
the individual editing sections for the text, pattern and the layout from 
one another can be realized in desired manners through the operation 
procedure described above. By way of example, switching of the field 
editing section, i.e. changing-over from text to pattern results in the 
screen display state shown in FIG. 31E. 
As mentioned above, upon window switching, the activate code is returned as 
input to the task restarted by the window management section. 
In the case of the example described above, when the pattern edit section 
is switched to the document editing section 561, the latter receives the 
activate code as the input thereto after having been restarted and 
executed the processing mentioned below (see FIGS. 22J and 22K). 
In the first place, the decision is made on the basis of the document data 
if there exists a field undergoing editing on the page being displayed 
currently (step 3601). If present, the display flag is set to "1" (step 
3602), since the content of that field may possibly be renewed by editing. 
On the other hand, when such field is absent, the display flag is set to 
"0" (step 3603), whereupon the processing for displaying again the layout 
is executed in succession to the processing of message. Subsequently, a 
message reception request is issued to the system control section 53. If 
the message is present, end procession for the relevant field editing 
section is performed, as mentioned below (step 3604 to 3606). At first, 
the field number is acquired from the task number of the field editing 
section contained in the message and the ETMT (FIG. 29) (step 3651). 
Subsequently, the status of the relevant field management block is reset 
to "0" (step 3652). Information about the task of concern is deleted from 
the ETMT (FIG. 29) (step 3653). Finally, that task itself is also deleted 
(step 3654). On the other hand, unless message is received, it is then 
decided whether the display flag is set to "1" (step 3607). If so, the 
layout of the relevant page is displayed again (step 3608). 
Finally, the end processing performed by the document editing section 561 
will be described by referring to FIG. 22L and FIG. 12H. 
Upon inputting of the end or termination command by operator, decision is 
made on the basis of the aforementioned ETMT whether there exists the 
editing task being currently activated (step 3702). If present, the 
corresponding task number and the field number are retrieved from the ETMT 
(FIG. 29) (step 3703). The status of the relevant field is reset to "0" 
(step 3704). Subsequently, the forcible task end request is issued to the 
system control section 53 (step 3705). Accordingly, the system control 
section 53 releases the resource used by the designated task (step 1161) 
and issues the forcible end processing request to the window management 
section (step 1162), as shown in FIG. 12H. The window management section 
52 performs the processing similar to the window closing processing, as 
shown in FIG. 16. On the basis of the designated task number (No.), the 
corresponding TCB, if any, is released from the header 533 of the READY 
queue, and the TCB is set to the DORMANT state (step 1163). After the 
forcible processing mentioned above completed, the document editing 
section 561 deletes the task (step 3706). 
The above-mentioned processing is executed repeatedly on the editing tasks 
being activated (step 3707). Upon completion of the forcible end 
processing for all the task being activated, the document data is 
registered (step 3708). The window opened by the document editing section 
is closed (step 3709), and a message to the effect that the processing has 
come to an end is transmitted to the system management section 57 (step 
3710). The task is then terminated. 
As will be understood, all the field editing sections 562 performing the 
respective editing operations can be simultaneously stopped, in response 
to the end request issued to the document editing section 561. 
As will be appreciated from the foregoing description, the document 
creating apparatus or so-called word processor according to the present 
invention is capable of mutually changing over editing operations such as 
intra-field data creation and editing as well as displayed pages and field 
editions on the layout image without terminating the functions of the 
individual editing sections, whereby operability for creation of the 
documents in which plural different types of data coexist mixedly can be 
significantly enhanced.