Method and apparatus for providing visual feedback during manipulation of text on a computer screen

A method and apparatus providing visual feedback to a computer user while dragging selected text is described. As its first step, the processing logic creates a text object from the selected text once the computer user has initiated a drag. Simultaneously, the selected text is visually de-emphasized. Secondly, the processing logic snaps the text object to the cursor so that the text object follows the cursor without obscuring text at the insertion point. Finally, when the computer user selects the final insertion point, the selected text is visually zoomed from the source location to the final insertion point.

FIELD OF THE INVENTION 
The present invention pertains to a method and apparatus for providing user 
feedback in a computer system. More particularly, the present invention 
pertains to a method and apparatus for providing visual feedback to a 
computer user while manipulating text on a computer screen. 
BACKGROUND OF THE INVENTION 
Many computer systems include graphical user interfaces. Graphical user 
interfaces typically include a user interface window, more commonly 
referred to as a desktop window. While operating within the desktop window 
computer users are able to manipulate graphical objects, i.e. icons, using 
a cursor control device such as a mouse or trackball. Icons can be moved 
simply by pointing, clicking and dragging. During these operations the 
computer user receives visual feedback that enhances the feeling of 
physical control over the desktop window and the icons therein. For 
example, selected icons are highlighted and, while the mouse button is 
held down, the selected icon moves with the cursor. 
Moving text within word processor files is not as easy. Highlighted text 
cannot be dragged about a document as if it were an icon. There is no way 
to "grab" the highlighted text. As a result, computer users do not have a 
feeling of physical control during cut, copy and paste operations. 
SUMMARY OF THE INVENTION 
The present invention provides a method and apparatus providing visual 
feedback to a computer user while dragging selected text. As its first 
step, the processing logic of the present invention creates a text object 
from the selected, highlighted text when the computer user initiates a 
drag. Simultaneously, the selected text is visually de-emphasized. 
Secondly, after the cursor begins to move, the processing logic snaps the 
text object to the cursor so that the text object follows the cursor 
without obscuring the insertion point. The computer user is then free to 
move about text onscreen in search of an insertion point. Finally, when 
the computer user selects the insertion point, the selected text is 
visually zoomed from the source location to the insertion point. As a 
result, the computer user has a feeling of physical control while moving 
selected text within a document. 
Other objects, features, and advantages of the present invention will be 
apparent from the accompanying drawings and the detailed description that 
follows.

DETAILED DESCRIPTION 
FIG. 1 illustrates a computer system 10 in which the present processing 
logic of the invention operates. Computer system 10 is illustrated as an 
Apple Macintosh.TM. computer system, however, those of ordinary skill in 
the art will understand that alternative computer systems may be used. 
Computer system 10 includes a monitor 12 for visually displaying 
information to a computer user, a central processing unit (CPU), and 
internal memory, enclosed by housing 14. Keyboard 16 allows a computer 
user to provide input to the CPU. Computer system 10 also includes a 
cursor control device, such as mouse 18, or a trackball, joystick, or 
special keys capable of signaling movement in a particular direction. By 
moving mouse 18 the computer user is able to control the movement of the 
two or three dimensional movement of a visible symbol, such as cursor 20, 
on monitor 12. Computer system 10 also includes a signal generation device 
for signaling active and inactive control states. The signal generation 
device may be realized using a switch or button 19 on or near the cursor 
control device. The up position of button 19 signals the inactive control 
state while the down position of button 19 signals the active control 
state. 
Computer system 10 includes an operating system capable of tracking the 
position of mouse 18 and cursor 20. The operating system also detects the 
state of the signal generation device and reports the position of cursor 
20 in each state of the signal generation device. These features of an 
operating system are well known in the art. Therefore, they will not be 
described in detail here. 
The processing logic of the present invention is stored within the internal 
memory of computer system 10, or on other machine readable media, and 
executed by the CPU. The processing logic can be separately compiled or 
loaded entity or incorporated as part of a larger word processing system. 
In either case, the processing logic of the present invention may be 
activated using techniques well known to those of ordinary skill in the 
art. 
Briefly described, the processing logic of the present invention provides 
visual feedback to users of computer system 10 during direct manipulation 
of text within a word processing application. That visual feedback 
includes de-emphasizing selected text at a source location, creating a 
text object resembling the selected text and "snapping" the text object to 
the pointer such that the text object travels with the pointer. Once a 
destination location is chosen, the selected text is visually "zoomed" 
from the source location to the destination location. 
FIG. 2 illustrates in flow diagram form the operation of the processing 
logic of the present invention. FIG. 3 illustrates the effect of the 
processing logic upon selected text 30 in relation to displayed text 32. 
Referring now to FIG. 2, the processing logic performs two major tasks: 
determining whether visual feedback is required and providing that visual 
feedback. In steps 50-58 the processing logic determines whether visual 
feedback is required. The computer user indicates the desire for visual 
feedback by pressing mouse button 19 down while cursor 20 is over selected 
text 30, continuing to hold down mouse button 19 and moving cursor 20 from 
its position at the time of the mouse down event. The processing logic 
generates visual feedback during the manipulation of selected text 30 in 
steps 60-90. The processing logic generates visual feedback for the 
computer user until after mouse button 19 is released; i.e., returns to 
the up position and the inactive state. Visual feedback while mouse button 
19 is down includes generation of a text object, snapping the text object 
to the cursor, flashing the insertion caret at location under cursor and 
moving the text object with the cursor. Once the computer user releases 
mouse button 19 it returns to its up position, selected text 30 is 
visually zoomed from the source location to the destination location. 
The processing logic is not activated until after text has been selected 
from the text displayed on monitor 12. In FIG. 3A, selected text 30, "Once 
upon a time", is indicated by reverse video, which distinguishes it from 
text 32 displayed on monitor 12. 
After text 30 has been selected, the processing logic waits in step 50 for 
a mouse down event. When the mouse down event occurs, the processing logic 
is also informed of the cursor position at the time of the mouse down 
event. Let us refer to this cursor position as the "mouse down position". 
Afterward, the processing logic advances to step 52. 
In step 52 the processing logic determines whether the computer user may 
require visual feedback to accompany the manipulation of selected text 30. 
This determination is made by comparing the mouse down position to the 
coordinates of selected text 30. The user does not require visual feedback 
for text manipulation if the computer user pressed mouse button 19 down 
while cursor 20 was not over selected text 30. In that case, the 
processing logic branches to step 54 to handle the mouse down event in a 
conventional and appropriate manner. On the other hand, visual feedback 
may be required if the mouse down position was over selected text 30. The 
processing logic advances to step 56 to determine if so. 
In step 56 the processing logic waits to see if the computer user requires 
visual feedback to accompany manipulation of selected text. The computer 
user does not require visual feedback if a mouse up event occurs before 
cursor 20 is moved from the mouse down position. Accordingly, the 
processing logic branches to step 54 to handle the mouse up as if a mouse 
down event occurred at the original mouse down location. However, in the 
absence of a mouse up event, the processing logic branches to step 58. 
In step 58 the processing logic determines the current position of cursor 
20. Let us refer to this position as the "current cursor position". If the 
current cursor position is some arbitrary distance away from the mouse 
down position the computer user has indicated a desire to move, or 
pick-up, selected text 30. In one embodiment, the current cursor position 
is chosen to be three pixels away from the mouse down position to indicate 
a desire to manipulate selected text 30. The distance chosen may vary 
according to needs of the computer user. The processing logic responds to 
movement of cursor 20 while mouse button 19 is still down by branching to 
step 60. On the other hand, if the cursor current position is still very 
close to the mouse down position, then the processing logic continues to 
await indication of whether or not visual feedback is desired by branching 
back up to step 56. 
With step 60 the processing logic begins providing visual feedback to the 
computer user by de-emphasizing selected text 30. Selected text 30 can be 
de-emphasized in a number of ways that will be apparent to those skilled 
in the art. In one embodiment, de-emphasis of selected text 30 is 
performed using a QuickDraw.TM. brand graphics processing routine, which 
transforms the white areas surrounding the text to light gray and black 
letters of the text to medium gray. FIG. 3C illustrates de-emphasized 
selected text 30a according to this scheme. De-emphasis of selected text 
30 achieved, the processing logic advances to step 62. 
In step 62 the processing logic creates text object 34 from selected text 
30. As used herein "text object" refers to a visual representation of 
selected text 30, which may or may not include all of selected text 30. 
Text object 34 need only include sufficient text to remind the computer 
user selected text 30 without unnecessarily obscuring much of the text 32 
displayed on monitor 12. Text object 34 may be created by generating a bit 
map of selected text 30 and limiting its size. Text object 34 may also be 
represented by a dotted outline of selected text 30, similar to what 
computer users see when they drag icons within the desktop window. Such a 
representation of text object 34 requires less CPU time but does not 
inform the computer user of selected text 30 which is being moved. 
Text object 34 may also be emphasized as compared to displayed text 32. In 
one embodiment, text object 34 is emphasized using reverse video. Other 
methods of emphasizing text object 34 will be obvious to those skilled in 
the art. Therefore, the manner of creating and emphasizing text object 34 
will not be described in detail herein. The processing logic branches to 
step 64 after its creation of text object 34. 
The processing logic displays text object 34 at the source location during 
step 64. As used herein, "source location" refers to the initial location 
of selected text 30. Stated another way, "source location" refers to the 
location that is the source of selected text 30. 
Because it is initially displayed at the source location, text object 34 
obscures de-emphasized selected text 30 if they are both the same size. 
Once text object 34 is moved it no longer obscures selected text 30. The 
processing logic also displays insertion caret 36 near cursor 20 in step 
64. As using herein "insertion caret" refers to any visual representation 
that indicates to the computer user the precise location in a body of text 
where selected text 30 may be inserted. According to common word 
processing conventions, insertion caret 36 is visually represented by a 
thin vertical line. 
To provide further visual emphasis that the computer user is able to 
manipulate selected text 30, cursor 20 may be displayed as an arrow. 
Processing logic for doing so will be described in detail herein below. 
When cursor 20 is displayed as an arrow, insertion caret 36 is preferably 
displayed near tip 20a of cursor 20, as shown in FIGS. 3C and 3E. Initial 
display of insertion caret 36 and text object 34 begun, the processing 
logic proceeds to step 66. 
The processing logic begins the process of snapping text object 34 to 
cursor 20 in step 66. The processing logic does this by initializing an 
interpolation factor, which is used to snap text object 34 to cursor 20 in 
a discrete and finite number of steps. Text object 34 is gradually moved 
to cursor 20 to prevent computer users from becoming disoriented by text 
object 34 appearing in an unfamiliar location. This done, the processing 
logic enters the snapping and tracking logic by branching to step 68. 
The loop of steps 68-90 snaps text object 34 to cursor 20 and, once 
snapped, ensures that text object follows the movement of cursor 20 on 
monitor 12. The first step within the loop is determining whether the 
interpolation factor has reached its maximum value of one. If it has not, 
text object 34 has not yet snapped to cursor 20. To continue snapping, the 
processing logic branches to step 70. On the other hand, if text object 34 
has snapped to cursor 20, as indicated by the maximum value of the 
interpolation factor, the processing logic advances to step 72. 
During step 70 the interpolation factor is incremented. The amount by which 
the interpolation factor is incremented depends upon the choice of the 
number of steps for text object 34 to reach cursor 20. For example, if the 
number of steps chosen for text object 34 to reach cursor 20 is four, then 
the interpolation factor is incremented by 0.25 each pass through step 70. 
The number of steps chosen will depend upon the visual effect and response 
time desired. After incrementing the interpolation factor, the processing 
logic branches to step 72. 
The processing logic moves text object 34 in step 72 to a location 
determined by the interpolation factor and the current distance between 
the source location and cursor 20. Thus, if the interpolation factor has 
not yet reached its maximum value, text object 34 will be moved toward 
cursor 20 along an imaginary straight line between the source location and 
cursor 20 to a locating determined by the distance multiplied by the 
interpolation factor. Stated another way, during step 72 text object 34 is 
moved to a location determined by a weighted average of the source 
location and the destination location using the interpolation factor. When 
the interpolation factor reaches its maximum value, text object 34 snaps 
to cursor 20. Thereafter, text object 34 follows the movement of cursor 20 
providing a visual impression that text object 34 is attached to cursor 
20. This, in turn, gives the computer user a feeling of physical control. 
In one embodiment, text object 34 is snapped to the lower left hand of 
cursor 20, as shown in FIGS. 3C and 3D. This location prevents text object 
34 from obscuring insertion caret 36 and focuses the computer user's 
attention on insertion caret 36 and cursor 20 while maintaining the strong 
visual impression that text object 34 is attached to cursor 20. Those 
skilled in the art will appreciate that other locations near or on cursor 
20 may also convey the same visual impression. 
After moving text object in step 72, the processing logic advances to step 
74. There the processing logic moves insertion caret 36 if cursor 20 has 
moved. Insertion caret 36 is moved to a location between the two 
characters nearest to cursor 20. This done the processing logic advances 
to step 76. 
During step 76 the processing logic compares the current location of 
insertion caret 36 to its previous location. If insertion caret 36 has not 
moved from its previous location, the processing logic advances to step 
78. There insertion caret 36 is "flashed", or blinked on and off, 
indicating an idle state. On the other hand, if insertion caret 36 changed 
its location during step 74 then the processing logic advances to step 80. 
In step 80 the processing logic determines whether the computer user has 
selected an insertion point, or destination location, for selected text 
30. (As used herein "destination location" refers to the position of 
cursor 20 at the time of a mouse up event.) The processing logic makes 
this determination by discovering whether a mouse up event has occurred. A 
mouse up event necessarily accompanies selection of a destination location 
or insertion point. The location of cursor 20 at the time of the mouse up 
event determines the insertion point for selected text 30. The processing 
logic responds to a mouse up event by branching to step 82. Conversely, 
the absence of a mouse up event indicates that the computer user has not 
yet selected the destination location. The processing logic responds to 
this state of affairs by branching back to the start of the tracking and 
snapping loop, step 68. 
After the mouse up event, with step 82 the processing logic begins the 
process of indicating visually to the computer user the movement of 
selected text 30 from the source location to the destination location. 
This involves three steps. First, the processing logic calculates bounding 
rectangles for selected text 30 at both the source location and the 
destination location. Second, the processing logic zooms from the first 
bounding rectangle at the source location to the second bounding rectangle 
at the destination location. Finally, selected text 30 is displayed at the 
destination location in the third and final step. 
In step 82 the processing logic computes a bounding rectangle for selected 
text 30 at the source location. This step, and the second, are illustrated 
in FIG. 4 using selected text 31; i.e., "Jack and Jill". Bounding 
rectangle 100 is defined by two points of selected text 31: the point 
furthest to the top left and the point furthest to the bottom right. The 
dimensions of bounding rectangle 100 computed, the processing logic 
proceeds to step 84. These points are chosen because the selected text may 
span vertically more than one line. 
In step 84, offscreen the processing logic moves selected text 31 to the 
destination location. As understood by those skilled in the art, computer 
10 maintains in internal memory a copy of the text file that text 
displayed monitor 12 is part of. This copy is said to be "offscreen". 
Thus, it will be understood that the activities of step 84 do not alter 
the text displayed on monitor 12. 
In moving selected text 31 to the destination location in step 84, the 
processing logic performs an intelligent paste, which is also commonly 
referred to as intelligent cut and paste. Intelligent cut and paste is a 
set of editing features that account for the need for spaces between 
words. FIGS. 4A and 4B illustrate how intelligent cut and paste performs. 
In FIG. 4A, insertion caret 102 is the space immediately following the 
word "the". Without intelligent cut and paste, after inserting selected 
text 31 displayed text 33 would not include a space between "Jack" and 
"the" unless selected text 32 includes a space before "Jack". Stated 
another way, without intelligent cut and paste, after inserting selected 
text 31 the sixth line 104 of displayed text 33 would read as "assumed 
theJack". However, using intelligent cut and paste, the sixth line 104 
includes a space between "the" and "Jack," regardless of whether selected 
text 31 includes a space before "Jack". Thus, using intelligent cut and 
paste sixth line 104 reads as "assumed the Jack," as illustrated in FIG. 
4B. 
After moving selected text 31 to the destination location, the processing 
logic emphasizes selected text 31. As a result when the offscreen copy of 
the file is finally displayed, the computer user's attention will be 
called to selected text 31 at the destination location. Selected text 31 
may be emphasized visually in a great many ways, including displaying 
selected text 31 in reverse video. 
Whether selected text 31 is also removed from the source location during 
step 78 depends upon whether the computer user has requested a cut and 
paste or a copy and paste. If a cut and paste operation was selected text 
31 is removed from the source location. Otherwise, selected text 31 
remains at the source location, but it will no longer be de-emphasized. 
The processing logic proceeds to step 86 from step 84. Having moved 
selected text 31 to the destination location, the processing logic now 
computes a bounding rectangle for selected text 31 at the destination 
location. Like bounding rectangle 100, bounding rectangle 104 is defined 
by two points of selected text 31: the point of text furthest to the top 
left and the text point furthest to the bottom right. Given insertion 
point 102, the dimensions of bounding rectangle 104 may vary from those of 
bounding rectangle 100. This is the case in FIG. 4B. 
Preparations for zooming complete, the processing logic branches to step 88 
from step 86. In step 88, the processing logic zooms from selected text 31 
at the source location to selected text 31 at the destination location. 
Zooming is a well known visual effect that animates the movement of an 
object between two points on monitor 12. Methods for animating zooms are 
well known and will not be described in detail herein. The dimensions of 
bounding rectangles 100 and 104 are provided to a zoom processor. Given 
these, the zoom starts with a bounding rectangle 100 displayed near the 
source location. Two or more rectangles are displayed on monitor 12 at a 
time, each successive rectangle more closely approaching the dimensions 
and final location of bounding rectangle 104. FIG. 4C attempts to 
illustrate this idea. The dimensions of intervening rectangle 106 differ 
slightly from those bounding rectangle 100, just starting to approach 
those of bounding rectangle 104. Similarly, the dimensions of intervening 
rectangle 108 differ from those of intervening rectangle 106, approaching 
more closely the dimensions of bounding rectangle 104. The zooms ends with 
the display of bounding rectangle 104 near the destination location. 
The processing logic advances to step 90 after the zoom is complete. There 
the processing logic displays onscreen selected text 31 at the destination 
location. Following as it does the zoom, the effect of step 78 is that the 
zoom drops selected text 31 at the destination location. 
The processing logic branches to step 92 from step 90 to await activation 
again. 
Additional visual feedback may be provided to the computer user to 
emphasize that selected text 30 may be dragged within a window, or between 
windows. Displaying cursor 20 as an arrow, rather than an I-beam, while 
cursor 20 is over selected text 30 emphasizes this fact. FIG. 5 
illustrates in flow diagram form a method for doing so as a background 
process. 
The processing logic begins in step 110 by determining whether cursor 20 is 
over selected text 30. If cursor 20 is not, the processing logic branches 
to step 112. There cursor 20 is displayed as an I-beam. On the other hand, 
if cursor 20 is over selected text 30, the processing logic advances to 
step 114. During this step the processing logic displays cursor 20 as an 
arrow, indicating that cursor 20 is over a draggable item. 
Thus, a method and apparatus for providing visual feedback to a computer 
user while manipulating text has been described. The visual feedback 
includes creation of a text object from selected text, tracking the 
insertion point as user moves mouse and zooming the selected text from its 
source location to its destination location. 
In the foregoing specification, the invention has been described with 
reference to specific exemplary embodiments thereof. It will, however, be 
evident that various modifications and changes may be made thereto without 
departing from the broader spirit and scope of the invention as set forth 
in the appended claims. The specification and drawings are, accordingly, 
to be regarded in an illustrative rather than a restrictive sense.