Often, the information that you want to display on a computer
is too big to fit on the screen at the same time.
A common way to handle this is to pretend
that the information is on a large piece of paper,
and the part you can view is visible through a window.
The widget that allows you to control
what part of the information is in the window is called
the Scroll Bar since you can think of the information
is being on a large scroll.
Here are some examples of Scroll Bars.
When the cursor enters Bravo's Scroll Bar,
it changes shape to indicate that scrolling is enabled.
Each of the three mouse buttons corresponds
to a scrolling operation.
When a mouse button is depressed,
the cursor shape indicates the enabled scrolling action.
When the mouse button is released,
the command is invoked.
Scroll up moves the line of text adjacent to the cursor
to the top of the document window.
Scroll down moves the line of text
at the top of the document window
to be adjacent to the cursor.
Thumb causes the entire document to jump
to the location in the document corresponding
to the vertical position of the cursor in the Scroll Bar.
The boxed arrow indicates the location
in the document that is currently visible.
In this version of Smalltalk, the scroll bars
pop up when the mouse pointer enters the window.
Scroll Bar has three regions.
The one on the right, clicking there
causes the text to move up.
The one on the left causes to move down.
And the one in the center can be used
to scroll smoothly to arbitrary portions of the total text.
This gray rectangle with respect to the entire Scroll Bar
indicates the fraction of the text that you see.
Scroll bars in Interlisp-D appear on a window
only when they are needed.
The user indicates this by rolling out
of the content area of the window
into either the left or bottom margin.
What appears is a Scroll Bar showing the position
of the material that is visible as a small section, which
is grayed out.
The length of this indicates how much is actually visible.
Scrolling can be done by using the left button for going up,
and the right button for going down.
You scroll farther the farther you are away
from the top of the window.
In addition, the middle button is used to thumb
to the place in the whole document which you want to see.
Releasing there will produce that section of the material.
Notice that when some output is generated,
the length of the grain elevator in the Scroll Bar
stays in proportion to the number of lines
of output in the window.
When the mouse is moved into the Scroll Bar,
the Right Mouse Button can be used to scroll the current line
to the bottom of the window.
And the Left Mouse Button can be used to scroll the current line
to the top of the window.
Holding the button down initiates continuous scrolling
in that direction.
The Middle Button can be used to directly specify
a point in the history to scroll to.
The Xerox Development Environment
provides both vertical and horizontal Scroll Bars.
Scroll Bars are natural regions on the left side of the window.
To scroll up, click the Left Mouse Button
inside the Scroll Bar region.
The cursor changes shape to indicate
the direction of scrolling.
The amount of scrolling is related
to where in the Scroll Bar the cursor is placed.
If the cursor is near the top of the Scroll Bar,
less will be scrolled than if the cursor is near the bottom.
To scroll down, click the Right Mouse Button
down inside the region.
To scroll quickly to a position in the window,
hold both mouse buttons down and then
position the cursor inside the Scroll Bar
at the relative position desired.
In Star and Viewpoint, each window
has a vertical Scroll Bar on the right.
The horizontal Scroll Bar, which is optional,
is at the bottom of the window.
The Scroll Bar has several buttons
to provide scrolling of the window data.
The arrow buttons scroll the data up or down
and left or right in the window.
The Plus button scrolls to the top of the next page,
while the Minus button scrolls to the top
of the previous page.
The thumbing region or elevator is the area between buttons.
It provides feedback about which portion of the document
is currently being viewed and also allows quick access
to any page of the document.
When the Left Mouse Button is pressed over the elevator,
the page number is displayed in a window
at the top of the screen.
Apollo computers Display Manager, or DM,
was one of the first commercially successful window
manager systems.
The DM was designed to be keyboard driven,
as early systems had no mouse.
To scroll a window in the DM, use the scroll keys rather than
a Scroll Bar.
You can scroll left and right as well as up and down.
You may go directly to the top or bottom of a window.
You may go to a specified line number.
And you may go to the location of a search string.
To scroll by one line, click in an arrow.
To repeatedly scroll a line at a time,
hold the mouse button down in a arrow.
Note that the arrows point towards the data that
will be exposed when the arrow is pressed.
To scroll by one window full, click in a gray region.
To repeatedly scroll by window fulls,
hold the mouse button down in a gray region.
To scroll immediately to a desired location,
press in the thumb, drag to the desired location and release.
To abort the scroll, drag out of the Scroll Bar
before releasing the button.
The Cedar document editor, Tioga,
provides vertical Scroll Bars at the left edge
of document windows.
When the cursor enters a Scroll Bar,
the Scroll Bar darkens and the cursor
indicates that scrolling is available.
Each of the three mouse buttons corresponds
to a scrolling operation.
When a mouse button is depressed,
the cursor shape indicates the enabled scrolling action.
When the mouse button is released,
the command is invoked.
Scroll up moves the line of text adjacent to the cursor
to the top of the document window.
Scroll down moves the line of text
at the top of the document window
to be adjacent to the cursor.
Thumb causes display of the location in the document
corresponding to the vertical position of the cursor
in the Scroll Bar.
The gray rectangle indicates the location
in the document which is currently visible.
The Alternate Reality Kit is actually a vast plane.
One can move over the plane by bumping the hand
against the edge of the window.
This can be used to move left or right, up or down.
Now, there are special objects in ARK called teleporters.
Clicking with the Middle Button over a teleporter
causes the hand to hop from one to the other.
This is a useful device for jumping large distances
with a single click.
And can even be used to send objects
through to the other end.
Let's go through ourselves to the other end
and see the object we just sent out.
There it is.
In Viewpoint the Scroll Bar is almost identical to Star,
except for three interesting changes.
First, when thumbing through the document,
the cursors not required to stay inside the thumb in region.
Also, instead of showing the page number
in a window at the top of the screen,
it is now shown in the cursor.
These two changes reduce the hand-eye coordination problems
users were experiencing.
Second, by pressing and holding the Right Mouse
Button inside the elevator, the user
can select a location in the current page by percentage.
Finally, using the Right Mouse Button on the Plus or Minus
buttons moves the document up or down
by a full window rather than a full page.
The Andrew Scroll Bar provides both coarse and fine
grained scrolling of the object being presented.
A left mouse click moves the position of the image
across from the cursor up to the top of its window.
A right mouse click moves the top
of the image down to the position of the cursor.
Scrolling by pages is done by positioning
the cursor near the bottom.
Fine scrolling is done by positioning the cursor
near the top of the Scroll Bar.
Holding down the mouse button results
in continuous scrolling.
Clicking at the top of the Scroll Bar
moves directly to the beginning of the objects image.
Clicking at the bottom of the scroll bar
moves to the end of the image.
The user can also move within the image
by dragging the elevator.
The elevator in the Andrew Scroll Bar
shows what portion of the image is visible.
The relative position and size of the current selection
is also displayed.
The Peridot UI [INAUDIBLE] supplied
a two-dimensional scroll box.
Pressing the left button down in the top arrow
moves the contents one increment.
Pressing on the bottom arrow moves the contents down
one increment.
The contents continue to move as long
as the button is held down.
Pressing on the indicator and dragging it to a point
we will scroll to that part of the file.
Pressing above or below the indicator, but still
inside the bar will scroll by pages in that direction
so long as the button is down.
Direction keys provide the keyboard interface
to Scroll Bars.
One press of an arrow moves the file by one increment.
And holding the key down moves the contents continuously.
Pressing the PAGE UP will move the contents of one window.
Pressing the PAGE DOWN will move the contents down one window.
CONTROL+HOME or CONTROL+END moves the cursor
to the beginning or the end of the file.
OPEN LOOK's Scroll Bars are entirely
operated with the Select Mouse Button.
Clicking on the up arrow and down arrows
moves one line at a time.
Clicking above or below the elevator
scrolls one page backward or forward.
Continuing to hold the Select Mouse Button down
will cause these actions to repeat.
Note that the pointer is pushed along
with the motion of the elevator.
Dragging with the Select button is also
possible for random positioning.
Cable anchors behave as buttons providing a quick method
for scrolling to the beginning and the end of a document.
Scrollers let users view large documents in a window so
then the document.
This is a scroll knob.
Its position within the column indicates which part
of the document we are viewing.
If the user clicks on the column,
the knob jumps to that position and the document moves
accordingly.
If the user drags the knob, the document
smoothly follows his motion.
If the user holds down the ALTERNATE key while dragging
the knob, the document moves more gradually.
This is useful when scrolling through very large documents
in which normal scrolling does not
provide fine enough control.
The size of the scroll knob is proportional to the amount
of the document being viewed.
If we add some text to the document,
a smaller fraction of the document is being viewed
and the knob shrinks in size.
These are scroll buttons.
When a user clicks on these buttons,
the document moves in small increments.
If the buttons are held down, the document continues to move.
If the user holds down the ALTERNATE key while clicking
the buttons, the document moves by window fulls.
Notice that as the cursor moves over the thumb, it highlights.
I can grab the thumb and move up and down showing
updating in real time.
I also have the opportunity to select on the scroll bar
and have the thumb moved to that point.
I can also select an increment button
and have the text increment a line at a time.
If I wish to page up and down, I can hold the SHIFT key down
and select on an increment button.
Motif's Scroll Bars is provide for scrolling
by unit increment, pages, and other groupings.
Pressing Mouse Button One on a Scroll Bar arrow
provides a unit increment.
In a trough, a page increment.
Unit and page scrolling both auto repeat.
Dragging with Mouse Button One pressed in the slider box
scrolls continuously.
The relationship, the size of the thumb in the Scroll
Bar to the entire Scroll Bar shows how much of the document
you are viewing.
So the thumb will dynamically resize
with different data files.
Stepping arrows will move the data one unit at a time.
In this case, it's a line of text at a time.
You can hold down the mouse button
and get an auto repeat effect on the stepping arrows.
You can click above or below the thumb
to move a screen full at a time through data.
You can also press the mouse button on the thumb
and drag it to any portion that you'd like.
When you release, you'll be positioned at that spot.
The SVN Scroll Bar has two sets of stepping arrows.
The inner step set steps one line at a time.
The outer moves you through the hierarchy.
You can see that when you press on the slider in the DECwindows
mail application, you also get a index window, which shows you
where you will be positioned when you release the slider.