edit.gml

开放源码的编译器open watcom 1.6.0版的源代码

.*
.* (c) Copyright 1992 by WATCOM International Corp.
.*
.* All rights reserved. No part of this publication may be reproduced or
.* used in any form or by any means - graphic, electronic, or mechanical,
.* including photocopying, recording, taping or information storage and
.* retrieval systems - without written permission of WATCOM Publications
.* Limited.
.*
.* Date		By		Reason
.* ----		--		------
.* 13-may-93	Paul Fast	initial draft
.*
:CHAPTER.Edit Features
.if &ishelp eq 1 .do begin
:SECTION.Overview
.do end
In addition to the various tools,
&imgname provides many very useful edit
features which make image editing quick and easy.  This
chapter discusses these edit features which are found under the
:HILITE.Edit
menu in the menu bar and are displayed on the function bar.
:SECTION.Undo and Redo Operations
The first edit feature that &imgname supplies is a multiple undo and
redo capacity.  The number of operations that &imgname stores is
dependent on the amount of memory available in the current Windows
session, the number of images currently being edited and 
the size of the images being edited.  The storage of large bitmaps
requires more memory than for small images.  Hence the number of
recorded operations for large bitmaps may be less than the number of
operations stored for smaller images.
When &imgname detects that memory is getting low it
discards the oldest operations it has recorded, making room to store
more recent operations.  You can gain a longer operation history by
considering the following rules:
:UL compact.
:LI.close any Windows applications not currently being used as these
expend memory
:LI.have as few images open as possible in &imgname 
:LI.keep the image dimensions small if at all possible
:eUL.
While these rules are useful to bear in mind, the worst that will
happen if they are not followed is that the number of operations
recorded will be less than the total number of operations.  This 
means that you may not be able to undo
:ITALICS.all
operations.
:P.
An operation can be a number of things.  For most of the tools an
operation consists of the time from when the mouse button is pressed
down until it is released.  In general, whenever the image is altered
an operation is recorded.  The exception is the setting of the hot
spot for a cursor.  This operation cannot be undone.  
:P.
To undo an operation select 
:HILITE.Undo
from the 
:HILITE.Edit
menu or hit
:HILITE.Ctrl
and
:HILITE.U
:PERIOD.
Alternatively, you can click on the undo
button in the function bar.  The image will change to the form it
took before the last operation was performed.  You can undo as many
operations as are recorded by &imgname
:PERIOD.
The number of remaining operations will be displayed in the
:ITALICS.hint text
section of the status window.  
:P.
An operation that is undone, can afterwards be redone.  This is
useful if you have changed an image and forget what the change was. 
You are able to undo the operations and then redo them again.  Since
the redo operation undoes an undo operation, the
redo operation can only be performed after an undo operation.  As
soon as an operation is performed
other than an undo, all redo operations
are removed.  As consecutive undo operations are performed, the redo
stack grows.  To redo an undone operation, select
:HILITE.Redo
from the 
:HILITE.Edit
menu or hit
:HILITE.Ctrl
and
:HILITE.R
:PERIOD.
Alternatively, you can click on the redo
button which is beside the undo button on the function bar.  Again,
the
:ITALICS.hint text
will display the number of possible redo operations remaining.

:P.
A final undo operation pertains only to opened files or new files
that have been saved.  The 
:HILITE.Restore
item can be selected from the
:HILITE.Edit
menu to restore an image to its most recently saved
form.  This saves the user
from selecting undo numerous times when much editing has been
performed.  Moreover, if some undo operations get discarded because
of low memory, this function assures the user that the original image can
be restored.

:SECTION.Clipboard Functions
&imgname makes use of the Windows clipboard by allowing users to cut
bitmaps, copy bitmaps and paste bitmaps that exist in the Windows
clipboard into the current image.  The clipboard is consistent
throughout other Windows applications, so, if an application copies a
bitmap to the clipboard, that bitmap is then available to &imgname
:PERIOD.
Hence the clipboard can be thought of as a method for moving bitmaps
between different applications.

:SUBSECT.Cutting and Copying
Cutting and copying are similar operations, both being used in
conjunction with the region selecting tool.  The difference between
the functions is that cutting a region will fill that region with whiteness
and copying a region will leave the image unchanged.  Both functions
copy the selected region to the Windows clipboard. 
To cut a
region, indicate the region to be cut with the region selecting tool.
Select
:HILITE.Cut
from the 
:HILITE.Edit
menu, press
:HILITE.Ctrl-X
or click on the cut button in the function bar shown with the
scissors.  The rectangle that was selected will become white and that
region will be stored in the Windows clipboard.  Selecting
:HILITE.Cut
without a region specified will cut the entire image to the clipboard.
:P.
To copy a selected region, simply select
:HILITE.Copy
from the 
:HILITE.Edit
menu, press
:HILITE.Ctrl-C
or click on the copy button in the function bar.  The rectangle
displaying the selected region will disappear and that region will be
copied to the Windows clipboard; however, the image will not change. 
If a copy is selected without a region specified, the entire image is
copied to the clipboard.  The
:ITALICS.hint text
will display whether the cut or copy was successful.
:eSUBSECT.
:SUBSECT.Pasting from the Clipboard
There are a few variations of pasting images from the
clipboard.  All pasting operations are performed on the current image
being edited.
:P.
The first and most common form of pasting is the normal paste which
one obtains by selecting
:HILITE.Paste
from the 
:HILITE.Edit
menu, pressing
:HILITE.Ctrl-V
key or clicking on the paste button in the function bar.  For the
normal paste, no region should be selected in the current edit
window.  Once the paste operation is selected, the cursor changes to
a pointer and moving it around the edit window shows an outline of
the bitmap to be pasted into the current image.  Moreover, the
:ITALICS.hint text
section of the status window states the dimensions of the bitmap in
the clipboard.  Move the cursor to the position at which the bitmap
should be pasted and click the left mouse button.  This pastes the
bitmap in the position selected over the existing image.  If the
normal paste is selected and you wish to cancel it, you can hit the
:HILITE.ESC
key.
:P.
The second method of pasting involves selecting a region first with
the region selecting tool.  This allows you the flexibility to first
choose the location and size of the pasted bitmap.  Once a region has
been selected, the result of selecting the paste operation depends on
the current settings of the editing session.
&imgname can be set to stretch the
bitmap into the region or clip the bitmap into the region.  The preference
can be set in the