SELECTION
The selection is the area of and image defined by the Selection Marquee. It can be produced several ways:
- doing a Place,
- doing a Paste,
- doing a "Set Selection Marquee" menu function,
- doing a "Set to Stashed Selection Marquee" menu function,
- doing a drag-select with the Selection Marquee paint tool active.
The selection can be moved by pointing at it and dragging, as in most paint programs. It can also be moved by the "Move Selection Marquee" menu item.
The selection can be manipulated by selecting the desired Edit or Palette Menu function. 
If Control Panel:Monitors is set to 256 colors, the selection may not appear with its true colors, since the main image tends to hog the colors for itself. However, once the selection is painted onto the main image, the actual true colors will appear correctly.  
IMPORTANT NOTE: the selection marquee can be in 2 states: 
 (1) Empty: Initially, after being drawn, the selection marquee is "empty". It's just a pointer to a rectangular area in the image. It may be moved without affecting the image by manually dragging it with the Command key held down.
 (2) Contains image: When the selection marquee is dragged to a new location for the first time, or just before any function is executed when there is a selection marquee, the image under the selection marquee is copied into the selection marquee.

Selection Paint Tool: See the "Paint Tools" topic.

Copy:
An Edit Menu command, this puts a copy of the entire image (or the selection rectangle if one is active) into the Clipboard for transfer to other programs or into the Scrapbook. If the image is magnified, it is copied in magnified form.

Cut:
An Edit Menu command, this does a "Copy" (see above) and then a "Clear" (see below).

Paste:
An Edit Menu command, this opens a new window the size of the Clipboard and puts the contents of the clipboard (of type PICT or TEXT) into it if there is no image currently open (similar to doing a "New", setting the size to that of what is on the clipboard, and then doing a Paste). If there is an image currently open, this places the clipboard contents into a selection marquee which "floats" over the current image.

Clear:
An Edit Menu command, this sets the area under the selection marquee to the clear specified in the color swatch in the Image Info window.

Select All:
An Edit Menu command, this will create a Selection Marquee containing the entire image.

Selection Transparency:
An Edit Menu command, this submenu contains options which determine which pixels get overwritten when the current selection is pasted (painted) onto the current image. The pixels which could be affected are positioned “under” the current selection.
- Not Transparent: all the pixels in the current selection will write over the pixels in the current image.
- Color 0: all the pixels in the current selection EXCEPT those with value 0 (usually white) will write over the pixels in the current image.
- White: all the pixels in the current selection EXCEPT the white pixels will write over the pixels in the current image. If the selection has a palette, the first white will be found and used as the definitive "white" pixel.
- Black: all the pixels in the current selection EXCEPT the black pixels will write over the pixels in the current image. If the selection has a palette, the first black will be found and used as the definitive "black" pixel.
- Alpha Channel: each pixel in the current selection will be blended with the corresponding pixel in the current image as follows.
---- Alpha 0: no blending, the current image's pixel will remain intact.
---- Alpha 255: no blending, the current selection's pixel overwrites the image's pixel.
---- Alpha values 1 through 254: blending, from 1 giving the most weight to the selection's pixel, to 254 giving the most weight to the image's pixel. 128 gives a 50-50 blend.
- Background Color: all the pixels in the current selection EXCEPT the Background Color pixels will write over the pixels in the current image. The Background Color is defined in the Palette:Options:Dithering & Background Color dialog box.

Move Selection Marquee:
This command will move the marquee to an absolute position or to a position relative to its current position.
Selecting the "Move Selection Marquee…" function from the Extra Functions popup menu in the Edit Script dialog brings up a dialog which allows you to specify (A) the distance by which to move the current selection or (B) the absolute position for the current selection.
To specify the absolute position, uncheck all the checkboxes and enter the absolute position in the box after the "+". Do this for both the vertical and horizontal position.
To specify the relative position, you may add the current selection's width and a border quantity to its current position. You may also specify what to do when it hits the edge of the current page. You may also do the moving by columns instead of (or in addition to) rows. A special Loop function is provided to make it easy to do all the cells on a page.

The main use for this function would be to perform some operation on a matrix of images which are on the currently open picture.  For example, you have a page on which you are doing a flip book animation. It has 36 cells each 128x128 pixels, and they are spaced evenly across the current picture (page) starting at the upper left corner, going across to the right, and down. Each cell is the same picture, rotated 10 degrees. You want to flip each cell. Make the following script:

Set Selection Marquee (set to 0,0,128,128) or before starting, draw the selection marquee at that location.
LOOP While Selection Marquee Is On Page
Flip Left to Right (or any other operation which works on a selection)
Move Selection Marquee (check "New Left  = Old Left", check "+ width", set + "0", set "Wrap to left" = 0, check "+ height".
LOOP End

Now execute the script. It will flip each cell for you.

- Note:  If you are doing the Loop, it is important that you follow the order indicated in the previous example.
- Wrapping occurs when any part of the selection marquee goes over the edge of the page (current picture). If wrapping occurs, the selection marquee is moved according to the rules you specified in the "Wrap to..." dialog items. Normally when you wrap around the right edge of the page, you would start the next row at column 0 (for the left edge of the selection marquee) and at the row immediately below the bottom of the previous row (check "Wrap to new top = old top + height").

Move Selection Marquee Relative To Page:
This command will move the marquee to a position relative to the page.
Selecting the "Move Selection Marquee Relative To Page…" function from the Extra Functions popup menu in the Edit Script dialog brings up a dialog which allows you to specify the new position as "centered", or as a specific distance from any edge.
The horizontal and vertical positions are set separately. For each dimension, select the desired placing method from the popup menu. If a method requires the entry of a distance from an edge, a box will appear next to the popup; enter the distance from the edge in that box. The Units popup may be used to control the unit of measurement for the distance from the edge.
At the bottom of the dialog the selection marquee's old and new positions are displayed.

Set Selection Marquee:
Available from the Extra Functions popup menu in the Edit Script dialog, this produces the same dialog as clicking on the Selection Marquee Paint Tool. See description under "Paint Tools".

Stash Selection Marquee:
Available from the Extra Functions popup menu in the Edit Script dialog, this stores the current Selection Marquee internally for recall later by "Set To Stashed Marquee". This is useful when the Selection Marquee must be preserved through an operation which clears it such as "Revert To Original".

Set To Stashed Marquee:
Available from the Extra Functions popup menu in the Edit Script dialog, this recalls the internally stashed Selection Marquee (see "Stash Selection Marquee").

Paint Selection On Image:
Available from the Extra Functions popup menu in the Edit Script dialog, this is useful in a script to produce the same effect as holding down the Option key and clicking the mouse while there is an active selection floating over the current image. It "paints" the selection image onto the current image at the location of the Selection Marquee, using the current Selection Transparency Mode.

Copy From Image To Selection:
Available from the Extra Functions popup menu in the Edit Script dialog, this copies the area under the selection marquee into the selection (as opposed to an empty selection marquee). It does not clear the area copied from the image. This is similar to what happens manually when the selection is Option dragged.

Copy+Clear From Image To Selection:
Available from the Extra Functions popup menu in the Edit Script dialog,this copies the area under the selection marquee into the selection (as opposed to an empty selection marquee). It clears the area copied from the image after the copy. This is similar to what happens when the selection is dragged.