4.5. Float

The Float command converts a normal selection into a “floating selection”.

A floating selection (sometimes called a “floating layer”) is a type of temporary layer which is similar in function to a normal layer, except that before you can resume working on any other layers in the image, a floating selection must be anchored. That is, you have to attach it to a normal (non-floating) layer, usually the original layer (the one which was active previously), for instance, by clicking on the image outside of the floating selection (see below).

	重要
	You cannot perform any operations on other layers while the image has a floating selection!

You can use various operations to change the image data on the floating selection. There can only be one floating selection in an image at a time.

	提示
	If you display the layer boundary by using the Show Layer Boundary command, you may have difficulty selecting a precise area of the image which you want in a layer. To avoid this problem, you can make a rectangular selection, transform it into a floating selection and anchor it to a new layer. Then simply remove the original layer.

In early versions of GIMP, floating selections were used for performing operations on a limited part of an image. You can do that more easily now with layers, but you can still use this way of working with images.

4.5.1. Activate the Command

• You can access this command from the image menubar through Select → Float,

• or by using the keyboard shortcut Shift+Ctrl+L.

4.5.2. Creating a Floating Selection Automatically

Some image operations create a floating selection automatically:

• The “paste” operations, Paste Named Buffer, Paste or Paste Into, also create a floating selection.

• In addition, the Transform tools, Flip, Shear, Scale, Rotate and Perspective, create a floating selection when they are used on a selection, rather than a layer. When the Affect mode is Transform Layer and a selection already exists, these tools transform the selection and create a floating selection with the result. If a selection does not exist, they transform the current layer and do not create a floating selection. (If the Affect mode is Transform Selection, they also do not create a floating selection.)

• By click-and-dragging a selection while pressing the Ctrl+Alt keys (see 第 2.1 节 “Moving or Resizing a Selection”) you also automatically create a floating selection.

4.5.3. Anchor a Floating Selection

You can anchor a floating selection in various ways:

• You can anchor the floating selection to the current layer the selection is originating from. To do this, click anywhere on the image except on the floating selection. This merges the floating selection with the current layer.

• Or you can use the Anchor layer command (Ctrl+H).

• You can also anchor the floating selection to the current layer by clicking on the anchor button of the Layers dialog, that appears, since GIMP-2.10.18, when the floating selection is created, instead of the default Merge layers icon.

• If you create a New Layer while there is a floating selection, the floating selection is anchored to this newly created layer.