A text window is simply an area of the screen set aside for displaying textual information. A typical example is the Output and Error windows seen on the main gap4 screen. See the illustration in section The Output and Error Windows.
The most basic use of text windows is to display data. If the data is large then there will usually be scrollbars on the right and bottom sides of the text display. If the data is of an editable nature (such as the comments in a tag in gap4) we may perform many editing operations on the text. The simplest commands follow.
Arrow keys Moves the editing cursor Left mouse button Sets the editing cursor Middle mouse button Panning - controls both scrollbars at once Alt left mouse button Panning - controls both scrollbars at once Delete Deletes the character to the left of the cursor Most other keys Adds text to the window
In addition to the above, some more advanced features are available,
mostly following the Emacs style of key bindings.
Delete Delete region (when highlighted), otherwise as above Control D Delete character to the right of the cursor Control N Down one line Control P Up one line Control B Move back on character Control F Move forward on character Control A Move to start of line Control E Move to end of line Meta b Move back one word Meta f Move forward one word Meta < Move to start Meta > Move to end Control Up Move up one paragraph Control Down Move down one paragraph Next Move done one page Prev Move up one page Control K Delete to end of line Control T Transpose two characters Drag left button Highlights a region (for cut and paste) Control / Select all (for cut and paste) Control \ Deselect all (for cut and paste)