Info Catalog elisp: Quitting Windows elisp: Windows elisp: Window Start and End

elisp: Window Point

 
 27.19 Windows and Point
 =======================
 
 Each window has its own value of point (Point), independent of
 the value of point in other windows displaying the same buffer.  This
 makes it useful to have multiple windows showing one buffer.
 
    • The window point is established when a window is first created; it
      is initialized from the buffer’s point, or from the window point of
      another window opened on the buffer if such a window exists.
 
    • Selecting a window sets the value of point in its buffer from the
      window’s value of point.  Conversely, deselecting a window sets the
      window’s value of point from that of the buffer.  Thus, when you
      switch between windows that display a given buffer, the point value
      for the selected window is in effect in the buffer, while the point
      values for the other windows are stored in those windows.
 
    • As long as the selected window displays the current buffer, the
      window’s point and the buffer’s point always move together; they
      remain equal.
 
    Emacs displays the cursor, by default as a rectangular block, in each
 window at the position of that window’s point.  When the user switches
 to another buffer in a window, Emacs moves that window’s cursor to where
 point is in that buffer.  If the exact position of point is hidden
 behind some display element, such as a display string or an image, Emacs
 displays the cursor immediately before or after that display element.
 
  -- Function: window-point &optional window
      This function returns the current position of point in WINDOW.  For
      a nonselected window, this is the value point would have (in that
      window’s buffer) if that window were selected.  The default for
      WINDOW is the selected window.
 
      When WINDOW is the selected window, the value returned is the value
      of point in that window’s buffer.  Strictly speaking, it would be
      more correct to return the top-level value of point, outside of any
      ‘save-excursion’ forms.  But that value is hard to find.
 
  -- Function: set-window-point window position
      This function positions point in WINDOW at position POSITION in
      WINDOW’s buffer.  It returns POSITION.
 
      If WINDOW is selected, this simply does ‘goto-char’ in WINDOW’s
      buffer.
 
  -- Variable: window-point-insertion-type
      This variable specifies the marker insertion type (Marker
      Insertion Types) of ‘window-point’.  The default is ‘nil’, so
      ‘window-point’ will stay behind text inserted there.
 

Info Catalog elisp: Quitting Windows elisp: Windows elisp: Window Start and End