Provide additional support for child frames

Provide mouse dragging and resizing of frames.  Allow resizing
frames proportionally.  Provide additional functionality for
child frames.  Minor bug fixes.

* lisp/frame.el (frame-border-width, frame-pixel-width)
(frame-pixel-height): Alias to `frame-internal-border-width',
`frame-native-width' and `frame-native-height'.
(frame-inner-width, frame-inner-height, frame-outer-width)
(frame-outer-height): New functions.
* lisp/minibuffer.el (completion-auto-help): Fix typo.
* lisp/mouse.el (mouse-drag-line, mouse-drag-mode-line)
(mouse-drag-header-line): Allow moving a frame by dragging the
mode line of its bottommost window (on a minibuffer-less frame)
or the header line of its topmost window.
(mouse-drag-vertical-line): Mention argument in doc-string.
(mouse-resize-frame, mouse-drag-frame, mouse-drag-left-edge)
(mouse-drag-top-left-corner, mouse-drag-top-edge)
(mouse-drag-top-right-corner, mouse-drag-right-edge)
(mouse-drag-bottom-right-corner, mouse-drag-bottom-edge)
(mouse-drag-bottom-left-corner): New functions for resizing a
frame by dragging its internal border together with
corresponding key bindings.
* lisp/tooltip.el (tooltip-frame-parameters): Add
'no-special-glyphs' to default parameters and update version
tag.
* lisp/window.el (frame-auto-hide-function): Add choice to make
frame invisible and update version tag.
(window--delete): Handle 'auto-hide-function' frame parameter.
(window--maybe-raise-frame): Respect 'no-focus-on-map' and
'no-accept-focus' frame parameters.
(display-buffer--action-function-custom-type): Add
`display-buffer-in-child-frame'.
(display-buffer): Mention `display-buffer-in-child-frame' in
doc-string.
(display-buffer-in-child-frame): New action function for
`display-buffer'.
(window--sanitize-margin): Return zero when MARGIN cannot be
sanitized.
(fit-frame-to-buffer): Major rewrite to handle child frames and
'fit-frame-to-buffer-sizes' and 'fit-frame-to-buffer-margins'
frame parameters.
(window-largest-empty-rectangle--maximums-1)
(window-largest-empty-rectangle--maximums)
(window-largest-empty-rectangle--disjoint-maximums)
(window-largest-empty-rectangle): New functions.

* src/dispextern.h (WINDOW_WANTS_MODELINE_P)
(WINDOW_WANTS_HEADER_LINE_P): Remove.  Functionality is now
provided by corresponding functions window_wants_modeline and
window_wants_header_line in window.c.  Adjust users.
* src/dispnew.c (adjust_glyph_matrix)
(buffer_posn_from_coords): Use window_wants_modeline and
window_wants_header_line instead of WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P.
* src/frame.c (keep_ratio): New function.
(adjust_frame_size): Call keep_ratio for each of F's child
frames.
(make_frame): Initialize no_special_glyphs slot.
(frame_internal_border_part): New function.
(Fframe_pixel_width, Fframe_pixel_height, Fborder_width): Rename
to Fframe_native_width, Fframe_native_height mand
Fframe_internal_border_width.
(frame_parm_table): Add Qno_special_glyphs entry.
(frame_float_type): New enumeration type.
(frame_float): New function to handle frame size and position
ratios.
(x_set_frame_parameters): Handle size and position ratios.
(x_set_no_special_glyphs): New function
(x_figure_window_size): Handle size and position ratios.
(syms_of_frame): Add Qdisplay_monitor_attributes_list,
Qno_special_glyphs, Qframe_edges, Qkeep_ratio, Qwidth_only,
Qheight_only, Qleft_only and Qtop_only.
* src/frame.h (internal_border_part): New enumeration type.
(struct frame): New slot no_special_glyphs.
(FRAME_NO_SPECIAL_GLYPHS): New macro.
* src/gtkutil.c (xg_frame_restack): Return immediately for
GTK versions before 2.18.0.
* src/keyboard.c (internal_border_parts): New array constant.
(make_lispy_position): For frames with border dragging enabled
return internal border part.
(syms_of_keyboard): New symbols Qdrag_internal_border,
Qleft_edge, Qtop_left_corner, Qtop_edge, Qtop_right_corner,
Qright_edge, Qbottom_right_corner, Qbottom_edge and
Qbottom_left_corner.
* src/minibuf.c (read_minibuf_unwind): When exiting the
minibuffer deal with frames that have the 'minibuffer-exit'
parameter set.
(syms_of_minibuf): New symbol Qminibuffer_exit.
* src/nsfns.m (frame_parm_handler): Add entry for
x_set_no_special_glyphs.
(Fx_create_frame): Handle 'no-special-glyphs' parameter.
Intitialize new cursor types for dragging frame borders.
* src/nsterm.h (struct ns_output): Add new cursor types for
dragging frame borders.
* src/w32fns.c (w32_frame_parm_handlers): Add entry for
x_set_no_special_glyphs.
(Fx_create_frame): Handle 'no-special-glyphs' parameter.
Intitialize new cursor types for dragging frame borders.
* src/w32term.h (struct w32_output): Add new cursor types for
dragging frame borders.
* src/window.c (coordinates_in_window)
(Fwindow_line_height, window_internal_height): Use
window_wants_modeline and window_wants_header_line instead of
WINDOW_WANTS_MODELINE_P and WINDOW_WANTS_HEADER_LINE_P.
(Fwindow_lines_pixel_dimensions): New function.
(window_parameter): New function.
(Fwindow_parameter): Call window_parameter.
(window_wants_mode_line, window_wants_header_line): New
functions replacing the macros WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P from dispextern.h.
(syms_of_window): New symbols Qmode_line_format and
Qheader_line_format.
* src/window.h: Reorganize and re-comment macros.  Use
window_wants_modeline and window_wants_header_line instead of
WINDOW_WANTS_MODELINE_P and WINDOW_WANTS_HEADER_LINE_P.
(MINI_NON_ONLY_WINDOW_P, MINI_ONLY_WINDOW_P): Minor rewrite.
(WINDOW_BUFFER): New macro.
(WINDOW_BOX_LEFT_EDGE_COL, WINDOW_BOX_RIGHT_EDGE_COL): Remove.
* src/xdisp.c (window_text_bottom_y, window_box_height)
(window_box, start_display)
(compute_window_start_on_continuation_line)
(try_cursor_movement, redisplay_window)
(try_window_reusing_current_matrix, try_window_id)
(display_line, expose_window): Use window_wants_modeline and
window_wants_header_line instead of WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P.
(pos_visible_p, display_mode_lines): Respect W's
'mode-line-format' and 'header-line-format' window parameters.
(init_iterator): Use window_wants_modeline and
window_wants_header_line instead of WINDOW_WANTS_MODELINE_P and
WINDOW_WANTS_HEADER_LINE_P.  For tip frames respect
no_special_glyphs value.
(note_mouse_highlight): Set frame border cursors when on
internal border.
(x_draw_right_divider, x_draw_bottom_divider): Try to improve
drawing of window dividers.
* src/xfns.c (mouse_cursor): Add entries for border parts.
(mouse_cursor_types): Add entries for cursor types to drag
frame borders.
(INSTALL_CURSOR): Add entries for new cursor types to drag
frame borders.
(Fx_create_frame): Handle 'no-special-glyphs' parameter.
(x_frame_parm_handlers): Add entry for
x_set_no_special_glyphs.
(Vx_window_left_edge_shape, Vx_window_top_left_corner_shape)
(Vx_window_top_edge_shape, Vx_window_top_right_corner_shape)
(Vx_window_right_edge_shape)
(Vx_window_bottom_right_corner_shape)
(Vx_window_bottom_edge_shape)
(Vx_window_bottom_left_corner_shape): New variables.
(x_frame_restack): Call xg_frame_restack only for GTK versions
starting with 2.18.0.
* src/xterm.c (x_free_frame_resources): Remove new cursors for
dragging frame borders.
* src/xterm.h (struct x_output): Add new cursor types for
dragging frame borders.

* doc/lispref/display.texi (Size of Displayed Text): Document
`window-lines-pixel-dimensions'.
* doc/lispref/elisp.texi (Top): Add entry for "Mouse Dragging
Parameters".
* doc/lispref/frames.texi (Frame Size): Replace
frame-pixel-width/-height by frame-native-width/-height.  Add
frame-inner-width/-height and frame-outer-width/-height docs.
(Position Parameters): Describe specifying position as ratios.
Clarify remark about positions relative to bottom/ridge display
edge.
(Size Parameters): Describe specifying sizes as ratios.
Describe 'fit-frame-to-buffer-margins' and
'fit-frame-to-buffer-sizes' parameters.
(Layout Parameters): Describe 'no-special-glyphs' parameter.
(Frame Interaction Parameters): Describe 'auto-hide-function',
'minibuffer-exit' and 'keep-ratio' parameters.
(Mouse Dragging Parameters): New section describing
'drag-internal-border', 'drag-with-header-line',
'drag-with-mode-line', 'snap-width', 'top-visible' and
'bottom-visible' parameters.
(Management Parameters): Mention that `override-redirect' has
no effect on MS Windows.
(Font and Color Parameters): Mention child frames for `alpha'
parameter.
(Child Frames): Rewrite section with description and cross
references to new frame parameters added.
* doc/lispref/modes.texi (Mode Line Basics): Mention
'mode-line-format' and 'header-line-format' window parameters.
* doc/lispref/windows.texi (Resizing Windows): Mention effect
of `fit-frame-to-buffer-margins' for child frames.
(Display Action Functions): New action function
`display-buffer-in-child-frame'.
(Quitting Windows): Mention `make-frame-invisible' as optional
value of `frame-auto-hide-function' and `auto-hide-function'
frame paameter.
(Coordinates and Windows): Describe new function
`window-largest-empty-rectangle'.
(Window Parameters): Describe new parameters 'mode-line-format'
and 'header-line-format'.  Index all window parameters described
in this section.

1 files changed, 122 insertions, 23 deletions

diff --git a/doc/lispref/windows.texi b/doc/lispref/windows.texi
index d9b4b743a3b..eb5c2fc46be 100644
--- a/doc/lispref/windows.texi
+++ b/doc/lispref/windows.texi
@@ -752,6 +752,7 @@ The optional argument @var{pixelwise} non-@code{nil} means to return the
 minimum size of @var{window} counted in pixels.
 @end defun
 
+
 @node Resizing Windows
 @section Resizing Windows
 @cindex window resizing
@@ -943,7 +944,8 @@ help of the two options listed next.
 @defopt fit-frame-to-buffer-margins
 This option can be used to specify margins around frames to be fit by
 @code{fit-frame-to-buffer}.  Such margins can be useful to avoid, for
-example, that such frames overlap the taskbar.
+example, that the resized frame overlaps the taskbar or parts of its
+parent frame.
 
 It specifies the numbers of pixels to be left free on the left, above,
 the right, and below a frame that shall be fit.  The default specifies
@@ -2484,6 +2486,25 @@ the function specified in @code{pop-up-frame-function}
 is added to the newly created frame's parameters.
 @end defun
 
+@defun display-buffer-in-child-frame buffer alist
+This function tries to display @var{buffer} in a child frame
+(@pxref{Child Frames}) of the selected frame, either reusing an existing
+child frame or by making a new one.  If @var{alist} has a non-@code{nil}
+@code{child-frame-parameters} entry, the corresponding value is an alist
+of frame parameters to give the new frame.  A @code{parent-frame}
+parameter specifying the selected frame is provided by default.  If the
+child frame should be or become the child of another frame, a
+corresponding entry must be added to @var{alist}.
+
+The appearance of child frames is largely dependent on the parameters
+provided via @var{alist}.  It is advisable to use at least ratios to
+specify the size (@pxref{Size Parameters}) and the position
+(@pxref{Position Parameters}) of the child frame and to add the
+@code{keep-ratio} in order to make sure that the child frame remains
+visible.  For other parameters that should be considered see @ref{Child
+Frames}.
+@end defun
+
 @defun display-buffer-use-some-frame buffer alist
 This function tries to display @var{buffer} by trying to find a
 frame that meets a predicate (by default any frame other than the
@@ -3124,12 +3145,17 @@ killed.
 The default is to call @code{iconify-frame} (@pxref{Visibility of
 Frames}).  Alternatively, you may specify either @code{delete-frame}
 (@pxref{Deleting Frames}) to remove the frame from its display,
-@code{ignore} to leave the frame unchanged, or any other function that
-can take a frame as its sole argument.
+@code{make-frame-invisible} to make the frame invisible, @code{ignore}
+to leave the frame unchanged, or any other function that can take a
+frame as its sole argument.
 
 Note that the function specified by this option is called only if the
 specified frame contains just one live window and there is at least one
 other frame on the same terminal.
+
+For a particular frame, the value specified here may be overridden by
+that frame's @code{auto-hide-function} frame parameter (@pxref{Frame
+Interaction Parameters}).
 @end defopt
 
 
@@ -4364,13 +4390,12 @@ is off the screen due to horizontal scrolling:
 @cindex coordinate, relative to frame
 @cindex window position
 
-This section describes functions that report the position of a window.
-Most of these functions report positions relative to an origin at the
-native position of the window's frame (@pxref{Frame Geometry}).  Some
-functions report positions relative to the origin of the display of the
-window's frame.  In any case, the origin has the coordinates (0, 0) and
-X and Y coordinates increase rightward and downward
-respectively.
+This section describes functions that report positions of and within a
+window.  Most of these functions report positions relative to an origin
+at the native position of the window's frame (@pxref{Frame Geometry}).
+Some functions report positions relative to the origin of the display of
+the window's frame.  In any case, the origin has the coordinates (0, 0)
+and X and Y coordinates increase rightward and downward respectively.
 
   For the following functions, X and Y coordinates are reported in
 integer character units, i.e., numbers of lines and columns
@@ -4608,6 +4633,49 @@ point in the selected window, it's sufficient to write:
 @end example
 @end defun
 
+The following function returns the largest rectangle that can be
+inscribed in a window without covering text displayed in that window.
+
+@defun window-largest-empty-rectangle &optional window count min-width min-height positions left
+This function calculates the dimensions of the largest empty rectangle
+that can be inscribed in the specified @var{window}'s text area.
+@var{window} must be a live window and defaults to the selected one.
+
+The return value is a triple of the width and the start and end
+y-coordinates of the largest rectangle that can be inscribed into the
+empty space (space not displaying any text) of the text area of
+@var{window}.  No x-coordinates are returned by this function---any such
+rectangle is assumed to end at the right edge of @var{window}'s text
+area.  If no empty space can be found, the return value is @code{nil}.
+
+The optional argument @var{count}, if non-@code{nil}, specifies a
+maximum number of rectangles to return.  This means that the return
+value is a list of triples specifying rectangles with the largest
+rectangle first.  @var{count} can be also a cons cell whose car
+specifies the number of rectangles to return and whose @sc{cdr}, if
+non-@code{nil}, states that all rectangles returned must be disjoint.
+
+The optional arguments @var{min-width} and @var{min-height}, if
+non-@code{nil}, specify the minimum width and height of any rectangle
+returned.
+
+The optional argument @var{positions}, if non-@code{nil}, is a cons cell
+whose @sc{car} specifies the uppermost and whose @sc{cdr} specifies the
+lowermost pixel position that must be covered by any rectangle returned.
+These positions measure from the start of the text area of @var{window}.
+
+The optional argument @var{left}, if non-@code{nil}, means to return
+values suitable for buffers displaying right to left text.  In that
+case, any rectangle returned is assumed to start at the left edge of
+@var{window}'s text area.
+
+Note that this function has to retrieve the dimensions of each line of
+@var{window}'s glyph matrix via @code{window-lines-pixel-dimensions}
+(@pxref{Size of Displayed Text}).  Hence, this function may also return
+@code{nil} when the current glyph matrix of @var{window} is not
+up-to-date.
+@end defun
+
 
 @node Mouse Window Auto-selection
 @section Mouse Window Auto-selection
@@ -4911,37 +4979,45 @@ windows when exiting that function.
 The following parameters are currently used by the window management
 code:
 
-@table @asis
-@item @code{delete-window}
+@table @code
+@item delete-window
+@vindex delete-window, a window parameter
 This parameter affects the execution of @code{delete-window}
 (@pxref{Deleting Windows}).
 
-@item @code{delete-other-windows}
+@item delete-other-windows
+@vindex delete-other-windows, a window parameter
 This parameter affects the execution of @code{delete-other-windows}
 (@pxref{Deleting Windows}).
 
-@item @code{no-delete-other-window}
+@item no-delete-other-window
+@vindex no-delete-other-window, a window parameter
 This parameter marks the window as not deletable by
 @code{delete-other-windows} (@pxref{Deleting Windows}).
 
-@item @code{split-window}
+@item split-window
+@vindex split-window, a window parameter
 This parameter affects the execution of @code{split-window}
 (@pxref{Splitting Windows}).
 
-@item @code{other-window}
+@item other-window
+@vindex other-window, a window parameter
 This parameter affects the execution of @code{other-window}
 (@pxref{Cyclic Window Ordering}).
 
-@item @code{no-other-window}
+@item no-other-window
+@vindex no-other-window, a window parameter
 This parameter marks the window as not selectable by @code{other-window}
 (@pxref{Cyclic Window Ordering}).
 
-@item @code{clone-of}
+@item clone-of
+@vindex clone-of, a window parameter
 This parameter specifies the window that this one has been cloned
 from.  It is installed by @code{window-state-get} (@pxref{Window
 Configurations}).
 
-@item @code{preserved-size}
+@item preserved-size
+@vindex preserved-size, a window parameter
 This parameter specifies a buffer, a direction where @code{nil} means
 vertical and @code{t} horizontal, and a size in pixels.  If this window
 displays the specified buffer and its size in the indicated direction
@@ -4950,7 +5026,8 @@ preserve the size of this window in the indicated direction.  This
 parameter is installed and updated by the function
 @code{window-preserve-size} (@pxref{Preserving Window Sizes}).
 
-@item @code{quit-restore}
+@item quit-restore
+@vindex quit-restore, a window parameter
 This parameter is installed by the buffer display functions
 (@pxref{Choosing Window}) and consulted by @code{quit-restore-window}
 (@pxref{Quitting Windows}).  It contains four elements:
@@ -4981,15 +5058,37 @@ only if it still shows that buffer.
 See the description of @code{quit-restore-window} in @ref{Quitting
 Windows} for details.
 
-@item @code{window-side} @code{window-slot}
+@item window-side window-slot
+@vindex window-side, a window parameter
+@vindex window-slot, a window parameter
 These parameters are used for implementing side windows (@pxref{Side
 Windows}).
 
-@item @code{window-atom}
+@item window-atom
+@vindex window-atom, a window parameter
 This parameter is used for implementing atomic windows, see @ref{Atomic
 Windows}.
 
-@item @code{min-margins}
+@item mode-line-format
+@vindex mode-line-format, a window parameter
+This parameter replaces the value of the buffer-local variable
+@code{mode-line-format} (@pxref{Mode Line Basics}) of this window's
+buffer whenever this window is displayed.  The symbol @code{none} means
+to suppress display of a mode line for this window.  Display and
+contents of the mode line on other windows showing this buffer are not
+affected.
+
+@item header-line-format
+@vindex header-line-format, a window parameter
+This parameter replaces the value of the buffer-local variable
+@code{header-line-format} (@pxref{Mode Line Basics}) of this window's
+buffer whenever this window is displayed.  The symbol @code{none} means
+to suppress display of a header line for this window.  Display and
+contents of the header line on other windows showing this buffer are not
+affected.
+
+@item min-margins
+@vindex min-margins, a window parameter
 The value of this parameter is a cons cell whose @sc{car} and @sc{cdr},
 if non-@code{nil}, specify the minimum values (in columns) for the left
 and right margin of this window.  When present, Emacs will use these