text: /* vi:set ts=8 sts=4 sw=4:
   *
   * VIM - Vi IMproved	by Bram Moolenaar
   *
   * Do ":help uganda"  in Vim to read copying and usage conditions.
   * Do ":help credits" in Vim to see a list of people who contributed.
   * See README.txt for an overview of the Vim source code.
   */
  
  /*
   * popupmnu.c: Popup menu (PUM)
   */
  #include "vim.h"
  
  #if defined(FEAT_INS_EXPAND) || defined(PROTO)
  
  static pumitem_T *pum_array = NULL;	/* items of displayed pum */
  static int pum_size;			/* nr of items in "pum_array" */
  static int pum_selected;		/* index of selected item or -1 */
  static int pum_first = 0;		/* index of top item */
  
  static int pum_height;			/* nr of displayed pum items */
  static int pum_width;			/* width of displayed pum items */
  static int pum_base_width;		/* width of pum items base */
  static int pum_kind_width;		/* width of pum items kind column */
  static int pum_scrollbar;		/* TRUE when scrollbar present */
  
  static int pum_row;			/* top row of pum */
  static int pum_col;			/* left column of pum */
  
  static int pum_do_redraw = FALSE;	/* do redraw anyway */
  
  static int pum_set_selected __ARGS((int n, int repeat));
  
  #define PUM_DEF_HEIGHT 10
  #define PUM_DEF_WIDTH  15
  
  /*
   * Show the popup menu with items "array[size]".
   * "array" must remain valid until pum_undisplay() is called!
   * When possible the leftmost character is aligned with screen column "col".
   * The menu appears above the screen line "row" or at "row" + "height" - 1.
   */
      void
  pum_display(array, size, selected)
      pumitem_T	*array;
      int		size;
      int		selected;	/* index of initially selected item, none if
  				   out of range */
  {
      int		w;
      int		def_width;
      int		max_width;
      int		kind_width;
      int		extra_width;
      int		i;
      int		top_clear;
      int		row;
      int		context_lines;
      int		col;
      int		above_row = cmdline_row;
      int		redo_count = 0;
  
  redo:
      def_width = PUM_DEF_WIDTH;
      max_width = 0;
      kind_width = 0;
      extra_width = 0;
  
      /* Pretend the pum is already there to avoid that must_redraw is set when
       * 'cuc' is on. */
      pum_array = (pumitem_T *)1;
      validate_cursor_col();
      pum_array = NULL;
  
      row = curwin->w_wrow + W_WINROW(curwin);
  
      if (firstwin->w_p_pvw)
  	top_clear = firstwin->w_height;
      else
  	top_clear = 0;
  
      /* When the preview window is at the bottom stop just above it.  Also
       * avoid drawing over the status line so that it's clear there is a window
       * boundary. */
      if (lastwin->w_p_pvw)
  	above_row -= lastwin->w_height + lastwin->w_status_height + 1;
  
      /*
       * Figure out the size and position of the pum.
       */
      if (size < PUM_DEF_HEIGHT)
  	pum_height = size;
      else
  	pum_height = PUM_DEF_HEIGHT;
      if (p_ph > 0 && pum_height > p_ph)
  	pum_height = p_ph;
  
      /* Put the pum below "row" if possible.  If there are few lines decide on
       * where there is more room. */
      if (row  + 2 >= above_row - pum_height
  					 && row > (above_row - top_clear) / 2)
      {
  	/* pum above "row" */
  
  	/* Leave two lines of context if possible */
  	if (curwin->w_wrow - curwin->w_cline_row >= 2)
  	    context_lines = 2;
  	else
  	    context_lines = curwin->w_wrow - curwin->w_cline_row;
  
  	if (row >= size + context_lines)
  	{
  	    pum_row = row - size - context_lines;
  	    pum_height = size;
  	}
  	else
  	{
  	    pum_row = 0;
  	    pum_height = row - context_lines;
  	}
  	if (p_ph > 0 && pum_height > p_ph)
  	{
  	    pum_row += pum_height - p_ph;
  	    pum_height = p_ph;
  	}
      }
      else
      {
  	/* pum below "row" */
  
  	/* Leave two lines of context if possible */
  	if (curwin->w_cline_row + curwin->w_cline_height - curwin->w_wrow >= 3)
  	    context_lines = 3;
  	else
  	    context_lines = curwin->w_cline_row
  				+ curwin->w_cline_height - curwin->w_wrow;
  
  	pum_row = row + context_lines;
  	if (size > above_row - pum_row)
  	    pum_height = above_row - pum_row;
  	else
  	    pum_height = size;
  	if (p_ph > 0 && pum_height > p_ph)
  	    pum_height = p_ph;
      }
  
      /* don't display when we only have room for one line */
      if (pum_height < 1 || (pum_height == 1 && size > 1))
  	return;
  
      /* If there is a preview window at the top avoid drawing over it. */
      if (firstwin->w_p_pvw
  	    && pum_row < firstwin->w_height
  	    && pum_height > firstwin->w_height + 4)
      {
  	pum_row += firstwin->w_height;
  	pum_height -= firstwin->w_height;
      }
  
      /* Compute the width of the widest match and the widest extra. */
      for (i = 0; i < size; ++i)
      {
  	w = vim_strsize(array[i].pum_text);
  	if (max_width < w)
  	    max_width = w;
  	if (array[i].pum_kind != NULL)
  	{
  	    w = vim_strsize(array[i].pum_kind) + 1;
  	    if (kind_width < w)
  		kind_width = w;
  	}
  	if (array[i].pum_extra != NULL)
  	{
  	    w = vim_strsize(array[i].pum_extra) + 1;
  	    if (extra_width < w)
  		extra_width = w;
  	}
      }
      pum_base_width = max_width;
      pum_kind_width = kind_width;
  
      /* Calculate column */
  #ifdef FEAT_RIGHTLEFT
      if (curwin->w_p_rl)
  	col = W_WINCOL(curwin) + W_WIDTH(curwin) - curwin->w_wcol - 1;
      else
  #endif
  	col = W_WINCOL(curwin) + curwin->w_wcol;
  
      /* if there are more items than room we need a scrollbar */
      if (pum_height < size)
      {
  	pum_scrollbar = 1;
  	++max_width;
      }
      else
  	pum_scrollbar = 0;
  
      if (def_width < max_width)
  	def_width = max_width;
  
      if (((col < Columns - PUM_DEF_WIDTH || col < Columns - max_width)
  #ifdef FEAT_RIGHTLEFT
  		&& !curwin->w_p_rl)
  	    || (curwin->w_p_rl && (col > PUM_DEF_WIDTH || col > max_width)
  #endif
         ))
      {
  	/* align pum column with "col" */
  	pum_col = col;
  
  #ifdef FEAT_RIGHTLEFT
  	if (curwin->w_p_rl)
  	    pum_width = pum_col - pum_scrollbar + 1;
  	else
  #endif
  	    pum_width = Columns - pum_col - pum_scrollbar;
  
  	if (pum_width > max_width + kind_width + extra_width + 1
  						 && pum_width > PUM_DEF_WIDTH)
  	{
  	    pum_width = max_width + kind_width + extra_width + 1;
  	    if (pum_width < PUM_DEF_WIDTH)
  		pum_width = PUM_DEF_WIDTH;
  	}
      }
      else if (Columns < def_width)
      {
  	/* not enough room, will use what we have */
  #ifdef FEAT_RIGHTLEFT
  	if (curwin->w_p_rl)
  	    pum_col = Columns - 1;
  	else
  #endif
  	    pum_col = 0;
  	pum_width = Columns - 1;
      }
      else
      {
  	if (max_width > PUM_DEF_WIDTH)
  	    max_width = PUM_DEF_WIDTH;	/* truncate */
  #ifdef FEAT_RIGHTLEFT
  	if (curwin->w_p_rl)
  	    pum_col = max_width - 1;
  	else
  #endif
  	    pum_col = Columns - max_width;
  	pum_width = max_width - pum_scrollbar;
      }
  
      pum_array = array;
      pum_size = size;
  
      /* Set selected item and redraw.  If the window size changed need to redo
       * the positioning.  Limit this to two times, when there is not much
       * room the window size will keep changing. */
      if (pum_set_selected(selected, redo_count) && ++redo_count <= 2)
  	goto redo;
  }
  
  /*
   * Redraw the popup menu, using "pum_first" and "pum_selected".
   */
      void
  pum_redraw()
  {
      int		row = pum_row;
      int		col;
      int		attr_norm = highlight_attr[HLF_PNI];
      int		attr_select = highlight_attr[HLF_PSI];
      int		attr_scroll = highlight_attr[HLF_PSB];
      int		attr_thumb = highlight_attr[HLF_PST];
      int		attr;
      int		i;
      int		idx;
      char_u	*s;
      char_u	*p = NULL;
      int		totwidth, width, w;
      int		thumb_pos = 0;
      int		thumb_heigth = 1;
      int		round;
      int		n;
  
      if (pum_scrollbar)
      {
  	thumb_heigth = pum_height * pum_height / pum_size;
  	if (thumb_heigth == 0)
  	    thumb_heigth = 1;
  	thumb_pos = (pum_first * (pum_height - thumb_heigth)
  			    + (pum_size - pum_height) / 2)
  						    / (pum_size - pum_height);
      }
  
      for (i = 0; i < pum_height; ++i)
      {
  	idx = i + pum_first;
  	attr = (idx == pum_selected) ? attr_select : attr_norm;
  
  	/* prepend a space if there is room */
  #ifdef FEAT_RIGHTLEFT
  	if (curwin->w_p_rl)
  	{
  	    if (pum_col < W_WINCOL(curwin) + W_WIDTH(curwin) - 1)
  		screen_putchar(' ', row, pum_col + 1, attr);
  	}
  	else
  #endif
  	    if (pum_col > 0)
  		screen_putchar(' ', row, pum_col - 1, attr);
  
  	/* Display each entry, use two spaces for a Tab.
  	 * Do this 3 times: For the main text, kind and extra info */
  	col = pum_col;
  	totwidth = 0;
  	for (round = 1; round <= 3; ++round)
  	{
  	    width = 0;
  	    s = NULL;
  	    switch (round)
  	    {
  		case 1: p = pum_array[idx].pum_text; break;
  		case 2: p = pum_array[idx].pum_kind; break;
  		case 3: p = pum_array[idx].pum_extra; break;
  	    }
  	    if (p != NULL)
  		for ( ; ; mb_ptr_adv(p))
  		{
  		    if (s == NULL)
  			s = p;
  		    w = ptr2cells(p);
  		    if (*p == NUL || *p == TAB || totwidth + w > pum_width)
  		    {
  			/* Display the text that fits or comes before a Tab.
  			 * First convert it to printable characters. */
  			char_u	*st;
  			int	saved = *p;
  
  			*p = NUL;
  			st = transstr(s);
  			*p = saved;
  #ifdef FEAT_RIGHTLEFT
  			if (curwin->w_p_rl)
  			{
  			    if (st != NULL)
  			    {
  				char_u	*rt = reverse_text(st);
  
  				if (rt != NULL)
  				{
  				    char_u	*rt_start = rt;
  				    int		size;
  
  				    size = vim_strsize(rt);
  				    if (size > pum_width)
  				    {
  					do
  					{
  					    size -= has_mbyte
  						    ? (*mb_ptr2cells)(rt) : 1;
  					    mb_ptr_adv(rt);
  					} while (size > pum_width);
  
  					if (size < pum_width)
  					{
  					    /* Most left character requires
  					     * 2-cells but only 1 cell is
  					     * available on screen.  Put a
  					     * '<' on the left of the pum
  					     * item */
  					    *(--rt) = '<';
  					    size++;
  					}
  				    }
  				    screen_puts_len(rt, (int)STRLEN(rt),
  						   row, col - size + 1, attr);
  				    vim_free(rt_start);
  				}
  				vim_free(st);
  			    }
  			    col -= width;
  			}
  			else
  #endif
  			{
  			    if (st != NULL)
  			    {
  				screen_puts_len(st, (int)STRLEN(st), row, col,
  									attr);
  				vim_free(st);
  			    }
  			    col += width;
  			}
  
  			if (*p != TAB)
  			    break;
  
  			/* Display two spaces for a Tab. */
  #ifdef FEAT_RIGHTLEFT
  			if (curwin->w_p_rl)
  			{
  			    screen_puts_len((char_u *)"  ", 2, row, col - 1,
  									attr);
  			    col -= 2;
  			}
  			else
  #endif
  			{
  			    screen_puts_len((char_u *)"  ", 2, row, col, attr);
  			    col += 2;
  			}
  			totwidth += 2;
  			s = NULL;	    /* start text at next char */
  			width = 0;
  		    }
  		    else
  			width += w;
  		}
  
  	    if (round > 1)
  		n = pum_kind_width + 1;
  	    else
  		n = 1;
  
  	    /* Stop when there is nothing more to display. */
  	    if (round == 3
  		    || (round == 2 && pum_array[idx].pum_extra == NULL)
  		    || (round == 1 && pum_array[idx].pum_kind == NULL
  					  && pum_array[idx].pum_extra == NULL)
  		    || pum_base_width + n >= pum_width)
  		break;
  #ifdef FEAT_RIGHTLEFT
  	    if (curwin->w_p_rl)
  	    {
  		screen_fill(row, row + 1, pum_col - pum_base_width - n + 1,
  						    col + 1, ' ', ' ', attr);
  		col = pum_col - pum_base_width - n + 1;
  	    }
  	    else
  #endif
  	    {
  		screen_fill(row, row + 1, col, pum_col + pum_base_width + n,
  							      ' ', ' ', attr);
  		col = pum_col + pum_base_width + n;
  	    }
  	    totwidth = pum_base_width + n;
  	}
  
  #ifdef FEAT_RIGHTLEFT
  	if (curwin->w_p_rl)
  	    screen_fill(row, row + 1, pum_col - pum_width + 1, col + 1, ' ',
  								    ' ', attr);
  	else
  #endif
  	    screen_fill(row, row + 1, col, pum_col + pum_width, ' ', ' ',
  									attr);
  	if (pum_scrollbar > 0)
  	{
  #ifdef FEAT_RIGHTLEFT
  	    if (curwin->w_p_rl)
  		screen_putchar(' ', row, pum_col - pum_width,
  			i >= thumb_pos && i < thumb_pos + thumb_heigth
  						  ? attr_thumb : attr_scroll);
  	    else
  #endif
  		screen_putchar(' ', row, pum_col + pum_width,
  			i >= thumb_pos && i < thumb_pos + thumb_heigth
  						  ? attr_thumb : attr_scroll);
  	}
  
  	++row;
      }
  }
  
  /*
   * Set the index of the currently selected item.  The menu will scroll when
   * necessary.  When "n" is out of range don't scroll.
   * This may be repeated when the preview window is used:
   * "repeat" == 0: open preview window normally
   * "repeat" == 1: open preview window but don't set the size
   * "repeat" == 2: don't open preview window
   * Returns TRUE when the window was resized and the location of the popup menu
   * must be recomputed.
   */
      static int
  pum_set_selected(n, repeat)
      int	    n;
      int	    repeat;
  {
      int	    resized = FALSE;
      int	    context = pum_height / 2;
  
      pum_selected = n;
  
      if (pum_selected >= 0 && pum_selected < pum_size)
      {
  	if (pum_first > pum_selected - 4)
  	{
  	    /* scroll down; when we did a jump it's probably a PageUp then
  	     * scroll a whole page */
  	    if (pum_first > pum_selected - 2)
  	    {
  		pum_first -= pum_height - 2;
  		if (pum_first < 0)
  		    pum_first = 0;
  		else if (pum_first > pum_selected)
  		    pum_first = pum_selected;
  	    }
  	    else
  		pum_first = pum_selected;
  	}
  	else if (pum_first < pum_selected - pum_height + 5)
  	{
  	    /* scroll up; when we did a jump it's probably a PageDown then
  	     * scroll a whole page */
  	    if (pum_first < pum_selected - pum_height + 1 + 2)
  	    {
  		pum_first += pum_height - 2;
  		if (pum_first < pum_selected - pum_height + 1)
  		    pum_first = pum_selected - pum_height + 1;
  	    }
  	    else
  		pum_first = pum_selected - pum_height + 1;
  	}
  
  	/* Give a few lines of context when possible. */
  	if (context > 3)
  	    context = 3;
  	if (pum_height > 2)
  	{
  	    if (pum_first > pum_selected - context)
  	    {
  		/* scroll down */
  		pum_first = pum_selected - context;
  		if (pum_first < 0)
  		    pum_first = 0;
  	    }
  	    else if (pum_first < pum_selected + context - pum_height + 1)
  	    {
  		/* scroll up */
  		pum_first = pum_selected + context - pum_height + 1;
  	    }
  	}
  
  #if defined(FEAT_WINDOWS) && defined(FEAT_QUICKFIX)
  	/*
  	 * Show extra info in the preview window if there is something and
  	 * 'completeopt' contains "preview".
  	 * Skip this when tried twice already.
  	 * Skip this also when there is not much room.
  	 * NOTE: Be very careful not to sync undo!
  	 */
  	if (pum_array[pum_selected].pum_info != NULL
  		&& Rows > 10
  		&& repeat <= 1
  		&& vim_strchr(p_cot, 'p') != NULL)
  	{
  	    win_T	*curwin_save = curwin;
  	    int		res = OK;
  
  	    /* Open a preview window.  3 lines by default.  Prefer
  	     * 'previewheight' if set and smaller. */
  	    g_do_tagpreview = 3;
  	    if (p_pvh > 0 && p_pvh < g_do_tagpreview)
  		g_do_tagpreview = p_pvh;
  	    resized = prepare_tagpreview(FALSE);
  	    g_do_tagpreview = 0;
  
  	    if (curwin->w_p_pvw)
  	    {
  		if (curbuf->b_fname == NULL
  			&& curbuf->b_p_bt[0] == 'n' && curbuf->b_p_bt[2] == 'f'
  			&& curbuf->b_p_bh[0] == 'w')
  		{
  		    /* Already a "wipeout" buffer, make it empty. */
  		    while (!bufempty())
  			ml_delete((linenr_T)1, FALSE);
  		}
  		else
  		{
  		    /* Don't want to sync undo in the current buffer. */
  		    ++no_u_sync;
  		    res = do_ecmd(0, NULL, NULL, NULL, ECMD_ONE, 0, NULL);
  		    --no_u_sync;
  		    if (res == OK)
  		    {
  			/* Edit a new, empty buffer. Set options for a "wipeout"
  			 * buffer. */
  			set_option_value((char_u *)"swf", 0L, NULL, OPT_LOCAL);
  			set_option_value((char_u *)"bt", 0L,
  					       (char_u *)"nofile", OPT_LOCAL);
  			set_option_value((char_u *)"bh", 0L,
  						 (char_u *)"wipe", OPT_LOCAL);
  			set_option_value((char_u *)"diff", 0L,
  							     NULL, OPT_LOCAL);
  		    }
  		}
  		if (res == OK)
  		{
  		    char_u	*p, *e;
  		    linenr_T	lnum = 0;
  
  		    for (p = pum_array[pum_selected].pum_info; *p != NUL; )
  		    {
  			e = vim_strchr(p, '\n');
  			if (e == NULL)
  			{
  			    ml_append(lnum++, p, 0, FALSE);
  			    break;
  			}
  			else
  			{
  			    *e = NUL;
  			    ml_append(lnum++, p, (int)(e - p + 1), FALSE);
  			    *e = '\n';
  			    p = e + 1;
  			}
  		    }
  
  		    /* Increase the height of the preview window to show the
  		     * text, but no more than 'previewheight' lines. */
  		    if (repeat == 0)
  		    {
  			if (lnum > p_pvh)
  			    lnum = p_pvh;
  			if (curwin->w_height < lnum)
  			{
  			    win_setheight((int)lnum);
  			    resized = TRUE;
  			}
  		    }
  
  		    curbuf->b_changed = 0;
  		    curbuf->b_p_ma = FALSE;
  		    curwin->w_cursor.lnum = 1;
  		    curwin->w_cursor.col = 0;
  
  		    if (curwin != curwin_save && win_valid(curwin_save))
  		    {
  			/* Return cursor to where we were */
  			validate_cursor();
  			redraw_later(SOME_VALID);
  
  			/* When the preview window was resized we need to
  			 * update the view on the buffer.  Only go back to
  			 * the window when needed, otherwise it will always be
  			 * redraw. */
  			if (resized)
  			{
  			    win_enter(curwin_save, TRUE);
  			    update_topline();
  			}
  
  			/* Update the screen before drawing the popup menu.
  			 * Enable updating the status lines. */
  			pum_do_redraw = TRUE;
  			update_screen(0);
  			pum_do_redraw = FALSE;
  
  			if (!resized && win_valid(curwin_save))
  			    win_enter(curwin_save, TRUE);
  
  			/* May need to update the screen again when there are
  			 * autocommands involved. */
  			pum_do_redraw = TRUE;
  			update_screen(0);
  			pum_do_redraw = FALSE;
  		    }
  		}
  	    }
  	}
  #endif
      }
  
      /* Never display more than we have */
      if (pum_first > pum_size - pum_height)
  	pum_first = pum_size - pum_height;
  
      if (!resized)
  	pum_redraw();
  
      return resized;
  }
  
  /*
   * Undisplay the popup menu (later).
   */
      void
  pum_undisplay()
  {
      pum_array = NULL;
      redraw_all_later(SOME_VALID);
  #ifdef FEAT_WINDOWS
      redraw_tabline = TRUE;
  #endif
      status_redraw_all();
  }
  
  /*
   * Clear the popup menu.  Currently only resets the offset to the first
   * displayed item.
   */
      void
  pum_clear()
  {
      pum_first = 0;
  }
  
  /*
   * Return TRUE if the popup menu is displayed.
   * Overruled when "pum_do_redraw" is set, used to redraw the status lines.
   */
      int
  pum_visible()
  {
      return !pum_do_redraw && pum_array != NULL;
  }
  
  /*
   * Return the height of the popup menu, the number of entries visible.
   * Only valid when pum_visible() returns TRUE!
   */
      int
  pum_get_height()
  {
      return pum_height;
  }
  
  #endif
  