/****************************************************************************
 * This module is all new
 * by Rob Nation 
 *
 * This code handles colormaps for fvwm.
 *
 * Copyright 1994 Robert Nation. No restrictions are placed on this code,
 * as long as the copyright notice is preserved . No guarantees or
 * warrantees of any sort whatsoever are given or implied or anything.
 ****************************************************************************/

#include <FVWMconfig.h>

#include <stdio.h>
#include <unistd.h>
#include "fvwm.h"
#include <X11/Xatom.h>
#include "menus.h"
#include "misc.h"
#include "parse.h"
#include "screen.h"
#include "module.h"

FvwmWindow *colormap_win;
Colormap last_cmap = None;
extern FvwmWindow *Tmp_win;

/***********************************************************************
 *
 *  Procedure:
 *	HandleColormapNotify - colormap notify event handler
 *
 * This procedure handles both a client changing its own colormap, and
 * a client explicitly installing its colormap itself (only the window
 * manager should do that, so we must set it correctly).
 *
 ***********************************************************************/
void HandleColormapNotify(void)
{
  XColormapEvent *cevent = (XColormapEvent *) & Event;
  Bool ReInstall = False;


  if (!Tmp_win) {
    return;
  }
  if (cevent->new) {
    XGetWindowAttributes(dpy, Tmp_win->w, &(Tmp_win->attr));
    if ((Tmp_win == colormap_win) && (Tmp_win->number_cmap_windows == 0))
      last_cmap = Tmp_win->attr.colormap;
    ReInstall = True;
  }
    else if ((cevent->state == ColormapUninstalled) &&
	     (last_cmap == cevent->colormap)) {
    /* Some window installed its colormap, change it back */
    ReInstall = True;
  }

  while (XCheckTypedEvent(dpy, ColormapNotify, &Event)) {
    if (XFindContext(dpy, cevent->window,
		     FvwmContext, (caddr_t *) & Tmp_win) == XCNOENT)
      Tmp_win = NULL;
    if ((Tmp_win) && (cevent->new)) {
      XGetWindowAttributes(dpy, Tmp_win->w, &(Tmp_win->attr));
      if ((Tmp_win == colormap_win) && (Tmp_win->number_cmap_windows == 0))
	last_cmap = Tmp_win->attr.colormap;
      ReInstall = True;
    }
      else if ((Tmp_win) &&
	       (cevent->state == ColormapUninstalled) &&
	       (last_cmap == cevent->colormap)) {
      /* Some window installed its colormap, change it back */
      ReInstall = True;
    }
      else if ((Tmp_win) &&
	       (cevent->state == ColormapInstalled) &&
	       (last_cmap == cevent->colormap)) {
      /* The last color map installed was the correct one. Don't 
       * change anything */
      ReInstall = False;
    }
  }

  /* Reinstall the colormap that we think should be installed,
   * UNLESS and unrecognized window has the focus - it might be
   * an override-redirect window that has its own colormap. */
  if ((ReInstall) && (Scr.UnknownWinFocused == None)) {
    XInstallColormap(dpy, last_cmap);
  }
}

/************************************************************************
 *
 * Re-Install the active colormap 
 *
 *************************************************************************/
void ReInstallActiveColormap(void)
{
  InstallWindowColormaps(colormap_win);
}

/***********************************************************************
 *
 *  Procedure:
 *	InstallWindowColormaps - install the colormaps for one fvwm window
 *
 *  Inputs:
 *	type	- type of event that caused the installation
 *	tmp	- for a subset of event types, the address of the
 *		  window structure, whose colormaps are to be installed.
 *
 ************************************************************************/

void InstallWindowColormaps(FvwmWindow * tmp)
{
  int i;
  XWindowAttributes attributes;
  Window w;
  Bool ThisWinInstalled = False;


  /* If no window, then install root colormap */
  if (!tmp)
    tmp = &Scr.FvwmRoot;

  colormap_win = tmp;
  /* Save the colormap to be loaded for when force loading of
   * root colormap(s) ends.
   */
  Scr.pushed_window = tmp;
  /* Don't load any new colormap if root colormap(s) has been
   * force loaded.
   */
  if (Scr.root_pushes) {
    return;
  }

  if (tmp->number_cmap_windows > 0) {
    for (i = tmp->number_cmap_windows - 1; i >= 0; i--) {
      w = tmp->cmap_windows[i];
      if (w == tmp->w)
	ThisWinInstalled = True;
      XGetWindowAttributes(dpy, w, &attributes);

      if (last_cmap != attributes.colormap) {
	last_cmap = attributes.colormap;
	XInstallColormap(dpy, attributes.colormap);
      }
    }
  }

  if (!ThisWinInstalled) {
    if (last_cmap != tmp->attr.colormap) {
      last_cmap = tmp->attr.colormap;
      XInstallColormap(dpy, tmp->attr.colormap);
    }
  }
}


/***********************************************************************
 *
 *  Procedures:
 *	<Uni/I>nstallRootColormap - Force (un)loads root colormap(s)
 *
 *	   These matching routines provide a mechanism to insure that
 *	   the root colormap(s) is installed during operations like
 *	   rubber banding or menu display that require colors from
 *	   that colormap.  Calls may be nested arbitrarily deeply,
 *	   as long as there is one UninstallRootColormap call per
 *	   InstallRootColormap call.
 *
 *	   The final UninstallRootColormap will cause the colormap list
 *	   which would otherwise have be loaded to be loaded, unless
 *	   Enter or Leave Notify events are queued, indicating some
 *	   other colormap list would potentially be loaded anyway.
 ***********************************************************************/
void InstallRootColormap()
{
  FvwmWindow *tmp;
  if (Scr.root_pushes == 0) {
    tmp = Scr.pushed_window;
    InstallWindowColormaps(&Scr.FvwmRoot);
    Scr.pushed_window = tmp;
  }
  Scr.root_pushes++;
  return;
}

/***************************************************************************
 * 
 * Unstacks one layer of root colormap pushing 
 * If we peel off the last layer, re-install th e application colormap
 * 
 ***************************************************************************/
void UninstallRootColormap()
{
  if (Scr.root_pushes)
    Scr.root_pushes--;

  if (!Scr.root_pushes) {
    InstallWindowColormaps(Scr.pushed_window);
  }

  return;
}



/*****************************************************************************
 *
 * Gets the WM_COLORMAP_WINDOWS property from the window
 *   This property typically doesn't exist, but a few applications
 *   use it. These seem to occur mostly on SGI machines.
 *
 ****************************************************************************/
void FetchWmColormapWindows(FvwmWindow * tmp)
{
  if (tmp->cmap_windows != (Window *) NULL)
    XFree((void *) tmp->cmap_windows);

  if (!XGetWMColormapWindows(dpy, tmp->w, &(tmp->cmap_windows),
			     &(tmp->number_cmap_windows))) {
    tmp->number_cmap_windows = 0;
    tmp->cmap_windows = NULL;
  }
}
