/* Copyright 1996 Acorn Computers Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
  Purpose: management of multiple windows on a Text object.
  Author: W. Stoye
  Status: experimental
          system-independent
  History:
    21-Feb-88: started
    02-Mar-88: WRS: C coding complete.
*/

#define BOOL int
#define TRUE 1
#define FALSE 0

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "trace.h"
#include "werr.h"
#include "txt.h"
#include "EditIntern/txtundo.h"
#include "EditIntern/txt1.h"
#include "EditIntern/txt3.h"

static void txt3_initw(txt t)
{
      txt1_donewmarker(t, &t->w->firstvis);
      txt1_donewmarker(t, &t->w->lastvis);
      txt1_donewmarker(t, &t->w->caret);
      t->w->firstvisy = 0;
      t->w->lastvisy = 0;
      t->w->caretx = 0;
      t->w->carety = 0;
      t->w->caretoffsetx = 0;
      t->w->caretoffsety = 0;
      t->w->ioffset = 0;
      t->w->isize = 0;
}

BOOL txt3_inittxt(txt t)
{
  t->w = malloc(sizeof(txt1_window));
  if (t->w == 0) return FALSE;
  t->windows[1] = t->w;
  t->nwindows = 1;
  t->witer = 0;
  txt3_initw(t);
  return TRUE;
}

BOOL txt3_preparetoaddwindow(txt t)
{
  if (t->nwindows == txt1_MAXWINDOWSPERTEXT) {
    return FALSE;
  } else {
    txt1_window *parent = t->w;

    txt1_domovemarker(t, &t->windows[1]->caret, txt1_dodot(t));
    t->windows[++t->nwindows] = t->windows[1];
    t->w = malloc(sizeof(txt1_window));
    if (t->w == 0) {
      t->nwindows--;
      t->w = t->windows[1];
      return FALSE;
    };
    t->windows[1] = t->w;
    *t->w = *parent; /* initialise all fields similar to parent. */
    txt1_donewmarker(t, &t->w->firstvis);
    txt1_donewmarker(t, &t->w->lastvis);
    txt1_donewmarker(t, &t->w->caret);
#if FALSE
    txt_movemarker(t, (txt_marker*) &t->w->firstvis,
      txt_indexofmarker(t, (txt_marker*) &parent->firstvis));
    txt_movemarker(t, (txt_marker*) &t->w->lastvis,
      txt_indexofmarker(t, (txt_marker*) &parent->lastvis));
#endif
    return TRUE;
  };
}

static txt1_windex txt3__findwindow(txt t, void *handle)
{
  txt1_windex i = 1;

  while (1) {
    if (handle == t->windows[i]->syshandle) {
      tracef1("findwindow returns %i.\n", i);
      return i;
    };
    i++;
#if TRACE
    if (i > txt1_MAXWINDOWSPERTEXT) werr(TRUE, "internal: t-3-1");
#endif
  };
}

BOOL txt3_foreachwindow(txt t)
{
  if (t->witer == t->nwindows) { /* finished */
    t->witer = 0;
    txt3_resetprimarywindow(t);
    tracef0("foreachwindow terminates.\n");
    return FALSE;
  } else {
    t->witer++;
    t->w = t->windows[t->witer];
    tracef1("foreachwindow, setting window %i.\n", (int) t->w);
    return TRUE;
  };
}

void txt3_disposeallwindows(txt t)
{
  while (txt3_foreachwindow(t)) {
    t->w->disposewindow(t);
    free(t->w);
  };
}

void txt3_disposewindow(txt t, txt1_windex wi)
{
  int i;

  tracef3("disposing of window %i %i %i.\n",
    wi, (int) t->windows[wi], (int) t->windows[wi]->syshandle);
  if (wi == 1) {
    txt3_setprimarywindow(t, t->windows[2]->syshandle);
    wi = 2;
  };
  txt1_dodisposemarker(t, &(t->windows[wi]->caret));
  t->w = t->windows[wi];
  t->w->disposewindow(t);
  txt3_resetprimarywindow(t);
  for (i = wi; i < t->nwindows; i++) t->windows[i] = t->windows[i+1];
  t->nwindows--;
  tracef4("windows now %i %i %i, nwindows=%i.\n",
    (int) t->windows[1],
    (int) t->windows[2],
    (int) t->windows[3],
    t->nwindows);
}

static void txt3__setprimarywindowno(txt t, txt1_windex wi)
{
  txt1_window *w2;

  w2 = t->windows[wi];
  t->windows[wi] = t->windows[1];
  t->windows[1] = w2;
  t->w = t->windows[1];
}

void txt3_setprimarywindow(txt t, void *handle)
{
  BOOL display;

  tracef1("set primary window to have %i.\n", (int) handle);
  if (handle == t->windows[1]->syshandle) {
    t->w = t->windows[1]; /* just clear any temporary window. */
    tracef0("window already set.\n");
  } else {
    txt1_domovemarker(t, &t->windows[1]->caret, txt1_dodot(t));
    txt3__setprimarywindowno(t, txt3__findwindow(t, handle));
    display = (0 != (t->charoptionset & txt_DISPLAY));
    t->charoptionset &= ~txt_DISPLAY; /* turn display off */
    txt1_domovedottomarker(t, &t->w->caret);
    if (display) t->charoptionset |= txt_DISPLAY;
    tracef0("set primary window done.\n");
  };
}
/* The move is "secret" in that, taking the change in window into account, no
display update is required for the screen to be entirely correct. The
supression of the simple case is quite important, because otherwise the undo
buffer gets clogged with meaningless movement. */

void txt3_settemporarywindow(txt t, void *handle)
{
  t->w = t->windows[txt3__findwindow(t, handle)];
}

void txt3_resetprimarywindow(txt t)
{
  t->w = t->windows[1];
}

/* end */