/*
** Routines that deal with indexes
**
** Copyright (C) 1997-2000 D. Richard Hipp
**
** This library is free software; you can redistribute it and/or
** modify it under the terms of the GNU Library General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This library is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** Library General Public License for more details.
**
** You should have received a copy of the GNU Library General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA 02111-1307, USA.
**
** Author contact information:
** drh@acm.org
** http://www.hwaci.com/drh/
*/
#include <ctype.h>
#include <tk.h>
#include <string.h>
#include "htmlindex.h"
/*
** Return a pointer to the Nth HtmlElement in the list. If there
** is no Nth element, return 0 if flag==0 and return either the first
** or last element (whichever is closest) if flag!=0
*/
HtmlElement *HtmlTokenByIndex(HtmlWidget *htmlPtr, int N, int flag){
HtmlElement *p;
int n;
if( N > htmlPtr->nToken/2 ){
/* Start at the end and work back toward the beginning */
for(p=htmlPtr->pLast, n=htmlPtr->nToken; p; p=p->base.pPrev){
if( p->base.type!=Html_Block ){
if( n==N ){ TestPoint(0); break; }
n--;
TestPoint(0);
}else{
TestPoint(0);
}
}
}else{
/* Start at the beginning and work forward */
for(p=htmlPtr->pFirst; p; p = p->base.pNext){
if( p->base.type!=Html_Block ){
N--;
if( N<=0 ){ TestPoint(0); break; }
}else{
TestPoint(0);
}
}
}
return p;
}
/*
** Return the token number for the given HtmlElement
*/
int HtmlTokenNumber(HtmlElement *p){
int n = 0;
while( p ){
if( p->base.type!=Html_Block ){
TestPoint(0);
n++;
}else{
TestPoint(0);
}
p = p->base.pPrev;
}
return n;
}
/*
** Find the maximum index for the given token
*/
static void maxIndex(HtmlElement *p, int *pIndex){
if( p==0 ){
*pIndex = 0;
TestPoint(0);
}else{
switch( p->base.type ){
case Html_Text:
*pIndex = p->base.count-1;
TestPoint(0);
break;
case Html_Space:
if( p->base.style.flags & STY_Preformatted ){
*pIndex = p->base.count-1;
TestPoint(0);
}else{
*pIndex = 0;
TestPoint(0);
}
break;
default:
*pIndex = 0;
TestPoint(0);
break;
}
}
}
/*
** Given a Block and an x coordinate, find the Index of the character
** that is closest to the given x coordinate.
**
** The x-coordinate might specify a point to the left of the block,
** in which case the procedure returns the first token and a character
** index of 0. Or the x-coordinate might specify a point to the right
** of the block, in which case the last token is returned with an index
** equal to its last character.
*/
static void FindIndexInBlock(
HtmlWidget *htmlPtr, /* The widget */
HtmlBlock *pBlock, /* The block */
int x, /* The x coordinate */
HtmlElement **ppToken, /* Write the closest token here */
int *pIndex /* Write the charater index in ppToken here */
){
HtmlElement *p;
Tk_Font font;
int len;
int n;
p = pBlock->base.pNext;
HtmlLock(htmlPtr);
font = HtmlGetFont(htmlPtr, p->base.style.font);
if( HtmlUnlock(htmlPtr) ){
*ppToken = p;
*pIndex = 0;
return;
}
if( x <= pBlock->left ){
*ppToken = p;
*pIndex = 0;
TestPoint(0);
return;
}else if( x>= pBlock->right ){
*ppToken = p;
*pIndex = 0;
while( p && p->base.type!=Html_Block ){
*ppToken = p;
p = p->base.pNext;
TestPoint(0);
}
p = *ppToken;
if( p && p->base.type==Html_Text ){
*pIndex = p->base.count - 1;
TestPoint(0);
}else{
TestPoint(0);
}
return;
}
if( pBlock->n==0 ){
*ppToken = p;
*pIndex = 0;
TestPoint(0);
}else{
TestPoint(0);
}
n = Tk_MeasureChars(font, pBlock->z, pBlock->n, x - pBlock->left, 0, &len);
*pIndex = 0;
*ppToken = 0;
while( p && n>=0 ){
switch( p->base.type ){
case Html_Text:
if( n<p->base.count ){
*pIndex = n;
TestPoint(0);
}else{
*pIndex = p->base.count - 1;
TestPoint(0);
}
*ppToken = p;
n -= p->base.count;
break;
case Html_Space:
if( p->base.style.flags & STY_Preformatted ){
if( n<p->base.count ){
*pIndex = n;
TestPoint(0);
}else{
*pIndex = p->base.count - 1;
TestPoint(0);
}
*ppToken = p;
n -= p->base.count;
}else{
*pIndex = 0;
*ppToken = p;
n--;
TestPoint(0);
}
break;
default:
TestPoint(0);
break;
}
if( p ){
p = p->base.pNext;
TestPoint(0);
}else{
TestPoint(0);
}
}
}
/*
** Convert an Element-based index into a Block-based index.
**
** In other words, given a pointer to an element and an index
** of a particular character within that element, compute a
** pointer to the HtmlBlock used to display that character and
** the index in the HtmlBlock of the character.
*/
void HtmlIndexToBlockIndex(
HtmlWidget *htmlPtr, /* The widget */
HtmlIndex sIndex, /* The index to be translated */
HtmlBlock **ppBlock, /* Write the corresponding block here */
int *piIndex /* Write the block index here */
){
int n = sIndex.i;
HtmlElement *p;
if( sIndex.p==0 ){
*ppBlock = 0;
*piIndex = 0;
TestPoint(0);
return;
}
p = sIndex.p->base.pPrev;
while( p && p->base.type!=Html_Block ){
switch( p->base.type ){
case Html_Text:
n += p->base.count;
TestPoint(0);
break;
case Html_Space:
if( p->base.style.flags & STY_Preformatted ){
n += p->base.count;
TestPoint(0);
}else{
n++;
TestPoint(0);
}
break;
default:
TestPoint(0);
break;
}
p = p->base.pPrev;
}
if( p ){
*ppBlock = &p->block;
*piIndex = n;
TestPoint(0);
return;
}
for(p=sIndex.p; p && p->base.type!=Html_Block; p=p->base.pNext){
TestPoint(0);
}
*ppBlock = &p->block;
*piIndex = 0;
}
/*
** Given a base index name (without any modifiers) return a pointer
** to the token described, and the character within that token.
**
** Valid input forms include:
**
** N.M Token number N (with numbering starting at 1) and
** character number M (with numbering starting at 0).
**
** end The end of all text
**
** N.last Last character of token number N.
**
** sel.first First character of the selection.
**
** sel.last Last character of the selection.
**
** ins The character holding the insertion cursor.
**
** @X,Y The character a location X,Y of the clipping window.
**
** Zero is returned if we are successful and non-zero if there is
** any kind of error.
**
** If the given token doesn't exist (for example if there are only 10
** tokens and 11.5 is requested) then *ppToken is left pointing to NULL.
** But the function still returns 0 for success.
*/
static int DecodeBaseIndex(
HtmlWidget *htmlPtr, /* The HTML widget we are dealing with */
const char *zBase, /* The base index string */
HtmlElement **ppToken, /* Write the pointer to the token here */
int *pIndex /* Write the character offset here */
){
int x, y;
int n;
int i;
HtmlElement *p;
HtmlBlock *pBlock;
HtmlBlock *pNearby;
int dist = 1000000;
int rc = 0;
while( isspace(*zBase) ){ TestPoint(0); zBase++; }
switch( *zBase ){
case '1': case '2': case '3': case '4': case '5':
case '6': case '7': case '8': case '9':
n = sscanf(zBase,"%d.%d",&x,&y);
if( n>0 ){
p = *ppToken = HtmlTokenByIndex(htmlPtr, x, 0);
TestPoint(0);
}else{
TestPoint(0);
}
if( n==2 ){
*pIndex = y;
TestPoint(0);
}else{
for(i=1; isdigit(zBase[i]); i++){ TestPoint(0); }
if( zBase[i]==0 ){
*pIndex = 0;
TestPoint(0);
}else if( strcmp(&zBase[i],".last")==0 ){
maxIndex(p,pIndex);
TestPoint(0);
}else{
rc = 1;
TestPoint(0);
}
}
break;
case 'e':
if( strcmp(zBase,"end")==0 ){
p = *ppToken = htmlPtr->pLast;
maxIndex(p,pIndex);
TestPoint(0);
}else{
rc = 1;
TestPoint(0);
}
break;
case 's':
if( strcmp(zBase,"sel.first")==0 ){
*ppToken = htmlPtr->selBegin.p;
*pIndex = htmlPtr->selBegin.i;
TestPoint(0);
}else if( strcmp(zBase,"sel.last")==0 ){
*ppToken = htmlPtr->selEnd.p;
*pIndex = htmlPtr->selEnd.i;
TestPoint(0);
}else{
rc = 1;
TestPoint(0);
}
break;
case 'i':
if( strcmp(zBase,"insert")==0 ){
*ppToken = htmlPtr->ins.p;
*pIndex = htmlPtr->ins.i;
TestPoint(0);
}else{
rc = 1;
TestPoint(0);
}
break;
case '@':
n = sscanf(zBase,"@%d,%d",&x,&y);
if( n!=2 ){
rc = 1;
TestPoint(0);
break;
}
x += htmlPtr->xOffset;
y += htmlPtr->yOffset;
pNearby = 0;
*ppToken = htmlPtr->pLast;
*pIndex = 0;
for(pBlock=htmlPtr->firstBlock; pBlock; pBlock=pBlock->pNext){
int dotest;
if( pBlock->n==0 ){
switch( pBlock->base.pNext->base.type ){
case Html_LI:
case Html_IMG:
case Html_INPUT:
case Html_TEXTAREA:
case Html_SELECT:
dotest = 1;
TestPoint(0);
break;
default:
dotest = 0;
TestPoint(0);
break;
}
}else{
dotest = 1;
TestPoint(0);
}
if (dotest){
if( pBlock->top <= y && pBlock->bottom >= y ){
if( pBlock->left > x ){
if( pBlock->left - x < dist ){
dist = pBlock->left - x;
pNearby = pBlock;
TestPoint(0);
}else{
TestPoint(0);
}
}else if( pBlock->right < x ){
if( x - pBlock->right < dist ){
dist = x - pBlock->right;
pNearby = pBlock;
TestPoint(0);
}else{
TestPoint(0);
}
}else{
HtmlLock(htmlPtr);
FindIndexInBlock(htmlPtr, pBlock, x, ppToken, pIndex);
if( HtmlUnlock(htmlPtr) ) return 1;
TestPoint(0);
break;
}
}else{
int distY;
int distX;
if( pBlock->bottom < y ){
distY = y - pBlock->bottom;
TestPoint(0);
}else{
distY = pBlock->top - y;
TestPoint(0);
}
if( pBlock->left > x ){
distX = pBlock->left - x;
TestPoint(0);
}else if( pBlock->right < x ){
distX = x - pBlock->right;
TestPoint(0);
}else{
distX = 0;
TestPoint(0);
}
if( distX + 4*distY < dist ){
dist = distX + 4*distY;
pNearby = pBlock;
TestPoint(0);
}else{
TestPoint(0);
}
}
}
}
if( pBlock==0 ){
if( pNearby ){
HtmlLock(htmlPtr);
FindIndexInBlock(htmlPtr, pNearby, x, ppToken, pIndex);
if( HtmlUnlock(htmlPtr) ) return 1;
TestPoint(0);
}else{
TestPoint(0);
}
}else{
TestPoint(0);
}
break;
default:
rc = 1;
TestPoint(0);
break;
}
return rc;
}
/*
** This routine decodes a complete index specification. A complete
** index consists of the base specification followed by modifiers.
*/
int HtmlGetIndex(
HtmlWidget *htmlPtr, /* The widget */
const char *zIndex, /* Complete text of the index spec */
HtmlElement **ppToken, /* Write the pointer to the token here */
int *pIndex /* Write the character offset here */
){
TestPoint(0);
return DecodeBaseIndex(htmlPtr, zIndex, ppToken, pIndex);
}