gecko-dev/layout/style/nsStyleUtil.cpp

649 lines
20 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (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.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include <math.h>
#include "nsStyleUtil.h"
#include "nsCRT.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsUnitConversion.h"
#include "nsIServiceManager.h"
#include "nsIPref.h"
static NS_DEFINE_CID(kPrefCID, NS_PREF_CID);
#define POSITIVE_SCALE_FACTOR 1.10 /* 10% */
#define NEGATIVE_SCALE_FACTOR .90 /* 10% */
#if DEBUG
#define DUMP_FONT_SIZES 0
#endif
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
/*
* Return the scaling percentage given a font scaler
* Lifted from layutil.c
*/
float nsStyleUtil::GetScalingFactor(PRInt32 aScaler)
{
double scale = 1.0;
double mult;
PRInt32 count;
if(aScaler < 0) {
count = -aScaler;
mult = NEGATIVE_SCALE_FACTOR;
}
else {
count = aScaler;
mult = POSITIVE_SCALE_FACTOR;
}
/* use the percentage scaling factor to the power of the pref */
while(count--) {
scale *= mult;
}
return (float)scale;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
static PRBool gNavAlgorithmPref = PR_FALSE;
static int NavAlgorithmPrefChangedCallback(const char * name, void * closure)
{
nsresult rv;
NS_WITH_SERVICE(nsIPref, prefs, kPrefCID, &rv);
if (NS_SUCCEEDED(rv) && prefs) {
prefs->GetBoolPref(name, &gNavAlgorithmPref);
}
return 0;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
static PRBool UseNewFontAlgorithm()
{
static PRBool once = PR_TRUE;
if (once)
{
once = PR_FALSE;
nsresult rv;
NS_WITH_SERVICE(nsIPref, prefs, kPrefCID, &rv);
if (NS_SUCCEEDED(rv) && prefs) {
prefs->GetBoolPref("font.size.nav4algorithm", &gNavAlgorithmPref);
prefs->RegisterCallback("font.size.nav4algorithm", NavAlgorithmPrefChangedCallback, NULL);
}
}
return (gNavAlgorithmPref ? PR_FALSE : PR_TRUE);
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
/*
* Lifted from winfe/cxdc.cpp
*/
static nscoord OldCalcFontPointSize(PRInt32 aHTMLSize, PRInt32 aBasePointSize,
float aScalingFactor)
{ // lifted directly from Nav 5.0 code to replicate rounding errors
double dFontSize;
switch(aHTMLSize) {
case 1:
dFontSize = 7 * aBasePointSize / 10;
break;
case 2:
dFontSize = 85 * aBasePointSize / 100;
break;
case 3:
dFontSize = aBasePointSize;
break;
case 4:
dFontSize = 12 * aBasePointSize / 10;
break;
case 5:
dFontSize = 3 * aBasePointSize / 2;
break;
case 6:
dFontSize = 2 * aBasePointSize;
break;
case 7:
dFontSize = 3 * aBasePointSize;
break;
default:
if (aHTMLSize < 1) {
dFontSize = (7 * aBasePointSize / 10) / pow(1.1, 1 - aHTMLSize);
}
else { // 7 < aHTMLSize
dFontSize = (3 * aBasePointSize) * pow(1.2, aHTMLSize - 7);
}
}
dFontSize *= aScalingFactor;
if (1.0 < dFontSize) {
return (nscoord)dFontSize;
}
return (nscoord)1;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
static nscoord NewCalcFontPointSize(PRInt32 aHTMLSize, PRInt32 aBasePointSize,
float aScalingFactor, nsIPresContext* aPresContext,
nsFontSizeType aFontSizeType)
{
#define sFontSizeTableMin 9
#define sFontSizeTableMax 16
// This table seems to be the one used by MacIE5. We hope its adoption in Mozilla
// and eventually in WinIE5.5 will help to establish a standard rendering across
// platforms and browsers. For now, it is used only in Strict mode. More can be read
// in the document written by Todd Farhner at:
// http://style.verso.com/font_size_intervals/altintervals.html
//
static PRInt32 sStrictFontSizeTable[sFontSizeTableMax - sFontSizeTableMin + 1][8] =
{
{ 9, 9, 9, 9, 11, 14, 18, 27},
{ 9, 9, 9, 10, 12, 15, 20, 30},
{ 9, 9, 10, 11, 13, 17, 22, 33},
{ 9, 9, 10, 12, 14, 18, 24, 36},
{ 9, 10, 12, 13, 16, 20, 26, 39},
{ 9, 10, 12, 14, 17, 21, 28, 42},
{ 9, 10, 13, 15, 18, 23, 30, 45},
{ 9, 10, 13, 16, 18, 24, 32, 48}
};
// HTML 1 2 3 4 5 6 7
// CSS xxs xs s m l xl xxl
// |
// user pref
//
//------------------------------------------------------------
//
// This table gives us compatibility with WinNav4 for the default fonts only.
// In WinNav4, the default fonts were:
//
// Times/12pt == Times/16px at 96ppi
// Courier/10pt == Courier/13px at 96ppi
//
// The 2 lines below marked "anchored" have the exact pixel sizes used by
// WinNav4 for Times/12pt and Courier/10pt at 96ppi. As you can see, the
// HTML size 3 (user pref) for those 2 anchored lines is 13px and 16px.
//
// All values other than the anchored values were filled in by hand, never
// going below 9px, and maintaining a "diagonal" relationship. See for
// example the 13s -- they follow a diagonal line through the table.
//
static PRInt32 sQuirksFontSizeTable[sFontSizeTableMax - sFontSizeTableMin + 1][8] =
{
{ 9, 9, 9, 9, 11, 14, 18, 28 },
{ 9, 9, 9, 10, 12, 15, 20, 31 },
{ 9, 9, 9, 11, 13, 17, 22, 34 },
{ 9, 9, 10, 12, 14, 18, 24, 37 },
{ 9, 9, 10, 13, 16, 20, 26, 40 }, // anchored (13)
{ 9, 9, 11, 14, 17, 21, 28, 42 },
{ 9, 10, 12, 15, 17, 23, 30, 45 },
{ 9, 10, 13, 16, 18, 24, 32, 48 } // anchored (16)
};
// HTML 1 2 3 4 5 6 7
// CSS xxs xs s m l xl xxl
// |
// user pref
#if 0
//
// These are the exact pixel values used by WinIE5 at 96ppi.
//
{ ?, 8, 11, 12, 13, 16, 21, 32 }, // smallest
{ ?, 9, 12, 13, 16, 21, 27, 40 }, // smaller
{ ?, 10, 13, 16, 18, 24, 32, 48 }, // medium
{ ?, 13, 16, 19, 21, 27, 37, ?? }, // larger
{ ?, 16, 19, 21, 24, 32, 43, ?? } // largest
//
// HTML 1 2 3 4 5 6 7
// CSS ? ? ? ? ? ? ? ?
//
// (CSS not tested yet.)
//
#endif
static PRInt32 sFontSizeFactors[8] = { 60,75,89,100,120,150,200,300 };
static PRInt32 sCSSColumns[7] = {0, 1, 2, 3, 4, 5, 6}; // xxs...xxl
static PRInt32 sHTMLColumns[7] = {1, 2, 3, 4, 5, 6, 7}; // 1...7
double dFontSize;
if (aFontSizeType == eFontSize_HTML) {
aHTMLSize--; // input as 1-7
}
if (aHTMLSize < 0)
aHTMLSize = 0;
else if (aHTMLSize > 6)
aHTMLSize = 6;
PRInt32* column;
switch (aFontSizeType)
{
case eFontSize_HTML: column = sHTMLColumns; break;
case eFontSize_CSS: column = sCSSColumns; break;
}
float t2p;
aPresContext->GetTwipsToPixels(&t2p);
PRInt32 fontSize = NSTwipsToIntPixels(aBasePointSize, t2p);
if ((fontSize >= sFontSizeTableMin) && (fontSize <= sFontSizeTableMax))
{
float p2t;
aPresContext->GetPixelsToTwips(&p2t);
PRInt32 row = fontSize - sFontSizeTableMin;
nsCompatibility mode;
aPresContext->GetCompatibilityMode(&mode);
if (mode == eCompatibility_NavQuirks) {
dFontSize = NSIntPixelsToTwips(sQuirksFontSizeTable[row][column[aHTMLSize]], p2t);
} else {
dFontSize = NSIntPixelsToTwips(sStrictFontSizeTable[row][column[aHTMLSize]], p2t);
}
}
else
{
PRInt32 factor = sFontSizeFactors[column[aHTMLSize]];
dFontSize = (factor * aBasePointSize) / 100;
}
dFontSize *= aScalingFactor;
if (1.0 < dFontSize) {
return (nscoord)dFontSize;
}
return (nscoord)1;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
nscoord nsStyleUtil::CalcFontPointSize(PRInt32 aHTMLSize, PRInt32 aBasePointSize,
float aScalingFactor, nsIPresContext* aPresContext,
nsFontSizeType aFontSizeType)
{
#if DUMP_FONT_SIZES
extern void DumpFontSizes(nsIPresContext* aPresContext);
DumpFontSizes(aPresContext);
#endif
if (UseNewFontAlgorithm())
return NewCalcFontPointSize(aHTMLSize, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType);
else
return OldCalcFontPointSize(aHTMLSize, aBasePointSize, aScalingFactor);
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
PRInt32 nsStyleUtil::FindNextSmallerFontSize(nscoord aFontSize, PRInt32 aBasePointSize,
float aScalingFactor, nsIPresContext* aPresContext,
nsFontSizeType aFontSizeType)
{
PRInt32 index;
PRInt32 indexMin;
PRInt32 indexMax;
PRInt32 fontSize = NSTwipsToFloorIntPoints(aFontSize);
if (aFontSizeType == eFontSize_HTML) {
indexMin = 1;
indexMax = 7;
} else {
indexMin = 0;
indexMax = 6;
}
if (NSTwipsToFloorIntPoints(CalcFontPointSize(indexMin, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType)) < fontSize) {
if (fontSize <= NSTwipsToFloorIntPoints(CalcFontPointSize(indexMax, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType))) { // in HTML table
for (index = indexMax; index > indexMin; index--)
if (fontSize > NSTwipsToFloorIntPoints(CalcFontPointSize(index, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType)))
break;
}
else { // larger than HTML table
return indexMax;
// for (index = 8; ; index++)
// if (fontSize < NSTwipsToFloorIntPoints(CalcFontPointSize(index, aBasePointSize, aScalingFactor, aPresContext))) {
// index--;
// break;
// }
}
}
else { // smaller than HTML table
return indexMin;
// for (index = 0; -25<index ; index--) //prevent infinite loop (bug 17045)
// if (fontSize > NSTwipsToFloorIntPoints(CalcFontPointSize(index, aBasePointSize, aScalingFactor, aPresContext))) {
// break;
// }
}
return index;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
PRInt32 nsStyleUtil::FindNextLargerFontSize(nscoord aFontSize, PRInt32 aBasePointSize,
float aScalingFactor, nsIPresContext* aPresContext,
nsFontSizeType aFontSizeType)
{
PRInt32 index;
PRInt32 indexMin;
PRInt32 indexMax;
PRInt32 fontSize = NSTwipsToFloorIntPoints(aFontSize);
if (aFontSizeType == eFontSize_HTML) {
indexMin = 1;
indexMax = 7;
} else {
indexMin = 0;
indexMax = 6;
}
if (NSTwipsToFloorIntPoints(CalcFontPointSize(indexMin, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType)) <= fontSize) {
if (fontSize < NSTwipsToFloorIntPoints(CalcFontPointSize(indexMax, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType))) { // in HTML table
for (index = indexMin; index < indexMax; index++)
if (fontSize < NSTwipsToFloorIntPoints(CalcFontPointSize(index, aBasePointSize, aScalingFactor, aPresContext, aFontSizeType)))
break;
}
else { // larger than HTML table
return indexMax;
// for (index = 8; ; index++)
// if (fontSize < NSTwipsToFloorIntPoints(CalcFontPointSize(index, aBasePointSize, aScalingFactor, aPresContext)))
// break;
}
}
else { // smaller than HTML table
return indexMin;
// for (index = 0; -25<index ; index--) //prevent infinite loop (bug 17045)
// if (fontSize > NSTwipsToFloorIntPoints(CalcFontPointSize(index, aBasePointSize, aScalingFactor, aPresContext))) {
// index++;
// break;
// }
}
return index;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
PRInt32
nsStyleUtil::ConstrainFontWeight(PRInt32 aWeight)
{
aWeight = ((aWeight < 100) ? 100 : ((aWeight > 900) ? 900 : aWeight));
PRInt32 base = ((aWeight / 100) * 100);
PRInt32 step = (aWeight % 100);
PRBool negativeStep = PRBool(50 < step);
PRInt32 maxStep;
if (negativeStep) {
step = 100 - step;
maxStep = (base / 100);
base += 100;
}
else {
maxStep = ((900 - base) / 100);
}
if (maxStep < step) {
step = maxStep;
}
return (base + ((negativeStep) ? -step : step));
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
const nsStyleColor* nsStyleUtil::FindNonTransparentBackground(nsIStyleContext* aContext,
PRBool aStartAtParent /*= PR_FALSE*/)
{
const nsStyleColor* result = nsnull;
nsIStyleContext* context;
if (aStartAtParent) {
context = aContext->GetParent(); // balance ending release
} else {
context = aContext;
NS_IF_ADDREF(context); // balance ending release
}
NS_ASSERTION( context != nsnull, "Cannot find NonTransparentBackground in a null context" );
while (nsnull != context) {
result = (const nsStyleColor*)context->GetStyleData(eStyleStruct_Color);
if (0 == (result->mBackgroundFlags & NS_STYLE_BG_COLOR_TRANSPARENT)) {
break;
}
else {
nsIStyleContext* last = context;
context = context->GetParent();
NS_RELEASE(last);
}
}
NS_IF_RELEASE(context);
return result;
}
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
#if DUMP_FONT_SIZES
#include "nsIDeviceContext.h"
PRInt32 RoundSize(nscoord aVal, nsIPresContext* aPresContext, bool aWinRounding)
{
PRInt32 lfHeight;
nsIDeviceContext* dc;
aPresContext->GetDeviceContext(&dc);
float app2dev, app2twip, scale;
dc->GetAppUnitsToDevUnits(app2dev);
if (aWinRounding)
{
dc->GetDevUnitsToTwips(app2twip);
dc->GetCanonicalPixelScale(scale);
app2twip *= app2dev * scale;
// This interesting bit of code rounds the font size off to the floor point
// value. This is necessary for proper font scaling under windows.
PRInt32 sizePoints = NSTwipsToFloorIntPoints(nscoord(aVal*app2twip));
float rounded = ((float)NSIntPointsToTwips(sizePoints)) / app2twip;
// round font size off to floor point size to be windows compatible
// this is proper (windows) rounding
// lfHeight = NSToIntRound(rounded * app2dev);
// this floor rounding is to make ours compatible with Nav 4.0
lfHeight = long(rounded * app2dev);
return lfHeight;
}
else
return NSToIntRound(aVal*app2dev);
}
#endif
//------------------------------------------------------------------------------
//
//------------------------------------------------------------------------------
#if DUMP_FONT_SIZES
void DumpFontSizes(nsIPresContext* aPresContext)
{
static gOnce = true;
if (gOnce)
{
gOnce = false;
PRInt32 baseSize;
PRInt32 htmlSize;
PRInt32 cssSize;
nscoord val;
nscoord oldVal;
nsIDeviceContext* dc;
aPresContext->GetDeviceContext(&dc);
float dev2app;
dc->GetDevUnitsToAppUnits(dev2app);
bool doWinRounding = true;
for (short i=0; i<2; i ++)
{
doWinRounding ^= true;
printf("\n\n\n");
printf("---------------------------------------------------------------\n");
printf(" CSS \n");
printf(" Rounding %s\n", (doWinRounding ? "ON" : "OFF"));
printf("---------------------------------------------------------------\n");
printf("\n");
printf("NEW SIZES:\n");
printf("----------\n");
printf(" xx-small x-small small medium large x-large xx-large\n");
for (baseSize = 9; baseSize <= 20; baseSize++) {
printf("%2d: ", baseSize);
for (cssSize = 0; cssSize <= 6; cssSize++) {
val = NewCalcFontPointSize(cssSize, baseSize*dev2app, 1.0f, aPresContext, eFontSize_CSS);
printf("%2d ", RoundSize(val, aPresContext, false));
}
printf("\n");
}
printf("\n");
printf("OLD SIZES:\n");
printf("----------\n");
printf(" xx-small x-small small medium large x-large xx-large\n");
for (baseSize = 9; baseSize <= 20; baseSize++) {
printf("%2d: ", baseSize);
for (cssSize = 0; cssSize <= 6; cssSize++) {
val = OldCalcFontPointSize(cssSize, baseSize*dev2app, 1.0f);
printf("%2d ", RoundSize(val, aPresContext, doWinRounding));
}
printf("\n");
}
printf("\n");
printf("DIFFS:\n");
printf("------\n");
printf(" xx-small x-small small medium large x-large xx-large\n");
for (baseSize = 9; baseSize <= 20; baseSize++) {
printf("%2d: ", baseSize);
for (cssSize = 0; cssSize <= 6; cssSize++) {
oldVal = OldCalcFontPointSize(cssSize, baseSize*dev2app, 1.0f);
val = NewCalcFontPointSize(cssSize, baseSize*dev2app, 1.0f, aPresContext, eFontSize_CSS);
if (RoundSize(oldVal, aPresContext, doWinRounding) <= 8)
printf(" .");
else
printf("%2d", (RoundSize(val, aPresContext, false)-RoundSize(oldVal, aPresContext, doWinRounding)));
printf(" ");
}
printf("\n");
}
printf("\n\n\n");
printf("---------------------------------------------------------------\n");
printf(" HTML \n");
printf(" Rounding %s\n", (doWinRounding ? "ON" : "OFF"));
printf("---------------------------------------------------------------\n");
printf("\n");
printf("NEW SIZES:\n");
printf("----------\n");
printf(" #1 #2 #3 #4 #5 #6 #7\n");
for (baseSize = 9; baseSize <= 20; baseSize++) {
printf("%2d: ", baseSize);
for (htmlSize = 1; htmlSize <= 7; htmlSize++) {
val = NewCalcFontPointSize(htmlSize, baseSize*dev2app, 1.0f, aPresContext, eFontSize_HTML);
printf("%2d ", RoundSize(val, aPresContext, false));
}
printf("\n");
}
printf("\n");
printf("OLD SIZES:\n");
printf("----------\n");
printf(" #1 #2 #3 #4 #5 #6 #7\n");
for (baseSize = 9; baseSize <= 20; baseSize++) {
printf("%2d: ", baseSize);
for (htmlSize = 1; htmlSize <= 7; htmlSize++) {
val = OldCalcFontPointSize(htmlSize, baseSize*dev2app, 1.0f);
printf("%2d ", RoundSize(val, aPresContext, doWinRounding));
}
printf("\n");
}
printf("\n");
printf("DIFFS:\n");
printf("------\n");
printf(" #1 #2 #3 #4 #5 #6 #7\n");
for (baseSize = 9; baseSize <= 20; baseSize++) {
printf("%2d: ", baseSize);
for (htmlSize = 1; htmlSize <= 7; htmlSize++) {
oldVal = OldCalcFontPointSize(htmlSize, baseSize*dev2app, 1.0f);
val = NewCalcFontPointSize(htmlSize, baseSize*dev2app, 1.0f, aPresContext, eFontSize_HTML);
if (RoundSize(oldVal, aPresContext, doWinRounding) <= 8)
printf(" .");
else
printf("%2d", (RoundSize(val, aPresContext, false)-RoundSize(oldVal, aPresContext, doWinRounding)));
printf(" ");
}
printf("\n");
}
printf("\n\n\n");
}
}
}
#endif