render_text.cpp

khtml在gtk上的移植版本

/**
 * This file is part of the DOM implementation for KDE.
 *
 * (C) 1999 Lars Knoll ([e-mail])
 * (C) 2000 Dirk Mueller ([e-mail])
 * Copyright (C) 2004 Apple Computer, Inc.
 *
 * 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; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */
//#define DEBUG_LAYOUT
//#define BIDI_DEBUG

#include "rendering/render_canvas.h"
#include "rendering/render_text.h"
#include "rendering/break_lines.h"
#include "xml/dom_nodeimpl.h"
#include "xml/dom_docimpl.h"
#include "xml/dom_position.h"
#include "render_arena.h"

#include "misc/loader.h"

#include <qpainter.h>
#include <kdebug.h>
#include <assert.h>

using namespace khtml;
using namespace DOM;

#ifndef NDEBUG
static bool inInlineTextBoxDetach;
#endif

void InlineTextBox::detach(RenderArena* renderArena)
{
#ifndef NDEBUG
    inInlineTextBoxDetach = true;
#endif
    delete this;
#ifndef NDEBUG
    inInlineTextBoxDetach = false;
#endif
    
    // Recover the size left there for us by operator delete and free the memory.
    renderArena->free(*(size_t *)this, this);
}

void* InlineTextBox::operator new(size_t sz, RenderArena* renderArena) throw()
{
    return renderArena->allocate(sz);
}

void InlineTextBox::operator delete(void* ptr, size_t sz)
{
    assert(inInlineTextBoxDetach);
    
    // Stash size where detach can find it.
    *(size_t *)ptr = sz;
}

void InlineTextBox::deleteLine(RenderArena* arena)
{
    static_cast<RenderText*>(m_object)->removeTextBox(this);
    detach(arena);
}

void InlineTextBox::extractLine()
{
    if (m_extracted)
        return;

    static_cast<RenderText*>(m_object)->extractTextBox(this);
}

void InlineTextBox::attachLine()
{
    if (!m_extracted)
        return;
    
    static_cast<RenderText*>(m_object)->attachTextBox(this);
}

int InlineTextBox::placeEllipsisBox(bool ltr, int blockEdge, int ellipsisWidth, bool& foundBox)
{
    if (foundBox) {
        m_truncation = cFullTruncation;
        return -1;
    }

    int ellipsisX = ltr ? blockEdge - ellipsisWidth : blockEdge + ellipsisWidth;
    
    // For LTR, if the left edge of the ellipsis is to the left of our text run, then we are the run that will get truncated.
    if (ltr) {
        if (ellipsisX <= m_x) {
            // Too far.  Just set full truncation, but return -1 and let the ellipsis just be placed at the edge of the box.
            m_truncation = cFullTruncation;
            foundBox = true;
            return -1;
        }

        if (ellipsisX < m_x + m_width) {
            if (m_reversed)
                return -1; // FIXME: Support LTR truncation when the last run is RTL someday.

            foundBox = true;

            int offset = offsetForPosition(ellipsisX, false);
            if (offset == 0) {
                // No characters should be rendered.  Set ourselves to full truncation and place the ellipsis at the min of our start
                // and the ellipsis edge.
                m_truncation = cFullTruncation;
                return kMin(ellipsisX, m_x);
            }
            
            // Set the truncation index on the text run.  The ellipsis needs to be placed just after the last visible character.
            m_truncation = offset + m_start;
            return m_x + static_cast<RenderText*>(m_object)->width(m_start, offset, m_firstLine);
        }
    }
    else {
        // FIXME: Support RTL truncation someday, including both modes (when the leftmost run on the line is either RTL or LTR)
    }
    return -1;
}

void InlineTextBox::paintSelection(const Font *f, RenderText *text, QPainter *p, RenderStyle* style, int tx, int ty, int startPos, int endPos, bool extendSelection)
{
    int offset = m_start;
    int sPos = kMax(startPos - offset, 0);
    int ePos = kMin(endPos - offset, (int)m_len);

    if (sPos >= ePos)
        return;

    p->save();
#if APPLE_CHANGES
    // Macintosh-style text highlighting is to draw with a particular background color, not invert.
    QColor textColor = style->color();
    QColor c = p->selectedTextBackgroundColor();
    
    // if text color and selection background color are identical, invert background color.
    if (textColor == c)
        c = QColor(0xff - c.red(), 0xff - c.green(), 0xff - c.blue());

    RenderStyle* pseudoStyle = object()->getPseudoStyle(RenderStyle::SELECTION);
    if (pseudoStyle && pseudoStyle->backgroundColor().isValid())
        c = pseudoStyle->backgroundColor();
    p->setPen(c); // Don't draw text at all!
    
#else
    QColor c = style->color();
    p->setPen(QColor(0xff-c.red(),0xff-c.green(),0xff-c.blue()));
    ty + m_baseline;
#endif
    
#if APPLE_CHANGES
    // Do the calculations to draw selections as tall as the line.
    // Use the bottom of the line above as the y position (if there is one, 
    // otherwise use the top of this renderer's line) and the height of the line as the height. 
    // This mimics Cocoa.
    RenderBlock *cb = object()->containingBlock();

    if (root()->prevRootBox())
        ty = root()->prevRootBox()->bottomOverflow();
    else
        ty = root()->topOverflow();

    int h = root()->bottomOverflow() - ty;

    int absx, absy;
    cb->absolutePosition(absx, absy);
    
    int x = m_x + tx;
    int minX = x;
    int maxX = x;
    if ((extendSelection || startPos < m_start) && root()->firstLeafChild() == this)
        minX = absx + kMax(cb->leftOffset(ty), cb->leftOffset(root()->blockHeight()));
    if ((extendSelection || endPos > m_start + m_len) && root()->lastLeafChild() == this)
        maxX = absx + kMin(cb->rightOffset(ty), cb->rightOffset(root()->blockHeight()));
    
    f->drawHighlightForText(p, x, minX, maxX, absy + ty, h, text->str->s, text->str->l, m_start, m_len,
		m_toAdd, m_reversed ? QPainter::RTL : QPainter::LTR, style->visuallyOrdered(), sPos, ePos, c);
#else
    f->drawHighlightForText(p, m_x + tx, m_y + ty, text->str->s, text->str->l, m_start, m_len,
		m_toAdd, m_reversed ? QPainter::RTL : QPainter::LTR, sPos, ePos, c);
#endif
    p->restore();
}

#ifdef APPLE_CHANGES
void InlineTextBox::paintDecoration( QPainter *pt, int _tx, int _ty, int deco)
{
    _tx += m_x;
    _ty += m_y;

    if (m_truncation == cFullTruncation)
        return;
    
    int width = (m_truncation == cNoTruncation) ? 
                m_width : static_cast<RenderText*>(m_object)->width(m_start, m_truncation - m_start, m_firstLine);
    
    // Get the text decoration colors.
    QColor underline, overline, linethrough;
    object()->getTextDecorationColors(deco, underline, overline, linethrough, true);
    
    // Use a special function for underlines to get the positioning exactly right.
    if (deco & UNDERLINE) {
        pt->setPen(underline);
        pt->drawLineForText(_tx, _ty, m_baseline, width);
    }
    if (deco & OVERLINE) {
        pt->setPen(overline);
        pt->drawLineForText(_tx, _ty, 0, width);
    }
    if (deco & LINE_THROUGH) {
        pt->setPen(linethrough);
        pt->drawLineForText(_tx, _ty, 2*m_baseline/3, width);
    }
}
#else
void InlineTextBox::paintDecoration( QPainter *pt, int _tx, int _ty, int decoration)
{
    _tx += m_x;
    _ty += m_y;

    int width = m_width - 1;

    QColor underline, overline, linethrough;
    object()->getTextDecorationColors(decoration, underline, overline, linethrough, true);
    
    int underlineOffset = ( pt->fontMetrics().height() + m_baseline ) / 2;
    if(underlineOffset <= m_baseline) underlineOffset = m_baseline+1;

    if(deco & UNDERLINE){
        pt->setPen(underline);
        pt->drawLine(_tx, _ty + underlineOffset, _tx + width, _ty + underlineOffset );
    }
    if (deco & OVERLINE) {
        pt->setPen(overline);
        pt->drawLine(_tx, _ty, _tx + width, _ty );
    }
    if(deco & LINE_THROUGH) {
        pt->setPen(linethrough);
        pt->drawLine(_tx, _ty + 2*m_baseline/3, _tx + width, _ty + 2*m_baseline/3 );
    }
    // NO! Do NOT add BLINK! It is the most annouing feature of Netscape, and IE has a reason not to
    // support it. Lars
}
#endif

long InlineTextBox::caretMinOffset() const
{
    return m_start;
}

long InlineTextBox::caretMaxOffset() const
{
    return m_start + m_len;
}

unsigned long InlineTextBox::caretMaxRenderedOffset() const
{
    return m_start + m_len;
}

#define LOCAL_WIDTH_BUF_SIZE	1024

int InlineTextBox::offsetForPosition(int _x, bool includePartialGlyphs)
{
    RenderText* text = static_cast<RenderText*>(m_object);
    const Font* f = text->htmlFont(m_firstLine);
    return f->checkSelectionPoint(text->str->s, text->str->l, m_start, m_len, m_toAdd, _x - m_x, m_reversed, includePartialGlyphs);
}

// -------------------------------------------------------------------------------------

RenderText::RenderText(DOM::NodeImpl* node, DOMStringImpl *_str)
    : RenderObject(node), m_linesDirty(false)
{
    // init RenderObject attributes
    setRenderText();   // our object inherits from RenderText

    m_minWidth = -1;
    m_maxWidth = -1;

#ifdef APPLE_CHANGES
    m_monospaceCharacterWidth = 0;
    m_allAsciiChecked = false;
    m_allAscii = false;
#endif

    str = _str;
    if (str) {
        str = str->replace('\\', backslashAsCurrencySymbol());
        str->ref();
    }
    KHTMLAssert(!str || !str->l || str->s);

    m_firstTextBox = m_lastTextBox = 0;
    
    m_selectionState = SelectionNone;

#ifdef DEBUG_LAYOUT
    QConstString cstr(str->s, str->l);
    kdDebug( 6040 ) << "RenderText ctr( "<< cstr.string().length() << " )  '" << cstr.string() << "'" << endl;
#endif
}

void RenderText::setStyle(RenderStyle *_style)
{
    if ( style() != _style ) {
        bool needToTransformText = (!style() && _style->textTransform() != TTNONE) ||
                                   (style() && style()->textTransform() != _style->textTransform());

        RenderObject::setStyle( _style );

        if (needToTransformText) {
            DOM::DOMStringImpl* textToTransform = originalString();
            if (textToTransform)
                setText(textToTransform, true);
        }
#if APPLE_CHANGES
        // setText also calls cacheWidths(), so there is no need to call it again in that case.
        else
            cacheWidths();
#endif
    }
}

RenderText::~RenderText()
{
    if(str) str->deref();
}

void RenderText::detach()
{
    if (!documentBeingDestroyed()) {
        if (firstTextBox())
            for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox())
                box->remove();
        else if (parent() && isBR())
            parent()->dirtyLinesFromChangedChild(this);
    }
    deleteTextBoxes();
    RenderObject::detach();
}

void RenderText::extractTextBox(InlineTextBox* box)
{
    m_lastTextBox = box->prevTextBox();
    if (box == m_firstTextBox)
        m_firstTextBox = 0;
    if (box->prevTextBox())
        box->prevTextBox()->setNextLineBox(0);
    box->setPreviousLineBox(0);
    for (InlineRunBox* curr = box; curr; curr = curr->nextLineBox())
        curr->setExtracted();
}

void RenderText::attachTextBox(InlineTextBox* box)
{
    if (m_lastTextBox) {
        m_lastTextBox->setNextLineBox(box);
        box->setPreviousLineBox(m_lastTextBox);
    }
    else
        m_firstTextBox = box;
    InlineTextBox* last = box;
    for (InlineTextBox* curr = box; curr; curr = curr->nextTextBox()) {