/*

 * (C) 1999 Lars Knoll (knoll@kde.org)

 * (C) 2000 Dirk Mueller (mueller@kde.org)

 * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.

 *

 * 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., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#include "config.h"

#include "InlineTextBox.h"

#include "Document.h"

#include "Editor.h"

#include "Frame.h"

#include "GraphicsContext.h"

#include "HitTestResult.h"

#include "RenderArena.h"

#include "RenderBlock.h"

#include "Text.h"

#include "TextStyle.h"

#include "break_lines.h"

#include <wtf/AlwaysInline.h>

#if PLATFORM(SYMBIAN)

#include "WebCoreGraphicsContext.h"

#include "ZoomFactor.h"

#endif

using namespace std;

namespace WebCore {

int InlineTextBox::selectionTop()

{

    return root()->selectionTop();

}

int InlineTextBox::selectionHeight()

{

    return root()->selectionHeight();

}

bool InlineTextBox::isSelected(int startPos, int endPos) const

{

    int sPos = max(startPos - m_start, 0);

    int ePos = min(endPos - m_start, (int)m_len);

    return (sPos < ePos);

}

RenderObject::SelectionState InlineTextBox::selectionState()

{

    RenderObject::SelectionState state = object()->selectionState();

    if (state == RenderObject::SelectionStart || state == RenderObject::SelectionEnd || state == RenderObject::SelectionBoth) {

        int startPos, endPos;

        object()->selectionStartEnd(startPos, endPos);

        // The position after a hard line break is considered to be past its end.

        int lastSelectable = start() + len() - (isLineBreak() ? 1 : 0);

        bool start = (state != RenderObject::SelectionEnd && startPos >= m_start && startPos < m_start + m_len);

        bool end = (state != RenderObject::SelectionStart && endPos > m_start && endPos <= lastSelectable);

        if (start && end)

            state = RenderObject::SelectionBoth;

        else if (start)

            state = RenderObject::SelectionStart;

        else if (end)

            state = RenderObject::SelectionEnd;

        else if ((state == RenderObject::SelectionEnd || startPos < m_start) &&

                 (state == RenderObject::SelectionStart || endPos > lastSelectable))

            state = RenderObject::SelectionInside;

        else if (state == RenderObject::SelectionBoth)

            state = RenderObject::SelectionNone;

    }

    return state;

}

IntRect InlineTextBox::selectionRect(int tx, int ty, int startPos, int endPos)

{

    int sPos = max(startPos - m_start, 0);

    int ePos = min(endPos - m_start, (int)m_len);

    if (sPos >= ePos)

        return IntRect();

    RenderText* textObj = textObject();

    int selTop = selectionTop();

    int selHeight = selectionHeight();

    const Font& f = textObj->style(m_firstLine)->font();

    IntRect r = enclosingIntRect(f.selectionRectForText(TextRun(textObj->text()->characters() + m_start, m_len),

                                                        TextStyle(textObj->allowTabs(), textPos(), m_toAdd, m_reversed, m_dirOverride),

                                                        IntPoint(tx + m_x, ty + selTop), selHeight, sPos, ePos));

    if (r.x() > tx + m_x + m_width)

        r.setWidth(0);

    else if (r.right() - 1 > tx + m_x + m_width)

        r.setWidth(tx + m_x + m_width - r.x());

    return r;

}

void InlineTextBox::deleteLine(RenderArena* arena)

{

    static_cast<RenderText*>(m_object)->removeTextBox(this);

    destroy(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 min(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;

            return m_x + static_cast<RenderText*>(m_object)->width(m_start, offset, textPos(), 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;

}

static Color correctedTextColor(Color textColor, Color backgroundColor) 

{

    // Adjust the text color if it is too close to the background color,

    // by darkening or lightening it to move it further away.

    int d = differenceSquared(textColor, backgroundColor);

    // semi-arbitrarily chose 65025 (255^2) value here after a few tests; 

    if (d > 65025) {

        return textColor;

    }

    int distanceFromWhite = differenceSquared(textColor, Color::white);

    int distanceFromBlack = differenceSquared(textColor, Color::black);

    if (distanceFromWhite < distanceFromBlack) {

        return textColor.dark();

    }

    return textColor.light();

}

static void updateGraphicsContext(GraphicsContext* context, const Color& fillColor, const Color& strokeColor, float strokeThickness)

{

    int mode = context->textDrawingMode();

    if (strokeThickness > 0) {

        int newMode = mode | cTextStroke;

        if (mode != newMode) {

            context->setTextDrawingMode(newMode);

            mode = newMode;

        }

    }

    if (mode & cTextFill && fillColor != context->fillColor())

        context->setFillColor(fillColor);

    if (mode & cTextStroke) {

        if (strokeColor != context->strokeColor())

            context->setStrokeColor(strokeColor);

        if (strokeThickness != context->strokeThickness())

            context->setStrokeThickness(strokeThickness);

    }

}

bool InlineTextBox::isLineBreak() const

{

    return object()->isBR() || (object()->style()->preserveNewline() && len() == 1 && (*textObject()->text())[start()] == '\n');

}

bool InlineTextBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty)

{

    if (isLineBreak())

        return false;

    IntRect rect(tx + m_x, ty + m_y, m_width, m_height);

    if (m_truncation != cFullTruncation && object()->style()->visibility() == VISIBLE && rect.contains(x, y)) {

        object()->updateHitTestResult(result, IntPoint(x - tx, y - ty));

        return true;

    }

    return false;

}

void InlineTextBox::paint(RenderObject::PaintInfo& paintInfo, int tx, int ty)

{

    if (isLineBreak() || !object()->shouldPaintWithinRoot(paintInfo) || object()->style()->visibility() != VISIBLE ||

            m_truncation == cFullTruncation || paintInfo.phase == PaintPhaseOutline)

        return;

    ASSERT(paintInfo.phase != PaintPhaseSelfOutline && paintInfo.phase != PaintPhaseChildOutlines);

    int xPos = tx + m_x - parent()->maxHorizontalVisualOverflow();

    int w = width() + 2 * parent()->maxHorizontalVisualOverflow();

    if (xPos >= paintInfo.rect.right() || xPos + w <= paintInfo.rect.x())

        return;

    bool isPrinting = textObject()->document()->printing();

    // Determine whether or not we're selected.

    bool haveSelection = !isPrinting && selectionState() != RenderObject::SelectionNone;

    if (!haveSelection && paintInfo.phase == PaintPhaseSelection)

        // When only painting the selection, don't bother to paint if there is none.

        return;

    // Determine whether or not we have composition underlines to draw.

    bool containsComposition = object()->document()->frame()->editor()->compositionNode() == object()->node();

    bool useCustomUnderlines = containsComposition && object()->document()->frame()->editor()->compositionUsesCustomUnderlines();

    // Set our font.

    RenderStyle* styleToUse = object()->style(m_firstLine);

    int d = styleToUse->textDecorationsInEffect();

    const Font* font = &styleToUse->font();

    if (*font != paintInfo.context->font())

        paintInfo.context->setFont(*font);

    // 1. Paint backgrounds behind text if needed. Examples of such backgrounds include selection

    // and composition underlines.

    if (paintInfo.phase != PaintPhaseSelection && !isPrinting) {

#if PLATFORM(MAC)

        // Custom highlighters go behind everything else.

        if (styleToUse->highlight() != nullAtom && !paintInfo.context->paintingDisabled())

            paintCustomHighlight(tx, ty, styleToUse->highlight());

#endif

        if (containsComposition && !useCustomUnderlines)

            paintCompositionBackground(paintInfo.context, tx, ty, styleToUse, font,

                object()->document()->frame()->editor()->compositionStart(),

                object()->document()->frame()->editor()->compositionEnd());

        paintDocumentMarkers(paintInfo.context, tx, ty, styleToUse, font, true);

        if (haveSelection && !useCustomUnderlines)

            paintSelection(paintInfo.context, tx, ty, styleToUse, font);

    }

    // 2. Now paint the foreground, including text and decorations like underline/overline (in quirks mode only).

    if (m_len <= 0)

        return;

    Color textFillColor;

    Color textStrokeColor;

    float textStrokeWidth = styleToUse->textStrokeWidth();

    if (paintInfo.forceBlackText) {

        textFillColor = Color::black;

        textStrokeColor = Color::black;

    } else {

        textFillColor = styleToUse->textFillColor();

        if (!textFillColor.isValid())

            textFillColor = styleToUse->color();

        // Make the text fill color legible against a white background

        if (styleToUse->forceBackgroundsToWhite())

            textFillColor = correctedTextColor(textFillColor, Color::white);

        textStrokeColor = styleToUse->textStrokeColor();

        if (!textStrokeColor.isValid())

            textStrokeColor = styleToUse->color();

        // Make the text stroke color legible against a white background

        if (styleToUse->forceBackgroundsToWhite())

            textStrokeColor = correctedTextColor(textStrokeColor, Color::white);

    }

    // For stroked painting, we have to change the text drawing mode.  It's probably dangerous to leave that mutated as a side

    // effect, so only when we know we're stroking, do a save/restore.

    if (textStrokeWidth > 0)

        paintInfo.context->save();

    updateGraphicsContext(paintInfo.context, textFillColor, textStrokeColor, textStrokeWidth);

    // Set a text shadow if we have one.

    // FIXME: Support multiple shadow effects.  Need more from the CG API before

    // we can do this.

    bool setShadow = false;

    if (styleToUse->textShadow()) {

        paintInfo.context->setShadow(IntSize(styleToUse->textShadow()->x, styleToUse->textShadow()->y),

                                     styleToUse->textShadow()->blur, styleToUse->textShadow()->color);

        setShadow = true;

    }

    bool paintSelectedTextOnly = (paintInfo.phase == PaintPhaseSelection);

    bool paintSelectedTextSeparately = false; // Whether or not we have to do multiple paints.  Only

                                              // necessary when a custom ::selection foreground color is applied.

    Color selectionFillColor = textFillColor;

    Color selectionStrokeColor = textStrokeColor;

    float selectionStrokeWidth = textStrokeWidth;

    ShadowData* selectionTextShadow = 0;

    if (haveSelection) {

        // Check foreground color first.

        Color foreground = object()->selectionForegroundColor();

        if (foreground.isValid() && foreground != selectionFillColor) {

            if (!paintSelectedTextOnly)

                paintSelectedTextSeparately = true;

            selectionFillColor = foreground;

        }

        RenderStyle* pseudoStyle = object()->getPseudoStyle(RenderStyle::SELECTION);

        if (pseudoStyle) {

            if (pseudoStyle->textShadow()) {

                if (!paintSelectedTextOnly)

                    paintSelectedTextSeparately = true;

                if (pseudoStyle->textShadow())

                    selectionTextShadow = pseudoStyle->textShadow();

            }

            float strokeWidth = pseudoStyle->textStrokeWidth();

            if (strokeWidth != selectionStrokeWidth) {

                if (!paintSelectedTextOnly)

                    paintSelectedTextSeparately = true;

                selectionStrokeWidth = strokeWidth;

            }

            Color stroke = pseudoStyle->textStrokeColor();

            if (!stroke.isValid())

                stroke = pseudoStyle->color();

            if (stroke != selectionStrokeColor) {

                if (!paintSelectedTextOnly)

                    paintSelectedTextSeparately = true;

                selectionStrokeColor = stroke;

            }

        }

    }

    StringImpl* textStr = textObject()->text();

    TextStyle textStyle(textObject()->allowTabs(), textPos(), m_toAdd, m_reversed, m_dirOverride || styleToUse->visuallyOrdered());

    if (!paintSelectedTextOnly && !paintSelectedTextSeparately) {

        // paint all the text

        // FIXME: Handle RTL direction, handle reversed strings.  For now truncation can only be turned on

        // for non-reversed LTR strings.

        int endPoint = m_len;

        if (m_truncation != cNoTruncation)

            endPoint = m_truncation;

        paintInfo.context->drawText(TextRun(textStr->characters() + m_start, endPoint), IntPoint(m_x + tx, m_y + ty + m_baseline), textStyle);

    } else {

        int sPos, ePos;

        selectionStartEnd(sPos, ePos);

        if (paintSelectedTextSeparately) {

            // paint only the text that is not selected

            if (sPos >= ePos)

                paintInfo.context->drawText(TextRun(textStr->characters() + m_start, m_len), IntPoint(m_x + tx, m_y + ty + m_baseline), textStyle);

            else {

                if (sPos - 1 >= 0)

                    paintInfo.context->drawText(TextRun(textStr->characters() + m_start, m_len), IntPoint(m_x + tx, m_y + ty + m_baseline), textStyle,  0, sPos);

                if (ePos < m_start + m_len)

                    paintInfo.context->drawText(TextRun(textStr->characters() + m_start, m_len), IntPoint(m_x + tx, m_y + ty + m_baseline), textStyle, ePos);

            }

        }

        if (sPos < ePos) {

            // paint only the text that is selected

            if (selectionStrokeWidth > 0)

                paintInfo.context->save();

            updateGraphicsContext(paintInfo.context, selectionFillColor, selectionStrokeColor, selectionStrokeWidth);

            if (selectionTextShadow)

                paintInfo.context->setShadow(IntSize(selectionTextShadow->x, selectionTextShadow->y),

                                             selectionTextShadow->blur, selectionTextShadow->color);

            paintInfo.context->drawText(TextRun(textStr->characters() + m_start, m_len), IntPoint(m_x + tx, m_y + ty + m_baseline), textStyle, sPos, ePos);

            if (selectionTextShadow)

                paintInfo.context->clearShadow();

            if (selectionStrokeWidth > 0)

                paintInfo.context->restore();

        }

    }

    // Paint decorations

    if (d != TDNONE && paintInfo.phase != PaintPhaseSelection && styleToUse->htmlHacks()) {

        paintInfo.context->setStrokeColor(styleToUse->color());

        paintDecoration(paintInfo.context, tx, ty, d);

    }

    if (paintInfo.phase != PaintPhaseSelection) {

        paintDocumentMarkers(paintInfo.context, tx, ty, styleToUse, font, false);

        if (useCustomUnderlines) {

            const Vector<CompositionUnderline>& underlines = object()->document()->frame()->editor()->customCompositionUnderlines();

            size_t numUnderlines = underlines.size();

            for (size_t index = 0; index < numUnderlines; ++index) {

                const CompositionUnderline& underline = underlines[index];

                if (underline.endOffset <= start())

                    // underline is completely before this run.  This might be an underline that sits

                    // before the first run we draw, or underlines that were within runs we skipped 

                    // due to truncation.

                    continue;

                if (underline.startOffset <= end()) {

                    // underline intersects this run.  Paint it.

                    paintCompositionUnderline(paintInfo.context, tx, ty, underline);

                    if (underline.endOffset > end() + 1)

                        // underline also runs into the next run. Bail now, no more marker advancement.

                        break;

                } else

                    // underline is completely after this run, bail.  A later run will paint it.

                    break;

            }

        }

    }

    if (setShadow)

        paintInfo.context->clearShadow();

    if (textStrokeWidth > 0)

        paintInfo.context->restore();

}

void InlineTextBox::selectionStartEnd(int& sPos, int& ePos)

{

    int startPos, endPos;

    if (object()->selectionState() == RenderObject::SelectionInside) {

        startPos = 0;

        endPos = textObject()->textLength();

    } else {

        textObject()->selectionStartEnd(startPos, endPos);

        if (object()->selectionState() == RenderObject::SelectionStart)

            endPos = textObject()->textLength();

        else if (object()->selectionState() == RenderObject::SelectionEnd)

            startPos = 0;

    }

    sPos = max(startPos - m_start, 0);

    ePos = min(endPos - m_start, (int)m_len);

}

void InlineTextBox::paintSelection(GraphicsContext* p, int tx, int ty, RenderStyle* style, const Font* f)

{

    // See if we have a selection to paint at all.

    int sPos, ePos;

    selectionStartEnd(sPos, ePos);

    if (sPos >= ePos)

        return;

    Color textColor = style->color();

    Color c = object()->selectionBackgroundColor();

    if (!c.isValid() || c.alpha() == 0)

        return;

    // If the text color ends up being the same as the selection background, invert the selection

    // background.  This should basically never happen, since the selection has transparency.

    if (textColor == c)

        c = Color(0xff - c.red(), 0xff - c.green(), 0xff - c.blue());

    p->save();

    updateGraphicsContext(p, c, c, 0);  // Don't draw text at all!

    int y = selectionTop();

    int h = selectionHeight();

#if PLATFORM(SYMBIAN)

    IntRect r(m_x + tx, y + ty, m_width, h);

    IntRect clipRect = xForm(p->platformContext()->clippingRect());

    clipRect.intersect(r);

    //p->clip(clipRect);

#else

    p->clip(IntRect(m_x + tx, y + ty, m_width, h));

#endif

    p->drawHighlightForText(TextRun(textObject()->text()->characters() + m_start, m_len), IntPoint(m_x + tx, y + ty), h, 

                            TextStyle(textObject()->allowTabs(), textPos(), m_toAdd, m_reversed, m_dirOverride || style->visuallyOrdered()), c,

                            sPos, ePos);

    p->restore();

}

void InlineTextBox::paintCompositionBackground(GraphicsContext* p, int tx, int ty, RenderStyle* style, const Font* f, int startPos, int endPos)

{

    int offset = m_start;

    int sPos = max(startPos - offset, 0);

    int ePos = min(endPos - offset, (int)m_len);

    if (sPos >= ePos)

        return;