/*

 * Copyright (C) 2008 Apple Inc. All Rights Reserved.

 * Copyright (C) 2008, 2009 Google Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "ScrollbarThemeChromiumWin.h"

#include <windows.h>

#include <vsstyle.h>

#include "ChromiumBridge.h"

#include "GraphicsContext.h"

#include "PlatformContextSkia.h"

#include "PlatformMouseEvent.h"

#include "Scrollbar.h"

#include "WindowsVersion.h"

namespace WebCore {

ScrollbarTheme* ScrollbarTheme::nativeTheme()

{

    static ScrollbarThemeChromiumWin theme;

    return &theme;

}

// The scrollbar size in DumpRenderTree on the Mac - so we can match their

// layout results.  Entries are for regular, small, and mini scrollbars.

// Metrics obtained using [NSScroller scrollerWidthForControlSize:]

static const int kMacScrollbarSize[3] = { 15, 11, 15 };

// Constants used to figure the drag rect outside which we should snap the

// scrollbar thumb back to its origin.  These calculations are based on

// observing the behavior of the MSVC8 main window scrollbar + some

// guessing/extrapolation.

static const int kOffEndMultiplier = 3;

static const int kOffSideMultiplier = 8;

int ScrollbarThemeChromiumWin::scrollbarThickness(ScrollbarControlSize controlSize)

{

    static int thickness;

    if (!thickness) {

        if (ChromiumBridge::layoutTestMode())

            return kMacScrollbarSize[controlSize];

        thickness = GetSystemMetrics(SM_CXVSCROLL);

    }

    return thickness;

}

bool ScrollbarThemeChromiumWin::invalidateOnMouseEnterExit()

{

    return isVistaOrNewer();

}

bool ScrollbarThemeChromiumWin::shouldSnapBackToDragOrigin(Scrollbar* scrollbar, const PlatformMouseEvent& evt)

{

    // Find the rect within which we shouldn't snap, by expanding the track rect

    // in both dimensions.

    IntRect rect = trackRect(scrollbar);

    const bool horz = scrollbar->orientation() == HorizontalScrollbar;

    const int thickness = scrollbarThickness(scrollbar->controlSize());

    rect.inflateX((horz ? kOffEndMultiplier : kOffSideMultiplier) * thickness);

    rect.inflateY((horz ? kOffSideMultiplier : kOffEndMultiplier) * thickness);

    // Convert the event to local coordinates.

    IntPoint mousePosition = scrollbar->convertFromContainingWindow(evt.pos());

    mousePosition.move(scrollbar->x(), scrollbar->y());

    // We should snap iff the event is outside our calculated rect.

    return !rect.contains(mousePosition);

}

void ScrollbarThemeChromiumWin::paintTrackPiece(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart partType)

{

    bool horz = scrollbar->orientation() == HorizontalScrollbar;

    int partId;

    if (partType == BackTrackPart)

        partId = horz ? SBP_UPPERTRACKHORZ : SBP_UPPERTRACKVERT;

    else

        partId = horz ? SBP_LOWERTRACKHORZ : SBP_LOWERTRACKVERT;

    IntRect alignRect = trackRect(scrollbar, false);

    // Draw the track area before/after the thumb on the scroll bar.

    ChromiumBridge::paintScrollbarTrack(

        gc,

        partId,

        getThemeState(scrollbar, partType),

        getClassicThemeState(scrollbar, partType),

        rect,

        alignRect);

}

void ScrollbarThemeChromiumWin::paintButton(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart part)

{

    bool horz = scrollbar->orientation() == HorizontalScrollbar;

    int partId;

    if (part == BackButtonStartPart || part == ForwardButtonStartPart)

        partId = horz ? DFCS_SCROLLLEFT : DFCS_SCROLLUP;

    else

        partId = horz ? DFCS_SCROLLRIGHT : DFCS_SCROLLDOWN;

    // Draw the thumb (the box you drag in the scroll bar to scroll).

    ChromiumBridge::paintScrollbarArrow(

        gc,

        getThemeArrowState(scrollbar, part),

        partId | getClassicThemeState(scrollbar, part),

        rect);

}

void ScrollbarThemeChromiumWin::paintThumb(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect)

{

    bool horz = scrollbar->orientation() == HorizontalScrollbar;

    // Draw the thumb (the box you drag in the scroll bar to scroll).

    ChromiumBridge::paintScrollbarThumb(

        gc,

        horz ? SBP_THUMBBTNHORZ : SBP_THUMBBTNVERT,

        getThemeState(scrollbar, ThumbPart),

        getClassicThemeState(scrollbar, ThumbPart),

        rect);

    // Draw the gripper (the three little lines on the thumb).

    ChromiumBridge::paintScrollbarThumb(

        gc,

        horz ? SBP_GRIPPERHORZ : SBP_GRIPPERVERT,

        getThemeState(scrollbar, ThumbPart),

        getClassicThemeState(scrollbar, ThumbPart),

        rect);

}

int ScrollbarThemeChromiumWin::getThemeState(Scrollbar* scrollbar, ScrollbarPart part) const

{

    // When dragging the thumb, draw thumb pressed and other segments normal

    // regardless of where the cursor actually is.  See also four places in

    // getThemeArrowState().

    if (scrollbar->pressedPart() == ThumbPart) {

        if (part == ThumbPart)

            return SCRBS_PRESSED;

        return isVistaOrNewer() ? SCRBS_HOVER : SCRBS_NORMAL;

    }

    if (!scrollbar->enabled())

        return SCRBS_DISABLED;

    if (scrollbar->hoveredPart() != part || part == BackTrackPart || part == ForwardTrackPart)

        return (scrollbar->hoveredPart() == NoPart || !isVistaOrNewer()) ? SCRBS_NORMAL : SCRBS_HOVER;

    if (scrollbar->pressedPart() == NoPart)

        return SCRBS_HOT;

    return (scrollbar->pressedPart() == part) ? SCRBS_PRESSED : SCRBS_NORMAL;

}

int ScrollbarThemeChromiumWin::getThemeArrowState(Scrollbar* scrollbar, ScrollbarPart part) const

{

    // We could take advantage of knowing the values in the state enum to write

    // some simpler code, but treating the state enum as a black box seems

    // clearer and more future-proof.

    if (part == BackButtonStartPart || part == ForwardButtonStartPart) {

        if (scrollbar->orientation() == HorizontalScrollbar) {

            if (scrollbar->pressedPart() == ThumbPart)

                return !isVistaOrNewer() ? ABS_LEFTNORMAL : ABS_LEFTHOVER;

            if (!scrollbar->enabled())

                return ABS_LEFTDISABLED;

            if (scrollbar->hoveredPart() != part)

                return ((scrollbar->hoveredPart() == NoPart) || !isVistaOrNewer()) ? ABS_LEFTNORMAL : ABS_LEFTHOVER;

            if (scrollbar->pressedPart() == NoPart)

                return ABS_LEFTHOT;

            return (scrollbar->pressedPart() == part) ?

                ABS_LEFTPRESSED : ABS_LEFTNORMAL;

        }

        if (scrollbar->pressedPart() == ThumbPart)

            return !isVistaOrNewer() ? ABS_UPNORMAL : ABS_UPHOVER;

        if (!scrollbar->enabled())

            return ABS_UPDISABLED;

        if (scrollbar->hoveredPart() != part)

            return ((scrollbar->hoveredPart() == NoPart) || !isVistaOrNewer()) ? ABS_UPNORMAL : ABS_UPHOVER;

        if (scrollbar->pressedPart() == NoPart)

            return ABS_UPHOT;

        return (scrollbar->pressedPart() == part) ? ABS_UPPRESSED : ABS_UPNORMAL;

    }

    if (scrollbar->orientation() == HorizontalScrollbar) {

        if (scrollbar->pressedPart() == ThumbPart)

            return !isVistaOrNewer() ? ABS_RIGHTNORMAL : ABS_RIGHTHOVER;

        if (!scrollbar->enabled())

            return ABS_RIGHTDISABLED;

        if (scrollbar->hoveredPart() != part)

            return ((scrollbar->hoveredPart() == NoPart) || !isVistaOrNewer()) ? ABS_RIGHTNORMAL : ABS_RIGHTHOVER;

        if (scrollbar->pressedPart() == NoPart)

            return ABS_RIGHTHOT;

        return (scrollbar->pressedPart() == part) ? ABS_RIGHTPRESSED : ABS_RIGHTNORMAL;

    }

    if (scrollbar->pressedPart() == ThumbPart)

        return !isVistaOrNewer() ? ABS_DOWNNORMAL : ABS_DOWNHOVER;

    if (!scrollbar->enabled())

        return ABS_DOWNDISABLED;

    if (scrollbar->hoveredPart() != part)

        return ((scrollbar->hoveredPart() == NoPart) || !isVistaOrNewer()) ? ABS_DOWNNORMAL : ABS_DOWNHOVER;

    if (scrollbar->pressedPart() == NoPart)

        return ABS_DOWNHOT;

    return (scrollbar->pressedPart() == part) ? ABS_DOWNPRESSED : ABS_DOWNNORMAL;

}

int ScrollbarThemeChromiumWin::getClassicThemeState(Scrollbar* scrollbar, ScrollbarPart part) const

{

    // When dragging the thumb, draw the buttons normal even when hovered.

    if (scrollbar->pressedPart() == ThumbPart)

        return 0;

    if (!scrollbar->enabled())

        return DFCS_INACTIVE;

    if (scrollbar->hoveredPart() != part || part == BackTrackPart || part == ForwardTrackPart)

        return 0;

    if (scrollbar->pressedPart() == NoPart)

        return DFCS_HOT;

    return (scrollbar->pressedPart() == part) ? (DFCS_PUSHED | DFCS_FLAT) : 0;

}

bool ScrollbarThemeChromiumWin::shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent& evt)

{

    return evt.shiftKey() && evt.button() == LeftButton;

}

IntSize ScrollbarThemeChromiumWin::buttonSize(Scrollbar* scrollbar)

{

    // Our desired rect is essentially thickness by thickness.

    // Our actual rect will shrink to half the available space when we have < 2

    // times thickness pixels left.  This allows the scrollbar to scale down

    // and function even at tiny sizes.

    int thickness = scrollbarThickness(scrollbar->controlSize());

    // In layout test mode, we force the button "girth" (i.e., the length of

    // the button along the axis of the scrollbar) to be a fixed size.

    // FIXME: This is retarded!  scrollbarThickness is already fixed in layout

    // test mode so that should be enough to result in repeatable results, but

    // preserving this hack avoids having to rebaseline pixel tests.

    const int kLayoutTestModeGirth = 17;

    int girth = ChromiumBridge::layoutTestMode() ? kLayoutTestModeGirth : thickness;

    if (scrollbar->orientation() == HorizontalScrollbar) {

        int width = scrollbar->width() < 2 * girth ? scrollbar->width() / 2 : girth;

        return IntSize(width, thickness);

    }

    int height = scrollbar->height() < 2 * girth ? scrollbar->height() / 2 : girth;

    return IntSize(thickness, height);

}

} // namespace WebCore