/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER 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.
 */

#ifndef WebThemeEngine_h
#define WebThemeEngine_h

#include "../WebCanvas.h"
#include "../WebColor.h"
#include "../WebSize.h"

namespace WebKit {

struct WebRect;

class WebThemeEngine {
public:
    // The UI part which is being accessed.
    enum Part {
        PartScrollbarDownArrow,
        PartScrollbarLeftArrow,
        PartScrollbarRightArrow,
        PartScrollbarUpArrow,
        PartScrollbarHorizontalThumb,
        PartScrollbarVerticalThumb,
        PartScrollbarHoriztonalTrack,
        PartScrollbarVerticalTrack
    };

    // The current state of the associated Part.
    enum State {
        StateDisabled,
        StateHover,
        StateNormal,
        StatePressed,
    };

    // Extra parameters for drawing the PartScrollbarHoriztonalTrack and
    // PartScrollbarVerticalTrack.
    struct ScrollbarTrackExtraParams {
        // The bounds of the entire track, as opposed to the part being painted.
        int trackX;
        int trackY;
        int trackWidth;
        int trackHeight;
    };

    union ExtraParams {
        ScrollbarTrackExtraParams scrollbarTrack;
    };

    // Gets the size of the given theme part. For variable sized items
    // like vertical scrollbar thumbs, the width will be the required width of
    // the track while the height will be the minimum height.
    virtual WebSize getSize(Part) { return WebSize(); }
    // Paint the given the given theme part.
    virtual void paint(
        WebCanvas*, Part, State, const WebRect&, const ExtraParams*) {}
};

} // namespace WebKit

#endif