scrolltextbox.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef NANCY_UI_SCROLLTEXTBOX_H
#define NANCY_UI_SCROLLTEXTBOX_H

#include "engines/nancy/commontypes.h"
#include "engines/nancy/misc/hypertext.h"
#include "engines/nancy/renderobject.h"

namespace Nancy {

struct NancyInput;
struct UIPopupHeader;
struct TBOX;

namespace UI {

// Nancy 10+ game text box: a UIPopupHeader overlay popup at the bottom of the
// screen for narration and inventory/timer captions. The header comes from UICO
// (Nancy 10) or SCTB (Nancy 11), which are structurally identical, so one widget
// serves both. Shows caption text only (no response hotspots; conversation
// dialogue uses ConversationPopup). The legacy Textbox forwards to it for
// Nancy 10+.
class ScrollTextBox : public RenderObject, public Misc::HypertextParser {
public:
    ScrollTextBox();
    ~ScrollTextBox() override = default;

    void init() override;
    void registerGraphics() override;
    void updateGraphics() override;
    void handleInput(NancyInput &input);

    // Append a line of text. The popup is shown on the first non-empty
    // addition. A non-zero autoClearTime schedules an automatic clear() after
    // that many milliseconds (used by inventory closed captions).
    void addTextLine(const Common::String &text, uint32 autoClearTime = 0);
    void setOverrideFont(uint fontID);
    // Nancy 10 only: pick the full box (AR 74) or the strip (AR 75). Ignored from
    // Nancy 11 on, which picks by line count.
    void setFullMode(bool fullMode);
    // True while the full box is showing and covering the taskbar buttons.
    bool coversTaskbar() const { return _isVisible && _expanded; }
    void clear() override;

private:
    void drawBackground();
    void drawContent();
    // Render the text into the scratch surface, wrapping at wrapWidth.
    void layoutText(int wrapWidth, uint16 fontID);
    // Re-composite the expanded overlay at the current scroll position without
    // re-laying out the text; used for cheap scrollbar-drag updates.
    void redrawScroll();
    void drawScrollbar(UIButtonState state);
    uint16 getInnerHeight() const;

    // The text content area in popup-local coordinates (the screen-space text
    // viewport brought into the popup surface's space).
    Common::Rect textViewportLocal() const;

    // Width the strip wraps at: its own text area from TBOX, not the viewport.
    int stripTextWidth() const;

    // Popup-local bounding rect of the scrollbar thumb at the current scroll
    // position, or an empty rect when the slider is disabled.
    Common::Rect computeThumbRect() const;

    Common::Rect toPopupLocal(const Common::Rect &chunkRect, bool useGameFrame) const;
    Common::Point popupLocalMouse(const Common::Point &screenMouse) const;

    // Popup chrome (overlay image, dest rects, slider) supplied by the
    // version-specific chunk: UICO in Nancy 10, SCTB in Nancy 11.
    const UIPopupHeader *_header;
    // Text content area, in screen coordinates.
    Common::Rect _textViewportScreen;
    // The fully-expanded popup rect on screen, with the game-frame offset
    // applied. The mini strip shares its top edge.
    Common::Rect _fullPopupRect;
    // Screen rect the taskbar reserves for the caption strip (TASK chunk). The
    // strip's text is aligned to it; empty when there is no taskbar data.
    Common::Rect _stripScreenRect;
    const TBOX *_tboxData;

    Graphics::ManagedSurface _overlayImage;

    float _scrollPos;
    bool _scrollbarDragging;
    bool _scrollbarHovered;
    int _scrollbarGrabOffset;

    // Nancy 10 only: true selects the AR 74 full box, false the AR 75 strip.
    // Defaults false since every writer but AR 74 uses the strip.
    bool _fullMode;
    // True for the full, taskbar-covering box (with scrollbar); false for the strip.
    bool _expanded;

    int _fontIDOverride;
    uint32 _autoClearTime;
};

} // End of namespace UI
} // End of namespace Nancy

#endif // NANCY_UI_SCROLLTEXTBOX_H