/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002 The ScummVM project
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 */

#include "stdafx.h"
#include "ScrollBarWidget.h"
#include "dialog.h"
#include "newgui.h"


/*
 * TODO:
 * - Dragging the slider with the mouse
 * - Auto-repeast: if one clicks & holds on one of the arrows, then after a
 *   brief delay, it should start to contiously scroll
 * - Allow for a horizontal scrollbar, too?
 */

#define UP_DOWN_BOX_HEIGHT	10

// Up arrow
static uint32 up_arrow[8] = {
	0x00000000,
	0x00000000,
	0x00001000,
	0x00001000,
	0x00011100,
	0x00011100,
	0x00110110,
	0x00100010,
};

// Up arrow
static uint32 down_arrow[8] = {
	0x00000000,
	0x00000000,
	0x00100010,
	0x00110110,
	0x00011100,
	0x00011100,
	0x00001000,
	0x00001000,
};

ScrollBarWidget::ScrollBarWidget(Dialog *boss, int x, int y, int w, int h)
	: Widget (boss, x, y, w, h), CommandSender(boss)
{
	_flags = WIDGET_ENABLED | WIDGET_TRACK_MOUSE | WIDGET_CLEARBG;
	_type = kScrollBarWidget;

	_part = kNoPart;
	_isDraggingSlider = false;

}

void ScrollBarWidget::handleClick(int x, int y, int button)
{
	int old_pos = _currentPos;

	if (y <= UP_DOWN_BOX_HEIGHT) {
		// Up arrow
		_currentPos--;
	} else if (y >= _h - UP_DOWN_BOX_HEIGHT) {
		// Down arrow
		_currentPos++;
	} else if (y < _sliderPos) {
		_currentPos -= _entriesPerPage;
	} else if (y >= _sliderPos + _sliderHeight) {
		_currentPos += _entriesPerPage;
	} else {
		_isDraggingSlider = true;
		_sliderDeltaMouseDownPos = y - _sliderPos;
	}

	// Make sure that _currentPos is still inside the bounds
	checkbounds();

	if (old_pos != _currentPos) {
		recalc();
		draw();
		sendCommand(kSetPositionCmd, _currentPos);
	}
}

void ScrollBarWidget::handleMouseMoved(int x, int y, int button)
{
	if (button == 0)
		_isDraggingSlider = false;

	if (_isDraggingSlider) {
		int old_pos = _currentPos;
		_sliderPos = y - _sliderDeltaMouseDownPos;

		if (_sliderPos < UP_DOWN_BOX_HEIGHT)
			_sliderPos = UP_DOWN_BOX_HEIGHT;

		if (_sliderPos > _h - UP_DOWN_BOX_HEIGHT - _sliderHeight + 1)
			_sliderPos = _h - UP_DOWN_BOX_HEIGHT - _sliderHeight + 1;

		_currentPos =
			(_sliderPos - UP_DOWN_BOX_HEIGHT) * (_numEntries - _entriesPerPage) / (_h - _sliderHeight -
																																						 2 * UP_DOWN_BOX_HEIGHT);
		checkbounds();

		if (_currentPos != old_pos) {
			draw();
			sendCommand(kSetPositionCmd, _currentPos);
		}
	} else {
		int old_part = _part;

		if (y <= UP_DOWN_BOX_HEIGHT)	// Up arrow
			_part = kUpArrowPart;
		else if (y >= _h - UP_DOWN_BOX_HEIGHT)	// Down arrow
			_part = kDownArrowPart;
		else if (y < _sliderPos)
			_part = kPageUpPart;
		else if (y >= _sliderPos + _sliderHeight)
			_part = kPageDownPart;
		else
			_part = kSliderPart;

		if (old_part != _part)
			draw();
	}
}

void ScrollBarWidget::checkbounds()
{
	if (_currentPos > _numEntries - _entriesPerPage)
		_currentPos = _numEntries - _entriesPerPage;
	else if (_currentPos < 0)
		_currentPos = 0;
}

void ScrollBarWidget::recalc()
{
	_sliderHeight = (_h - 2 * UP_DOWN_BOX_HEIGHT) * _entriesPerPage / _numEntries;
	if (_sliderHeight < 4)
		_sliderHeight = 4;

	_sliderPos =
		UP_DOWN_BOX_HEIGHT + (_h - 2 * UP_DOWN_BOX_HEIGHT - _sliderHeight + 1) * _currentPos / (_numEntries -
																																														_entriesPerPage);
	if (_sliderPos < 0)
		_sliderPos = 0;
}


void ScrollBarWidget::drawWidget(bool hilite)
{
	NewGui *gui = _boss->getGui();
	int bottomY = _y + _h;

	gui->frameRect(_x, _y, _w, _h, gui->_shadowcolor);

	// Up arrow
	gui->frameRect(_x, _y, _w, UP_DOWN_BOX_HEIGHT, gui->_color);
	gui->drawBitmap(up_arrow, _x, _y,
									(hilite && _part == kUpArrowPart) ? gui->_textcolorhi : gui->_textcolor);

	// Down arrow
	gui->frameRect(_x, bottomY - UP_DOWN_BOX_HEIGHT + 1, _w, UP_DOWN_BOX_HEIGHT, gui->_color);
	gui->drawBitmap(down_arrow, _x, bottomY - UP_DOWN_BOX_HEIGHT + 1,
									(hilite && _part == kDownArrowPart) ? gui->_textcolorhi : gui->_textcolor);

	// Slider
	gui->checkerRect(_x, _y + _sliderPos, _w, _sliderHeight,
									(hilite && _part == kSliderPart) ? gui->_textcolorhi : gui->_textcolor);
	gui->frameRect(_x, _y + _sliderPos, _w, _sliderHeight, gui->_color);
}