/*

 * Copyright (c) 2008-2011, Matthias Mann

 *

 * 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 Matthias Mann 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.

 */

package inventory;

import de.matthiasmann.twl.Event;

import de.matthiasmann.twl.ThemeInfo;

import de.matthiasmann.twl.Widget;

/**

 *

 * @author Matthias Mann

 */

public class InventoryPanel extends Widget {

    private int numSlotsX;

    private int numSlotsY;

    private final ItemSlot[] slot;

    private int slotSpacing;

    private ItemSlot dragSlot;

    private ItemSlot dropSlot;

    public InventoryPanel(int numSlotsX, int numSlotsY) {

        this.numSlotsX = numSlotsX;

        this.numSlotsY = numSlotsY;

        this.slot = new ItemSlot[numSlotsX * numSlotsY];

        ItemSlot.DragListener listener = new ItemSlot.DragListener() {

            public void dragStarted(ItemSlot slot, Event evt) {

                InventoryPanel.this.dragStarted(slot, evt);

            }

            public void dragging(ItemSlot slot, Event evt) {

                InventoryPanel.this.dragging(slot, evt);

            }

            public void dragStopped(ItemSlot slot, Event evt) {

                InventoryPanel.this.dragStopped(slot, evt);

            }

        };

        for(int i=0 ; i<slot.length ; i++) {

            slot[i] = new ItemSlot();

            slot[i].setListener(listener);

            add(slot[i]);

        }

        slot[0].setItem("red");

        slot[1].setItem("green");

        slot[2].setItem("blue");

        slot[3].setItem("yellow");

    }

    @Override

    public int getPreferredInnerWidth() {

        return (slot[0].getPreferredWidth() + slotSpacing)*numSlotsX - slotSpacing;

    }

    @Override

    public int getPreferredInnerHeight() {

        return (slot[0].getPreferredHeight() + slotSpacing)*numSlotsY - slotSpacing;

    }

    @Override

    protected void layout() {

        int slotWidth  = slot[0].getPreferredWidth();

        int slotHeight = slot[0].getPreferredHeight();

        for(int row=0,y=getInnerY(),i=0 ; row<numSlotsY ; row++) {

            for(int col=0,x=getInnerX() ; col<numSlotsX ; col++,i++) {

                slot[i].adjustSize();

                slot[i].setPosition(x, y);

                x += slotWidth + slotSpacing;

            }

            y += slotHeight + slotSpacing;

        }

    }

    @Override

    protected void applyTheme(ThemeInfo themeInfo) {

        super.applyTheme(themeInfo);

        slotSpacing = themeInfo.getParameter("slotSpacing", 5);

    }

    void dragStarted(ItemSlot slot, Event evt) {

        if(slot.getItem() != null) {

            dragSlot = slot;

            dragging(slot, evt);

        }

    }

    void dragging(ItemSlot slot, Event evt) {

        if(dragSlot != null) {

            Widget w = getWidgetAt(evt.getMouseX(), evt.getMouseY());

            if(w instanceof ItemSlot) {

                setDropSlot((ItemSlot)w);

            } else {

                setDropSlot(null);

            }

        }

    }

    void dragStopped(ItemSlot slot, Event evt) {

        if(dragSlot != null) {

            dragging(slot, evt);

            if(dropSlot != null && dropSlot.canDrop() && dropSlot != dragSlot) {

                dropSlot.setItem(dragSlot.getItem());

                dragSlot.setItem(null);

            }

            setDropSlot(null);

            dragSlot = null;

        }

    }

    private void setDropSlot(ItemSlot slot) {

        if(slot != dropSlot) {

            if(dropSlot != null) {

                dropSlot.setDropState(false, false);

            }

            dropSlot = slot;

            if(dropSlot != null) {

                dropSlot.setDropState(true, dropSlot == dragSlot || dropSlot.canDrop());

            }

        }

    }

}