/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

package javax.microedition.lcdui;

import org.eclipse.ercp.swt.mobile.CaptionedControl;

import org.eclipse.ercp.swt.mobile.MobileShell;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.FocusEvent;

import org.eclipse.swt.events.FocusListener;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

import org.eclipse.swt.widgets.*;

/**

 * Abstract base class for Item layouters.

 */

abstract class ItemLayouter {

    /**

     * Key name for paint listener.

     */

    private static final String FOCUS_LISTENER = "itemfocus";

    protected static final String MIN_TEXT = "...";

    protected DefaultFormInteraction dfi;

    protected Composite formComposite;

    private static Label staticLabel;

    private static CaptionedControl staticCC;

    private static MobileShell staticShell;

    private static Point captionedTrim;

    protected static int formWidth;

    protected static int formHeigh;

    /**

     * Gets static singleton off-screen Shell which can be used by item

     * layouters when creating temporary Controls.

     *

     * @return Static Shell. Never null.

     */

    static MobileShell eswtGetStaticShell() {

        if (staticShell == null) {

            staticShell = new MobileShell(ESWTUIThreadRunner.getInstance()

                    .getDisplay(), SWT.SYSTEM_MODAL | SWT.VERTICAL);

            staticShell.getVerticalBar().setVisible(true);

            formWidth = staticShell.getClientArea().width;

            formHeigh = staticShell.getClientArea().height;

        }

        return staticShell;

    }

    /**

     * Gets static singleton off-screen Label control.

     */

    private static Label eswtGetStaticLabel() {

        if (staticLabel == null) {

            staticLabel = new Label(eswtGetStaticShell(), SWT.NONE);

        }

        return staticLabel;

    }

    /**

     * Gets static singleton off-screen Captioned control.

     */

    private static CaptionedControl eswtGetStaticCC() {

        if (staticCC == null) {

            staticCC = new CaptionedControl(eswtGetStaticShell(), SWT.VERTICAL);

        }

        return staticCC;

    }

    /**

     * The static "layouting" shell's size is updated.

     */

    static void eswtUpdateStaticShellSize(int width, int height) {

        if (staticShell != null) {

            staticShell.setBounds(staticShell.computeTrim(0, 0, width, height));

            formWidth = width;

            formHeigh = height;

        }

    }

    /**

     * Constructor.

     *

     * @param dflp - DefaultFormLayoutPolicy used for layouting.

     */

    ItemLayouter(DefaultFormLayoutPolicy dflp) {

        this.dfi = (DefaultFormInteraction) dflp;

        formComposite = dflp.getForm().getFormComposite();

        ESWTUIThreadRunner.syncExec(new Runnable() {

            public void run() {

                ItemLayouter.eswtGetStaticShell();

            }

        });

    }

    /**

     * Label alignment directive.

     */

    int eswtGetLabelAlignmentDirective() {

        return dfi.getLanguageSpecificLayoutDirective();

    }

    /**

     * Layout Item in a row.

     *

     * @param row current Row

     * @param item Item to layout

     */

    void eswtLayoutItem(Row row, Item item) {

        LayoutObject lo = new LayoutObject(item, eswtGetCaptionedControl(item));

        dfi.eswtAddNewLayoutObject(lo);

    }

    /**

     * Wraps this item's control in the necessary composites.<br>

     * Based on the item, the result of this method can be:

     * <li> specific Control

     * <li> labeled CaptionedControl (containing the specific Control) <br>

     * <br>

     * The method will set the size of these using the eswtCaptionedResize

     * method.

     *

     * @param item Item to be layouted

     */

    final Control eswtGetCaptionedControl(Item item) {

        if (item.hasLabel()) {

            CaptionedControl captioned = new CaptionedControl(formComposite, SWT.VERTICAL);

            captioned.setText(item.getLabel());

            eswtGetControl(captioned, item);

            eswtCaptionedResize(item, captioned, item.getLayoutWidth(), item.getLayoutHeight());

            return captioned;

        }

        else {

            Control ret = eswtGetControl(formComposite, item);

            eswtCaptionedResize(item, ret, item.getLayoutWidth(), item.getLayoutHeight());

            return ret;

        }

    }

    /**

     * This abstract method creates the eSWT control.

     *

     * @param parent where to create

     * @param item on which it is based

     * @return Control

     */

    abstract Control eswtGetControl(Composite parent, Item item);

    /**

     * Update size of an LayoutObject.

     */

    final void eswtResizeObject(LayoutObject lo) {

        Item item = lo.getOwningItem();

        eswtCaptionedResize(item, lo.getControl(), item.getLayoutWidth(), item.getLayoutHeight());

        lo.eswtUpdateSize();

    }

    /**

     * Set the size of a LayoutObject.

     *

     * @param lo LayoutObject

     * @param width

     * @param height

     */

    final void eswtResizeObject(LayoutObject lo, int width, int height) {

        eswtCaptionedResize(lo.getOwningItem(), lo.getControl(), width, height);

        lo.eswtUpdateSize();

    }

    final void eswtCaptionedResize(Item item, Control control, int width, int height) {

        if (control instanceof CaptionedControl) {

            CaptionedControl cc = (CaptionedControl) control;

            cc.setSize(width, height);

            Rectangle ccArea = cc.getClientArea();

            eswtResizeControl(item, eswtFindSpecificControl(item, control),

                    ccArea.width, ccArea.height);

        }

        else {

            eswtResizeControl(item, eswtFindSpecificControl(item, control),

                    width, height);

        }

    }

    /**

     * Should be implemented in sub-classes where resizing might happen.

     *

     * @param item Item

     * @param control layouted Control

     * @param width item width.

     * @param height item height

     */

    void eswtResizeControl(Item item, Control control, int width, int height) {

        control.setSize(width, height);

    }

    /**

     * Add listeners to layouted control.

     *

     * @param item Item

     * @param lo LayoutObject

     */

    void eswtAddListeners(Item item, LayoutObject lo) {

        lo.eswtAddSelectionListenerForCommands();

        Control specific = eswtFindSpecificControl(item, lo.getControl());

        if (specific != null) {

            eswtAddSpecificListeners(item, specific);

        }

        else {

            Logger.warning(this + "::eswtAddListeners didnt find control for " + item);

        }

    }

    /**

     * Add listeners to Layouter specific control.

     *

     * @param item Item

     * @param control specific Control

     */

    void eswtAddSpecificListeners(Item item, Control control) {

        if (item.isFocusable()) {

            ItemFocusListener ifl = new ItemFocusListener(item);

            control.addFocusListener(ifl);

            control.setData(FOCUS_LISTENER, ifl);

        }

    }

    /**

     * Remove listeners from layouted control.

     *

     * @param item Item

     * @param lo LayoutObject

     */

    void eswtRemoveListeners(Item item, LayoutObject lo) {

        lo.eswtRemoveSelectionListenerForCommands();

        Control specific = eswtFindSpecificControl(item, lo.getControl());

        if (specific != null) {

            eswtRemoveSpecificListeners(item, specific);

        }

        else {

            Logger.warning(this + "::eswtRemoveListeners didnt find control for " + item);

        }

    }

    /**

     * Remove listeners from Layouter specific control.

     *

     * @param item Item

     * @param control specific Control

     */

    void eswtRemoveSpecificListeners(Item item, Control control) {

        if (item.isFocusable()) {

            ItemFocusListener ifl = (ItemFocusListener) control

                    .getData(FOCUS_LISTENER);

            if (ifl != null) {

                control.removeFocusListener(ifl);

                control.setData(FOCUS_LISTENER, null);

            }

        }

    }

    /**

     * Update control of an Item.

     *

     * @param item Item to update

     * @param reason reason of update

     * @param param optional parameter

     */

    final void updateItem(final Item item, final Control control,

            final int reason, final Object param) {

        ESWTUIThreadRunner.syncExec(new Runnable() {

            public void run() {

                Control specific = eswtFindSpecificControl(item, control);

                if (specific != null) {

                    if (!specific.isDisposed()) {

                        eswtUpdateItem(item, specific, reason, param);

                    }

                    else {

                        Logger.warning(ItemLayouter.this

                                + "::updateItem found a disposed widget for " + item);

                    }

                }

                else {

                    Logger.warning(ItemLayouter.this

                            + "::updateItem didnt find control for " + item);

                }

            }

        });

    }

    /**

     * This abstract method updates the eSWT control.

     *

     * @param item Item to update

     * @param control layouted eSWT control

     * @param reason reason of update

     * @param param optional parameter

     */

    abstract void eswtUpdateItem(Item item, Control control, int reason,

            Object param);

    /**

     * Finds the Layouter specific eSWT control in the eSWT Composite tree.

     *

     * @param item Item

     * @param control eSWT control

     * @return a specific control or null if not found

     */

    final Control eswtFindSpecificControl(Item item, Control control) {

        Control ret = null;

        if (eswtIsSpecificControl(item, control)) {

            ret = control;

        }

        else if (control != null && control instanceof Composite) {

            Control[] children = ((Composite) control).getChildren();

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

                Control result = eswtFindSpecificControl(item, children[i]);

                if (result != null) {

                    ret = result;

                    break;

                }

            }

        }

        return ret;

    }

    /**

     * Returns the unlocked preferred size needed to display an Item.

     * Subclasses may overwrite this. By default returns (0,0).

     *

     * @param item Item.

     * @return Preferred area needed to display Item. x is width

     *      and y is height.

     */

    static Point calculatePreferredBounds(Item item) {

        return new Point(0, 0);

    }

    /**

     * Returns if this eSWT control is Layouter specific.

     *

     * @param item Item

     * @param control eSWT control

     * @return true if this is Layouter specific

     */

    abstract boolean eswtIsSpecificControl(Item item, Control control);

    /**

     * Gets the first control of an Item.

     *

     * @param item Item

     * @return layouted Control

     */

    Control eswtGetFirstControl(Item item) {

        LayoutObject lo = dfi.getFirstLayoutObjectOfItem(item);

        if (lo != null) {

            return lo.getControl();

        }

        return null;

    }

    /**

     * Gets the first layouter specific control of an Item.

     *

     * @param item Item

     * @return layouted specific Control

     */

    Control eswtGetFirstSpecificControl(Item item) {

        LayoutObject lo = dfi.getFirstLayoutObjectOfItem(item);

        if (lo != null) {

            Control control = lo.getControl();

            if (control != null) {

                return eswtFindSpecificControl(item, control);

            }

        }

        return null;

    }

    /**

     * Offers a key event to be consumed by the control.<br>

     * If the key is not consumed (default) then it's used for scrolling.

     *

     * @param item Item

     * @param key eSWT key code

     * @param type eSWT key type

     * @return if the key was consumed or not

     */

    boolean eswtOfferKeyEvent(Item item, int key, int type) {

        if (type == SWT.KeyDown) {

            return eswtOfferKeyPressed(item, key);

        }

        else if (type == SWT.KeyUp) {

            return eswtOfferKeyReleased(item, key);

        }

        else {

            return eswtOfferKeyRepeated(item, key);

        }

    }

    boolean eswtOfferKeyPressed(Item item, int key) {

        // Do not consume these by default

        return false;

    }

    boolean eswtOfferKeyRepeated(Item item, int key) {

        // Do not consume these by default

        return false;

    }

    boolean eswtOfferKeyReleased(Item item, int key) {

        // Do not consume these by default

        return false;

    }

    /**

     * Processing for item when it gets focus.

     *

     * @param item

     * @param dir

     */

    void eswtFocusGained(Item item, int dir) {

        Logger.method(item, "focusGained", String.valueOf(dir));

        item.internalSetFocused(true);

    }

    /**

     * Processing for item when it looses focus.

     *

     * @param item item which looses focus.

     */

    void eswtFocusLost(Item item) {

        Logger.method(item, "focusLost");

        item.internalSetFocused(false);

    }

    final void eswtHandleVisibilityChange(Item item, boolean visible) {

        if (item.isVisible() != visible) {

            item.internalSetVisible(visible);

            if (visible) {

                eswtHandleShow(item);

            }

            else {

                eswtHandleHide(item);

            }

        }

    }

    /**

     * Special processing of Item when it becomes visible.

     *

     * @param item which becomes visible.

     */

    void eswtHandleShow(Item item) {

        // Implementation not needed. Subclasses may override.

    }

    /**

     * Special processing for item which becomes not visible due to scrolling.

     *

     * @param item which becomes hidden.

     */

    void eswtHandleHide(Item item) {

        // Implementation not needed. Subclasses may override.

    }

    static void applyMinMargins(Item item, Point size) {

        if (item.hasLabel()) {

            applyCaptionedTrim(MIN_TEXT, size);

        }

        size.x = Math.min(size.x, formWidth);

    }

    static void applyPrefMargins(Item item, Point size) {

        if (item.hasLabel()) {

            applyCaptionedTrim(item.getLabel(), size);

        }

        size.x = Math.min(size.x, formWidth);

    }

    static final void applyCaptionedTrim(final String text, Point size) {

        final Point localSize = size;

        ESWTUIThreadRunner.syncExec(new Runnable() {

            public void run() {

                CaptionedControl cc = eswtGetStaticCC();

                cc.setText(text);

                Rectangle rect = cc.computeTrim(0, 0, localSize.x, localSize.y);

                captionedTrim = new Point(rect.width, rect.height);

            }

        });

        size.x = captionedTrim.x;

        size.y = captionedTrim.y;

    }

    /**

     * Applies the label size to the unlocked preferred area needed to display

     * an Item.

     *

     * @param size

     *            Point where the Label's size is added.

     * @param item

     *            Item containing the label.

     */

    static Point getLabelSize(final String labelStr) {

        final Point size = new Point(0, 0);

        ESWTUIThreadRunner.syncExec(new Runnable() {

            public void run() {

                Label label = eswtGetStaticLabel();

                label.setText(labelStr);