* Copyright (c) 2001, 2007 Oracle Corporation and others.

* All rights reserved. This program and the accompanying materials

* are made available under the terms of the Eclipse Public License v1.0

* which accompanies this distribution, and is available at

* http://www.eclipse.org/legal/epl-v10.html

*

* Contributors:

*     Oracle Corporation - initial API and implementation

*******************************************************************************/

* A default implementation of the drop location strategy

* @author cbateman

*

*/

    // the amount of vertical offset below the mouse pointer to place

    // the upper left of the drop hint tooltip

    private static final int DROP_HINT_VERTICAL_OFFSET = 20;

    /**

     * @param viewer

     */

    public DefaultDropLocationStrategy(EditPartViewer viewer) {

        super(viewer);

    }

    /* (non-Javadoc)

     * @see org.eclipse.jst.pagedesigner.viewer.AbstractDropLocationStrategy#calculateDesignPosition(org.eclipse.gef.EditPart, org.eclipse.draw2d.geometry.Point, org.eclipse.jst.pagedesigner.validation.caret.IPositionMediator)

     */

    @Override

    public DesignPosition calculateDesignPosition(EditPart host, Point p,

            IPositionMediator validator) {

        return EditPartPositionHelper.findEditPartPosition(

                host, p, validator);

    }

    /* (non-Javadoc)

     * @see org.eclipse.jst.pagedesigner.viewer.AbstractDropLocationStrategy#showTargetFeedback(org.eclipse.gef.EditPart, org.eclipse.jst.pagedesigner.viewer.DesignPosition, org.eclipse.gef.requests.DropRequest)

     */

    @Override

    public List showTargetFeedback(EditPart host, DesignPosition position, DropRequest request)

    {

        List feedback = new ArrayList(4);

        feedback.add(showFeedbackRect(createCaretBounds(position)));

        feedback.add(showDropHintLabel(request.getLocation(), position));

       

        return feedback;

    }

   

   

    /**

     * @param rect

     * @return the default rectangle figure for the requested visual rectangle

     */

    protected final RectangleFigure showFeedbackRect(Rectangle rect) {

        RectangleFigure pf = createFeedbackFigure();

        pf.translateToRelative(rect);

        pf.setBounds(rect);

        return pf;

    }

   

    /**

     * @param position

     * @return the bounding rectangle for the caret at the current

     * position in absolute coords

     */

    protected Rectangle createCaretBounds(DesignPosition position)

    {

        Rectangle rect = EditPartPositionHelper

            .convertToAbsoluteCaretRect(position);

        // to avoid enlarge feedback pane.

        rect = rect.intersect(getFeedbackLayer().getBounds());

       

        return rect;

    }

   

    /**

     * @return the newly created feedback figure

     */

    protected RectangleFigure createFeedbackFigure()

    {

        RectangleFigure feedbackFigure = new RectangleFigure();

        feedbackFigure.setFill(true);

        feedbackFigure.setOutline(true);

        feedbackFigure.setLineWidth(1);

        feedbackFigure.setForegroundColor(ColorConstants.red);

        feedbackFigure.setBounds(new Rectangle(0, 0, 0, 0));

        feedbackFigure.setXOR(true);

        addFeedback(feedbackFigure);

        return feedbackFigure;

    }

    /**

     * Shows a label in a position relative to the drop marker

     * that hints where the new component will be dropped in

     * respect of components already there

     * @param mousePosition

     * @param position

     * @return the drop hint label

     */

    protected final Label showDropHintLabel(Point mousePosition, DesignPosition position)

    {

        Label    dropHintLabel = new Label();

        dropHintLabel.setOpaque(true);

        dropHintLabel.setBackgroundColor(ColorConstants.tooltipBackground);

        dropHintLabel.setBorder(

                new LineBorder(ColorConstants.black, 1)

                {

                    // add an extra pixel of inset to make sure the text

                    // isn't pressed against the border

                    public Insets getInsets(IFigure figure) {

                        return new Insets(getWidth()+1);

                    }

                }

        );

        addFeedback(dropHintLabel);

        final String hintText = getDropHintText(position);

        dropHintLabel.setText(hintText);

        //TODO: need to handle viewport clipping and adjust label location appropriately

        Dimension hintSize = dropHintLabel.getPreferredSize();

        Point hintLocation = new Point(mousePosition.x, mousePosition.y+DROP_HINT_VERTICAL_OFFSET);

        Rectangle hintRect = new Rectangle(hintLocation, hintSize);

        //Bug 303524 - [WPE] design view flickers on dnd of jsf html column

        //    (translateToRelative BEFORE intersect, so intersection happens on final display bounds)

        dropHintLabel.translateToRelative(hintRect);

        // we need to intersect the rectangle with the feedback pane, otherwise, when the mouse

        // is dragged near the edge of the viewport with the drop hint active, the canvas will expand

        // away from the mouse.  In future a more ideal solution will be to relocate the tooltip

        // so that is is completely inside the viewport.

        hintRect = hintRect.intersect(getFeedbackLayer().getBounds());

        dropHintLabel.setBounds(hintRect);

       

        return dropHintLabel;

    }

   

    /**

     * @param position

     * @return the drop hint text for the current position

     */

    protected String getDropHintText(DesignPosition position)

    {

        StringBuffer buffer = new StringBuffer("Place"); //$NON-NLS-1$

       

        EditPart prevPart = position.getSiblingEditPart(false);

        EditPart nextPart = position.getSiblingEditPart(true);

        if (nextPart instanceof ElementEditPart)

        {

            buffer.append(" before "); //$NON-NLS-1$

            buffer.append(((ElementEditPart)nextPart).getTagConvert().getHostElement().getNodeName());

            buffer.append(","); //$NON-NLS-1$

        }

       

        if (prevPart instanceof ElementEditPart)

        {

            buffer.append(" after "); //$NON-NLS-1$

            buffer.append(((ElementEditPart)prevPart).getTagConvert().getHostElement().getNodeName());

            buffer.append(","); //$NON-NLS-1$

        }

       

        buffer.append(" inside "); //$NON-NLS-1$

        buffer.append(position.getContainerNode().getNodeName());

       

        return buffer.toString();

    }

}