/*
* Copyright (c) 2010-2012 Research In Motion Limited. All rights reserved.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Public License, Version 1.0,
* which accompanies this distribution and is available at
*
* http://www.eclipse.org/legal/epl-v10.html
*
*/
package net.rim.ejde.internal.ui.widgets.dialog;

import org.eclipse.jdt.internal.ui.util.SWTUtil;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;

/**
 * Dialog field containing a label, text control and a button control.
 */
public class StringButtonDialogField extends StringDialogField {

    private Button fBrowseButton;
    private String fBrowseButtonLabel;
    private IStringButtonAdapter fStringButtonAdapter;

    private boolean fButtonEnabled;

    public StringButtonDialogField( IStringButtonAdapter adapter ) {
        super();
        fStringButtonAdapter = adapter;
        fBrowseButtonLabel = "!Browse...!"; //$NON-NLS-1$
        fButtonEnabled = true;
    }

    /**
     * Sets the label of the button.
     */
    public void setButtonLabel( String label ) {
        fBrowseButtonLabel = label;
    }

    // ------ adapter communication

    /**
     * Programmatical pressing of the button
     */
    public void changeControlPressed() {
        fStringButtonAdapter.changeControlPressed( this );
    }

    // ------- layout helpers

    /*
     * @see DialogField#doFillIntoGrid
     */
    public Control[] doFillIntoGrid( Composite parent, int nColumns ) {
        assertEnoughColumns( nColumns );

        Label label = getLabelControl( parent );
        label.setLayoutData( gridDataForLabel( 1 ) );
        Text text = getTextControl( parent );
        text.setLayoutData( gridDataForText( nColumns - 2 ) );
        Button button = getChangeControl( parent );
        button.setLayoutData( gridDataForButton( button, 1 ) );

        return new Control[] { label, text, button };
    }

    /*
     * @see DialogField#getNumberOfControls
     */
    public int getNumberOfControls() {
        return 3;
    }

    protected static GridData gridDataForButton( Button button, int span ) {
        GridData gd = new GridData();
        gd.horizontalAlignment = GridData.FILL;
        gd.grabExcessHorizontalSpace = false;
        gd.horizontalSpan = span;
        gd.widthHint = SWTUtil.getButtonWidthHint( button );
        return gd;
    }

    // ------- ui creation

    /**
     * Creates or returns the created buttom widget.
     *
     * @param parent
     *            The parent composite or <code>null</code> if the widget has already been created.
     */
    public Button getChangeControl( Composite parent ) {
        if( fBrowseButton == null ) {
            assertCompositeNotNull( parent );

            fBrowseButton = new Button( parent, SWT.PUSH );
            fBrowseButton.setFont( parent.getFont() );
            fBrowseButton.setText( fBrowseButtonLabel );
            fBrowseButton.setEnabled( isEnabled() && fButtonEnabled );
            fBrowseButton.addSelectionListener( new SelectionListener() {
                public void widgetDefaultSelected( SelectionEvent e ) {
                    changeControlPressed();
                }

                public void widgetSelected( SelectionEvent e ) {
                    changeControlPressed();
                }
            } );

        }
        return fBrowseButton;
    }

    // ------ enable / disable management

    /**
     * Sets the enable state of the button.
     */
    public void enableButton( boolean enable ) {
        if( isOkToUse( fBrowseButton ) ) {
            fBrowseButton.setEnabled( isEnabled() && enable );
        }
        fButtonEnabled = enable;
    }

    /*
     * @see DialogField#updateEnableState
     */
    protected void updateEnableState() {
        super.updateEnableState();
        if( isOkToUse( fBrowseButton ) ) {
            fBrowseButton.setEnabled( isEnabled() && fButtonEnabled );
        }
    }
}