org.eclipse.birt.report.designer.ui.preferences.SelectionButtonDialogField.java Source code

Introduction

Here is the source code for org.eclipse.birt.report.designer.ui.preferences.SelectionButtonDialogField.java

Source

/*******************************************************************************
 * Copyright (c) 2004 Actuate Corporation.
 * 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:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/

package org.eclipse.birt.report.designer.ui.preferences;

import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * Dialog Field containing a single button such as a radio or checkbox button.
 */
public class SelectionButtonDialogField extends DialogField {

    private Button fButton;
    private boolean fIsSelected;
    private DialogField[] fAttachedDialogFields;
    private int fButtonStyle;

    /**
     * Creates a selection button. Allowed button styles: SWT.RADIO, SWT.CHECK,
     * SWT.TOGGLE, SWT.PUSH
     */
    public SelectionButtonDialogField(int buttonStyle) {
        super();
        fIsSelected = false;
        fAttachedDialogFields = null;
        fButtonStyle = buttonStyle;
    }

    /**
     * Attaches a field to the selection state of the selection button. The
     * attached field will be disabled if the selection button is not selected.
     */
    public void attachDialogField(DialogField dialogField) {
        attachDialogFields(new DialogField[] { dialogField });
    }

    /**
     * Attaches fields to the selection state of the selection button. The
     * attached fields will be disabled if the selection button is not selected.
     */
    public void attachDialogFields(DialogField[] dialogFields) {
        fAttachedDialogFields = dialogFields;
        for (int i = 0; i < dialogFields.length; i++) {
            dialogFields[i].setEnabled(fIsSelected);
        }
    }

    /**
     * Returns <code>true</code> is teh gived field is attached to the
     * selection button.
     */
    public boolean isAttached(DialogField editor) {
        if (fAttachedDialogFields != null) {
            for (int i = 0; i < fAttachedDialogFields.length; i++) {
                if (fAttachedDialogFields[i] == editor) {
                    return true;
                }
            }
        }
        return false;
    }

    // ------- layout helpers

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

        Button button = getSelectionButton(parent);
        GridData gd = new GridData();
        gd.horizontalSpan = nColumns;
        gd.horizontalAlignment = GridData.FILL;
        if (fButtonStyle == SWT.PUSH) {
            GC gc = new GC(button.getFont().getDevice());
            gc.setFont(button.getFont());
            FontMetrics fFontMetrics = gc.getFontMetrics();
            gc.dispose();
            int widthHint = Dialog.convertHorizontalDLUsToPixels(fFontMetrics, IDialogConstants.BUTTON_WIDTH);
            gd.widthHint = Math.max(widthHint, button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x);
        }

        button.setLayoutData(gd);

        return new Control[] { button };
    }

    /*
     * @see DialogField#getNumberOfControls
     */
    public int getNumberOfControls() {
        return 1;
    }

    // ------- ui creation

    /**
     * Returns the selection button widget. When called the first time, the
     * widget will be created.
     * 
     * @param group
     *            The parent composite when called the first time, or
     *            <code>null</code> after.
     */
    public Button getSelectionButton(Composite group) {
        if (fButton == null) {
            assertCompositeNotNull(group);

            fButton = new Button(group, fButtonStyle);
            fButton.setFont(group.getFont());
            fButton.setText(fLabelText);
            fButton.setEnabled(isEnabled());
            fButton.setSelection(fIsSelected);
            fButton.addSelectionListener(new SelectionListener() {

                public void widgetDefaultSelected(SelectionEvent e) {
                    doWidgetSelected(e);
                }

                public void widgetSelected(SelectionEvent e) {
                    doWidgetSelected(e);
                }
            });
        }
        return fButton;
    }

    private void doWidgetSelected(SelectionEvent e) {
        if (isOkToUse(fButton)) {
            changeValue(fButton.getSelection());
        }
    }

    private void changeValue(boolean newState) {
        if (fIsSelected != newState) {
            fIsSelected = newState;
            if (fAttachedDialogFields != null) {
                boolean focusSet = false;
                for (int i = 0; i < fAttachedDialogFields.length; i++) {
                    fAttachedDialogFields[i].setEnabled(fIsSelected);
                    if (fIsSelected && !focusSet) {
                        focusSet = fAttachedDialogFields[i].setFocus();
                    }
                }
            }
            dialogFieldChanged();
        } else if (fButtonStyle == SWT.PUSH) {
            dialogFieldChanged();
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jdt.internal.ui.wizards.dialogfields.DialogField#setLabelText(java.lang.String)
     */
    public void setLabelText(String labeltext) {
        fLabelText = labeltext;
        if (isOkToUse(fButton)) {
            fButton.setText(labeltext);
        }
    }

    // ------ model access

    /**
     * Returns the selection state of the button.
     */
    public boolean isSelected() {
        return fIsSelected;
    }

    /**
     * Sets the selection state of the button.
     */
    public void setSelection(boolean selected) {
        changeValue(selected);
        if (isOkToUse(fButton)) {
            fButton.setSelection(selected);
        }
    }

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

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

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jdt.internal.ui.wizards.dialogfields.DialogField#refresh()
     */
    public void refresh() {
        super.refresh();
        if (isOkToUse(fButton)) {
            fButton.setSelection(fIsSelected);
        }
    }

}