org.jboss.tools.vpe.editor.preferences.SliderFieldEditor.java Source code

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Here is the source code for org.jboss.tools.vpe.editor.preferences.SliderFieldEditor.java

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/*******************************************************************************
 * Copyright (c) 2007-2009 Exadel, Inc. and Red Hat, Inc.
 * Distributed under license by Red Hat, Inc. All rights reserved.
 * This program is 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:
 *     Exadel, Inc. and Red Hat, Inc. - initial API and implementation
 ******************************************************************************/
package org.jboss.tools.vpe.editor.preferences;

import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Slider;

public class SliderFieldEditor extends FieldEditor {

    private static final String SLIDER_LABEL_DEFAULT_TEXT = "50% "; //$NON-NLS-1$
    private static final String SLIDER_LABEL_MAX_SIZE_TEXT = "100% "; //$NON-NLS-1$
    private static final int MAX_SLIDER_VALUE = 1000;
    private static final int MIN_SLIDER_VALUE = 0;
    private static final int INCREMENT_SLIDER_VALUE = 10;
    private static final int DEFAULT_SLIDER_VALUE = 500;

    private Composite sliderComposite;
    private Label sliderLabel;
    private Slider slider;
    private int value;

    public SliderFieldEditor(String name, String labelText, Composite parent) {
        super(name, labelText, parent);
    }

    @Override
    protected void adjustForNumColumns(int numColumns) {
        if (numColumns > 1) {
            Control control = getLabelControl();
            int left = numColumns;
            if (control != null) {
                ((GridData) control.getLayoutData()).horizontalSpan = 1;
                left = left - 1;
            }
            if (sliderComposite != null) {
                ((GridData) sliderComposite.getLayoutData()).horizontalSpan = left;
            }
        } else {
            Control control = getLabelControl();
            if (control != null) {
                ((GridData) control.getLayoutData()).horizontalSpan = 1;
            }
            if (sliderComposite != null) {
                ((GridData) sliderComposite.getLayoutData()).horizontalSpan = 1;
            }
        }
    }

    @Override
    protected void createControl(Composite parent) {
        doFillIntoGrid(parent, 1);
    }

    @Override
    protected void doFillIntoGrid(Composite parent, int numColumns) {
        int sliderSpan = 1;
        if (numColumns > 1) {
            sliderSpan = numColumns - 1;
        }
        Control control = getLabelControl(parent);
        GridData gd = new GridData();
        gd.horizontalSpan = 1;
        control.setLayoutData(gd);
        control = getSliderComposite(parent);
        gd = new GridData();
        gd.horizontalSpan = sliderSpan;
        gd.horizontalAlignment = GridData.FILL;
        control.setLayoutData(gd);
        control.setFont(parent.getFont());
    }

    @Override
    protected void doLoad() {
        updateSliderForValue(getPreferenceStore().getInt(getPreferenceName()));
    }

    @Override
    protected void doLoadDefault() {
        updateSliderForValue(getPreferenceStore().getDefaultInt(getPreferenceName()));
    }

    @Override
    protected void doStore() {
        if (value < 0) {
            getPreferenceStore().setToDefault(getPreferenceName());
            return;
        }
        getPreferenceStore().setValue(getPreferenceName(), value);
    }

    @Override
    public int getNumberOfControls() {
        return 2;
    }

    private Composite getSliderComposite(Composite parent) {
        if (sliderComposite == null) {
            /*
             * Create composite control with label and slider in it. 
             */
            sliderComposite = new Composite(parent, SWT.NONE);
            GridLayout gridLayout = new GridLayout();
            gridLayout.numColumns = 2;
            gridLayout.marginWidth = 0;
            gridLayout.marginHeight = 0;
            gridLayout.horizontalSpacing = HORIZONTAL_GAP;
            sliderComposite.setLayout(gridLayout);
            GridData gd = new GridData(SWT.FILL, SWT.NONE, true, false, 1, 1);
            sliderComposite.setLayoutData(gd);

            /*
             * Create slider label
             */
            sliderLabel = new Label(sliderComposite, SWT.NONE);
            gd = new GridData(SWT.LEFT, SWT.NONE, false, false, 1, 1);
            sliderLabel.setLayoutData(gd);
            /*
             * Compute label size
             */
            sliderLabel.setText(SLIDER_LABEL_MAX_SIZE_TEXT);
            Point size = sliderLabel.computeSize(SWT.DEFAULT, SWT.DEFAULT);
            sliderLabel.setSize(size);
            sliderLabel.setText(SLIDER_LABEL_DEFAULT_TEXT);

            /*
             * Create slider
             */
            slider = new Slider(sliderComposite, SWT.HORIZONTAL);
            gd = new GridData(SWT.FILL, SWT.NONE, true, false, 1, 1);
            slider.setLayoutData(gd);
            slider.setMaximum(MAX_SLIDER_VALUE + slider.getThumb());
            slider.setMinimum(MIN_SLIDER_VALUE);
            slider.setIncrement(INCREMENT_SLIDER_VALUE);
            slider.setSelection(DEFAULT_SLIDER_VALUE);

            slider.addSelectionListener(new SelectionAdapter() {
                @Override
                public void widgetSelected(SelectionEvent e) {
                    updateSlider();
                }
            });
        }

        return sliderComposite;
    }

    private void updateSlider() {
        int oldValue = value;
        value = slider.getSelection();
        if (oldValue != value) {
            setPresentsDefaultValue(false);
            String weightsString = "" + (value / 10) + "%"; //$NON-NLS-1$ //$NON-NLS-2$
            slider.setToolTipText(weightsString);
            sliderLabel.setText(weightsString);
            fireValueChanged(VALUE, oldValue, value);
        }
    }

    private void updateSliderForValue(int value) {
        if (slider != null) {
            String weightsString = "" + (value / 10) + "%"; //$NON-NLS-1$ //$NON-NLS-2$
            this.value = value;
            slider.setSelection(value);
            slider.setToolTipText(weightsString);
            sliderLabel.setText(weightsString);
        }
    }

}