org.eclipse.riena.internal.ui.ridgets.swt.CComboRidget.java Source code

Introduction

Here is the source code for org.eclipse.riena.internal.ui.ridgets.swt.CComboRidget.java

Source

/*******************************************************************************
 * Copyright (c) 2007, 2013 compeople AG 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:
 *    compeople AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.riena.internal.ui.ridgets.swt;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import org.eclipse.core.databinding.BindingException;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.jface.databinding.swt.ISWTObservableValue;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CCombo;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Color;

import org.eclipse.riena.ui.ridgets.ICComboRidget;
import org.eclipse.riena.ui.ridgets.IRidget;
import org.eclipse.riena.ui.ridgets.swt.AbstractComboRidget;

/**
 * Ridget for {@link CCombo} widgets.
 */
public class CComboRidget extends AbstractComboRidget implements ICComboRidget {

    private static final String ORIGINAL_BACKGROUND_KEY = "CCR.orBaKe"; //$NON-NLS-1$

    private final ModifyListener modifyListener;

    public CComboRidget() {
        modifyListener = new CComboModifyListener();
        addPropertyChangeListener(IRidget.PROPERTY_ENABLED, new PropertyChangeListener() {
            public void propertyChange(final PropertyChangeEvent evt) {
                if (getUIControl() != null) {
                    final boolean isEnabled = ((Boolean) evt.getNewValue()).booleanValue();
                    updateBgColor(isEnabled);
                }
            }
        });

    }

    @Override
    public CCombo getUIControl() {
        return (CCombo) super.getUIControl();
    }

    @Override
    protected void addSelectionListener(final org.eclipse.swt.events.SelectionListener listener) {
        getUIControl().addSelectionListener(listener);
    }

    @Override
    protected void addTextModifyListener() {
        getUIControl().addModifyListener(modifyListener);
    }

    @Override
    protected void bindUIControl() {
        super.bindUIControl();
        if (getUIControl() != null) {
            updateBgColor(isEnabled());
        }
    }

    @Override
    protected void checkUIControl(final Object uiControl) {
        checkType(uiControl, CCombo.class);
        if (uiControl != null) {
            final int style = ((CCombo) uiControl).getStyle();
            if ((style & SWT.READ_ONLY) == 0) {
                throw new BindingException("Combo must be READ_ONLY"); //$NON-NLS-1$
            }
        }
    }

    @Override
    protected void clearUIControlListSelection() {
        getUIControl().deselectAll();
        // Workaround for an SWT feature: when the user clicks in the list,
        // an asynchronous selection event is added to the end of the event 
        // queue, which will silenty an item. We asynchronously clear the list 
        // as well
        getUIControl().getDisplay().asyncExec(new Runnable() {
            public void run() {
                final CCombo combo = getUIControl();
                if (combo != null && !combo.isDisposed()) {
                    combo.clearSelection(); // this does not change the text
                }
            }
        });
    }

    @Override
    protected String[] getUIControlItems() {
        return getUIControl().getItems();
    }

    @Override
    protected IObservableList getUIControlItemsObservable() {
        return SWTObservables.observeItems(getUIControl());
    }

    @Override
    protected ISWTObservableValue getUIControlSelectionObservable() {
        return SWTObservables.observeSelection(getUIControl());
    }

    @Override
    protected String getUIControlText() {
        return getUIControl().getText();
    }

    @Override
    protected int indexOfInUIControl(final String item) {
        return getUIControl().indexOf(item);
    }

    @Override
    protected void removeAllFromUIControl() {
        getUIControl().removeAll();
    }

    @Override
    protected void removeSelectionListener(final SelectionListener listener) {
        getUIControl().removeSelectionListener(listener);
    }

    @Override
    protected void removeTextModifyListener() {
        getUIControl().removeModifyListener(modifyListener);
    }

    @Override
    protected void selectInUIControl(final int index) {
        getUIControl().select(index);
    }

    @Override
    protected void setItemsToControl(final String[] arrItems) {
        getUIControl().setItems(arrItems);
    }

    @Override
    protected void setTextToControl(final String text) {
        getUIControl().setText(text);
    }

    @Override
    protected void updateEditable() {
        // unused
    }

    // helping methods
    //////////////////

    /**
     * This was introduced as to address Bug 323449.
     * <p>
     * The Text/CCombo widgets will not change their background to gray when disabled, once a non-null background color has been used in the enabled state.
     */
    private void updateBgColor(final boolean isEnabled) {
        // pre-condition: control is known to be != null
        final CCombo control = getUIControl();
        if (isEnabled) {
            if (control.getData(ORIGINAL_BACKGROUND_KEY) != null) {
                control.setBackground((Color) control.getData(ORIGINAL_BACKGROUND_KEY));
                control.setData(ORIGINAL_BACKGROUND_KEY, null);
            }
        } else {
            if (control.getData(ORIGINAL_BACKGROUND_KEY) == null) {
                control.setData(ORIGINAL_BACKGROUND_KEY, control.getBackground());
            }
            final Color disabledBg = control.getDisplay().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND);
            // note: the DisabledPainter will paint the DISABLED_MARKER_BACKGROUND over this, so we are good
            control.setBackground(disabledBg);
        }
        updateMarkers();
    }

    // helping classes
    //////////////////

    /**
     * Keeps the ridget's text value in-sync with the widget's text value
     */
    private final class CComboModifyListener implements ModifyListener {
        public void modifyText(final ModifyEvent e) {
            if (!isOutputOnly()) {
                setText(getUIControlText());
            }
        }
    }
}