/*******************************************************************************
 * Copyright (c) 2011 Google, Inc.
 * 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:
 *    Google, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.wb.internal.core.model.property.editor;

import org.eclipse.wb.core.controls.CCombo3;
import org.eclipse.wb.core.controls.CComboBox;
import org.eclipse.wb.internal.core.model.property.Property;
import org.eclipse.wb.internal.core.model.property.table.PropertyTable;
import org.eclipse.wb.internal.core.utils.execution.ExecutionUtils;
import org.eclipse.wb.internal.core.utils.execution.RunnableEx;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;

/**
 * The {@link PropertyEditor} for selecting single value using {@link CComboBox}. This editor has
 * in-line search-feature and is more suitable (vs {@link AbstractComboPropertyEditor}) for
 * properties with large lists of value items.
 * 
 * @author sablin_aa
 * @author scheglov_ke
 * @coverage core.model.property.editor
 */
public abstract class AbstractComboBoxPropertyEditor extends TextDisplayPropertyEditor {
  ////////////////////////////////////////////////////////////////////////////
  //
  // Editing
  //
  ////////////////////////////////////////////////////////////////////////////
  private CComboBox m_combo;
  private String m_dropDelayedText;

  @Override
  public final boolean activate(final PropertyTable propertyTable,
      final Property property,
      Point location) throws Exception {
    m_combo = new CComboBox(propertyTable, SWT.NONE);
    // initialize
    addItems(property, m_combo);
    selectItem(property, m_combo);
    // install listeners
    m_combo.addKeyListener(new KeyAdapter() {
      @Override
      public void keyPressed(KeyEvent e) {
        handleKeyPressed(propertyTable, property, e);
      }
    });
    m_combo.addFocusListener(new FocusAdapter() {
      @Override
      public void focusLost(FocusEvent e) {
        propertyTable.deactivateEditor(true);
      }
    });
    m_combo.addSelectionListener(new SelectionAdapter() {
      @Override
      public void widgetSelected(SelectionEvent e) {
        propertyTable.deactivateEditor(true);
      }
    });
    m_combo.setFocus();
    // schedule showing drop-down, because we don't have bounds yet
    ExecutionUtils.runAsync(new RunnableEx() {
      public void run() throws Exception {
        m_combo.comboDropDown(true);
        if (m_dropDelayedText != null) {
          m_combo.setEditText(m_dropDelayedText);
          m_combo.setEditSelection(m_dropDelayedText.length(), m_dropDelayedText.length());
          m_dropDelayedText = null;
        }
      }
    });
    // keep editor active
    return true;
  }

  private void handleKeyPressed(PropertyTable propertyTable, Property property, KeyEvent e) {
    if (e.keyCode == SWT.ESC) {
      propertyTable.deactivateEditor(false);
    } else if (e.keyCode == SWT.ARROW_UP || e.keyCode == SWT.ARROW_DOWN) {
      e.doit = false;
      propertyTable.deactivateEditor(true);
      propertyTable.navigate(e);
    }
  }

  @Override
  public final void deactivate(PropertyTable propertyTable, Property property, boolean save) {
    if (save) {
      toProperty(propertyTable, property);
    }
    if (m_combo != null) {
      m_combo.dispose();
      m_combo = null;
    }
  }

  private void toProperty(PropertyTable propertyTable, Property property) {
    try {
      toPropertyEx(property, m_combo);
    } catch (Throwable e) {
      propertyTable.handleException(e);
    }
  }

  @Override
  public void setBounds(Rectangle bounds) {
    m_combo.setBounds(bounds);
  }

  @Override
  public void keyDown(PropertyTable propertyTable, Property property, KeyEvent event)
      throws Exception {
    boolean withAlt = (event.stateMask & SWT.ALT) != 0;
    boolean withCtrl = (event.stateMask & SWT.CTRL) != 0;
    if (event.character > 0x20 && !(withAlt || withCtrl)) {
      propertyTable.activateEditor(property, null);
      m_dropDelayedText = "" + event.character;
    }
  }

  ////////////////////////////////////////////////////////////////////////////
  //
  // Abstract methods
  //
  ////////////////////////////////////////////////////////////////////////////
  /**
   * Adds items to given {@link CComboBox}.
   */
  protected abstract void addItems(Property property, CComboBox combo) throws Exception;

  /**
   * Selects current item in given {@link CCombo3}.
   */
  protected void selectItem(Property property, CComboBox combo) throws Exception {
  }

  /**
   * Transfers data from widget to {@link Property}.
   */
  protected abstract void toPropertyEx(Property property, CComboBox combo) throws Exception;
}