javauis/eswt_qt/org.eclipse.swt/Eclipse SWT/qt/org/eclipse/swt/widgets/Combo.java
branchRCL_3
changeset 65 ae942d28ec0e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/javauis/eswt_qt/org.eclipse.swt/Eclipse SWT/qt/org/eclipse/swt/widgets/Combo.java	Tue Aug 31 15:09:22 2010 +0300
@@ -0,0 +1,1350 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2004 IBM Corporation and others.
+ * Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
+ * 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:
+ *     IBM Corporation - initial API and implementation
+ *     Lynne Kues (IBM Corp) - modified to reflect eSWT API subset
+ *     Nokia Corporation - S60 implementation
+ *     Nokia Corporation - Qt implementation
+ *******************************************************************************/
+package org.eclipse.swt.widgets;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.ModifyListener;
+import org.eclipse.swt.events.SelectionListener;
+import org.eclipse.swt.events.VerifyListener;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.graphics.Internal_GfxPackageSupport;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.graphics.Rectangle;
+import org.eclipse.swt.internal.qt.OS;
+import org.eclipse.swt.internal.qt.TextUtils;
+import org.eclipse.swt.internal.qt.WidgetConstant;
+import org.eclipse.swt.internal.qt.WidgetState;
+
+/**
+ * Instances of this class are controls that allow the user to choose an item
+ * from a list of items, or optionally enter a new value by typing it into an
+ * editable text field. Often, <code>Combo</code>s are used in the same place
+ * where a single selection <code>List</code> widget could be used but space is
+ * limited. A <code>Combo</code> takes less space than a <code>List</code>
+ * widget and shows similar information.
+ * <p>
+ * Note: Since <code>Combo</code>s can contain both a list and an editable text
+ * field, it is possible to confuse methods which access one versus the other
+ * (compare for example, <code>clearSelection()</code> and
+ * <code>deselectAll()</code>). The API documentation is careful to indicate
+ * either "the receiver's list" or the "the receiver's text field" to
+ * distinguish between the two cases.
+ * </p>
+ * <p>
+ * Note that although this class is a subclass of <code>Composite</code>, it
+ * does not make sense to add children to it, or set a layout on it.
+ * </p>
+ * <dl>
+ * <dt><b>Styles:</b></dt>
+ * <dd>DROP_DOWN, READ_ONLY</dd>
+ * <dt><b>Events:</b></dt>
+ * <dd>DefaultSelection, Modify, Selection</dd>
+ * </dl>
+ * <p>
+ * </p>
+ * <p>
+ * IMPORTANT: This class is <em>not</em> intended to be subclassed.
+ * </p>
+ * 
+ * @see List
+ */
+
+public class Combo extends Composite {
+
+    int comboTextHandle; // needed for mouse events and defaultSelection
+
+    /**
+     * the operating system limit for the number of characters that the text
+     * field in an instance of this class can hold
+     */
+    public static final int LIMIT = 32767;
+
+    /**
+     * Constructs a new instance of this class given its parent and a style
+     * value describing its behavior and appearance.
+     * <p>
+     * The style value is either one of the style constants defined in class
+     * <code>SWT</code> which is applicable to instances of this class, or must
+     * be built by <em>bitwise OR</em>'ing together (that is, using the
+     * <code>int</code> "|" operator) two or more of those <code>SWT</code>
+     * style constants. The class description lists the style constants that are
+     * applicable to the class. Style bits are also inherited from superclasses.
+     * </p>
+     * 
+     * @param parent
+     *            a composite control which will be the parent of the new
+     *            instance (cannot be null)
+     * @param style
+     *            the style of control to construct
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the parent</li>
+     *                <li>ERROR_INVALID_SUBCLASS - if this class is not an
+     *                allowed subclass</li>
+     *                </ul>
+     * 
+     * @see SWT#DROP_DOWN
+     * @see SWT#READ_ONLY
+     * @see Widget#checkSubclass
+     * @see Widget#getStyle
+     */
+    public Combo(Composite parent, int style) {
+        super(parent, style);
+    }
+
+    void createHandle_pp(int index) {
+        topHandle = handle = OS.QComboBox_new();
+        // QComboBox to use text editor instead of button
+        OS.QComboBox_setEditable(handle, true);
+        OS.QComboBox_setSizeAdjustPolicy(handle,
+                OS.QT_QComboBox_AdjustToMinimumContentsLength);
+        // not to add edited text at the end
+        OS.QComboBox_setInsertPolicy(handle, OS.QT_QComboBox_NoInsert);
+        comboTextHandle = OS.QComboBox_lineEdit(handle);
+        if ((style & SWT.READ_ONLY) != 0) {
+            OS.QLineEdit_setReadOnly(comboTextHandle, true);
+        }
+        state |= WidgetState.HANDLE;
+    }
+
+    void register_pp() {
+        super.register_pp();
+        Display.addWidget(comboTextHandle, this);
+    }
+
+    void deregister_pp() {
+        super.deregister_pp();
+        Display.removeWidget(comboTextHandle);
+    }
+
+    void releaseHandle_pp() {
+        comboTextHandle = 0;
+        super.releaseHandle_pp();
+    }
+
+    /**
+     * Adds the argument to the end of the receiver's list.
+     * 
+     * @param string
+     *            the new item
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see #add(String,int)
+     */
+    public void add(String string) {
+        add(string, getItemCount());
+    }
+
+    /**
+     * Adds the argument to the receiver's list at the given zero-relative
+     * index.
+     * <p>
+     * Note: To add an item at the end of the list, use the result of calling
+     * <code>getItemCount()</code> as the index or use <code>add(String)</code>.
+     * </p>
+     * 
+     * @param string
+     *            the new item
+     * @param index
+     *            the index for the item
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                <li>ERROR_INVALID_RANGE - if the index is not between 0
+     *                and the number of elements in the list (inclusive)</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see #add(String)
+     */
+    public void add(String string, int index) {
+        checkWidget();
+        if (string == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        int count = getItemCount();
+        if (!(index <= count && index >= 0))
+            error(SWT.ERROR_INVALID_RANGE);
+        OS.QComboBox_insertItem(topHandle, string, index);
+    }
+
+    /**
+     * Adds the listener to the collection of listeners who will be notified
+     * when the receiver's text is modified, by sending it one of the messages
+     * defined in the <code>ModifyListener</code> interface.
+     * 
+     * @param listener
+     *            the listener which should be notified
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see ModifyListener
+     * @see #removeModifyListener
+     */
+    public void addModifyListener(ModifyListener listener) {
+        checkWidget();
+        if (listener == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        TypedListener typedListener = new TypedListener(listener);
+        addListener(SWT.Modify, typedListener);
+    }
+
+    /**
+     * Adds the listener to the collection of listeners who will be notified
+     * when the receiver's text is verified, by sending it one of the messages
+     * defined in the <code>VerifyListener</code> interface.
+     * 
+     * @param listener
+     *            the listener which should be notified
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see VerifyListener
+     * @see #removeVerifyListener
+     */
+    public void addVerifyListener(VerifyListener listener) {
+        checkWidget();
+        if (listener == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        TypedListener typedListener = new TypedListener(listener);
+        addListener(SWT.Verify, typedListener);
+    }
+
+    /**
+     * Adds the listener to the collection of listeners who will be notified
+     * when the receiver's selection changes, by sending it one of the messages
+     * defined in the <code>SelectionListener</code> interface.
+     * <p>
+     * <code>widgetSelected</code> is called when the combo's list selection
+     * changes. <code>widgetDefaultSelected</code> is typically called when
+     * ENTER is pressed the combo's text area.
+     * </p>
+     * 
+     * @param listener
+     *            the listener which should be notified
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see SelectionListener
+     * @see #removeSelectionListener
+     * @see SelectionEvent
+     */
+    public void addSelectionListener(SelectionListener listener) {
+        checkWidget();
+        if (listener == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        TypedListener typedListener = new TypedListener(listener);
+        addListener(SWT.Selection, typedListener);
+        addListener(SWT.DefaultSelection, typedListener);
+    }
+
+    void hookEvents_pp() {
+        super.hookEvents_pp();
+
+        int selectionSignalProxy = OS.SignalHandler_new(topHandle,
+                OS.QSIGNAL_SELECTIONCHANGED);
+        OS.QObject_connectOrThrow(topHandle,
+                "currentIndexChanged(const QString&)", selectionSignalProxy,
+                "widgetSignal(const QString&)", OS.QT_AUTOCONNECTION);
+
+        int returnPressedProxy = OS.SignalHandler_new(comboTextHandle, 
+                OS.QSIGNAL_RETURN_PRESSED);
+        OS.QObject_connectOrThrow(comboTextHandle, "returnPressed()",
+                returnPressedProxy, "widgetSignal()", OS.QT_AUTOCONNECTION);
+
+        int modifySignalProxy = OS.SignalHandler_new(topHandle,
+                OS.QSIGNAL_TEXT_CHANGED);
+        OS.QObject_connectOrThrow(topHandle,
+                "editTextChanged(const QString&)", modifySignalProxy,
+                "widgetSignal(const QString&)", OS.QT_AUTOCONNECTION);
+    }
+
+    void qt_signal_text_changed_pp(String text) {
+        sendEvent(SWT.Modify);
+    }
+
+    void qt_signal_selectionChanged_pp(int selectionHandle,
+            int deSelectionHandle) {
+        // this is hack to select text in combo editor when changes the current
+        // item in combo
+        setSelection(new Point(0, OS.QLineEdit_text(comboTextHandle).length()));
+        sendEvent(SWT.Selection);
+    }
+
+    void qt_signal_return_pressed_pp() {
+        sendEvent(SWT.DefaultSelection);
+    }
+
+    boolean qt_event_keypress_pp(int widgetHandle, int key,
+            int modifier, int character, int nativeScanCode) {
+        if (super.qt_event_keypress_pp(widgetHandle, key, modifier, character, nativeScanCode))
+            return true;
+        
+        if (!(hooks(SWT.Verify) || filters(SWT.Verify)) && getTextLimit() <= 0) {
+            return false;
+        }
+
+        Event keyEv = makeKeyEvent(key, modifier, character, nativeScanCode);
+        return TextUtils.handle_keypress(TextUtils.LINE_EDIT, comboTextHandle, 
+            key, modifier, character, keyEv, getTextLimit(), this);
+
+    }
+
+    int getTraversalTypeForKey(int key, int modifier, int character) {
+
+        int type = 0;
+        switch (key) {
+        case OS.QT_KEY_ENTER:
+        case OS.QT_KEY_RETURN:
+            type = SWT.TRAVERSE_NONE;
+            break;
+        default:
+            type = super.getTraversalTypeForKey(key, modifier, character);
+            break;
+        }
+        return type;
+    }
+
+    void setTraversalFlags_pp(int type, int key, int modifier,
+            int character) {
+        traverseDoit = false;
+        traverseCancel = false;
+
+        // If the system is about to traverse out of the Text because mnemonic
+        // shortcut of some widget was pressed then it is allowed.
+        // Note that if keys used to launch shortcuts overlap the keys that are
+        // used
+        // by Text then shortcut has priority over text with this
+        // implementation.
+        // However, platforms usually define the shortucts in such a way that
+        // they
+        // don't overlap. E.g. in X11 Alt+something.
+        if (type == SWT.TRAVERSE_MNEMONIC) {
+            traverseDoit = true;
+            return;
+        }
+
+        switch (key) {
+        case OS.QT_KEY_ENTER:
+        case OS.QT_KEY_RETURN:
+            traverseDoit = false;
+            break;
+        case OS.QT_KEY_TAB:
+            traverseDoit = true;
+            break;
+        case OS.QT_KEY_LEFT:
+        case OS.QT_KEY_RIGHT:
+            traverseDoit = false;
+            break;
+        case OS.QT_KEY_UP:
+        case OS.QT_KEY_DOWN:
+            traverseDoit = true;
+            break;
+        default:
+            break;
+        }
+    }
+
+    /**
+     * Sets the selection in the receiver's text field to an empty selection
+     * starting just before the first character. If the text field is editable,
+     * this has the effect of placing the i-beam at the start of the text.
+     * <p>
+     * Note: To clear the selected items in the receiver's list, use
+     * <code>deselectAll()</code>.
+     * </p>
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see #deselectAll
+     */
+    public void clearSelection() {
+        checkWidget();
+        OS.QLineEdit_setCursorPosition(comboTextHandle, 0);
+    }
+
+    /**
+     * Copies the selected text.
+     * <p>
+     * The current selection is copied to the clipboard.
+     * </p>
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 2.1
+     */
+    public void copy() {
+        checkWidget();
+        TextUtils.copy(TextUtils.LINE_EDIT, comboTextHandle);
+    }
+
+    /**
+     * Cuts the selected text.
+     * <p>
+     * The current selection is first copied to the clipboard and then deleted
+     * from the widget.
+     * </p>
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 2.1
+     */
+    public void cut() {
+        checkWidget();
+        TextUtils.cut(TextUtils.LINE_EDIT, comboTextHandle, this);
+    }
+
+    /**
+     * Deselects the item at the given zero-relative index in the receiver's
+     * list. If the item at the index was already deselected, it remains
+     * deselected. Indices that are out of range are ignored.
+     * 
+     * @param index
+     *            the index of the item to deselect
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public void deselect(int index) {
+        checkWidget();
+        if (getSelectionIndex() == index)
+            deselectAll();
+    }
+
+    /**
+     * Deselects all selected items in the receiver's list.
+     * <p>
+     * Note: To clear the selection in the receiver's text field, use
+     * <code>clearSelection()</code>.
+     * </p>
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see #clearSelection
+     */
+    public void deselectAll() {
+        checkWidget();
+        OS.QComboBox_swt_deselect(topHandle);
+    }
+
+    /**
+     * Returns the item at the given, zero-relative index in the receiver's
+     * list. Throws an exception if the index is out of range.
+     * 
+     * @param index
+     *            the index of the item to return
+     * @return the item at the given index
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_INVALID_RANGE - if the index is not between 0
+     *                and the number of elements in the list minus 1 (inclusive)
+     *                </li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public String getItem(int index) {
+        checkWidget();
+        int count = getItemCount();
+        if (!(index < count && index >= 0))
+            error(SWT.ERROR_INVALID_RANGE);
+
+        String item = OS.QComboBox_itemText(topHandle, index);
+        return item;
+    }
+
+    /**
+     * Returns the number of items contained in the receiver's list.
+     * 
+     * @return the number of items
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int getItemCount() {
+        checkWidget();
+        return OS.QComboBox_count(topHandle);
+    }
+
+    /**
+     * Returns the height of the area which would be used to display
+     * <em>one</em> of the items in the receiver's list.
+     * 
+     * @return the height of one item
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int getItemHeight() {
+        checkWidget();
+        return OS.QComboBox_swt_getItemHeight(topHandle);
+    }
+
+    /**
+     * Returns an array of <code>String</code>s which are the items in the
+     * receiver's list.
+     * <p>
+     * Note: This is not the actual structure used by the receiver to maintain
+     * its list of items, so modifying the array will not affect the receiver.
+     * </p>
+     * 
+     * @return the items in the receiver's list
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public String[] getItems() {
+        checkWidget();
+        int count = getItemCount();
+        String[] array = new String[count];
+        for (int i = 0; i < count; ++i) {
+            array[i] = getItem(i);
+        }
+
+        return array;
+    }
+
+    /**
+     * Returns the orientation of the receiver.
+     * 
+     * @return the orientation style
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 2.1.2
+     */
+    public int getOrientation() {
+        checkWidget();
+        return style & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
+    }
+
+    /**
+     * Returns a <code>Point</code> whose x coordinate is the start of the
+     * selection in the receiver's text field, and whose y coordinate is the end
+     * of the selection. The returned values are zero-relative. An "empty"
+     * selection as indicated by the the x and y coordinates having the same
+     * value.
+     * 
+     * @return a point representing the selection start and end
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public Point getSelection() {
+        checkWidget();
+        return OS.QComboBox_swt_getSelection(topHandle);
+    }
+
+    /**
+     * Returns the zero-relative index of the item which is currently selected
+     * in the receiver's list, or -1 if no item is selected.
+     * 
+     * @return the index of the selected item
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int getSelectionIndex() {
+        checkWidget();
+        return OS.QComboBox_currentIndex(topHandle);
+    }
+
+    /**
+     * Returns a string containing a copy of the contents of the receiver's text
+     * field.
+     * 
+     * @return the receiver's text
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public String getText() {
+        checkWidget();
+        return TextUtils.getText(TextUtils.LINE_EDIT, comboTextHandle);
+    }
+
+    /**
+     * Returns the height of the receivers's text field.
+     * 
+     * @return the text height
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int getTextHeight() {
+        checkWidget();
+        return OS.QComboBox_swt_getTextHeight(topHandle);
+    }
+
+    /**
+     * Returns the maximum number of characters that the receiver's text field
+     * is capable of holding. If this has not been changed by
+     * <code>setTextLimit()</code>, it will be the constant
+     * <code>Combo.LIMIT</code>.
+     * 
+     * @return the text limit
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int getTextLimit() {
+        checkWidget();
+        return OS.QLineEdit_maxLength(comboTextHandle);
+    }
+
+    /**
+     * Gets the number of items that are visible in the drop down portion of the
+     * receiver's list.
+     * 
+     * @return the number of items that are visible
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 3.0
+     */
+    public int getVisibleItemCount() {
+        checkWidget();
+        return OS.QComboBox_maxVisibleItems(topHandle);
+    }
+
+    /**
+     * Searches the receiver's list starting at the first item (index 0) until
+     * an item is found that is equal to the argument, and returns the index of
+     * that item. If no item is found, returns -1.
+     * 
+     * @param string
+     *            the search item
+     * @return the index of the item
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int indexOf(String string) {
+        return indexOf(string, 0);
+    }
+
+    /**
+     * Searches the receiver's list starting at the given, zero-relative index
+     * until an item is found that is equal to the argument, and returns the
+     * index of that item. If no item is found or the starting index is out of
+     * range, returns -1.
+     * 
+     * @param string
+     *            the search item
+     * @param start
+     *            the zero-relative index at which to begin the search
+     * @return the index of the item
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public int indexOf(String string, int start) {
+        checkWidget();
+        if (string == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        int index = OS.QComboBox_findText(topHandle, string);
+        if (!(0 <= start && start <= index))
+            return -1;
+        return index;
+    }
+
+    /**
+     * Pastes text from clipboard.
+     * <p>
+     * The selected text is deleted from the widget and new text inserted from
+     * the clipboard.
+     * </p>
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 2.1
+     */
+    public void paste() {
+        checkWidget();
+        TextUtils.paste(TextUtils.LINE_EDIT, comboTextHandle, getTextLimit(), this);
+    }
+
+    /**
+     * Removes the item from the receiver's list at the given zero-relative
+     * index.
+     * 
+     * @param index
+     *            the index for the item
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_INVALID_RANGE - if the index is not between 0
+     *                and the number of elements in the list minus 1 (inclusive)
+     *                </li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public void remove(int index) {
+        checkWidget();
+        int count = getItemCount();
+        if (!(index < count && index >= 0))
+            error(SWT.ERROR_INVALID_RANGE);
+        OS.QComboBox_removeItem(topHandle, index);
+    }
+
+    /**
+     * Removes the items from the receiver's list which are between the given
+     * zero-relative start and end indices (inclusive).
+     * 
+     * @param start
+     *            the start of the range
+     * @param end
+     *            the end of the range
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_INVALID_RANGE - if either the start or end are
+     *                not between 0 and the number of elements in the list minus
+     *                1 (inclusive)</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public void remove(int start, int end) {
+        checkWidget();
+        int count = getItemCount();
+        if (!((start < count && start >= 0) && end < count))
+            error(SWT.ERROR_INVALID_RANGE);
+        if (start > end)
+            return;
+        for (int i = end; i >= start; --i) {
+            OS.QComboBox_removeItem(topHandle, i);
+        }
+    }
+
+    /**
+     * Searches the receiver's list starting at the first item until an item is
+     * found that is equal to the argument, and removes that item from the list.
+     * 
+     * @param string
+     *            the item to remove
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                <li>ERROR_INVALID_ARGUMENT - if the string is not found in
+     *                the list</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public void remove(String string) {
+        checkWidget();
+        int index = indexOf(string, 0);
+        if (index == -1)
+            error(SWT.ERROR_INVALID_ARGUMENT);
+        remove(index);
+    }
+
+    /**
+     * Removes all of the items from the receiver's list.
+     * <p>
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     */
+    public void removeAll() {
+        checkWidget();
+        OS.QComboBox_clear(topHandle);
+    }
+
+    /**
+     * Removes all of the items from the receiver's list and clear the contents
+     * of receiver's text field.
+     * 
+     * @param listener
+     *            the listener which should no longer be notified
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see ModifyListener
+     * @see #addModifyListener
+     */
+    public void removeModifyListener(ModifyListener listener) {
+        checkWidget();
+        if (listener == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        if (eventTable == null)
+            return;
+        eventTable.unhook(SWT.Modify, listener);
+    }
+
+    /**
+     * Removes the listener from the collection of listeners who will be
+     * notified when the receiver's selection changes.
+     * 
+     * @param listener
+     *            the listener which should no longer be notified
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see SelectionListener
+     * @see #addSelectionListener
+     */
+    public void removeSelectionListener(SelectionListener listener) {
+        checkWidget();
+        if (listener == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        if (eventTable == null)
+            return;
+        eventTable.unhook(SWT.Selection, listener);
+        eventTable.unhook(SWT.DefaultSelection, listener);
+    }
+
+    /**
+     * Removes the listener from the collection of listeners who will be
+     * notified when the control is verified.
+     * 
+     * @param listener
+     *            the listener which should no longer be notified
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @see VerifyListener
+     * @see #addVerifyListener
+     */
+    public void removeVerifyListener(VerifyListener listener) {
+        checkWidget();
+        if (listener == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        if (eventTable == null)
+            return;
+        eventTable.unhook(SWT.Verify, listener);
+    }
+
+    /**
+     * Selects the item at the given zero-relative index in the receiver's list.
+     * If the item at the index was already selected, it remains selected.
+     * Indices that are out of range are ignored.
+     * 
+     * @param index
+     *            the index of the item to select
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     */
+    public void select(int index) {
+        checkWidget();
+        int count = getItemCount();
+        if (index < 0 || index >= count)
+            return;
+        OS.QComboBox_setCurrentIndex(topHandle, index);
+    }
+
+    /**
+     * Sets the text of the item in the receiver's list at the given
+     * zero-relative index to the string argument. This is equivalent to
+     * <code>remove</code>'ing the old item at the index, and then
+     * <code>add</code>'ing the new item at that index.
+     * 
+     * @param index
+     *            the index for the item
+     * @param string
+     *            the new text for the item
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_INVALID_RANGE - if the index is not between 0
+     *                and the number of elements in the list minus 1 (inclusive)
+     *                </li> <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     */
+    public void setItem(int index, String string) {
+        checkWidget();
+        int count = getItemCount();
+        if (index < 0 || index >= count)
+            error(SWT.ERROR_INVALID_RANGE);
+        if (string == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        OS.QComboBox_setItemText(topHandle, string, index);
+    }
+
+    /**
+     * Sets the receiver's list to be the given array of items.
+     * 
+     * @param items
+     *            the array of items
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the items array is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     */
+    public void setItems(String[] items) {
+        checkWidget();
+        if (items == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        OS.QComboBox_swt_setItems(topHandle, items);
+    }
+
+    /**
+     * Sets the orientation of the receiver, which must be one of the constants
+     * <code>SWT.LEFT_TO_RIGHT</code> or <code>SWT.RIGHT_TO_LEFT</code>.
+     * <p>
+     * 
+     * @param orientation
+     *            new orientation style
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 2.1.2
+     */
+    public void setOrientation(int orientation) {
+        state &= ~WidgetState.FOLLOWS_SYSLANG_DIRECTION;
+        setOrientation(topHandle, orientation);
+    }
+
+    /**
+     * Sets the selection in the receiver's text field to the range specified by
+     * the argument whose x coordinate is the start of the selection and whose y
+     * coordinate is the end of the selection.
+     * 
+     * @param selection
+     *            a point representing the new selection start and end
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the point is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
+     *                called from the thread that created the receiver</li>
+     *                </ul>
+     */
+    public void setSelection(Point selection) {
+        checkWidget();
+        if (selection == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+        TextUtils.setSelection(TextUtils.LINE_EDIT, comboTextHandle, selection.x, selection.y);
+    }
+
+    /**
+     * Sets the contents of the receiver's text field to the given string.
+     * <p>
+     * Note: The text field in a <code>Combo</code> is typically only capable of
+     * displaying a single line of text. Thus, setting the text to a string
+     * containing line breaks or other special characters will probably cause it
+     * to display incorrectly.
+     * </p>
+     * 
+     * @param string
+     *            the new text
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_NULL_ARGUMENT - if the string is null</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public void setText(String string) {
+        checkWidget();
+        if (string == null)
+            error(SWT.ERROR_NULL_ARGUMENT);
+
+        if (getText().equals(string) == true)
+            return;
+        string = TextUtils.verify(TextUtils.LINE_EDIT, comboTextHandle, string, 
+            this, getTextLimit(), 0, OS.QLineEdit_text(comboTextHandle).length());
+        if (string == null)
+            return;
+
+        OS.QComboBox_swt_setText(topHandle, string);
+    }
+
+    /**
+     * Sets the maximum number of characters that the receiver's text field is
+     * capable of holding to be the argument.
+     * 
+     * @param limit
+     *            new text limit
+     * 
+     * @exception IllegalArgumentException
+     *                <ul>
+     *                <li>ERROR_CANNOT_BE_ZERO - if the limit is zero</li>
+     *                </ul>
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     */
+    public void setTextLimit(int limit) {
+        checkWidget();
+        if (limit <= 0)
+            error(SWT.ERROR_CANNOT_BE_ZERO);
+        if (limit > LIMIT)
+            limit = LIMIT;
+        OS.QLineEdit_setMaxLength(comboTextHandle, limit);
+    }
+
+    /**
+     * Sets the number of items that are visible in the drop down portion of the
+     * receiver's list.
+     * 
+     * @param count
+     *            the new number of items to be visible
+     * 
+     * @exception SWTException
+     *                <ul>
+     *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
+     *                disposed</li>
+     *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
+     *                thread that created the receiver</li>
+     *                </ul>
+     * 
+     * @since 3.0
+     */
+    public void setVisibleItemCount(int count) {
+        checkWidget();
+        OS.QComboBox_setMaxVisibleItems(topHandle, count);
+    }
+
+    int setBounds(int x, int y, int width, int height, boolean move,
+            boolean resize) {
+        int comboHeight = height;
+        if (resize) {
+            // Height of the combo is fixed
+            Point preferedSize = OS.QWidget_sizeHint(topHandle);
+            comboHeight = preferedSize.y;
+            if (height < preferedSize.y)
+                comboHeight = height;
+        }
+        return super.setBounds(x, y, width, comboHeight, move, resize);
+    }
+
+    public Point computeSize(int wHint, int hHint, boolean changed) {
+        checkWidget();
+        if (changed)
+            OS.QWidget_updateGeometry(topHandle);
+
+        // to get the maximum row length depending on the content,
+        // set size policy to QComboBox::AdjustToContents. but it has drawback
+        // that
+        // it doesn't allow resizing so we have to set back size policy after
+        // compute size
+        OS.QComboBox_setSizeAdjustPolicy(topHandle,
+                OS.QT_QComboBox_AdjustToContents);
+        Point sizeHint = OS.QWidget_sizeHint(topHandle);
+        int width = WidgetConstant.DEFAULT_WIDTH;
+        int height = WidgetConstant.DEFAULT_HEIGHT;
+        if (sizeHint.x >= 0)
+            width = sizeHint.x;
+        if (sizeHint.y >= 0)
+            height = sizeHint.y;
+        if (wHint != SWT.DEFAULT)
+            width = wHint;
+        if (hHint != SWT.DEFAULT && hHint < sizeHint.y)
+            height = hHint;
+
+        // sets the size policy back to default so that resizing will be allowed
+        OS.QComboBox_setSizeAdjustPolicy(topHandle,
+                OS.QT_QComboBox_AdjustToMinimumContentsLength);
+        return new Point(width, height);
+    }
+
+    public Rectangle computeTrim(int x, int y, int width, int height) {
+        checkWidget();
+
+        Point frameSize = OS.QWidget_frameSize(topHandle);
+        Rectangle viewPortRect = OS.QWidget_rect(handle);
+        Point pos = OS.QWidget_mapTo(handle, topHandle,
+                viewPortRect.x, viewPortRect.y);
+        int leftTrim = pos.x;
+        int topTrim = pos.y;
+        int rightTrim = frameSize.x - viewPortRect.width - leftTrim;
+        int buttomTrim = frameSize.y - viewPortRect.height - topTrim;
+
+        Point computeSize = computeSize(SWT.DEFAULT, height, false);
+
+        return new Rectangle(x - leftTrim, y - topTrim, width + leftTrim
+                + rightTrim, (height < computeSize.y ? height : computeSize.y)
+                + topTrim + buttomTrim);
+    }
+
+    void setBackground_pp () {
+        // View might have custom palette in case background image was inherited.
+        // Default palette needs to be restored.
+        int view = OS.QComboBox_view(handle);
+        if(view != 0) {
+            OS.QWidget_swt_unsetPalette(view);
+        }
+        super.setBackground_pp();
+    }
+
+    void backgroundImageInherited(Image image) {
+        // Combo can't inherit the background for the view pop-up. View has to draw
+        // the background image by itself.
+        int palette = 0;
+        int view = OS.QComboBox_view(handle);
+        if(view == 0) return;
+        try {
+            palette = OS.QWidget_swt_palette_new(view);
+            int[] bkRoles = getBackgroundImageRoles();
+            for(int i = 0; i < bkRoles.length; ++i) {
+                OS.QPalette_swt_setBrush(palette, bkRoles[i], Internal_GfxPackageSupport.getPixmapHandle(image));
+            }
+            OS.QWidget_setPalette(view, palette);
+        } finally {
+            OS.QPalette_delete(palette);
+        }
+    }
+}