1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 package javax.microedition.lcdui;

    18 

    19 import org.eclipse.swt.SWT;

    20 import org.eclipse.swt.graphics.Point;

    21 import org.eclipse.swt.graphics.Rectangle;

    22 import org.eclipse.swt.widgets.Composite;

    23 import org.eclipse.swt.widgets.Event;

    24 import org.eclipse.swt.widgets.Label;

    25 import org.eclipse.swt.widgets.Layout;

    26 import org.eclipse.swt.widgets.Listener;

    27 import org.eclipse.swt.widgets.ScrollBar;

    28 

    29 /**

    30  * Composite control which is able to scroll text with a vertical scroll bar.

    31  */

    32 class ScrolledTextComposite extends Composite {

    33 

    34     private Label iESWTTextLabel;

    35     private ScrollBar vBar;

    36     private boolean resizing;

    37     private boolean iTextScrolling;

    38 

    39     /**

    40      * Constructor.

    41      */

    42     public ScrolledTextComposite(Composite parent, ScrollBar vertBar) {

    43         super(parent, 0);

    44         vBar = vertBar;

    45         vBar.setVisible(false);

    46         vBar.setMaximum(0);

    47         vBar.setThumb(0);

    48         vBar.setSelection(0);

    49 

    50         vBar.addListener(SWT.Selection, new Listener() {

    51             public void handleEvent(Event e) {

    52                 vScroll();

    53             }

    54         });

    55 

    56         addListener(SWT.Resize, new Listener() {

    57             public void handleEvent(Event e) {

    58                 resize();

    59             }

    60         });

    61 

    62         iESWTTextLabel = new Label(this, SWT.WRAP);

    63         iESWTTextLabel.setLocation(0, 0);

    64         layout();

    65 

    66         iESWTTextLabel.addListener(SWT.Resize, new Listener() {

    67             public void handleEvent(Event e) {

    68                 if (e.type == SWT.Resize) {

    69                     resize();

    70                 }

    71             }

    72         });

    73     }

    74 

    75     public void setText(String aText) {

    76         iESWTTextLabel.setText(aText);

    77         iESWTTextLabel.setSize(calculateTextSize());

    78     }

    79 

    80     private Point calculateTextSize() {

    81         iTextScrolling = false;

    82         vBar.setVisible(false);

    83         Point nextSize = iESWTTextLabel.computeSize(getClientArea().width,

    84                                                     SWT.DEFAULT);

    85         if (nextSize.y > getClientArea().height) {

    86             iTextScrolling = true;

    87             vBar.setVisible(true);

    88             nextSize = iESWTTextLabel.computeSize(getClientArea().width,

    89                                                   SWT.DEFAULT);

    90         }

    91         return nextSize;

    92     }

    93 

    94     /**

    95      * Return if the text is scrolling. The vBar.isVisible() is not good,

    96      * because it depends on parent's visibility.

    97      */

    98     public boolean isTextScrolling() {

    99         return iTextScrolling;

   100     }

   101 

   102     public void setLayout(Layout layout) {

   103         // do not allow a layout to be set

   104     }

   105 

   106     public void layout(boolean changed) {

   107         iESWTTextLabel.setSize(calculateTextSize());

   108 

   109         Rectangle contentRect = iESWTTextLabel.getBounds();

   110         Rectangle hostRect = getClientArea();

   111         vBar.setMaximum(contentRect.height);

   112         vBar.setThumb(Math.min(contentRect.height, hostRect.height));

   113         int vPage = contentRect.height - hostRect.height;

   114         int vSelection = vBar.getSelection();

   115         if (vSelection >= vPage) {

   116             if (vPage <= 0) {

   117                 vSelection = 0;

   118                 vBar.setSelection(0);

   119             }

   120             contentRect.y = -vSelection;

   121         }

   122         iESWTTextLabel.setLocation(contentRect.x, contentRect.y);

   123     }

   124 

   125     public Point computeSize(int wHint, int hHint, boolean changed) {

   126         Point size = iESWTTextLabel.computeSize(wHint, hHint, changed);

   127         Rectangle trim = computeTrim(0, 0, size.x, size.y);

   128         return new Point(trim.width, trim.height);

   129     }

   130 

   131     public Point getOrigin() {

   132         Point location = iESWTTextLabel.getLocation();

   133         return new Point(-location.x, -location.y);

   134     }

   135 

   136     public void setOrigin(Point origin) {

   137         setOrigin(origin.x, origin.y);

   138     }

   139 

   140     public void setOrigin(int x, int y) {

   141         if (iESWTTextLabel != null) {

   142             vBar.setSelection(y);

   143             iESWTTextLabel.setLocation(0, -vBar.getSelection());

   144         }

   145     }

   146 

   147     private void resize() {

   148         if (!resizing) {

   149             resizing = true;

   150             layout();

   151             resizing = false;

   152         }

   153     }

   154 

   155     private void vScroll() {

   156         Point location = iESWTTextLabel.getLocation();

   157         int vSelection = vBar.getSelection();

   158         iESWTTextLabel.setLocation(location.x, -vSelection);

   159     }

   160 }