problem with touchEvent in customButtonField?

[sagare]

Hi All,

Here is the code i wrote for creating the customButtonField



package com.rim.samples.device.helloworlddemo;


import net.rim.device.api.ui.*;
import net.rim.device.api.system.*;


/**
*Custom button field that uses images as button backgrounds.
*/
public class PictureBackgroundButtonField extends Field
{
private String _label;
private int _labelHeight;
private int _labelWidth;
private Font _font;

private Bitmap _currentPicture;
private Bitmap _onPicture;
private Bitmap _offPicture;

/**
*Constructor.
*@param imgOn, imgOff - images on top of which the label (if any) will be drwan.
*@param text - the text to be displayed on the button
*@param style - combination of field style bits to specify display
attributes
*/
public PictureBackgroundButtonField(String imgOn, String imgOff, String text, long style)
{
super(style);
_onPicture = Bitmap.getBitmapResource(imgOn);
_offPicture = Bitmap.getBitmapResource(imgOff);
_font = Font.getDefault().derive(Font.PLAIN, Font.getDefault().getHeight() - 4); //getFont();
_label = text;
_labelHeight = _font.getHeight();
_labelWidth = _font.getAdvance(_label);
_currentPicture = _offPicture;
}

public PictureBackgroundButtonField(Bitmap imgOn, Bitmap imgOff, String text, long style)
{
super(style);
_onPicture = imgOn;
_offPicture = imgOff;
_font = Font.getDefault().derive(Font.PLAIN, Font.getDefault().getHeight() - 4); //getFont();
_label = text;
_labelHeight = _font.getHeight();
_labelWidth = _font.getAdvance(_label);
_currentPicture = _offPicture;
}

/**
*@return The text on the button
*/
String getText()
{
return _label;
}

/**
*Field implementation.
*@see net.rim.device.api.ui.Field#getPreferredHeight()
*/
public int getPreferredHeight()
{
//return _labelHeight + 4;
return _currentPicture.getHeight();
}

/**
*Field implementation.
*@see net.rim.device.api.ui.Field#getPreferredWidth()
*/
public int getPreferredWidth()
{
//return _labelWidth + 8;
return _currentPicture.getWidth();
}

/**
*Field implementation. Changes the picture when focus is gained.
*@see net.rim.device.api.ui.Field#onFocus(int)
*/
protected void onFocus(int direction)
{
_currentPicture = _onPicture;
invalidate();
}

/**
*Field implementation. Changes picture back when focus is lost.
*@see net.rim.device.api.ui.Field#onUnfocus()
*/
protected void onUnfocus()
{
_currentPicture = _offPicture;
invalidate();
}

/**
*Field implementation.
*@see net.rim.device.api.ui.Field#drawFocus(Graphics, boolean)
*/
protected void drawFocus(Graphics graphics, boolean on)
{//Do nothing
}

/**
*Field implementation.
*@see net.rim.device.api.ui.Field#layout(int, int)
*/
protected void layout(int width, int height)
{
setExtent(Math.min(width, getPreferredWidth()), Math.min(height, getPreferredHeight()));
}

/**
*Field implementation.
*@see net.rim.device.api.ui.Field#paint(Graphics)
*/
protected void paint(Graphics graphics)
{
//First draw the background colour and picture
//graphics.setColor(Color.LIGHTPINK);
//graphics.fillRect(0, 0, getWidth(), getHeight());
graphics.drawBitmap(0, 0, _currentPicture.getWidth(), _currentPicture.getHeight(), _currentPicture, 0, 0);
if (_label != null && (_label.length() > 0)) {
//Then draw the text
graphics.setColor(0x47a13d);
graphics.setFont(_font);
int yOffset = (_currentPicture.getHeight() - _font.getHeight()) / 2;

graphics.drawText(_label, 4, yOffset, (int) (getStyle() & DrawStyle.ELLIPSIS | DrawStyle.HALIGN_MASK), _currentPicture.getWidth() - 6);
}
}

/**
*Overridden so that the Event Dispatch thread can catch this event
*instead of having it be caught here..
*@see net.rim.device.api.ui.Field#navigationClick(int, int)
*/
protected boolean navigationClick(int status, int time)
{
fieldChangeNotify(1);
return true;
}

}





I use it in the sample helloWorld application that comes with the jde as follows





package com.rim.samples.device.helloworlddemo;

import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.RichTextField;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.ui.FieldChangeListener;

/*
* BlackBerry applications that provide a user interface must extend
* UiApplication.
*/
class HelloWorldDemo extends UiApplication
{
/**
* Entry point for application.
*/
public static void main(String[] args)
{
// Create a new instance of the application.
HelloWorldDemo theApp = new HelloWorldDemo();

// To make the application enter the event thread and start processing messages,
// we invoke the enterEventDispatcher() method.
theApp.enterEventDispatcher();
}

/**
* <p>The default constructor. Creates all of the RIM UI components and pushes the
* application's root screen onto the UI stack.
*/
private HelloWorldDemo()
{
// Push the main screen instance onto the UI stack for rendering.
pushScreen(new HelloWorldScreen());
//pushScreen(new TestScreen());
}
}


/**
* Create a new screen that extends MainScreen, which provides default standard
* behavior for BlackBerry applications.
*/
/*package*/
final class HelloWorldScreen extends MainScreen implements FieldChangeListener
{

private PictureBackgroundButtonField _searchButton;

/**
* HelloWorldScreen constructor.
*/
HelloWorldScreen()
{
// Add a field to the title region of the screen. We use a simple LabelField
// here. The ELLIPSIS option truncates the label text with "..." if the text
// is too long for the space available.
LabelField title = new LabelField("Hello World Demo" , LabelField.ELLIPSIS | LabelField.USE_ALL_WIDTH);
setTitle(title);

// Add a read only text field (RichTextField) to the screen. The RichTextField
// is focusable by default. In this case we provide a style to make the field
// non-focusable.
//add(new RichTextField("Hello World!" ,Field.NON_FOCUSABLE));

_searchButton = new PictureBackgroundButtonField(Bitmap.getBitmapResou rce("button_on_small.png"),
Bitmap.getBitmapResource("button_off_small.png"), "Find", Field.FOCUSABLE | Field.FIELD_HCENTER);
_searchButton.setChangeListener(this);
add(_searchButton);
}

/**
*We are implementing this method to intercept property changes on the send button.
*/
public void fieldChanged(Field field, int context)
{
if (field == _searchButton){
System.out.println("Search Button Field Changed ************************************************** *************************");
}
}

/**
* Display a dialog box to the user with "Goodbye!" when the application
* is closed.
*
* @see net.rim.device.api.ui.Screen#close()
*/
public void close()
{
// Display a farewell message before closing application.
Dialog.alert("Goodbye!");
System.exit(0);

super.close();
}
}





Now note that here irrespective of where i click on my screen the fieldChanged method is called for _searchButton.I expect the fieldChanged method of _searchButton to be called when i click on thatcustom button only and not when i click anywhere else on the screen.Can anyone plz help me with this.Waiting for your valuable suggestions.





Thanks

Sagar