Editfield scroll fails to reach top in blackberry - blackberry

I am having 2 EditFields in my login form with names Email: and Password:. Just below email I have login button. Suppose I come down till login, I can scroll back only till password field.The cursor fails to reach Email field. In simulator, I tried using arrow keys as well as trackpad. Please help how to scroll back to first editfield
AbsoluteFieldManager ab = new AbsoluteFieldManager();
add(ab);
new SeparatorField();
et=new EditField("Email-id:","");
pwd=new PasswordEditField("Password:","");
ab.add(et,35,110);
ab.add(pwd,35,150);
I am using AbsoluteFieldManager and developing for OS 6.0. I want the loginscreen to look like facebook login page.
Kindly let me know what can possibly be the reason for not able to scroll up

Maybe it is a RIM bug with the AbsoluteFieldManager. Never used it before so I don't know about it. You can create a work around to solve this problem. Find it below:
et=new EditField("Email-id:","");
pwd=new PasswordEditField("Password:","") {
protected int moveFocus(int amount, int status, int time) {
int cursorPosition = this.getCursorPosition();
if ((cursorPosition == 0) && (amount < 0)) {
et.setFocus();
return 0;
}
else {
return super.moveFocus(amount, status, time);
}
}
};
In this way, when you arrive to the first element in the password edit field, you will oblige the email field to get focused. This will work for you as a work around.
Another way to solve the problem is to add the two fields in an horizontal field manager, in that way I guess this will work for you for sure. If not use the first method. You can find below the code for HorizontalFieldManager:
et=new EditField("Email-id:","");
pwd=new PasswordEditField("Password:","");
HorizontalFieldManager manager = new HorizontalFieldManager();
manager.add(et);
manager.add(pwd);
ab.add(manager, yourX, yourY);

It also may be a RIM bug. What OS do you use? Is it OS 5+? Do you use custom paddings/margins/borders for some of the UI elements on the screen (including the screen itself)? If yes, try to comment out any code that sets paddings/margins/borders to check whether this it the case.

You can use this code for your login page:
public class loginscreen extends MainScreen implements FieldChangeListener {
private int deviceWidth = Display.getWidth();
private int deviceHeight = Display.getHeight();
private VerticalFieldManager subManager;
private VerticalFieldManager mainManager;
public long mycolor = 0x00FFFFFF;
Screen _screen = home.Screen;
TextField heading = new TextField(Field.NON_FOCUSABLE);
TextField username_ef = new TextField();
PasswordEditField password_ef = new PasswordEditField();
CheckboxField rememberpass = new CheckboxField();
public ButtonField login_bt = new ButtonField("Login", ButtonField.CONSUME_CLICK);
public ButtonField register_bt = new ButtonField("Register", ButtonField.CONSUME_CLICK);
public loginscreen()
{
super();
final Bitmap backgroundBitmap = Bitmap.getBitmapResource("bgd.png");
HorizontalFieldManager hfm = new HorizontalFieldManager(Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR )
{
protected void sublayout(int width, int height)
{
Field field;
int numberOfFields = getFieldCount();
int x = 245;
int y = 0;
for (int i = 0;i < numberOfFields;i++)
{
field = getField(i);
setPositionChild(field,x,y);
layoutChild(field, width, height);
x +=_screen.getWidth()-381;
y += 0;//l17
}
width=_screen.getWidth();
height=48;//w19
setExtent(width, height);
}
};
mainManager = new VerticalFieldManager(Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR )
{
public void paint(Graphics graphics)
{
graphics.clear();
graphics.drawBitmap(0, 0, deviceWidth, deviceHeight, backgroundBitmap, 0, 0);
super.paint(graphics);
}
};
//this manger is used for adding the componentes
subManager = new VerticalFieldManager(Manager.VERTICAL_SCROLL | Manager.VERTICAL_SCROLLBAR )
{
protected void sublayout( int maxWidth, int maxHeight )
{
int displayWidth = deviceWidth;
int displayHeight = deviceHeight;
super.sublayout( displayWidth, displayHeight);
setExtent( displayWidth, displayHeight);
}
public void paint(Graphics graphics)
{
graphics.setColor((int) mycolor);
super.paint(graphics);
}
};
username_ef.setLabel("Username: ");
password_ef.setLabel("Password: ");
rememberpass.setLabel("Remember Password");
heading.setLabel("Please enter your credentials: ");
username_ef.setMaxSize(8);
password_ef.setMaxSize(20);
subManager.add(heading);
subManager.add(username_ef);
subManager.add(password_ef);
subManager.add(rememberpass);
subManager.add(new SeparatorField());
login_bt.setChangeListener(this);
register_bt.setChangeListener(this);
hfm.add(login_bt);
hfm.add(register_bt);
subManager.add(hfm);
mainManager.add(subManager);
this.add(mainManager);
}
public boolean onSavePrompt()
{
return true;
}
public void fieldChanged(Field field, int context) {
// TODO Auto-generated method stub
if(field == login_bt)
{
//do your code for login button click
}
if(field == register_bt)
{
//code for register button click
}
}}

What you have described is not normal behavior.
My conclusion is that your code has one or more bugs, in order to solve your problem you should modify your code to fix the bugs. You will then be able to scroll up and down through the various fields.
note: As this question stands it's not possible for me to be more specific about the exact bugs. So instead I will show you an example of the layout you described that would scroll properly and you can use as a default to determine which of your deviations have caused your bugs.
// inside MainScreen constructor
add(new EditField("Username:","",0));
add(new EditField("Password:","",0));
add(new ButtonField(buttonBMP,ButtonField.CONSUME_CLICK));

Related

Custom layout in blackberry

I need a custom layout as below in BlackBerry.
I did same layout in Android. Now I need same layout in BlackBerry. I am new to BlackBerryapp development. The Fields of BlackBerry like Views in Android seem to be very confusing things to me.
I tried with VerticalFieldManager & HorizontalFieldManager by mixing these with BitmapField & LabelField to produce my layout.
I failed particularly in placing LabelField at bottom of screen. I used USE_ALL_HEIGHT & FIELD_BOTTOM style to put at bottom, but it is showing after scrolling long time.
My requirement is the header and footer should not scroll when my middle list is scrolling.
The easiest way to add header and footer fields that don't scroll with the content in the middle of the screen is to use MainScreen#setBanner() and MainScreen#setStatus().Here's an example:
public class HeaderFooterListScreen extends MainScreen {
private static final int BG_COLOR = Color.BLACK;
private static final int HIGHLIGHT_COLOR = Color.BLUE;
private static final int FONT_COLOR = Color.WHITE;
private static final int ROW_HEIGHT = 60;
private Object[] _rowData;
private Field _header;
private Field _footer;
private Field _spacer;
private int _orientation;
public HeaderFooterListScreen() {
super(MainScreen.VERTICAL_SCROLL | MainScreen.VERTICAL_SCROLLBAR);
Background bg = BackgroundFactory.createSolidBackground(BG_COLOR);
setBackground(bg);
getMainManager().setBackground(bg);
// header
Bitmap headerImg = Bitmap.getBitmapResource("header.png");
_header = new BitmapField(headerImg);
setBanner(_header);
// list
_rowData = new Object[] { "row one", "row two", "row three" }; //, "row four", "row five", "row six", "row seven", "row eight", "row nine", "row ten" };
ListField list = new ListField();
int c = Color.RED;
XYEdges edgeColors = new XYEdges(c, c, c, c);
XYEdges edgeThicknesses = new XYEdges(5, 5, 5, 5);
list.setBorder(BorderFactory.createSimpleBorder(edgeThicknesses, edgeColors, Border.STYLE_SOLID));
list.setCallback(new CustomListFieldCallback());
list.setRowHeight(ROW_HEIGHT);
list.setSize(_rowData.length);
add(list);
// footer
_footer = new LabelField("Footer Showing Status As Text", Field.USE_ALL_WIDTH | DrawStyle.HCENTER) {
public void paint(Graphics g) {
// change font color
int oldColor = g.getColor();
g.setColor(FONT_COLOR);
super.paint(g);
g.setColor(oldColor);
}
};
_footer.setFont(_footer.getFont().derive(Font.PLAIN, 24));
setStatus(_footer);
}
private void centerList() {
if (_spacer != null && _spacer.getManager() != null) {
// delete the old spacer field, if there was one
delete(_spacer);
}
int listHeight = _rowData.length * ROW_HEIGHT;
int availableHeight = getHeight() - _footer.getHeight() - _header.getHeight();
if (availableHeight > listHeight) {
boolean firstRun = (_spacer == null);
// add a spacer above the list to force it down enough to be centered
final int SPACE = (availableHeight - listHeight) / 2;
_spacer = new Field() {
protected void layout(int width, int height) {
setExtent(width, SPACE);
}
protected void paint(Graphics graphics) {
}
};
insert(_spacer, 0);
if (firstRun) {
getMainManager().setVerticalScroll(0);
}
}
}
// called when device orientation changes
protected void sublayout(int width, int height) {
super.sublayout(width, height);
if (_orientation != Display.getOrientation()) {
_orientation = Display.getOrientation();
// run with invokeLater() to avoid recursive sublayout() calls
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
// TODO: may have to adjust header, too?
centerList();
}
});
}
}
private class CustomListFieldCallback implements ListFieldCallback {
private final int PAD = 10;
public void drawListRow(ListField listField, Graphics graphics,
int index, int y, int width) {
int oldColor = graphics.getColor();
if (listField.getSelectedIndex() == index) {
graphics.setColor(HIGHLIGHT_COLOR);
} else {
graphics.setColor(BG_COLOR);
}
graphics.fillRect(0, y, width, listField.getRowHeight());
graphics.setColor(FONT_COLOR);
String text = (String)get(listField, index);
graphics.drawText(text, PAD, y + PAD, DrawStyle.LEFT);
graphics.setColor(oldColor);
}
public Object get(ListField listField, int index) {
return _rowData[index];
}
public int getPreferredWidth(ListField listField) {
return Display.getWidth();
}
public int indexOfList(ListField listField, String prefix, int start) {
return -1; // TODO?
}
}
}
You didn't specify how you wanted the list in the middle to work, so I just made some guesses. I also wasn't sure if the red border was something you wanted, or just something you used to describe your layout. Edit your question, or post a new question, if you have more requirements for the list.
Field Concepts
If you're coming from Android, and are unclear about the role of BlackBerry UI classes, like Fields and Managers, here's some resources:
another Stack Overflow answer I posted
BlackBerry Advanced UI Sample Code on Github
BlackBerry Layout Managers Tutorial
Results

how to do instant update in BB RIM?

I want to manually display a field.
public class Main_NewsDetail extends MainScreen {
private Custom_FontField slider;
private boolean a;
public Main_NewsDetail() {
super(USE_ALL_WIDTH);
slider = new Custom_FontField(
Bitmap.getBitmapResource("slider_thumb_normal.png"),
Bitmap.getBitmapResource("slider_progress_normal.png"),
Bitmap.getBitmapResource("slider_base_normal.png"),
Bitmap.getBitmapResource("slider_thumb_focused.png"),
Bitmap.getBitmapResource("slider_progress_focused.png"),
Bitmap.getBitmapResource("slider_base_focused.png"),
Bitmap.getBitmapResource("slider_thumb_pressed.png"),
Bitmap.getBitmapResource("slider_progress_pressed.png"),
Bitmap.getBitmapResource("slider_base_pressed.png"), 35, 10, 5,
5, FOCUSABLE);
if(a)
add(slider);
}
public class Custom_NewsDetailBottom extends Manager implements
FieldChangeListener {
Custom_NewsDetailBottom() {
super(Manager.USE_ALL_WIDTH | Manager.NO_VERTICAL_SCROLL
| Manager.NO_HORIZONTAL_SCROLL);
Background background = BackgroundFactory
.createBitmapBackground(bg);
setBackground(background);
fontbtn = new Custom_ButtonField(font, fontactive, fontactive) {
protected boolean navigationClick(int status, int time) {
a = !a; <-- here is to control field display
return true;
}
};
fontbtn.setChangeListener(this);
add(fontbtn);
}
protected void sublayout(int width, int height) {
Field field = getField(0);
layoutChild(field, font.getWidth(), font.getHeight());
setPositionChild(field, getGap(), 5);
width = Math.min(width, getPreferredWidth());
height = Math.min(height, getPreferredHeight());
setExtent(width, height);
}
public int getPreferredHeight() {
return 70;
}
public int getPreferredWidth() {
return Display.getWidth();
}
protected void paint(Graphics graphics) {
int rectHeight = getPreferredHeight();
int rectWidth = getPreferredWidth();
graphics.drawRect(0, 0, rectWidth, rectHeight);
super.paint(graphics);
}
private int getGap() {
return ((getPreferredWidth() / 4) - font.getWidth()) / 2;
}
public void fieldChanged(Field field, int context) {
if (field == sharebtn) {
} else if (field == commentbtn) {
Main.getUiApplication().pushScreen(new Main_Comments());
} else if (field == otherbtn) {
Main.getUiApplication().pushScreen(new Menu_Others());
}
}
public boolean keyDown(int keycode, int status) {
if (Keypad.key(keycode) == Keypad.KEY_ESCAPE) {
delete(slider);
return true;
}
return super.keyDown(keycode, status);
}
}
}
Above is the code that display a screen. In fontbtn, When click will change the variable true / false. However, it cannot update instant to display the field slider.
slider is something like seekbar in Android. In android, when click then can setvisibility but not blackberry RIM, so how to control it?
First of all, I would recommend not using variables with names like this if you can avoid it:
private boolean a;
Try to give it a name that's more descriptive, as that will help us understand your code better.
Next, it looks like you are testing the variable a before it ever has a chance to change, in the Main_NewsDetail constructor. So that won't work. Maybe try this in the Main_NewsDetail class:
/** separate boolean used because Field.isVisible() doesn't seem totally robust */
private boolean isSliderVisible = false;
private void setSliderVisible(boolean isVisible) {
if (isVisible != isSliderVisible) {
if (isVisible) {
add(slider);
} else {
delete(slider);
// but, we still retain the "slider" member variable, so it can be
// added again later
}
isSliderVisible = isVisible;
// I'm not actually sure that this is needed. I include it because I can't run this code right now!
invalidate();
}
}
Then, in your button click handler:
fontbtn = new Custom_ButtonField(font, fontactive, fontactive) {
protected boolean navigationClick(int status, int time) {
setSliderVisible(!isSliderVisible);
return true;
}
};
Now, this code can work because your Main_NewsDetail has only one Field in it, the slider. If there are actually multiple Field objects (which you probably will have), then you may need more complicated logic. You may want to show the slider in the same location every time. For that, you can record the index of the slider, in the list of all the Main_NewsDetails fields (for example, is the slider the 1st field, the 2nd, the 5th?). Then, instead of calling add(slider), you would do:
private void setSliderVisible(boolean isVisible) {
if (isVisible != isSliderVisible) {
if (isVisible) {
insert(slider, sliderIndex);
You might need to make Main_NewsDetail a subclass of Manager and implement the sublayout() method. That way, you can make sure that if isSliderVisible, you always lay out the slider in the same position.
Try calling Manager's invalidate-method to force a repaint for the managed area:
Marks this entire manager as requiring repainting.
Invoke this method to signal that this manager's entire region requires repainting.

Custom BitmapField bug on unfocus and scroll (BlackBerry)

I have been having this annoying problem when trying to implement a picture gallery on BlackBerry 6.
Everything works, however when the focus changes from the top buttons to say the pictures further down the screen, the images seem to glitch and not paint themselves correctly. Please see the images below for an example:
(Focus is on the top of the screen(not shown))
(Focus is now on the bottom left image, note that the top image is now blank for an unknown reason)
And this happens no matter how many pictures I add to the tumbnail gallery.
Now here is my code, (a part of it concerning the drawing of the thumbnails)
public ProductImage(String productName){
super(VERTICAL_SCROLL|VERTICAL_SCROLLBAR);
currentProduct = productName;
createGUI();
}
public void createGUI(){
deleteAll();
try{
Storage.loadPicture();
}catch(NullPointerException e){
e.printStackTrace();
}
this.setTitle(new LabelField(_resources.getString(PRODUCT_IMAGE), Field.FIELD_HCENTER));
if(ToolbarManager.isToolbarSupported())
{
Toolbar tb = new Toolbar();
setToolbar(tb.createToolBar());
}
else{
Toolbar tb = new Toolbar();
add(tb.createNavBar());
}
picVector = Storage.getPicture(currentProduct);
EncodedImage enc = EncodedImage.getEncodedImageResource("camera.png");
EncodedImage sizeEnc = ImageResizer.sizeImage(enc, Display.getHeight(), Display.getHeight());
takenPicture = new BitmapField(enc.getBitmap());
vfMain = new VerticalFieldManager();
vfMain.add(logo);
vfMain.add(new SeparatorField());
add(vfMain);
prepareBmpFields();
}
private void prepareBmpFields() {
System.out.println("This is the vector size: " + picVector.getPicVector().size());
LayoutManager manager = new LayoutManager();
FieldChangeListener itemListener = new ButtonListener();
mBmpFields = new ImageButtonField[picVector.getPicVector().size()];
for (int i = 0; i < picVector.getPicVector().size(); i++) {
/*EncodedImage image = EncodedImage
.getEncodedImageResource((String)imageVector.elementAt(i));*/
byte[] data = getData((String)picVector.getPicVector().elementAt(i));
//Encode and Resize image
EncodedImage eImage = EncodedImage.createEncodedImage(data,0,data.length);
eImage = ImageResizer.resizeImage(eImage, mImgWidth, mImgHeight);
ImageButtonField currentImage = new ImageButtonField(eImage.getBitmap());
currentImage.setAssociatedPath((String)picVector.getPicVector().elementAt(i));
mBmpFields[i] = currentImage;
mBmpFields[i].setChangeListener(itemListener);
manager.add(mBmpFields[i]);
}
vfMain.add(manager);
}
private class LayoutManager extends VerticalFieldManager {
public LayoutManager() {
super(VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
}
protected void sublayout(int width, int height) {
int columns = mScrWidth / (mImgWidth + 2 * mImgMargin);
int scrWidth = Display.getWidth();
int rows = mBmpFields.length / columns
+ (mBmpFields.length % columns > 0 ? 1 : 0);
int counter = 0;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < columns; j++) {
int posX = j * (mImgWidth + 2 * mImgMargin) + mImgMargin;
int posY = i * (mImgHeight + 2 * mImgMargin) + mImgMargin;
if(mBmpFields.length > counter){
Field field = mBmpFields[counter];
layoutChild(field, mImgWidth, mImgHeight);
setPositionChild(field, posX, posY);
counter++;
};
}
}
if(Display.getWidth() < Display.getHeight()){
setExtent(mScrWidth, (int)(mScrHeight*1.25));
}
else{
setExtent(mScrWidth, (int)(mScrHeight*2));
}
}
public int getPreferredWidth() {
return mScrWidth;
}
public int getPreferredHeight() {
return mScrHeight;
}
}
}
I have removed many non relevant parts of the code, but the needed code is there.
Does anyone know what could be causing this problem? Thanks for your help!
Edit: as requested, here is my implementation of ImageButtonField class:
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Characters;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.BitmapField;
public class ImageButtonField extends BitmapField{
String associatedPath ="";
BitmapField image2;
public ImageButtonField(Bitmap image) {
super(image);
}
public void setAssociatedPath(String path){
associatedPath = path;
}
public String getAssociatedPath(){
return associatedPath;
}
public boolean isFocusable() {
return true;
}
protected void applyTheme(Graphics arg0, boolean arg1) {
}
protected void drawFocus(Graphics graphics, boolean on) {
}
protected void onFocus(int direction) {
// only change appearance if this button is enabled (aka editable)
if (isEditable()) {
invalidate(); // repaint
}
super.onFocus(direction);
}
public void onUnfocus() {
invalidate(); // repaint
super.onUnfocus();
}
protected boolean navigationClick(int status, int time) {
fieldChangeNotify(0);
return true;
}
protected boolean trackwheelClick(int status, int time) {
fieldChangeNotify(0);
return true;
}
protected void paint(Graphics graphics) {
super.paint(graphics);
if (isFocus()) {
graphics.setGlobalAlpha(128);
graphics.setColor(0x888888);
graphics.fillRect(0, 0, getWidth(), getHeight());
}else{
graphics.setGlobalAlpha(0);
graphics.setColor(0x000000);
graphics.fillRect(0, 0, getWidth(), getHeight());
//graphics.drawBitmap(0, 0, getWidth(), getHeight(), image2.getB, 0, 0);
}
}
protected boolean keyChar(char character, int status, int time) {
if(Characters.ENTER == character || Characters.SPACE == character) {
fieldChangeNotify(0);
return true;
}
return super.keyChar(character, status, time);
}
}
Ok, so you can disregard my first answer, but since I didn't have your ImageButtonField code at the time, I don't want to throw it out ... maybe someone else will find it useful.
In the end, I didn't need to make any changes to ImageButtonField, but I did change your LayoutManager class. The way I figured out that it was the problem was I just started replacing your custom UI classes with built-in ones. I replaced ImageButtonField with BitmapField. That didn't fix it. Then, I replaced LayoutManager with FlowFieldManager and that fixed it. So, I knew where the problem was.
My solution:
private class LayoutManager extends Manager {
public LayoutManager() {
super(VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
}
protected void sublayout(int width, int height) {
setExtent(width, height);
// TODO: maybe always set the same virtual extent?
if (Display.getWidth() < Display.getHeight()) {
setVirtualExtent(mScrWidth, (int) (mScrHeight * 1.25));
} else {
setVirtualExtent(mScrWidth, (int) (mScrHeight * 2));
}
int columns = mScrWidth / (mImgWidth + 2 * mImgMargin);
// int scrWidth = Display.getWidth();
int rows = mBmpFields.length / columns + (mBmpFields.length % columns > 0 ? 1 : 0);
int counter = 0;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < columns; j++) {
int posX = j * (mImgWidth + 2 * mImgMargin) + mImgMargin;
int posY = i * (mImgHeight + 2 * mImgMargin) + mImgMargin;
if (mBmpFields.length > counter) {
Field field = mBmpFields[counter];
layoutChild(field, mImgWidth, mImgHeight);
setPositionChild(field, posX, posY);
counter++;
}
}
}
}
public int getPreferredWidth() {
return mScrWidth;
}
public int getPreferredHeight() {
return mScrHeight;
}
}
I can't say for sure that I understand why your original code wasn't working, but I can say that I wouldn't have done a few of the things in the original code:
The original code was extending VerticalFieldManager but was doing all the work itself, in sublayout(). So, I don't think there was any point extending VerticalFieldManager. I changed it to just extend Manager.
The original code was calling setExtent() with different sizes. I don't think that's what you wanted. Extent is the actual size of the Field. Virtual extent is the virtual size, which is what you want to set larger than the actual extent, in order to enable scrolling. You don't need to dynamically calculate different extents for portrait vs. landscape because the width and height parameters passed to sublayout() will already reflect that. I'm not sure you really even need to be setting different virtual extents either. I think you should probably always set the virtual extent height to the number of rows times picture height, accounting for margins.
You had an unused variable scrWidth in your original code. I commented it out above.
You also posted this question recently, right? Am I correct in assuming that the ImageButtonField you refer to here is the same one you were working on in the other question?
I can't see your full implementation of ImageButtonField, which you should probably post here, too. However, looking at the answers to your other question, I have a feeling that you're doing some custom focus handling in ImageButtonField, and maybe it's not being done quite right. In any case, that class may be where the problem is.
I have a similar Field subclass of my own, and here are the focus handling methods I define:
public class CustomButtonField extends Field {
private Bitmap _button; // the currently displayed button image
private Bitmap _on; // image for 'on' state (aka in-focus)
private Bitmap _off; // image for 'off' state (aka out-of-focus)
protected void onFocus(int direction) {
// only change appearance if this button is enabled (aka editable)
if (isEditable()) {
_button = _on;
invalidate(); // repaint
}
super.onFocus(direction);
}
protected void onUnfocus() {
_button = _off;
invalidate(); // repaint
super.onUnfocus();
}
protected void drawFocus(Graphics graphics, boolean on) {
// override superclass implementation and do nothing
}
public boolean isFocusable() {
return true;
}
I also have a custom implementation of paint(). I won't show it all here, because a lot of the code probably has nothing to do with your problem, but my paint() does include this call:
graphics.drawBitmap(_padding, _padding, _fieldWidth, _fieldHeight, _button, 0, 0);
You might not care about the fact that I have separate images for focused, and unfocused states ... maybe you show the same image at all times.
But, probably the thing to check is your onFocus() and onUnfocus() methods. You may need to add a call to invalidate() as I have.
Looking at Rupak's answer to your other question, it would also be good to check your ImageButtonField.paint() method, and make sure you aren't neglecting to do important drawing steps if the field is not in focus.

Vertical scrollbar with jump points - setVerticalScroll locking UI

I have a question about the BlackBerry VerticalScrollField and scrolling which seems to lock or make the UI unstable. The following code is a BlackBerry screen with worlds as content on the left (in a scroll field) and a jumpbar off to the right that allows clicking into the content.
When a jump letter is clicked the setVerticalScroll method is called, it performs the scroll but has the unfortunate side effect of rendering the UI unstable or unusable. The scroll call is done on the UI thread so its not clear what the source of the error is. The app is being tested in a 6.0 simulator.
I've included the class which can be copied into BB Eclipse for hacking/testing.
The section that kicks of the scrolling can be found towards the bottom with the following code:
UiApplication.getUiApplication().invokeLater(new Runnable(){
public void run() {
scroller.setVerticalScroll(y, true);
}});
Here's the full class:
package test;
import java.util.Vector;
import net.rim.device.api.system.ApplicationManager;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Font;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.TouchEvent;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.Status;
import net.rim.device.api.ui.container.HorizontalFieldManager;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;
public class Startup extends UiApplication {
private int[] jump;
static final String[] words = new String[]{
"auto", "apple", "bear", "car", "farm", "ferret", "gold",
"green", "garden", "hedge", "happy", "igloo", "infrared",
"jelly", "kangaroo", "lemon", "lion", "marble", "moon",
"nine", "opera", "orange", "people", "puppy", "pear",
"quince", "race", "run", "sunset", "token", "willow", "zebra"
};
private final static String[] alphabet = new String[]{"A","B","C","D","E",
"F","G","H","I","J","K","L","M","N","O","P","Q","R",
"S","T","U","V","W","X","Y","Z","#"};
private VerticalFieldManager scroller;
public Startup() {
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
UiApplication.getUiApplication().pushScreen(new ScrollScreen());
}
});
}
public static void main(String[] args) {
ApplicationManager app = ApplicationManager.getApplicationManager();
while (app.inStartup()) {
try { Thread.sleep(200); } catch (Throwable e) {}
}
Startup startup = new Startup();
startup.enterEventDispatcher();
}
/**
* Screen with content in a scrollbar left and a letters on the right that
* can be used to jump into the content.
*/
class ScrollScreen extends MainScreen {
public ScrollScreen() {
super(NO_HORIZONTAL_SCROLL | NO_VERTICAL_SCROLL);
HorizontalFieldManager hfm = new HorizontalFieldManager(USE_ALL_HEIGHT | NO_VERTICAL_SCROLL | NO_HORIZONTAL_SCROLL){
protected void sublayout(int maxWidth, int maxHeight) {
Field scroll = getField(0);
Field alpha = getField(1);
layoutChild(alpha, maxWidth, maxHeight);
layoutChild(scroll, maxWidth-alpha.getWidth(), maxHeight);
setPositionChild(scroll, 0, 0);
setPositionChild(alpha, maxWidth-alpha.getWidth(), 0);
setExtent(maxWidth, maxHeight);
}
};
hfm.add(createScrollContent());
hfm.add(createAlphabetJumpBar());
add(hfm);
}
private Field createScrollContent() {
Vector vocabulary = new Vector();
for (int ii=0; ii<alphabet.length; ii++)
vocabulary.addElement(alphabet[ii]);
scroller = new VerticalFieldManager(VERTICAL_SCROLL | USE_ALL_WIDTH) {
protected void sublayout(int maxWidth, int maxHeight) {
// Record the jump offsets
int y = 0;
for (int ii=0; ii<getFieldCount(); ii++) {
Field field = getField(ii);
layoutChild(field, maxWidth, maxHeight);
setPositionChild(field, 0, y);
if (field instanceof WordField) {
WordField object = (WordField)field;;
char character = object.getWord().toLowerCase().charAt(0);
int offset = ((int)character)-(int)alphabet[0].toLowerCase().charAt(0);
if (offset < 0 || offset > jump.length)
offset = jump.length-1;
while (offset >= 0 && offset < jump.length && jump[offset] == 0) {
jump[offset] = y;
offset--;
}
}
y += field.getHeight();
}
int offset = jump.length-1;
do {
jump[offset] = y;
offset--;
} while (offset >= 0 && jump[offset] == 0);
setExtent(maxWidth, maxHeight);
setVirtualExtent(maxWidth, y+10);
}
};
jump = new int[alphabet.length];
Font largeFont = Font.getDefault().derive(Font.PLAIN, 46);
for (int ii=0; ii<words.length; ii++) {
WordField wordField = new WordField(words[ii]);
wordField.setFont(largeFont);
scroller.add(wordField);
}
return scroller;
}
private Field createAlphabetJumpBar() {
VerticalFieldManager vfm = new VerticalFieldManager() {
protected void sublayout(int maxWidth, int maxHeight) {
int y = 0;
int width = 0;
double allowedAlphaHeight = (double)maxHeight / (double)getFieldCount();
for (int ii=0; ii<getFieldCount(); ii++) {
WordField field = (WordField)getField(ii);
layoutChild(field, maxWidth, (int)allowedAlphaHeight);
setPositionChild(field, 0, y);
y += field.getHeight();
double paddedY = Math.floor(allowedAlphaHeight*(ii+1));
if (y < paddedY) y = (int)paddedY;
width = Math.max(width, field.getWidth());
}
setExtent(width, maxHeight);
}
};
for (int ii=0; ii<alphabet.length; ii++) {
vfm.add(new AlphaField(alphabet[ii]){
protected boolean touchEvent(TouchEvent message) {
if (message.getEvent() == TouchEvent.UP) {
int startOffset = (int)alphabet[0].charAt(0);
int offset = ((int)getWord().charAt(0)) - startOffset;
final int y = offset == 0 ? 0 : jump[offset - 1];
UiApplication.getUiApplication().invokeLater(new Runnable(){
public void run() {
scroller.setVerticalScroll(y, true);
}});
}
return true;
}
});
}
return vfm;
}
class WordField extends LabelField {
private final String word;
public WordField(String word) {
super(word);
this.word = word;
}
public String getWord() { return word; }
}
Font alphaFont = null;
class AlphaField extends WordField {
public AlphaField(String word) {
super(word);
}
protected void layout(int width, int height) {
if (alphaFont == null)
alphaFont = Font.getDefault().derive(Font.PLAIN, height);
setExtent(alphaFont.getAdvance(getWord()), alphaFont.getHeight());
}
protected void paint(Graphics graphics) {
graphics.setFont(alphaFont);
graphics.drawText(getWord(), 0, 0);
}
}
/**
* For debugging.
* #see net.rim.device.api.ui.Screen#keyChar(char, int, int)
*/
protected boolean keyChar(char c, int status, int time) {
if ('o' == c) { // shows the jump offsets into the scroll field
UiApplication.getUiApplication().invokeLater(new Runnable(){
public void run() {
StringBuffer buf = new StringBuffer();
for (int ii=0; ii<jump.length; ii++) {
buf.append(alphabet[ii]+"="+jump[ii]);
if (ii<jump.length-1)
buf.append(",");
}
Status.show("offsets="+buf.toString());
}});
}
return super.keyChar(c, status, time);
}
}
}
You're using UiApplication.invokeLater in a few places where you're already on the UI event thread, so those are redundant - the debug code in keyChar and the setVerticalScroll call from the touchEvent handler. The Runnable is executed synchronously when you do an invokeLater from the UI thread, with no delay specified.
Are you sure you want to set the scroll explicitly? One option would be to set the focus on the WordField you are interested in, by calling setFocus(), then the OS will do the scrolling events to move that field on screen for you.
If you really need to explicitly set the vertical scroll, your problem may be that the touch event is already causing scroll, so setting it again causes problems. You can get around this by specifying a one millisecond delay for your invokeLater(...). This means your Runnable will be added to the event queue, instead of executing synchronously. That way the scroll won't be changed in the middle of another event call-stack.
Finally tracked down the issue - if the touchEvent for the alphabet label field returns a true then it locks up the main scroll field, if however return super.touchEvent(message) is called the scrolling happens and the scroll field can still be scrolled up and down by clicking on the screen.
This may be a bug in the BlackBerry OS or just the simulator. The Field.touchEvent() documentation for 6.0 recommends returning true if the method consumes the event; however doing so (at least in the above code) causes another UI field to loose the ability to detect touch events which would cause it to scroll.

Blackberry VerticalFieldManager with fixed size : Scroll issue

I'm trying to have a full screen UI with a fix header ( a manager with some fields) and a scrollable contents (a list of custom field). The idea is to emulate a kind of scrollable list.
For this I made a custom VerticalFieldManager that accept a maxHeight (the screen height - the header height).
I got the following problems:
The scroll arrows do not show up (ever)
On OS 4.7 (Storm), I can scroll lower that the last item, until having nothing on my screen but the header.
My code need to compile with the JDE 4.2.1 & 4.7 and to run on Pearl and Storm. (at worst I could have two version of this class)
I suspect the two problems are related. I probably do something wrong. I looked at a few example/forum and always found similar solution/code.
Do you guys can tell me what I did wrong?
/**
* custom class, so we can set a max height (to keep the header visible)
*/
class myVerticalFieldManager extends VerticalFieldManager{
private int maxHeight = 0;
myVerticalFieldManager(int _maxHeight){
super(
//this provoc an "empty scrollable zone" on Storm
// but if you don't put it, on other OS, the vertical manager does not scroll at all.
Manager.VERTICAL_SCROLL
| Manager.VERTICAL_SCROLLBAR
);
maxHeight = _maxHeight;
}
protected void sublayout(int width, int height){
super.sublayout(width, getPreferredHeight());
setExtent(width, getPreferredHeight());
}
public int getPreferredWidth() {
return Graphics.getScreenWidth();
}
/**
* allow the manager to use all the given height. (vs auto Height)
*/
public boolean forceMaxHeight = false;
public int getPreferredHeight() {
if (forceMaxHeight) return maxHeight;
int m = super.getPreferredHeight();
if (m > maxHeight) m = maxHeight;
return m;
}
////////////////////////////////////////////////////////////////////////////
protected boolean isUpArrowShown(){
//TODO: does not seem to work (4.2.1 emulator & 4.5 device). (called with good return value but the arrows are not painted)
int i = getFieldWithFocusIndex();
//Trace("isUpArrowShown " + i);
return i > 0;
// note: algo not correct, cause the up arrow will be visible event when no field are hidden.
// but not so bad, so the user "know" that he can go up.
}
protected boolean isDownArrowShown(){
int i = getFieldWithFocusIndex();
return i < getFieldCount();
}
////////////////////////////////////////////////////////////////////////////
// note : since 4.6 you can use
// http://www.blackberry.com/developers/docs/4.6.0api/net/rim/device/api/ui/decor/Background.html
public int myBackgroundColor = 0xffffff;
protected void paint(Graphics g){
g.setBackgroundColor(myBackgroundColor);
// Clears the entire graphic area to the current background
g.clear();
super.paint(g);
}
}
any helps is welcome.
so,
I came with this workaround for the "empty scrollable zone" problem on STORM
it's ugly and doesn't allow a custom ScrollChangeListener, but it's working on Pearl & Storm
implements ScrollChangeListener
//in constructor:
setScrollListener(null);
setScrollListener(this);
private boolean MY_CHANGING_SCROLL = false;
public void scrollChanged(Manager manager, int newHorizontalScroll, int newVerticalScroll){
if (!MY_CHANGING_SCROLL){
MY_CHANGING_SCROLL = true;
myCheckVerticalScroll();
MY_CHANGING_SCROLL = false;
}
}
protected int myMaxVerticalScrollPosition(){
int vh = getVirtualHeight();
int h = getHeight();
if (vh < h ) return 0; // no scroll
return vh - h; // don't scroll lower than limit.
}
protected void invCheckVerticalScroll() {
int i = getVerticalScroll();
int m = myMaxVerticalScrollPosition();
if ( i > m){
i = m;
setVerticalScroll(i);
}
}
I'm still looking for a solution to the scroll arrows problem...
If anybody got an idea...
You can use the method setBanner() instead of add for your header. Then you can add a default VerticalFieldManager to the screen and it will scroll normally but won't hide the header. Note that the MainScreen delegate manager is a VerticalScrollManager so you might not need a second vfm.
HorizontalFieldManager hfm = new HorizontalFieldManager();
setBanner(hfm)
add(new ButtonField("Hello 1");
add(new ButtonField("Hello 2");
...
Hey i did the same thing using a HorizontalFieldManager that contains an image and a title
header_img = Bitmap.getBitmapResource("header.png");
title = new LabelField("Welcome",LabelField.FIELD_RIGHT);
header_manager = new HorizontalFieldManager()
{
protected void paint(net.rim.device.api.ui.Graphics graphics)
{
int y = this.getVerticalScroll();
graphics.drawBitmap( 0, y, header_img.getWidth(), header_img.getHeight(), header_img, 0, 0 );
graphics.setColor(Color.LEMONCHIFFON);
super.paint( graphics );
}
protected void sublayout(int maxWidth, int maxHeight)
{
super.sublayout(Display.getWidth(), 240);
Field field = title;
layoutChild(field, title.getWidth(), title.getHeight());
setPositionChild(field, (Display.getWidth()/2) -10, 13);
setExtent(Display.getWidth(),55);
}
};
header_manager.add(title);

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