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I'm working on my own custom manager, and I've gotten it complete so far, but it setsMargins using a percentage of the screen resolution.
Here's how I call the following class:
LabelIconCommandManager licm3 = new LabelIconCommandManager("Address blah bklahblah ", 0);
licm3.add(new ImageButtonField(b1, b2, b3, Field.FIELD_LEFT | ImageButtonField.CONSUME_CLICK));
Here's the class [I've marked in a comment where it returns 0 and where it returns 219. please tell me why this happens:
public class LabelIconCommandManager extends HorizontalFieldManager implements BCMSField
{
LabelIconCommandManager me = this;
EvenlySpacedHorizontalFieldManager buttonManager = new EvenlySpacedHorizontalFieldManager(0);
LabelField labelField;
int side = 0;
int HPADDING = 3;
int VPADDING = 4;
int screenWidth = Display.getWidth();
int labelField_width = 40;
public LabelIconCommandManager()
{
this("", 0);
}
public LabelIconCommandManager(String label, long style)
{
super(USE_ALL_WIDTH| FOCUSABLE);
this.setBorder(BorderFactory.createBitmapBorder(new XYEdges(15, 20, 15, 20),Bitmap.getBitmapResource( "border_edit.png" )));
this.setMargin(1,10,1,10);
labelField = new LabelField(label,LabelField.ELLIPSIS)
{
public void layout(int width, int height)
{
// Done because otherwise ellipses dont work with labelfields
super.layout((int)(screenWidth * 0.61), getHeight());
setExtent((int)(screenWidth * 0.61), getHeight());
labelField_width = labelField.getWidth();
DisplayDialog.alert("labelField_width = " + labelField_width); // returns 219
}
};
// Top Right Bottom Left
labelField.setMargin(VPADDING, HPADDING, VPADDING, 0);
// super because we want this horizontalfieldManager to add it
super.add(labelField);
super.add(buttonManager);
}
public void alternateConstructor(Attributes atts)
{
labelField = new LabelField(atts.getValue("label"), 0);
}
public void onFocus(int direction)
{
this.setBorder(BorderFactory.createBitmapBorder(new XYEdges(15, 20, 15, 20),Bitmap.getBitmapResource( "border_edit_select.png" )));
// uses the same color as listStyleButtonField selections
this.setBackground(BackgroundFactory.createSolidBackground(0x186DEF));
super.onFocus(direction);
}
//Invoked when a field loses the focus.
public void onUnfocus()
{
//top, right,bottom,left
this.setBorder(BorderFactory.createBitmapBorder(new XYEdges(15, 20, 15, 20),Bitmap.getBitmapResource( "border_edit.png" )));
this.setBackground(BackgroundFactory.createSolidTransparentBackground(Color.GRAY, 0));
super.onUnfocus();
invalidate();
}
// Overrride this managers add function
public void add(Field imageButton)
{
// Add a button to the evenly spaced manager
buttonManager.add(imageButton);
// Based on how many buttons there are, set the margin of where the manager holding the buttons start [offset from labelField]
if(buttonManager.getFieldCount() == 1)
{
//side = (int)(screenWidth * 0.1388);
side = screenWidth - labelField_width - 32 - 10 - 15;
DisplayDialog.alert("Screen Width = " + screenWidth);
DisplayDialog.alert("labelField_width2 = " + labelField_width); // returns 0
DisplayDialog.alert("Side = " + side);
}
else side = (int)(screenWidth * 0.05);
buttonManager.setMargin(0,0,0,side);
}
public int getLabelWidth()
{
return labelField_width;
}
}
Here's a picture just to be more clear:
Note: when I ran your code, I didn't actually see labelField_width set to 0. You initialize the value to 40 in the code you posted above. So, I do sometimes see it set to 40, or 219 (on a 360 px wide screen).
But, the problem is that I think you're trying to access the value of labelField_width too soon. The only place it's properly assigned is in the layout() method of your anonymous LabelField. Just because you declare and implement the layout() method in line with the instantiation, doesn't mean that it's called when the LabelField is created. This is actually one of the reasons I don't like anonymous classes.
Anyway, this code:
LabelIconCommandManager licm3 = new LabelIconCommandManager("Address blah bklahblah ", 0);
licm3.add(new ImageButtonField(b1, b2, b3, Field.FIELD_LEFT | ImageButtonField.CONSUME_CLICK));
Will first instantiate the LabelField (inside the LabelIconCommandManager constructor). As I said, that does not trigger the layout() method. The second line above (add()) will trigger your overridden method:
// Overrride this managers add function
public void add(Field imageButton)
{
which is where you see the bad value for labelField_width. That method gets called before layout(). That's the problem.
Since it looks like you only use that width to set the buttonManager margin, you could just wait a little longer to do that. If you wait until the LabelIconCommandManager sublayout() method is called, your LabelField will have had its layout() method called, and labelField_width assigned correctly:
protected void sublayout(int maxWidth, int maxHeight) {
// make sure to call superclass method first!
super.sublayout(maxWidth, maxHeight);
// now, we can reliably use the label width:
side = screenWidth - labelField_width - 32 - 10 - 15;
buttonManager.setMargin(0,0,0,side);
}
That method goes in the LabelIconCommandManager class. And then, you can remove the other place you call buttonManager.setMargin().
Some brief summary from Nate post.
When you construct manager and add fields don't expect that it will be layouted correctly. Manager doesn't know the context - where it will be placed. So layout method for field will be called only when you add his manager to the screen (when layout for manager will be also called). And this is correct.
Move the calculation of your side variable to layout method.
If you really need side value before you put manager to screen. You could precalculate it by using Field.getPrefferedWidth() which returns meaningful values for standard fields (getFont().getAdvance(text) for LabelField, probably also with borders please check yourself). But be careful with this values.
Please review code below. It's manager which has label and buttons. And it puts label at the left side and buttons at the right.
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Manager;
import net.rim.device.api.ui.component.ButtonField;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.decor.Border;
import java.util.Vector;
public class TabFieldManager extends Manager {
public TabFieldManager(long style) {
super(style);
}
protected void sublayout(int width, int height) {
LabelField label = null;
Vector tabs = new Vector();
int tabsWidth = 0;
int tabHeight = 0;
int tabPaddingTop = 0;
int tabPaddingLeft = 0;
for (int i=0; i < getFieldCount(); i++) {
Field field = getField(i);
if (field instanceof LabelField) {
label = (LabelField) field;
} else if (field instanceof ButtonField){
tabs.addElement(field);
layoutChild(field, width, height);
int fieldwidth = field.getWidth() > 0 ? field.getWidth() : field.getPreferredWidth() ;
tabsWidth += fieldwidth + getBorderAndPaddingWidth(field);
int fieldHeight = field.getHeight() > 0 ? field.getHeight() : field.getPreferredHeight();
if (fieldHeight > tabHeight) {
tabHeight = getBorderAndPaddingHeight(field) + fieldHeight;
}
int fieldPaddingTop = field.getPaddingTop();
if (fieldPaddingTop > tabPaddingTop) {
tabPaddingTop = fieldPaddingTop;
}
int fieldPaddingLeft = field.getPaddingLeft();
if (fieldPaddingLeft > tabPaddingLeft) {
tabPaddingLeft = fieldPaddingLeft;
}
}
}
if (label != null) {
layoutChild(label, width - tabsWidth, height);
int y = tabHeight - label.getHeight() >> 1;
setPositionChild(label, tabPaddingLeft , y);
}
for (int i = 0; i < tabs.size(); i++) {
Field tabField = (Field) tabs.elementAt(i);
setPositionChild(tabField, width - tabsWidth, getBorderAndPaddingHeight(tabField));
tabsWidth -= tabField.getWidth() + getBorderAndPaddingWidth(tabField);
}
setExtent(width, tabHeight);
}
private int getBorderAndPaddingHeight( Field field ) {
int height = field.getPaddingTop() + field.getPaddingBottom();
Border border = field.getBorder();
if( border != null ) {
height += border.getTop() + border.getBottom();
}
return height;
}
private int getBorderAndPaddingWidth( Field field ){
int width = field.getPaddingLeft() + field.getPaddingRight();
Border border = field.getBorder();
if( border != null ) {
width += border.getLeft() + border.getRight();
}
return width;
}
protected int moveFocus(int amount, int status, int time) {
if ((status & Field.STATUS_MOVE_FOCUS_VERTICALLY) == Field.STATUS_MOVE_FOCUS_VERTICALLY && amount > 0) {
return amount;
} else
return super.moveFocus(amount, status, time);
}
protected int nextFocus(int amount, int axis) {
if (amount > 0 && axis == Field.AXIS_VERTICAL)
return -1;
else
return super.nextFocus(amount, axis);
}
}
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.
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.
i developed the code as below.in this i used listfield ,one bitmapfield and one label field,when i will run it ,it displays only text on the list field row,but not the image
i don't know where i did mistake,so,plz,any one help me to know where i did mistake
thanks for any help
class TaskListField extends MainScreen implements ListFieldCallback {
private Vector rows;
private Bitmap p1;
ListField list;
TableRowManager row;
public TaskListField() {
super();
list=new ListField() {
protected void drawFocus(Graphics graphics, boolean on) {
}
};
list.setRowHeight(40);
list.setEmptyString("Hooray, no tasks here!", DrawStyle.HCENTER);
list.setCallback(this);
p1 = Bitmap.getBitmapResource("res/images/10.png");
rows = new Vector();
for (int x = 1; x < 13; x++) {
row = new TableRowManager();
LabelField task = new LabelField("" + String.valueOf(x),
DrawStyle.ELLIPSIS);
row.add(task);
row.add(new BitmapField(p1));
rows.addElement(row);
}
list.setSize(rows.size());
add(list);
}
// ListFieldCallback Implementation
public void drawListRow(ListField listField, Graphics g, int index, int y,
int width) {
TableRowManager rowManager = (TableRowManager) rows
.elementAt(index);
rowManager.drawRow(g, 0, y, width, list.getRowHeight());
}
private class TableRowManager extends Manager {
public TableRowManager() {
super(0);
}
public void drawRow(Graphics g, int x, int y, int width, int height) {
layout(width, height);
setPosition(x, y);
g.pushRegion(getExtent());
// Paint this manager's controlled fields.
subpaint(g);
g.setColor(0x00CACACA);
g.drawLine(0, 0, getPreferredWidth(), 0);
// Restore the graphics context.
g.popContext();
}
protected void sublayout(int width, int height) {
int preferredWidth = getPreferredWidth();
Field field = getField(0);
layoutChild(field, 30, 30);
setPositionChild(field, 0, 0);
field = getField(1);
layoutChild(field, 40, 25);
setPositionChild(field, 120, 10);
setExtent(preferredWidth, getPreferredHeight());
}
// The preferred width of a row is defined by the list renderer.
public int getPreferredWidth() {
return Graphics.getScreenWidth();
}
// The preferred height of a row is the "row height" as defined in the
// enclosing list.
public int getPreferredHeight() {
return list.getRowHeight();
}
}
public Object get(ListField listField, int index) {
// TODO Auto-generated method stub
return null;
}
public int getPreferredWidth(ListField listField) {
// TODO Auto-generated method stub
return 0;
}
public int indexOfList(ListField listField, String prefix, int start) {
// TODO Auto-generated method stub
return 0;
}
Are you sure the bitmap is not null? I would check that first -- perhaps it's not finding the resource.
Could the LabelField be taking the entire width of the screen (it does that on certain situations)? When you only set the image without setting the label, does the image show?
The image path is not necessary as you put it
p1 = Bitmap.getBitmapResource (" res/images/10.png ");
only needs
p1 = Bitmap.getBitmapResource (" 10.png ");
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);