In BlackBerry I have developed a screen which display a image of size
480 X 360 in background. My BB screen is of size 480 X 360. As the image is bit big in size when I scroll vertically the screen gets scrolled and disturbs my screen.
I want to lock the scrolling such that I will not be able to do vertical scrolling.
My code is as follows:
public LaunchXtcMsngrScreen()
{
int intwidth = Display.getWidth();
int intheight = Display.getHeight();
//getting the height/width of BB screen
Debugger.debug(UrlInfo.workflow_File,"Screen Height ="+intheight);
Debugger.debug(UrlInfo.workflow_File,"Screen Width ="+intwidth);
BMbackground = Bitmap.getBitmapResource("xtclogo.jpg");
VerticalFieldManager VFM = new VerticalFieldManager(VerticalFieldManager.USE_ALL_WIDTH
| VerticalFieldManager.USE_ALL_HEIGHT
| VerticalFieldManager.NO_VERTICAL_SCROLL
| VerticalFieldManager.NO_VERTICAL_SCROLLBAR)
{
//Override the paint method to draw the background image.
public void paint(Graphics graphics)
{
//Draw the XTC Messenger logo
graphics.drawBitmap(0, 0,Display.getWidth(),Display.getHeight(),BMbackground, 0, 0);
super.paint(graphics);
}
};
Bitmap registerbitmap = Bitmap.getBitmapResource("register_button.PNG");
BFregister = new ImageButtonField(registerbitmap);
BFregister.setMargin(245,0,0,190);//vertical pos,0,0,horizontal pos
VFM.add(BFregister);
add(VFM);
}
add the below code as the next line of the function declaration
super(NO_VERTICAL_SCROLL|NO_VERTICAL_SCROLLBAR);
If you have placed your image inside a manager then u can follow any idea viz:
1) either create a custom manager and write setExtent(480,360) in its sublayout method.
2) you can also write setExtent(480,360) in any HorizontalfieldManager or VerticalFieldManager's sublayout method
have you tried using USE_ALL_WIDTH and USE_ALL_HEIGHT in any manager?
Related
I am an an Android Developer, developing an Blackberry application.
I have created a button of full width of screen. Getting problem in shifting the text to the center of the button area.
Used below code :
ButtonField _contactButton = new ButtonField(Constants.contactButtonTitle,Field.FIELD_HCENTER|Field.USE_ALL_WIDTH |
Field.ACTION_INVOKE | Field.FOCUSABLE | ButtonField.CONSUME_CLICK){
protected void layout(int width, int height) {
super.layout(width, height);
HARD_CODED_HEIGHT = this.getHeight()/2 + 6;
this.setExtent(contactButtonWidth, HARD_CODED_HEIGHT);
}
public int getPreferredWidth() {
return contactButtonWidth;
}
};
Now using the below code :
ButtonField _contactButton = new ButtonField(Constants.contactButtonTitle,Field.FIELD_VCENTER|Field.USE_ALL_WIDTH |
Field.ACTION_INVOKE | Field.FOCUSABLE | ButtonField.CONSUME_CLICK){
protected void layout(int width, int height) {
super.layout(getPreferredWidth(), height);
}
public int getPreferredWidth() {
return (Display.getWidth()-60);
}
};
Still getting the issue .. text of my button align to right corner. Please suggest
ButtonField appears to be a little 'broken'. But it also appears to be consistently broken in all the OS Levels that I have tested (OS 5.0 to OS 7.1), so I think we can achieve what you want by working round the broken bits and be confident the workaround will work in all levels you want.
As has been noted, ButtonField ignores USE_ALL_WIDTH, but does respect preferredWidth. So if you want to set the width of your ButtonField, then just override getPreferredWidth(). You should not do anything with width in layout.
Now you are using the styles for ButtonField already. Given that we have discarded USE_ALL_WIDTH as a useful style, I note that you also use FIELD_HCENTER. You should be aware that this is actually a directive to the Manager that is positioning this Field - telling the Manager to position the Field in the centre of the width the Manager has available. This style does not relate to how the contents of the ButtonField are drawn.
For that, you can look to use DrawStyle. By default, ButtonField uses DrawStyle.RIGHT. And it respects DrawStyle.Left - the text will be drawn on the left. It does not however, respect DrawStyle.HCENTER. So to get centred text, we need to paint the text ourselves.
There is one more complication. ButtonField passes a Context area into its paint() method, not the full Field canvas - presumably it does not pass in the edges because these are painted by a border. So to centre the text appropriately, we have to use the clipping region that has been passed in.
Here is the final, hopefully working, ButtonField. I appreciate you will have to spend some time creating a class for this, I'm sorry, I've been lazy and done in it 'in-line'. Please publish your CenteredTextButtonField class if you create one....
final String buttonText = "Test";
ButtonField _contactButton = new ButtonField(" ",
Field.ACTION_INVOKE | Field.FOCUSABLE | ButtonField.CONSUME_CLICK){
public int getPreferredWidth() {
return contactButtonWidth;
}
protected void paint(Graphics graphics) {
super.paint(graphics);
XYRect clippingRect = graphics.getClippingRect();
int centreY = (clippingRect.height - graphics.getFont().getHeight()) / 2;
graphics.drawText(buttonText, 0, centreY, DrawStyle.HCENTER, clippingRect.width);
}
};
USE_ALL_WIDTH is our instruction to the field. Surprisingly, ButtonField ignores such instructions. Even more surprisingly, it honors its own getPreferredWidth (as illogical as it sounds).
So drop that USE_ALL_WIDTH and define your ButtonField like this:
ButtonField testBtn = new ButtonField("Button") {
public int getPreferredWidth() {
return Display.getWidth();
}
};
I'm getting the following error when a screen should appear:
"WARNING: Cannot layout field, insufficient height or width".
Working with BB 5.0.
This screen es called from 3 different screen, and its shows 50% of the screen or 80%, depending on which screen is pushing it.
This one only have one banner at the top (field), some BasicEditField, one DateField, a vew ObjectChoiceField and at the end 2 buttons.
Why is this error showing up now? (2 days ago it didnt and is the same screen that worked fine before). Where should i check for errors?
Also, is there some limit of height or width that a screen can manage?
Code for the banner,
public static Field getBanner() {
Background bg = BackgroundFactory.createSolidBackground(Color.WHITE);
HorizontalFieldManager hfm = new HorizontalFieldManager(Field.USE_ALL_WIDTH | Field.FIELD_VCENTER);
final Bitmap logo = Bitmap.getBitmapResource("logo_40px.png");
BitmapField _bitmap1 = new BitmapField(logo);
int i = Display.getWidth();
i = i - logo.getWidth();
i = i / 2;
_bitmap1.setSpace(i, 5);
hfm.add(_bitmap1);
hfm.setBackground(bg);
return hfm;
}
Regards.
update:
on the screen creation i have this:
super(MainScreen.VERTICAL_SCROLL_MASK | MainScreen.VERTICAL_SCROLLBAR)
Without this, its works fine the screen. But i wont be able to scroll down, right?
You are adding both _bitmap1 and vfm to hfm, and vfm has Field.USE_ALL_WIDTH set. It would work better, I think, to add _bitmap1 to vfm.
EDIT
It may be that your logo (with the added space) is too big for the banner area on the screen. Perhaps something like this would work:
public static Field getBanner() {
Background bg = BackgroundFactory.createSolidBackground(Color.WHITE);
final Bitmap logo = Bitmap.getBitmapResource("logo_40px.png");
final BitmapField _bitmap1 = new BitmapField(logo);
_bitmap1.setSpace((Display.getWidth() - logo.getWidth()) / 2, 5);
HorizontalFieldManager hfm = new HorizontalFieldManager(Field.USE_ALL_WIDTH | Field.FIELD_VCENTER) {
protected void sublayout(int width, int height) {
super.sublayout(width, height);
setExtent(width, Math.min(_bitmap1.getPreferredHeight(), height));
}
}
hfm.add(_bitmap1);
hfm.setBackground(bg);
return hfm;
}
Developing on the blackberry (OS 7.0) and I have an extended Vertical Field manager created as such:
_myVFM = new MyViewManager(Manager.USE_ALL_WIDTH | Manager.USE_ALL_HEIGHT | Manager.VERTICAL_SCROLL){};
However, when I scroll the view, the virtual scroll view size appears way too big.
i.e, I can scroll quite alot further down than is needed and I cant work out why?
Any body any quick ideas? I do have a background image in there that is created as such:
public void paint(Graphics graphics)
{
Bitmap backgroundBitmap = Bitmap.getBitmapResource("bg.png");
Bitmap newBackground = new Bitmap(Display.getWidth(), Display.getHeight());
backgroundBitmap.scaleInto(newBackground, Bitmap.FILTER_LANCZOS, Bitmap.SCALE_TO_FILL);
graphics.clear();
graphics.drawBitmap(0, 0, Display.getWidth(),
Display.getHeight(), newBackground, 0, 0);
super.paint(graphics);
}
Please and thanks,
Burrows
You can redefine the method to define the height of the manager
protected void setExtent(int width, int height) {
super.setExtent(width, myHeight);
}
To not repeat the background image is necessary to redefine the following method, returning false
protected boolean isScrollCopyable() {
return false;
}
Another comment is that it is a bad practice to obtain an image from the paint method. What you are doing is every time you call the paint method is going to get this image.
It's best to get the image once and then use it.
public MyScreen() {
super(NO_VERTICAL_SCROLL);
I managed to fix the issue in my extension of MainScreen using 'NO_VERTICAL_SCROLL' style parameter
Combined with Rupak's suggestion of setting the Background in the constructor of my Vertical Field Manager rather than overriding paint (
https://gist.github.com/3248319)
everything seems Good now - thanks all for your help.
Burrows
No need to USE_ALL_HEIGHT in your constructor.
// instead use this
_myVFM = new MyViewManager(Manager.USE_ALL_WIDTH | Manager.VERTICAL_SCROLL){};
I am adding a VerticalFieldManager to a screen. I'm painting a background image and to remove whitespace at the bottom of screen when user scrolls down im overriding sublayout in my verticalfieldmanager like so:
protected void sublayout( int maxWidth, int maxHeight ) {
super.sublayout( maxWidth, maxHeight );
setExtent(maxWidth,Constants.BACKGROUND_IMAGE.getHeight());
}
This doesn't work -- white space appears at the bottom of the screen when the user scrolls down. I thought overriding sublayout, using the same code, on the screen object would take precedence over the VerticalFieldManager, which is a child of the screen.
A couple things to check. If, on your MainScreen, you're calling super(VERTICAL_SCROLL | USE_ALL_WIDTH) then your Screen's manager will be the one actually scrolling down, not the VFM you've customized. You may try overriding the paint() method of your VFM and do something as such:
protected void paint(Graphics graphics) {
graphics.drawBitmap(0, getVerticalScroll(), bg.getWidth(), bg.getHeight(), bg, 0, 0);
super.paint(graphics);
}
Which should make your background "move" with the scroll.
how to set the position of a button in java blackberry.
You can position a button or any other component on a screen by creating a Manager class and overriding the sublayout() method. A Manager is kind of like a Panel in java i.e an area of the screen you can add components to. In the sublayout() method you should
set the size of the component with layoutChild()
set the position of the component with setPositionChild()
Set the overall size of the Manager with setExtent()
something like
button = new ButtonField();
HorizontalFieldManager manager = new HorizontalFieldManager(){
protected void sublayout(int width, int height) {
int buttonWidth = button.getPreferredWidth();
int buttonHeight = button.getPreferredHeight();
layoutChild(button,buttonWidth, buttonHeight);
setPositionChild(button, 0, 0);
setExtent(width, height);
}
};
manager.add(button);
You can override getPreferredWidth() and getPreferredHeight() for your button if you want to specify a certain width and height.
See
Custom layout Manager
Manager class