BlackBerry - Create image viewer - blackberry

I need to create an image slideshow in my app (i.e. the image should be changed at a regular interval of time with a fade in / fade out effect). I have tried some code, but it throws illegal exception.
Is there any option to change images in picture scroll field programatically? i.e. from a thread or something?
public class SlideTransition extends MainScreen {
final Bitmap image000 = Bitmap.getBitmapResource("img1.jpg");
final Bitmap image001 = Bitmap.getBitmapResource("img2.jpg");
final Bitmap image002 = Bitmap.getBitmapResource("img3.jpg");
final BitmapField animationField = new BitmapField(image000);
int counter = 0;
Timer animationTimer = new Timer();
TimerTask animationTask;
public SlideTransition() {
animationTask = new TimerTask() {
public void run() {
if (counter == 0) {
animationField.setBitmap(image000);
}
if (counter == 1) {
animationField.setBitmap(image001);
}
if (counter == 2) {
animationField.setBitmap(image002);
counter = -1;
}
counter++;
}
};
animationTimer.scheduleAtFixedRate(animationTask, 0, 100);
add(animationField);
}
}

The code posted will throw an IllegalStateException because it is attempting to modify a UI element directly from a background (timer) thread:
animationField.setBitmap(image000);
You need to use UiApplication.getUiApplication().invokeLater(), or something similar, to modify the UI from a background thread.
Also, you can have your timer continuously adjust the bitmap field's alpha value (opacity) to produce a fade effect.
Here's an example, starting with the code you provided:
public class SlideTransition extends MainScreen {
private final Bitmap image000 = Bitmap.getBitmapResource("img1.jpg");
private final Bitmap image001 = Bitmap.getBitmapResource("img2.jpg");
private final Bitmap image002 = Bitmap.getBitmapResource("img3.jpg");
private AlphaBitmapField animationField = new AlphaBitmapField(image000);
private Timer animationTimer = new Timer();
private TimerTask animationTask;
private final int animationPeriodMsec = 40; // 25 Hz animation timer
public SlideTransition() {
animationTask = new AnimationTask();
add(animationField);
animationTimer.scheduleAtFixedRate(animationTask, 0, animationPeriodMsec);
}
// I separated your anonymous timer task into its own class for readability
private class AnimationTask extends TimerTask {
private final int fadeDurationMsec = 500;
private final int displayDurationMsec = 1500;
private final int fadeInEndCount = fadeDurationMsec / animationPeriodMsec;
private final int fadeOutStartCount = (fadeDurationMsec + displayDurationMsec) / animationPeriodMsec;
private final int endCount = (2 * fadeDurationMsec + displayDurationMsec) / animationPeriodMsec;
private int imgCounter = 0;
private int cycleCounter = 0;
public void run() {
if (cycleCounter >= endCount) {
cycleCounter = 0;
}
Bitmap newImage = null;
if (cycleCounter == 0) {
// time to switch the images
if (imgCounter == 0) {
newImage = image000;
} else if (imgCounter == 1) {
newImage = image001;
} else if (imgCounter == 2) {
newImage = image002;
imgCounter = -1;
}
imgCounter++;
}
// assign final variables to use inside a UI thread Runnable
final Bitmap currentImage = newImage;
final int i = cycleCounter;
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
if (i == 0) {
// switch images, and start with the image invisible (alpha = 0)
animationField.setAlpha(0);
animationField.setBitmap(currentImage);
} else if (i <= fadeInEndCount) {
// fade in by changing alpha
animationField.setAlpha(i * 255 / fadeInEndCount);
} else if (i >= fadeOutStartCount) {
// fade out by changing alpha
animationField.setAlpha(255 + (fadeOutStartCount - i) * 255 / (endCount - fadeOutStartCount));
}
}
});
cycleCounter++;
}
}
// this class extends BitmapField to allow alpha adjustment, and automatic repainting
private class AlphaBitmapField extends BitmapField {
private int _alpha;
public AlphaBitmapField(Bitmap img) {
super(img);
}
public void setAlpha(int alpha) {
if (alpha != _alpha) {
_alpha = alpha;
// force a repaint
invalidate();
}
}
protected void paint(Graphics graphics) {
graphics.setGlobalAlpha(_alpha);
super.paint(graphics);
}
}
}
I changed the time values from your code, but you can modify them to whatever you like. I had the animation timer run at 25 cycles per second. I find that this is a reasonable value for smartphone animations. It's fast enough to look fairly smooth, but is only about twice the rate that the human eye can process information like this ... any faster is probably wasteful.
I defined constants that you can use to control the length of time that the fade in and fade out takes (fadeDurationMsec) and the time that each image is displayed between fade in and fade out (displayDurationMsec). All values are in milliseconds.
Helpful References
BlackBerry AnimatedGIFField sample code.
BlackBerry forums thread about fade in / fade out

Related

MonoGame/XNA Mouse Offsets

I am trying to use Mouse.GetState() for my menu selection. Currently, it will only highlight if I hover over a region left and up from where the menu is. I used DrawString to display the mouses coordinates and found that the 0,0 point wasn't in the top left of my monitor or in the top left of the game window. It was somewhere about 100,100 pixels from the top left of the screen. Also, the 0,0 point moves every time I run the programme.
I looked at others people who have had the same problem but wasn't able to solve it. I tried using Mouse.WindowHandle = this.Window.Handle; in my Initialize() but it didn't nothing. I have two monitors and when I forced the game in fullscreen it would open on my second monitor so I disabled it but the problem remains.
here is a link to my code http://pastebin.com/PNaFADqp
Game1 class:
public class Game1 : Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
SpriteFont spriteFont;
public const int WINDOW_HEIGHT = 800;
public const int WINDOW_WIDTH = 600;
public int tree;
public TitleScreen titleScreen;
public SATDemo satDemo;
public SeparatingAxisTest separatingAxisTest;
public SATWithAABB sATWithAABB;
GameState currentState;
public static Dictionary<string, Texture2D> m_textureLibrary = new Dictionary<string, Texture2D>();
public static Dictionary<string, SpriteFont> m_fontLibrary = new Dictionary<string, SpriteFont>();
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
graphics.PreferredBackBufferHeight = WINDOW_HEIGHT;
graphics.PreferredBackBufferWidth = WINDOW_WIDTH;
}
protected override void Initialize()
{
Mouse.WindowHandle = this.Window.Handle;
//enable the mousepointer
IsMouseVisible = true;
currentState = GameState.TitleScreen;
//sets the windows mouse handle to client bounds handle
base.Initialize();
}
public void RequestSATDemo()
{
currentState = GameState.RequestSATDemo;
}
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
m_textureLibrary.Add("Pixel", Content.Load<Texture2D>("White_Pixel"));
m_fontLibrary.Add("Font", Content.Load<SpriteFont>("MotorwerkOblique"));
titleScreen = new TitleScreen();
satDemo = new SATDemo();
separatingAxisTest = new SeparatingAxisTest();
sATWithAABB = new SATWithAABB();
}
public void RequestSeparatingAxisTest()
{
currentState = GameState.SeparatingAxisTest;
}
public void RequestSATWithAABB()
{
currentState = GameState.SATWithAABB;
}
protected override void Update(GameTime gameTime)
{
MouseTestState = Mouse.GetState();
switch (currentState)
{
case GameState.TitleScreen:
{
titleScreen.Update(gameTime);
break;
}
case GameState.SeparatingAxisTest:
{
separatingAxisTest.Update(gameTime);
break;
}
case GameState.SATWithAABB:
{
sATWithAABB.Update(gameTime);
break;
}
case GameState.Exit:
{
Exit();
break;
}
default:
{
titleScreen.Update(gameTime);
break;
}
}
base.Update(gameTime);
}
protected override void Draw(GameTime gameTime)
{
spriteBatch.Begin();
spriteBatch.DrawString(m_fontLibrary["Font"], MouseTestState.ToString(), new Vector2(0, 0), Color.White);
switch (currentState)
{
case GameState.TitleScreen:
{
titleScreen.Draw(spriteBatch, spriteFont);
break;
}
case GameState.SeparatingAxisTest:
{
separatingAxisTest.Draw(gameTime, spriteBatch);
break;
}
case GameState.SATWithAABB:
{
sATWithAABB.Draw(gameTime, spriteBatch);
break;
}
case GameState.Exit:
{
Exit();
break;
}
default:
{
titleScreen.Update(gameTime);
break;
}
}
spriteBatch.End();
base.Draw(gameTime);
}
}
TitleScreen class:
public class TitleScreen : Screen
{
List<Button> buttonList = new List<Button>();
public Menu mainMenu;
public TitleScreen()
{
mainMenu = new Menu(new Vector2(200, 100), buttonList, 0);
buttonList.Add(new PushButton("Separating Axis Test"));
buttonList.Add(new PushButton("SAT With AABB"));
buttonList.Add(new PushButton("Awesome"));
buttonList.Add(new PushButton("Awesomere"));
buttonList.Add(new PushButton("Awesomere"));
}
public override void Update(GameTime gametime)
{
mainMenu.Update(gametime);
}
public void Draw(SpriteBatch sB, SpriteFont sF)
{
mainMenu.Draw(sB, sF);
}
}
PushButton class:
public class PushButton : Button
{
string m_text;
SpriteFont m_font;
Color m_static, m_onClick, m_onHover;
Texture2D m_sprite2D, m_onClick2D;
static public int Pbuttoncount;
//click processing
bool m_clickedInside = false,
m_releasedInside = false,
m_OnClicked = false,
selected = false;
Rectangle drawRectangle;
public PushButton(string Text)
{
m_text = Text;
drawRectangle = new Rectangle((int)Menu.m_position.X, (int)Menu.m_position.Y + (15 * Pbuttoncount), 200, 15);
ButtonRegion = new Rectangle((int)Position.X, (int)Position.Y, 200, 15);
Pbuttoncount++;
}
public PushButton(Rectangle ButtonRegion, SpriteFont Font, string Text, Color Static, Color OnClick, Color OnHover)
{
m_buttonRegion = ButtonRegion;
m_font = Font;
m_text = Text;
m_static = Static;
m_onClick = OnClick;
m_onHover = OnHover;
// drawRectangle = ButtonPosition(m_buttonRegion);
}
public PushButton(Rectangle ButtonRegion, Texture2D Sprite2D, Texture2D OnClick2D)
{
m_buttonRegion = ButtonRegion;
m_sprite2D = Sprite2D;
m_onClick2D = OnClick2D;
//drawRectangle = ButtonPosition(m_buttonRegion);
}
public override void Update(GameTime gameTime)
{
MouseState currentMouse = Mouse.GetState();
selected = MouseState(drawRectangle, currentMouse);
m_clickedInside = ClickInside(currentMouse, m_lastMouseState);
ReleaseInside(currentMouse, m_lastMouseState);
if (selected && m_clickedInside && m_releasedInside)
m_OnClicked = true;
else
m_OnClicked = false;
m_lastMouseState = currentMouse;
}
public override void Draw(SpriteBatch spriteBatch, SpriteFont spriteFont, int buttonCount, Vector2 Position)
{
spriteBatch.Draw(Game1.m_textureLibrary["Pixel"], new Rectangle((int)Position.X + 10, (int)(Position.Y + 15 * buttonCount), 180, 15), Color.Wheat);
if (selected)
spriteBatch.DrawString(Game1.m_fontLibrary["Font"], m_text, new Vector2(Position.X + 15, Position.Y + 15 * buttonCount), Color.Orange);
else
spriteBatch.DrawString(Game1.m_fontLibrary["Font"], m_text, new Vector2(Position.X + 15, Position.Y + 15 * buttonCount), Color.Black);
}
}
Menu class:
public class Menu
{
List<Button> m_buttonList;
float m_transparency;
public int n = 0;
public Rectangle buttonRegion, m_menuRegion, m_dimensions;
static public Vector2 m_position;
int m_WINDOW_HEIGHT = Game1.WINDOW_HEIGHT;
int m_WINDOW_WIDTH = Game1.WINDOW_WIDTH;
private Game1 m_managerClass;
public Menu(Vector2 Position, List<Button> ButtonList, float Transparency)
{
m_position = Position;
m_buttonList = ButtonList;
m_transparency = Transparency;
m_managerClass = new Game1();
}
public Rectangle MenuRegion
{
get { return m_menuRegion; }
set { m_menuRegion = value; }
}
static public Vector2 Position
{
get { return m_position; }
}
public void Update(GameTime gametime)
{
for (int i = 0; i < m_buttonList.Count; i++)
{
m_buttonList[i].Update(gametime);
if (m_buttonList[0].OnClicked)
{
SeperatingAxisTest();
}
}
}
public void Draw(SpriteBatch sB, SpriteFont sF)
{
sB.Draw(Game1.m_textureLibrary["Pixel"], new Rectangle((int)m_position.X - 5, (int)m_position.Y - 10, (m_buttonList[0].ButtonRegion.Width + 10), (m_buttonList[0].ButtonRegion.Height * m_buttonList.Count) + 20), Color.Blue);
for (int i = 0; i < m_buttonList.Count; i++)
{
m_buttonList[i].Draw(sB, sF, i, new Vector2(Position.X, Position.Y));
}
}
private void SeperatingAxisTest()
{
m_managerClass.RequestSeparatingAxisTest();
}
}
Program class:
public static class Program
{
[STAThread]
static void Main()
{
using (var game = new Game1())
game.Run();
}
}
Let me know if you need anything else. I'm still learning and will sell my soul to you for an answer.
Your Menu class is creating a new instance of Game1. This is, most likely, not what you want, since Game1 is instantiated in the entry point for you app. The Game1 instance has an instance of TitleScreen, which in turn has an instance of the Menu class, so a Menu should have no business creating its own game.
When this (other) instance is created, it invokes platform-specific (Windows) methods, creates an additional window handle (which is never shown) and configures the Mouse.WindowHandle.
And btw, setting WindowHandle manually does absolutely nothing in Monogame, so all these sources mentioning that are talking about XNA.
So, there are several remarks:
You should probably have a "screen manager" class which contains the current screen. It is strange to have a field of type TitleScreen in your game class, it should at least be of the base type (Screen), so that the game class draws and updates each screen transparently.
If you need a reference to the game class anywhere, don't instantiate a new one, but rather pass it along through the constructor.
m_managerClass is a bad name for a field which is actually a Game. Also google for C# naming conventions. Perhaps you even might want to download an existing monogame game template, e.g. check some of the samples online; the NetRumble sample seems to implement a screen manager.
Remove the Mouse.WindowHandle line, it should be set to your one-and-only game window by default.
tl;dr add the Game1 as a parameter wherever you might need it (but only where you need it).
abstract class Screen
{
private readonly Game1 _game;
public Game1 Game
{ get { return _game; } }
public Screen(Game1 game)
{
_game = game;
}
}
class TitleScreen : Screen
{
public TitleScreen(Game1 game)
: base(game)
{ ... }
}
class Menu
{
private readonly Screen _screen;
public Menu(Screen parentScreen, Vector2 pos, List<Button> list, float alpha)
{
_screen = parentScreen;
...
// if you need the game instance, just use _screen.Game
}
}

how to animate diff images in xna game?

i am having 19 images , which are animation frames of my player
in below i have created array of texture as frog which is my player.and there are 19 images.how to animate them.
public class Texture
{
public static Texture2D mBackground;
public static Texture2D mBackgroundOne;
public static Texture2D mBackgroundTwo;
public static Texture2D grassUp;
public static Texture2D grassDown;
public static Texture2D[] frog = new Texture2D[19];
public static Texture2D[] frogdie = new Texture2D[4];
public static Vector2 position;
public static void Load()
{
mBackground = GamePage.contentManager.Load<Texture2D>("layer_11");
mBackgroundOne = GamePage.contentManager.Load<Texture2D>("layer_11");
mBackgroundTwo = GamePage.contentManager.Load<Texture2D>("layer_11");
grassUp = GamePage.contentManager.Load<Texture2D>("layer_11");
grassDown = GamePage.contentManager.Load<Texture2D>("layer_11");
frog[0] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal1");
frog[1] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal2");
frog[2] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal3");
frog[3] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal4");
frog[4] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal5");
frog[5] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal6");
frog[6] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal7");
frog[7] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal8");
frog[8] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal9");
frog[9] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal10");
frog[10] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal11");
frog[11] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal12");
frog[12] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal13");
frog[13] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal14");
frog[14] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal15");
frog[15] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal16");
frog[16] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal17");
frog[17] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal18");
frog[18] = GamePage.contentManager.Load<Texture2D>("player/maindak_normal19");
}
public static void draw(SpriteBatch sprite)
{
for (int i = 0; i <= 18; i++)
{
sprite.Draw(frog[i],position= new Vector2(100, 100), Color.White);
}
}
Keeping with your current structure, you could animate your textures in the following manner:
//timer
private const float TIME_BETWEEN_FRAME = 0.1f;
private float timer = TIME_BETWEEN_FRAME;
//frame sequence
private int currentFrame = 0;
public void Update(GameTime gametime)
{
float elapsed = (float)gametime.ElapsedGameTime.TotalSeconds;
timer -= elapsed; //subtract elapsed time from timer
if (timer <= 0) //if our timer is elapsed
{
currentFrame++; //next frame
if (currentFrame >= frog.Count)
currentFrame = 0; //If we reach last frame, reset to loop
timer = TIME_BETWEEN_FRAME; //reset timer
}
}
public void draw(SpriteBatch spriteBatch)
{
spriteBatch.Draw(frog[currentFrame], position, Color.White);
}
This will work, however, if you want to take it a step further into the right direction, you should look into SpriteSheets, which will provide you with a much easier way to manage all of your animations.

To attach a ButtonField on every row of CustomListField in BlackBerry [duplicate]

i m writing one application in which i have created custom list field for displaying listview.
my CustomListField contains one image and text in a row. i m gettiing field change listener on click of listfield row but i want to put fieldchange listener on image too..
can anyone tell me how can i do that.
here is my code.
public class CustomListField extends ListField implements ListFieldCallback {
private Vector _listData;
private int _MAX_ROW_HEIGHT = 60;
public CustomListField(Vector data) {
_listData = data;
setSize(_listData.size());
setSearchable(true);
setCallback(this);
setRowHeight(_MAX_ROW_HEIGHT);
}
protected void drawFocus(Graphics graphics, boolean on) {
XYRect rect = new XYRect();
graphics.setGlobalAlpha(150);
graphics.setColor(Color.BLUE);
getFocusRect(rect);
drawHighlightRegion(graphics, HIGHLIGHT_FOCUS, true, rect.x, rect.y, rect.width, rect.height);
}
public int moveFocus(int amount, int status, int time) {
this.invalidate(this.getSelectedIndex());
return super.moveFocus(amount, status, time);
}
public void onFocus(int direction) {
super.onFocus(direction);
}
protected void onUnFocus() {
this.invalidate(this.getSelectedIndex());
}
public void refresh() {
this.getManager().invalidate();
}
public void drawListRow(ListField listField, Graphics graphics, int index, int y, int w) {
listField.setBackground(BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("listing_bg.png")));
ListRander listRander = (ListRander) _listData.elementAt(index);
graphics.setGlobalAlpha(255);
graphics.setFont(Font.getDefault().getFontFamily().getFont(Font.PLAIN, 24));
final int margin = 5;
final Bitmap thumb = listRander.getListThumb();
final String listHeading = listRander.getListTitle();
final Bitmap nevBar = listRander.getNavBar();
// list border
graphics.setColor(Color.GRAY);
graphics.drawRect(0, y, w, _MAX_ROW_HEIGHT);
// thumbnail border & thumbnail image
graphics.setColor(Color.BLACK);
// graphics.drawRoundRect(margin-2, y+margin-2,thumb.getWidth()+2, thumb.getHeight()+2, 5, 5);
graphics.drawBitmap(margin, y + margin, thumb.getWidth(), thumb.getHeight(), thumb, 0, 0);
// drawing texts
// graphics.setFont(Font.BOLD);
graphics.drawText(listHeading, margin + thumb.getWidth(), y + margin);
graphics.setColor(Color.GRAY);
// graphics.setFont(Font.smallFont); // graphics.drawText(listDesc, 2*margin+thumb.getWidth(), y+ margin+20); // //
// graphics.drawText(listDesc2, 2*margin+thumb.getWidth(), y+ margin+32);
// draw navigation button
final int navBarPosY = y + (_MAX_ROW_HEIGHT / 2 - nevBar.getHeight() / 2);
final int navBarPosX = Graphics.getScreenWidth() - nevBar.getWidth() + margin;
graphics.drawBitmap(navBarPosX, navBarPosY, nevBar.getWidth(), nevBar.getHeight(), nevBar, 0, 0);
}
public Object get(ListField listField, int index) {
String rowString = (String) _listData.elementAt(index);
return rowString;
}
public int indexOfList(ListField listField, String prefix, int start) {
for (Enumeration e = _listData.elements(); e.hasMoreElements();) {
String rowString = (String) e.nextElement();
if (rowString.startsWith(prefix)) {
return _listData.indexOf(rowString);
}
}
return 0;
}
public int getPreferredWidth(ListField listField) {
return 3 * listField.getRowHeight();
}
/*
protected boolean trackwheelClick(int status, int time) {
invalidate(getSelectedIndex());
Dialog.alert(" U have selected :" + getSelectedIndex());
return super.trackwheelClick(status, time);
}
*/
}
i want to put click listner on star image of listfield row
and following is output of abbove code.
I did something very similar to this on a past project:
Background
As Arhimed said in his answer, and as you can read about on the BlackBerry forums here, you can't have full-fledged Field objects within the ListField. The content of ListField rows is just drawn directly in drawListRow() as text, and Bitmaps, etc. The contents aren't Field instances, and therefore, are not focusable.
So, what I did was to replace ListField with a subclass of Manager. Originally, I used a VerticalFieldManager, but I ran into problems with that. I've also been seeing a lot of issues on stack overflow, where people subclass VerticalFieldManager, customize just one small behaviour, and everything starts breaking. It seems to me that VerticalFieldManager works well if you accept its normal behaviour, and if you need something more, just extend Manager directly. Performing layout for vertically stacked rows is pretty easy.
I then made each row its own Manager, and implemented custom layout in sublayout() to place the row's Fields where I wanted them. I could then also make the row focusable, and then a bitmap/button on the row separately focusable (like your star). Clicking the row invokes one action, and clicking the star invokes another one.
I will note, however, that in my app, performance was not an issue, because I only had 10-20 rows. Also, I did have to modify my code to match your example, so consider this code only lightly tested. However, I did build it into an app, so it should perform fine as long as my assumptions, and your description were valid.
Implementation
First, it wasn't clear to me what your ListRander is (you didn't show that code). However, in my code, I need a data class to contain details about one row. It looked like that's how you used ListRander, so that's what I used:
public class ListRander {
private String _title;
private Bitmap _thumb;
public ListRander(String title, Bitmap thumb) {
_title = title;
_thumb = thumb;
}
public String getTitle() {
return _title;
}
public Bitmap getThumb() {
return _thumb;
}
}
Then, I replaced your CustomListField class with my own:
public class CustomListField extends Manager implements FocusChangeListener {
private int _MAX_ROW_HEIGHT = 60;
private boolean _searchable = false;
private Vector _listData;
private FieldChangeListener _fieldListener;
public CustomListField(Vector data) {
super(FOCUSABLE | VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
setSearchable(true);
setEditable(false);
setListData(data);
}
public void setChangeListener(FieldChangeListener listener) {
// we need to save this listener, because we set it to listen to all new rows
_fieldListener = listener;
int numFields = getFieldCount();
for (int f = 0; f < numFields; f++) {
getField(f).setChangeListener(listener);
}
super.setChangeListener(listener);
}
public int getRowHeight() {
return _MAX_ROW_HEIGHT;
}
public void setSearchable(boolean searchable) {
_searchable = searchable;
}
public int getSelectedIndex() {
return getFieldWithFocusIndex(); // TODO??
}
public Object get(int index) {
return _listData.elementAt(index);
}
public int indexOfList(String prefix, int start) {
if (start >= _listData.size() || !_searchable) {
return -1;
} else {
int result = getSelectedIndex(); // the default result if we find no matches
for (Enumeration e = _listData.elements(); e.hasMoreElements(); ) {
String rowString = (String) e.nextElement();
if (rowString.startsWith(prefix)) {
return _listData.indexOf(rowString);
}
}
return result;
}
}
protected boolean navigationClick(int status, int time) {
CustomListRow focus = (CustomListRow) getFieldWithFocus();
if (focus != null) {
// see if the row wants to process this click
if (!focus.navigationClick(status, time)) {
// let our FieldChangeListener know that this row has been clicked
fieldChangeNotify(getFieldWithFocusIndex());
}
return true;
} else {
return false;
}
}
protected void sublayout(int width, int height) {
int w = Math.min(width, getPreferredWidth());
int h = Math.min(height, getPreferredHeight());
int rowHeight = getRowHeight();
int numRows = getFieldCount();
setExtent(w, h);
setVirtualExtent(w, rowHeight * numRows);
for (int i = 0; i < numRows; i++) {
Field f = getField(i);
setPositionChild(f, 0, rowHeight * i);
layoutChild(f, w, rowHeight);
}
}
public int getPreferredWidth() {
return Display.getWidth();
}
public int getPreferredHeight() {
return Display.getHeight();
}
public void setListData(Vector listData) {
_listData = listData;
if (listData != null) {
int listSize = listData.size();
int numRows = getFieldCount();
for (int s = 0; s < listSize; s++) {
if (s < numRows) {
// we can reuse existing CustomListRows
CustomListRow row = (CustomListRow) getField(s);
row.setData((ListRander) listData.elementAt(s));
} else {
CustomListRow row = new CustomListRow((ListRander) listData.elementAt(s));
row.setChangeListener(_fieldListener);
row.setFocusListener(this);
add(row);
}
}
if (listSize < numRows) {
// delete the excess rows
deleteRange(listSize, numRows - listSize);
}
} else {
deleteAll();
}
invalidate();
}
public void focusChanged(Field field, int eventType) {
// we handle scrolling here, when focus changes between rows
if (eventType == FOCUS_GAINED) {
if (field.getTop() < getVerticalScroll()) {
// field is off the top of the screen, so scroll up
setVerticalScroll(field.getTop());
} else if (field.getTop() >= getVerticalScroll() + getVisibleHeight()) {
// field is off the bottom of the screen, so scroll down
setVerticalScroll(field.getTop() - getVisibleHeight() + getRowHeight());
}
}
}
}
Finally, one row is represented by my CustomListRow class:
public class CustomListRow extends Manager implements FieldChangeListener {
private static final int _MAX_ROW_HEIGHT = 60;
private ListRander _data;
private BitmapField _thumb;
private LabelField _title;
private FocusableBitmapField _star;
private static final Bitmap _starImg = Bitmap.getBitmapResource("star.png");
private static final Bitmap _bgImg = Bitmap.getBitmapResource("listing_bg.png");
private SeparatorField _separator;
private int _fontColor = Color.BLACK;
private boolean _highlighted = false;
private int _width;
// subclass exists to expose focus methods (make public)
private class FocusableBitmapField extends BitmapField {
public FocusableBitmapField() {
super(_starImg, BitmapField.FOCUSABLE | BitmapField.EDITABLE);
}
public void onFocus(int direction) {
super.onFocus(direction);
}
public void onUnfocus() {
super.onUnfocus();
}
}
public CustomListRow(ListRander data) {
super(Field.FOCUSABLE | Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR);
setBackground(BackgroundFactory.createBitmapBackground(_bgImg));
_width = Display.getWidth();
long labelStyle = (DrawStyle.LEFT | DrawStyle.TOP | DrawStyle.ELLIPSIS);
_title = new LabelField("", labelStyle) { // custom anonymous class to change font color
protected void paint(Graphics g) {
int c = g.getColor();
g.setColor(_fontColor);
super.paint(g);
g.setColor(c);
}
};
_title.setFont(Font.getDefault().getFontFamily().getFont(Font.PLAIN, 24));
_thumb = new BitmapField();
_star = new FocusableBitmapField();
_star.setChangeListener(this);
_separator = new SeparatorField() { // custom anonymous class to change separator color
protected void paint(Graphics g) {
int c = g.getColor();
g.setColor(Color.GRAY);
super.paint(g);
g.setColor(c);
}
};
setData(data);
add(_thumb);
add(_title);
add(_star);
add(_separator);
}
public ListRander getData() {
return _data;
}
public void setData(ListRander value) {
if (value != _data) {
_data = value;
_title.setText(value.getTitle());
_thumb.setBitmap(value.getThumb());
}
}
private void onStarClicked() {
Dialog.alert("Star has been clicked or tapped!");
}
private void onRowClicked() {
Dialog.alert("Row has been clicked or tapped!");
}
public void fieldChanged(Field field, int context) {
if (field == _star) {
onStarClicked();
}
}
public boolean navigationClick(int status, int time) {
if (_star.isFocus()) {
onStarClicked();
return true;
} /* else {
onRowClicked();
return true;
} */
return false; // we will not consume this event
}
protected void highlight(boolean onRow) {
_fontColor = onRow ? Color.WHITE : Color.BLACK; // change font color for contrast
_highlighted = onRow;
invalidate();
}
protected void onFocus(int direction) {
// called when focus first transfers to this row, from another Field
if (direction == 1) {
// coming from top to bottom, we highlight the row first, not the star
highlight(true);
} else if (direction == -1) {
// coming from bottom to top, we highlight the star button first, not the row
_star.onFocus(direction);
highlight(false);
}
}
protected void onUnfocus() {
// remove highlighting of the row, if any
highlight(false);
super.onUnfocus();
}
protected int moveFocus(int amount, int status, int time) {
// called when this row already has focus (either on row, or star button)
if (amount > 0) {
// moving top to bottom
if (!_star.isFocus()) {
// we were on the row, now move to the star button
_star.onFocus(1);
highlight(false);
amount--; // consume one unit of movement
}
} else {
// moving from bottom to top
if (_star.isFocus()) {
// we were on the star button, now move back over to the row
_star.onUnfocus();
highlight(true);
amount++; // consume one unit of movement
}
}
return amount;
}
protected boolean touchEvent(net.rim.device.api.ui.TouchEvent event) {
// We take action when the user completes a click (a.k.a. unclick)
int eventCode = event.getEvent();
if ((eventCode == TouchEvent.UNCLICK) || (eventCode == TouchEvent.DOWN)) {
// Get the touch location, within this Manager
int x = event.getX(1);
int y = event.getY(1);
if ((x >= 0) && (y >= 0) && (x < _width) && (y < _MAX_ROW_HEIGHT)) {
int field = getFieldAtLocation(x, y);
if ((field >= 0) && (getField(field) == _star)) {
// Let event propagate to (star) button field
return super.touchEvent(event);
} else {
if (eventCode == TouchEvent.UNCLICK) {
// A completed click anywhere else in this row should popup details for this selection
fieldChangeNotify(1);
onRowClicked();
} else {
// This is just a soft touch (TouchEvent.DOWN), without full click
setFocus();
}
// Consume the event
return true;
}
}
}
// Event wasn't for us, let superclass handle in default manner
return super.touchEvent(event);
}
protected void sublayout(int width, int height) {
height = Math.min(getPreferredHeight(), height);
setExtent(_width, height);
final int margin = 5;
int thumbWidth = _thumb.getPreferredWidth();
layoutChild(_thumb, thumbWidth, _thumb.getPreferredHeight());
setPositionChild(_thumb, margin, margin);
int starWidth = _star.getPreferredWidth();
int starHeight = _star.getPreferredHeight();
layoutChild(_star, starWidth, starHeight);
setPositionChild(_star, width - starWidth - margin, (height - starHeight) / 2);
// this assumes you want margin between all fields, and edges
layoutChild(_title, width - thumbWidth - starWidth - 4 * margin, _title.getPreferredHeight());
setPositionChild(_title, margin + thumbWidth /* + margin */, margin); // TODO?
}
protected void paintBackground(Graphics g) {
super.paintBackground(g);
if (_highlighted) {
// you can't override drawFocus() for a Manager, so we'll handle that here:
int oldColor = g.getColor();
int oldAlpha = g.getGlobalAlpha();
XYRect rect = new XYRect();
g.setGlobalAlpha(150);
g.setColor(Color.BLUE);
getFocusRect(rect);
drawHighlightRegion(g, HIGHLIGHT_FOCUS, true, rect.x, rect.y, rect.width, rect.height);
g.setGlobalAlpha(oldAlpha);
g.setColor(oldColor);
}
}
public int getPreferredWidth() {
return _width;
}
public int getPreferredHeight() {
return _MAX_ROW_HEIGHT;
}
}
Usage
This is how you might use the whole list field (maybe in a Screen class):
public class ListScreen extends MainScreen implements FieldChangeListener {
public ListScreen() {
try {
Vector data = new Vector();
Bitmap icon = Bitmap.getBitmapResource("list_icon.png");
for (int i = 0; i < 15; i++) {
ListRander lr = new ListRander("Product Name " + i, icon);
data.addElement(lr);
}
CustomListField list = new CustomListField(data);
add(list);
list.setChangeListener(this);
} catch (Exception e) {
e.printStackTrace();
}
}
public void fieldChanged(Field field, int context) {
if (field instanceof CustomListRow) {
CustomListRow row = (CustomListRow) field;
Dialog.alert(row.getData().getTitle() + " was selected!");
}
}
}
In my app, it made sense for the CustomListRow itself to handle the equivalent of your star click. However, for me, it did not make sense to have the row click handled that way. So, I let you set a FieldChangeListener on the CustomListField itself, which is called back when any row is selected. See the example above in my screen class. If you want to handle the row click inside the CustomListRow class, too, that's fine. I laid out a onRowClicked() method there. Search in the code for where that's commented out, and you can reactivate, an implement that method (onRowClicked()).
Issues
My app didn't require list searching. I laid out a sample implementation of that, like ListField has. But, I didn't test it. That's your job, if you need it. I just got you started with the CustomListField implementation (see indexOfList()).
I didn't see what your "nav bar" was for. A bar is usually a full-width item, like a status bar, or toolbar. I don't see anything like that in your screenshot. A nav item might be a little arrow at the right side of each row, to bring up details. But, I didn't see that in your screenshot either. So, I ignored that code. If you need a nav bar, you obviously know what it should be, and can add that to my code above.
I couldn't tell whether or not you just added the star as part of the row's background image, or if you had a separate image for that. I added a separate star.png to represent the star. I would assume that clicking the star fills it in, or highlights it, or something. But, you didn't describe that problem, so I assume you can handle that. If you need a custom field to represent the star, that can have selected and unselected images, just post that as a new question.
You had some code that appeared like it was trying to set the row width to 3x the row height, but that didn't match your screen shot. Most lists are full-screen width anyway. So, I remove that code. My CustomListRow class implements getPreferredWidth() and requests the full screen width. Change if you like.
Unlike Android's ListView the BB's ListField is not designed to have a focusable/clickable fields inside of list items. So any attempt to workaround this will have some negative side effects.
A relatively easy/quick workaround would be to switch to VerticalFieldManager (check this other stack overflow question). But if the list is too long (more than several hundreds, I believe) you risk to "eat" too much memory.
If the app is designed for touch screens only, then you can try to stay with ListField + do some manual tracking of touch event coordinates. So when you detect a list field click (in a way you would normally do it) you can check whether the touch coordinates correspond to the star image area (at least on the X axis). I am not going to invent/provide an implementation, but just giving an idea.

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.

Blackberry UI Hint Box

I am very much new to the blackberry UI development and want to know that is there any way you can add a hint box on bitmap? just like a title attribute in an element of HTML
You can use the following TooltipScreen and add fields to the screen in the following way
add(new ButtonField(“myButton”), “My Tooltip text”);
TooltipScreen
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.XYRect;
import net.rim.device.api.ui.container.MainScreen;
public class TooltipScreen extends MainScreen {
TooltipScreen screen = this;
boolean doRedraw = false;//prevent infinte redrawing
Vector tooltips = new Vector();//vector to hold tooltip strings
private Timer tooltipTimer = new Timer();
private TimerTask tooltipTask;
boolean alive = false;//is the tooltip alive? used to pop it after our timeout
int count = 0;//used to calculate time tooltip is displayed
//tooltip popup colours:
int backgroundColour = 0xeeeeee;
int borderColour = 0xaaaaaa;
int fontColour = 0x666666;
//the tooltip:
String tooltip;
int tooltipWidth;
int yCoord;
int xCoord;
//region parameters:
XYRect contentArea;
int contentBottom;
int contentRight;
public TooltipScreen() {
super();
//when timeout reaches 100ms*20 ie. 2seconds set alive to false and redraw screen:
tooltipTask = new TimerTask() {
public void run() {
if (alive) {
count++;
if (count == 20) {
alive = false;
invalidate();
}
}
}
};
tooltipTimer.scheduleAtFixedRate(tooltipTask, 100, 100);
}
//override add method adds an empty string to tooltip vector:
public void add(Field field) {
tooltips.addElement("");
super.add(field);
}
//custom add method for fields with tooltip: add(myField, "myTooltip");
public void add(Field field, String tooltip) {
super.add(field);
tooltips.addElement(tooltip);
}
public void setColours(int backgroundColour, int borderColour, int fontColour) {
this.backgroundColour = backgroundColour;
this.borderColour = borderColour;
this.fontColour = fontColour;
}
//reset everything when user changes focus,
//possibly needs logic to check field has actually changed (for listfields, objectchoicefields etc etc)
protected boolean navigationMovement(int dx, int dy, int status, int time) {
count = 0;
alive = true;
doRedraw = true;
return super.navigationMovement(dx, dy, status, time);
}
protected void paint(Graphics graphics) {
super.paint(graphics);
if (alive) {
Field focusField = getFieldWithFocus();
tooltip = (String) tooltips.elementAt(screen.getFieldWithFocusIndex());
//don't do anything outside the norm unless this field has a tooltip:
if (!tooltip.equals("")) {
//get the field content region, this may fall inside the field actual region/coordinates:
contentArea = focusField.getContentRect();
contentBottom = contentArea.y + contentArea.height;
contentRight = contentArea.x + contentArea.width;
//+4 to accomodate 2 pixel padding on either side:
tooltipWidth = graphics.getFont().getAdvance(tooltip) + 4;
yCoord = contentBottom - focusField.getManager().getVerticalScroll();
//check the tooltip is being drawn fully inside the screen height:
if (yCoord > (getHeight() - 30)) {
yCoord = getHeight() - 30;
}
//check the tooltip doesn't get drawn off the right side of the screen:
if (contentRight + tooltipWidth < getWidth()) {
xCoord = contentRight;
} else {
xCoord = getWidth() - tooltipWidth;
}
//draw the tooltip
graphics.setColor(backgroundColour);
graphics.fillRect(xCoord, yCoord, tooltipWidth, 30);
graphics.setColor(borderColour);
graphics.drawRect(xCoord, yCoord, tooltipWidth, 30);
graphics.setColor(fontColour);
graphics.drawText(tooltip, xCoord + 2, yCoord);
}
}
//doRedraw logic prevents infinite loop
if (doRedraw) {
//System.out.println("redrawing screen: " + System.currentTimeMillis());
screen.invalidate();
doRedraw = false;
}
}
}

Resources