I used this link for showing more location but when I scroll the map, then marker does not scroll, i.e. the position is static. Please help me.
Use this:
map = new MapField(){
public void paint(Graphics g){
super.paint(g);
for(int i=0;i<=_longitude.size()-1;i++){
Coordinates coords = getCoordinates();
coords.setLatitude(Double.parseDouble((String) _latitude.elementsAt(i));
coords.setLongitude(Double.parseDouble((String) _longitude.elementsAt(i));
convertWorldToField(coords,_xypoint);
g.drawBitmap(_xypoint.x,_xypoint.y,_loc.getWidth(),_loc.getHeight(),_loc, 0, 0);
}
}
Note: _latitude and _longitude are the vectors containing respective values , this will make the markers that are not static.
Related
I'm writing my first Qt 5 application... This uses a third-party map library (QGeoView).
I need to draw an object (something like a stylized airplane) over this map. Following the library coding guidelines, I derived from the base class QGVDrawItem my QGVAirplane.
The airplane class contains heading and position values: such values must be used to draw the airplane on the map (of course in the correct position and with correct heading). The library requires QGVDrawItem derivatives to override three base class methods:
QPainterPath projShape() const;
void projPaint(QPainter* painter);
void onProjection(QGVMap* geoMap)
The first method is used to achieve the area of the map that needs to be updated. The second is the method responsible to draw the object on the map. The third method is needed to reproject the point from the coordinate space on the map (it's not relevant for the solution of my problem).
My code looks like this:
void onProjection(QGVMap* geoMap)
{
QGVDrawItem::onProjection(geoMap);
mProjPoint = geoMap->getProjection()->geoToProj(mPoint);
}
QPainterPath projShape() const
{
QRectF _bounding = createGlyph().boundingRect();
double _size = fmax(_bounding.height(), _bounding.width());
QPainterPath _bounding_path;
_bounding_path.addRect(0,0,_size,_size);
_bounding_path.translate(mProjPoint.x(), mProjPoint.y());
return _bounding_path;
}
// This function creates the path containing the airplane glyph
// along with its label
QPainterPath createGlyph() const
{
QPainterPath _path;
QPolygon _glyph = QPolygon();
_glyph << QPoint(0,6) << QPoint(0,8) << QPoint(14,6) << QPoint(28,8) << QPoint(28,6) << QPoint(14,0);
_path.addPolygon(_glyph);
_path.setFillRule(Qt::FillRule::OddEvenFill);
_path.addText(OFF_X_TEXT, OFF_Y_TEXT, mFont , QString::number(mId));
QTransform _transform;
_transform.rotate(mHeading);
return _transform.map(_path);
}
// This function is the actual painting method
void drawGlyph(QPainter* painter)
{
painter->setRenderHints(QPainter::Antialiasing, true);
painter->setBrush(QBrush(mColor));
painter->setPen(QPen(QBrush(Qt::black), 1));
QPainterPath _path = createGlyph();
painter->translate(mProjPoint.x(), mProjPoint.y());
painter->drawPath(_path);
}
Of course:
mProjPoint is the position of the airplane,
mHeading is the heading (the direction where the airplane is pointing),
mId is a number identifying the airplane (will be displayed as a label under airplane glyph),
mColor is the color assigned to the airplane.
The problem here is the mix of rotation and translation. Transformation: since the object is rotated, projShape() methods return a bounding rectangle that's not fully overlapping the object drawn on the map...
I also suspect that the center of the object is not correctly pointed on mProjPoint. I tried many times trying to translate the bounding rectangle to center the object without luck.
Another minor issue is the fillup of the font... the label under the airplane glyph is not solid, but it is filled with the same color of the airplane.
How can I fix this?
Generically speaking, the general pattern for rotation is to scale about the origin first and then finish with your final translation.
The following is pseudocode, but it illustrates the need to shift your object's origin to (0, 0) prior to doing any rotation or scaling. After the rotate and scale are done, the object can be moved back from (0, 0) back to where it came from. From here, any post-translation step may be applied.
translate( -origin.x, -origin.y );
rotate( angle );
scale( scale.x, scale y);
translate( origin.x, origin.y );
translate( translation.x, translation.y )
I finally managed to achieve the result I meant....
QPainterPath projShape() const
{
QPainterPath _path;
QRectF _glyph_bounds = _path.boundingRect();
QPainterPath _textpath;
_textpath.addText(0, 0, mFont, QString::number(mId));
QRectF _text_bounds = _textpath.boundingRect();
_textpath.translate(_glyph_bounds.width()/2-_text_bounds.width()/2, _glyph_bounds.height()+_text_bounds.height());
_path.addPath(_textpath);
QTransform _transform;
_transform.translate(mProjPoint.x(),mProjPoint.y());
_transform.rotate(360-mHeading);
_transform.translate(-_path.boundingRect().width()/2, -_path.boundingRect().height()/2);
return _transform.map(_path);
}
void projPaint(QPainter* painter)
{
painter->setRenderHint(QPainter::Antialiasing, true);
painter->setRenderHint(QPainter::TextAntialiasing, true);
painter->setRenderHint(QPainter::SmoothPixmapTransform, true);
painter->setRenderHint(QPainter::HighQualityAntialiasing, true);
painter->setBrush(QBrush(mColor));
painter->setPen(QPen(QBrush(Qt::black), 1));
painter->setFont(mFont);
QPainterPath _path = projShape();
painter->drawPath(_path);
}
Unluckly I still suffer the minor issue with text fill mode:
I would like to have a solid black fill for the text instead of the mColor fill I use for the glyph/polygon.
I'm developing a Codename One app for iOS.
I'm using a MapContainer (https://github.com/codenameone/codenameone-google-maps) and I set a tap listener for it, in order to draw a marker in the point of the screen pressed by the user.
This is the code snippet:
map.addTapListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
//Point of the screen where the user pressed
int x = evt.getX();
int y = evt.getY();
//I get the coordinates from the point of the screen
Coord coord = map.getCoordAtPosition(x, y);
//I create the marker, with a style
Style s = new Style();
s.setFgColor(0xff0000);
s.setBgTransparency(0);
FontImage markerImg = FontImage.createMaterial(FontImage.MATERIAL_PLACE, s);
EncodedImage icon = EncodedImage.createFromImage(markerImg, false);
map.addMarker(icon, coord, "My position", null, null);
map.zoom(coord, 15);
}
});
This code does not correctly place the marker in the point tapped by the user: it lacks in accuracy.
According to this question (How to get my MapContainer bounding box in Codename One), I also tried to get the North-East latitude and longitude:
map.addTapListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
//I get the coordinates of the NE point
Coord neCoords = map.getBoundingBox().getNorthEast();
ToastBar.showMessage("NE coords: (" + neCoords.getLatitude() + ";" + neCoords.getLongitude() + ")", FontImage.MATERIAL_PLACE);
}
});
The following picture is a screenshot from an iPhone:
As you can see, the North-East corner corresponds to via Ignazio Silone ("Silone" is missing in the picture). The coordinates the snippet gave are: 44.539829,11.367906.
I put that coordinates on Google Maps and I compared that place with the NE point shown in my app: they differ, as you can see in the following picture (the marker is placed in the coordinates 44.539829,11.367906, while the arrow represents the NE point shown in my app).
How can I solve it? Can I place the marker in the position tapped by the user, with more accuracy?
Why Vector2 (from XNA's library) uses float not int?
Position on computer screen is given in pixels so that cursor position can be defined by two integers. There is no such a thing like half a pixel. Why we use floats then?
In SpriteBatch class I've found 7 overloaded methods called Draw. Two of them:
public void Draw(Texture2D texture, Rectangle destinationRectangle, Color color);
public void Draw(Texture2D texture, Vector2 position, Color color);
So we can see that Draw accepts both int and float coordinates.
I came across this problem when I've been implementing screen coordinates of my game's objects. I assumed that Rectangle is good choice to hold object's size and screen coordinates. But now I'm not sure...
Mathematically, a vector is a motion, not a position. While a position on the screen might not technically be able to be between integers, a motion definitely can. If a vector used ints then the slowest you could move would be (1, 1). With floats you can move (.1, .1), (.001, .001), and so on.
(Notice also that the XNA struct Point does actually use ints.)
You could use both Vector2 and Rectangle to represent your objects coordinates. I usually do it like this:
public class GameObject
{
Texture2D _texture;
public Vector2 Position { get; set; }
public int Width { get; private set; } //doesn't have to be private
public int Height { get; private set; } //but it's nicer when it doesn't change :)
public Rectangle PositionRectangle
{
get
{
return new Rectangle((int)Position.X, (int)Position.Y, Width, Height);
}
}
public GameObject(Texture2D texture)
{
this._texture = texture;
this.Width = texture.Width;
this.Height = texture.Height;
}
}
To move objects, just set their Position property to a new value.
_player.Position = new Vector2(_player.Position.X, 100);
You don't have to worry about the rectangle, as it's value depends directly on Position.
My game objects also usually contain methods to draw themselves, such as
public void Draw(SpriteBatch spriteBatch, GameTime gameTime)
{
spriteBatch.Draw(this._texture, this.Position, Color.White);
}
Collision detection code in your Game.Update() could just use the PositionRectangle to test for collisions
//_player and _enemy are of type GameObject (or one that inherits it)
if(_player.PositionRectangle.Intersects(_enemy.PositionRectangle))
{
_player.Lives--;
_player.InvurnerabilityPeriod = 2000;
//or something along these lines;
}
You could also call the spriteBatch.Draw() with PositionRectangle, you shouldn't notice much difference.
There is such a thing as "half a pixel." Using float coordinates that aren't pixel-aligned will cause your sprites to be rendered at sub-pixel coordinates. This is often necessary to make objects appear to scroll smoothly, but it can also produce an unpleasant shimmering effect in some circumstances.
See here for a summary of the basic idea: Subpixel rendering
Below code defines a horizontal field manager with two fields. How can I amend the code so that the background is just set on the two fields being added not on the whole manager. Note, im not attempting to add an individual background image to each of the fields, instead a shared background image that spans behind the two fields.
LabelField label = new LabelField("name");
TextField e = new TextField(Field.FOCUSABLE);
final Bitmap b = Constants.SETTINGS;
final Background bg = BackgroundFactory.createBitmapBackground(Constants.SETTINGS);
HorizontalFieldManager manager = new HorizontalFieldManager()
{
public void sublayout (int width, int height)
{
Field field;
int x = 0;
super.sublayout(b.getWidth(), height);
super.setExtent(b.getWidth(), height);
for (int i = 0; i < getFieldCount(); i++)
{
field = getField(i);
layoutChild(field, Display.getWidth()/2, height);
setPositionChild(field, x, 10);
x += Display.getWidth()/2;
}
}
};
manager.add (label);
manager.add (e);
add (manager);
Rather than putting them in a custom Manager, it may be easier to just override the Fields' layout() calls to be
protected void layout(int width, int height) {
super.layout(width, height);
setExtent(Display.getWidth()/2, this.getHeight());
}
and then you can just use a normal HorizontalFieldManager you can set a background on and a padding (hfm.setPadding(10, 10, 10, 10);). Adding a padding will reduce the available width for your Fields, so you should decrease their widths in the layout() calls.
You can offset each of their individual backgrounds with some fancy, expensive Bitmap footwork (math) to appear to "share" one image using setBackGround(), or you can override their draw methods to achieve the same effect with the ability to "move" across the bitmap according to their relative position...
That what you're after? :)
edit:
create a custom field to use your bitmap and feed it whatever content you would like, then override the paint to draw what you like where you like it...
protected void paint(Graphics g){
// conditionals, etc
g.drawBitmap(x, y, width, height, bitmap, left, top);
// color changes, etc
g.drawText(yourText);
// clean up
}
I am working on an eBook app where I need to transition the screens from left to right and right to left. I tried many samples that I've found, but I am not successful. How do I change the screen frequently when user clicks on the screen from left to right and right to left. What is the basic idea for transition of pages. I went through the Developer Support Forum thread "page-flip effect" looking for a solution, but I can't see it.
The following code is not logical. In which position do I have to implement flip effect for flipping pages in the screen and how to implement it?
public class TransitionScreen extends FullScreen implements Runnable{
private int angle = 0;
Bitmap fromBmp,toBmp;
public TransitionScreen(){
}
public TransitionScreen(AnimatableScreen from,AnimatableScreen to) {
fromBmp = new Bitmap(Display.getWidth(), Display.getHeight());
toBmp = new Bitmap(Display.getWidth(), Display.getHeight());
Graphics fromGraphics = Graphics.create(fromBmp);
Graphics toGraphics = Graphics.create(toBmp);
Object eventLock = getApplication().getEventLock();
synchronized(eventLock) {
from.drawAnimationBitmap(fromGraphics);
to.drawAnimationBitmap(toGraphics);
// Interpolate myOffset to target
// Set animating = false if myOffset = target
invalidate();
}
try {
synchronized (Application.getEventLock()) {
Ui.getUiEngine().suspendPainting(true);
}
} catch (final Exception ex) {
}
}
protected void paint(Graphics g){
//control x,y positions of the bitmaps in the timer task and the paint will just paint where they go
g.drawBitmap(0,0, 360,
480, toBmp, 0, 0);
g.drawBitmap(0, 0, 360,
480, fromBmp, 0, 0);
// invalidate();
}
protected boolean touchEvent(TouchEvent event) {
if (!this.isFocus())
return true;
if (event.getEvent() == TouchEvent.CLICK) {
// invalidate();
}
return super.touchEvent(event);
}
}
Assuming you're working with version 5.0 or later of the OS, this page has a simple example:
http://docs.blackberry.com/en/developers/deliverables/11958/Screen_transitions_detailed_overview_806391_11.jsp
From where did you get the code sample posted in your question? That code does not appear to be close to working.
Update: you can actually animate transitions like this yourself fairly simply. Assuming you know how to use the Timer class, you basically have a class-level variable that stores the current x-position of your first Bitmap (the variable would have a value of 0 initially). In each timer tick, you subtract some amount from the x-position (however many pixels you want it to move each tick) and then call invalidate();.
In each call to the paint method, then, you just draw the first bitmap using the x-position variable for the call's x parameter, and draw the second bitmap using the x-position variable plus the width of the first bitmap. The resulting effect is to see the first bitmap slide off to the left while the second slides in from the right.
A caveat : Because this is java (which means the timer events are not real-time - they're not guaranteed to occur when you want them to), this animation will be kind of erratic and unsmooth. The best way to get smooth animation like this is to pre-render your animation cells (where each is a progressive combination of the two bitmaps you're transitioning between), so that in the paint method you're just drawing a single pre-rendered bitmap.