Develop Reference

Adding a label to a Point on map in ArcGIS

I have static points on a map.
I use this code to draw them:
point = GeometryEngine.project(longitude, latitude, mapSR);
pointGraphic = new Graphic(point, symbol);
graphicsLayer.addGraphic(pointGraphic);
The point is drawed on the map.
Now I want to add a label to it - show under the drawn point it's longitude and latitude.
I can do it using text adding, but then when I resize the map, the text placement changes.
I want to put it like a label - let's say on the bottom right from the point.
I want it to be sensitive for zooming, and binded to the Point.
I read about dinamic labels, but it seems very complex for such a simple request.
How can I do this?
Thanks.

Individual graphics don't have labels, but you can create two graphics with the same geometry. Use your current symbol for one of them. For the other graphic, use a TextSymbol, calling setOffsetX(float) and setOffsetY(float) to place it the way you want.

how to get cursor coordinates when it is on Chart2D (jchart2D library)

I'm using jchart2D library to plot functions. I need to get cursor coordinates. That question was asked already here. When I add MouseMotionListener to Chart2D, it gives location of cursor in pixels (but not coordinates). getNearestPoint function also doesn't work because it finds Point which is in Trace

It's unlikely that you want to interpolate between points on the chart, as shown here. Instead, use a ChartMouseListener, as illustrated here and here.

Using JPanel to draw straight lines and get point coordinates

I am at a total loss right now. I haven't worked much with building GUIs in Java, I've been reading all about swing and JPanel, and I think what I am trying to do is possible, I just haven't figured out how.
I'm trying to build a GUI in which you can draw straight lines within a certain drawing area, I would like to be able to get the start/endpoint coordinates in order to perform some math with those points. Any help would be greatly appreciated!

I will leave the code to you so here is the algorithm:
1. Create a JFrame and add a JPanel to it.
2. Add a mouse listener for the JPanel
3. Every time the mouse is pressed, get the x and y of the click. (starting points)
4. When the mouse is dragged , record x and y continuously.
5. When mouse is released, record the x and y. (ending points)
6. You could either use the drawLine() method of Graphics class or use draw() of Graphics2D in this case you will need a Line2D.Double -- the arguments remain the same - start x, start y, end x and end y
here is an image to explain a lil bit better:

Start with Performing Custom Painting and 2D Graphics.
Basically, you going to need a mouse listener to monitor the user interaction with your panel, check out How to write mouse listeners for more infor still.
Depending on your needs, if you need to maintain all the click points of the user, you would need to store them in something like a List, or if you just need to know the start and end points, the you just need a couple of Point objects.
You would be able to use these to paint onto your surface and performing your required calculations.
Remember, in this context, the points are contextual to the container they were generated on. That is 0x0 will be the top left of the container
Updated
You could also take advantage of the Shape API, using a Line2D to represent the two points. This would make it easier to distinguish between distinct lines/points

This is harder than just "draw straight lines with (x1,y1) and (x2, y2)" approach.
You need a Line(your custom) object that is dynamically created and placed on the JPanel which is listening for MouseEvents The canvas area being the JPanel itself. You also need to separate the MODEL from the VIEW so that your custom canvas JPanel will draw itself properly with an override for paintComponent()
The question is slightly vague, so I can't provide any code.

you need to add the mouse listener on JPanel.
then:
public void mouseClicked(MouseEvent me){
if(click==1){
int x1=me.getX();
int y1=me.getY();
click=click+1;
}
else{
int x2=me.getX();
int y2=me.getY();
click=1;
}
}
drawLine(x1,y1,x2,y2)
To draw line with mouse move you can also add mouse motion listener.

How to change the position of a view?

I have two views called x and y they are both black lines (for example I made the height of the x line is 1dp and width 230dp and as background filled with the color black).
Now i want to move the position of the lines programmatically (for example I want the y line 50dp to the right of the orginal position).
Can someone help me how to do this?
I have tried things such as setpadding but the line doesn't move.
Thanks in advance!
(ps: my minimum sdk is set for 7 so i can't use the newest api's).

Old Answer
Have a look at the Absolute Layout, it allows you to position
child elements using x, y coordinates. It is deprecated but it's the
only way in Android to do real x,y coordinate positioning.
I would ask what the main point behind what you are trying to do is
though? It sounds like you started with a goal, were led down a path
and now are asking how to get to the end of that path, rather than
asking how to do what you need to do.
Edited
For drawing graphs have a look instead at https://stackoverflow.com/questions/2271248/how-to-draw-charts-in-android.
Using a Layout class to draw a chart will only lead to a really slow app, since the layout classes are designed for creating relatively static layouts, not drawing full graphics.
Instead use either the Canvas and draw your drawables yourself or use the graphing packages listed in the SO question I linked above.

How to make vector line selectable?

I'm making a project for college, where I have to make my own primitive vector editor, and I have two questions:
Is it right to make vector line object by saving it's start point coordinates, end point coordinates, color and width of points, which it will consist of? Point is also my class, which is drawn on JPanel.
If it is right, how can I make this line selectable? The only thing I can think of is to check mouse coordinates to be inside of line width.
I also have a restriction not to use any standard functions for drawing lines, splines, etc.

Yes that's right. Or you could represent it in polar coordinates
the best thing to do is actually turn your line into an Area, which implements Shape and thus contains, which is the method you want. Area is a great abstraction because it can represent any shape but everything gets manipulated in the same way.

You can use Line2D Shape. To check selection you can gt stroked Shape from BasicStroke and check whether the stroked Shape contains clicked point.

To Point 1: You also need to save the direction of the vector.
To Point 2: There are some frameworks like GEF which do the job for you. Here you have to change your model. You need two classes: Point and Connection

You can use a class Vector if you have one with start and end Point for do it if you want.
You can have a method like that:
private static Shape generateVector(Point start, Point end)
In this method you can use one object of ´Area´ for build the vector, with Line2D. Tree lines if you want an arrow.
Or you can use a GeneralPath for build it.
For select a particular vector with the mouse, you can get the coordinates, with getX() and getY() on the MouseEvent and ask in the shape object with method contains and repaint with other color.
Good luck!