What's the best way to associate an image that's in a JPanel to a mouseclick in order to do something? I mean, is there any function in API that can do that? If not, what's the best solution?
By the way, for you who may be wondering why I'm asking for help in this matter is because I'm doing a Sudoku game, and my code already generates randomly all the numbers in the matrix, checks if the solution is correct, the only thing that's not done yet is the interface(the user choosing a square in order to select a number in there).
Thank you.
The "best" way? Use a JLabel
A different way, use a custom JPanel which is responsible for rendering a single image and paint it via the paintComponent method of the panel
A "interesting" way, use a custom JPanel to paint all the images, maintain in some kind of List where each image is associated with a Rectangle that describes the location and size of the image. When the panel is clicked, loop through the Rectangle List and use the contains method of the Rectangle to determine if the mouse event occurred within it, use the index of the Rectangle to loop up the image (or use some kind of Map to maintain a link between the two)
Which you do depends on how much work you want to do and what functionality you intend to implement.
Take a close look at:
How to Use Labels
Performing Custom Painting
How to Write a Mouse Listener
Would a clickable image help you?
ImageView clickableImg = new ImageView(new Image(getClass().getResourceAsStream("graphics/image.png")));
Tooltip image_tooltip = new Tooltip("Maybe add a tooltip to it, as well");
Tooltip.install(clickableImg, image_tooltip);
//Turn the cursor into a hand when hovering over it, too
about.setStyle("-fx-cursor: hand;");
about.setOnMouseClicked(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
System.out.println("The image was clicked!");
}
});
Well, you could do something like this to determine if a mouse click is inside a certain region(the image's bounds):
public boolean isIn(int x,int y,int width,int height,int thex,int they){
boolean b=
thex>=x
&&thex<=(x+width)
&&they>=y&&
they<=(y+height);
//b=true;
return b;
}
where:
x is the x-coordinate of the top left corner
y is the y-coordinate of the top left corner
width is the width of the image
height is the height of the image
and x and y are the x and y-coordinates of the mouse click.
After determining which square the mouse's click is inside, you can then make a pop up to get the number to place.
Related
I'm trying to figure out if there's any way to draw images (drawRect(), drawOval(), etc.) based on if/else statements or by using an ActionListener.
I don't want to post the complete problem because this is for an assignment, but for my own scenario:
If I have a button on a JPanel named "draw rectangle" and I have the x, y, width, and height from user input, is there any way I can attach an actionListener to "draw rectangle" that could somehow draw the rectangle using those values (passed by reference?).
I know I can use paintComponent, but I can't put that into the ActionListener and it seems to do things of its own accord and not based on a specific user's actions.
I don't really have any code for this because I can't figure out how to do it at all.
If I have a button on a
JPanel named "draw rectangle" and I have the
x, y, width, and height from user input, is there any way I can attach
an actionListener to "draw rectangle" that could somehow draw the
rectangle using those values (passed by reference?).
The short answer is yes.
Generally, you'll need to save the rectangle instructions in a model, and have the JPanel redraw the model when any of the shape buttons are pressed.
Let's take your rectangle example. What do you need to know to draw a rectangle on a JPanel? You need a starting point (upper left) and an ending point (lower right). You can use a java.awt.Point to hold the starting and ending point. You can set the thickness of the line, in pixels. You can set the color of the rectangle, using a JColorChooser. You can also set the rectangle to be an outline or filled with the chosen color.
That description will be similar for a line and a triangle. A circle is a little different, with a center point and a radius. As you can see, we already have a lot of information to keep track of just with these simple geometric shapes.
Then there's the issue of the drawing surface itself. It's possible to have a drawing surface larger than your computer screen can show. You can put the drawing surface inside of a JScrollPane.
All of these things must be determined so you can build the model of your application. You do this before you build the view using Swing components and the controller using action listeners.
I am making an app with javafx and I put Polygon shapes into a Pane and define the shapes (one for example below) as
shape.getPoints().addAll(new Double[] { ... points ... });
shape.setTranslateX(...);
shape.setTranslateY(...);
setOnMousePressed(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
System.out.println(hex.getResource().toString());
hex.pressed();
}
});
Then I add the shape to my pane
pane.getChildren().addAll(shape);
But when I click on the shapes, it seems like the click area is covering more than just the shape. It is covering up other click areas, so I am unable to click on some shapes, and I am accidentally clicking on others. But the shapes themselves are in the right position and look fine. They aren't physically covering each other up. Please let me know how I would fix the click area.
Also, I can't use the other layout classes since my shapes need to be put in a location explicitly, not just in a grid or next to each other.
What you're looking for is clipping.
Go ahead and add this to your code and that should resolve your issue.
pane.setClip(shape);
As for your second issue, I'm not sure what you're asking.
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.
I have a program containing five buttons:
i) Square ii) Rectangle iii) Circle iv) Triangle v) Clear
Clicking on any of the first four buttons will draw the respective shape on the drawing canvas using the following code:
The shapes can be dragged. They also should be resized. I was just trying to change the cursor of the mouse around the four edges of the shape (NW, NE, SW, SE). This works fine for squares and rectangles since they have four sides. However, I have some problem implementing the same for the circle and triangle.
This is what I did in my mouseClicked event:
What I want to do is that if the string shape_type contains circle, for example, it draws a border around it so that the user can see the boundaries of the shape.
However, I can't just use the following code inside the if statement:
How can I draw the border please? Thanks :)
You are correct that you can't do painting in a MouseListener method. What you can do is set shapeUnderMouse in your mouseClicked method, then call repaint. You'll get better performance if you only repaint the areas that you know are changing visually, but it's not strictly necessary.
The if (shapeUnderMouse != null) block should be placed in your paint method.
I have this picture and I wish to be able to read each individual picture, load it up into a paint method and add Mouse Listeners to each spot of color but not any of the black background. I do not wish to include ANY of the black background as a "button" and only have the colored spots have mouselisteners of their own so I can distinguish which color spot I have pressed. Does anyone have any ideas? Thanks!
I suppose you could approach it this way:
List<Shape> buttons = ...
for each pixel in the picture, top left to bottom right {
if the pixel is not black {
if the pixel is not already contained in one of the buttons {
iterate over every pixel towards the right until you reach a different color
iterate over every pixel towards the bottom until you reach a different color
// now you have the bounds of your button
// create a new Rectangle and add it to your list.
}
}
}
I've never attempted something like this, nor have I tested the above method, but to me it seems like it should work.
Why can't you just duplicate the picture with JButtons and JPanels and simplify your life?
The mouseListener returns a location, so I would use that location to inspect the image at the corresponding pixel, then branch to do the required action. If the pixel turns out to be black, you simple do nothing.
The image can be inspected via a BufferedImage object and a Raster.
Alternatively, one could inspect the image via BufferedImage and a Raster, and create corresponding Objects for each color square located, printing and handling each one separately.