I need some help with Java Swing components and its capabilities. I need to add a JPanel to a JFrame and paint an Ellipse2D on it. Onto the Ellipse2D I want to add another element, in my case it is a picture (right now I use an ImageIcon, maybe wrong). How can I achieve adding the Ellipse2D and the picture on the panel as shown in the image I attached?
The reason why I need the images separated is, because I need to change the filling color of the ellipse sometimes.
Thanks for any help.
What you need is to create a custom JPanel implementation and override paintComponent method.
Inside it, you just do:
public void paintComponent(Graphics g) {
super.paintComponent(g);
// Draw ellipse here
// Draw your image here. It will be drawn on top of the ellipse.
}
This way, you can hold the ellipse fill color in the CustomPanel class, and just call repaint() method after you change the color.
your idea could be very good described (including code example) in the Oracles tutorial How to Decorate Components with the JLayer Class
notice JLayer is available only for Java7, but its based on (for Java6) JXLayer
you can use (I'm using) GlassPane too, with the same / similair output to the Swing GUI
EDIT
quite easy and nice output is by using OverlayLayout, there is possible to overlay J/Component(s) with Graphics e.g., a few examples
take the two images as image icons like
ImageIcon car=new ImageIcon("image path");
ImageIcon elipse=new ImageIcon("image path");
add those two image icons two label
JLabel carLabel=new JLabel(car);
JLabel ellipseLabel=new JLabel(ellipse);
and set the position of ellipse and car
carLabel.setBounds(0,0,50,50);
ellipseLabel.setBounds(10,10,50,50);
Related
I want to be able to select part of an image in an ImageIcon on JLabel and fill it with color.
Is this possible I have become a little confused as I have read that an ImageIcon is not selectable but I am not sure if that means I have to find another way of displaying the image?
Possible, yes, difficult, yes.
You need to start with a BufferedImage, which you can then wrap in a ImageIcon and apply to a JLabel.
You would then need to register a MouseMotionListener and MouseListener to the label to detect the area which was selected, you would then modify the BufferedImage accordingly and repaint everything.
Having said that, I wouldn't use a JLabel, as you can't accurately calculate the location that the label renders the icon, instead, I'd make myself a custom component, extending from JPanel and encapsulate the functionality within it and use custom painting to paint the image (and the selection area)
Start by having a look at How to Write a Mouse Listener, Performing Custom Painting, 2D Graphics and possibly Reading/Loading an Image, Writing/Saving an Image
Referring to my earlier question:
Based on your valuable answers, I choose Java 2D library to cater my requirements.
I completely read the above said library and have full understanding of dealing with the graphics stuff, like what to draw and how to draw etc.Now i only left with one question that how do i draw my required shapes inside JPanel and after drawing all those shapes how do i place that JPanel inside a JScrollPane?
Override paintComponent(Graphics g) method.
Cast Graphics to Graphics2D and use drawShape() method passing all your Shapes
You will typically draw your stuff inside a subclass of JComponent, say, MyComponent.
Create an instance of MyComponent, MyComponent myc = new
MyComponent();
Put that inside a JScrollPane, e.g. JScrollPane jsp =
new JScrollPane(myComponent);
Then add the JScrollpane to the
JPanel (exact code depends on the layout manager)
I have a simple GUI component written in Java. The class draws an analog clock in a java.awt.canvas.
This canvas is then contained in a JFrame - What I want to do is give the canvas a 3d "raised" effect - almost like adding a drop shadow to a photo.
Is there a simple way to do this?
If you are using a JFrame, then you have two options:
Add your own component to a JPanel first and then add this to the JFrame.
Instead of inheriting from java.awt.Canvas, you can inherit from JComponent. Then you would have to do all your painting in the paintComponent() Method instead of just paint() (you can just rename your current paint method).
In both cases you can now set a border with the setBorder() Method (on the JPanel or your component) you can get from BorderFactory.
See also: How to Use Borders
If you were using a Swing element, you'd use the createRaisedBevelBorder() method of the BorderFactory and set the canvas' border to the resulting border. Canvas is an AWT component, so you'll need to wrap it in a Swing component to which you can set the border.
I would like to dynamically create a minimal transparent bar graph to display over a canvas.
I was thinking of using a custom renderer for a JButton or a JLabel; but how do I draw my bar graph in this renderer?
The standard way would be to create a subclass (possibly an anonymous one, if you prefer) of JLabel or JPanel and overload the paintComponent(Graphics g) method. You can then use the passed Graphics object to draw whatever rectangles (and so forth) that you need. For more information on that part of it, refer to the Java 2D Graphics Trail.
EDIT: Does that answer the question? I just re-read it and now I'm not sure.
I'm trying to make a paint editor with Java in which I have a toolbar with the objects that I would like to paste in the canvas. I'm using Swing components to make the GUI, but when I looked for the way of making the canvas, I only found the class canvas from AWT.
Is there any way to make something similar to canvas with Swing? (for example, JPanel?) I have read that using the class canvas from AWT with a GUI made with swing won't work correctly, is that true?
In order to make a custom 'Canvas' in swing you usually write a subclass of a JPanel. Then, you must overwrite the protected paintComponent(Graphics g) method of JPanel.
In the paint method, you can call methods on the Graphics object to actually draw on the JPanel.
As always, the Java Tutorials have a great reference on this to get you started.
You'll probably want to make a subclass of JPanel and implement your own way of painting components you want to draw onto the panel.
The basic approach will probably be along the line of assigning a MouseListener to the subclass of JPanel, then implement painting functionality.
The basic idea may be something along the line of:
class MyCanvas extends JPanel implements MouseListener
{
Image img; // Contains the image to draw on MyCanvas
public MyCanvas()
{
// Initialize img here.
this.addMouseListener(this);
}
public void paintComponent(Graphics g)
{
// Draws the image to the canvas
g.drawImage(img, 0, 0, null);
}
public void mouseClicked(MouseEvent e)
{
int x = e.getX();
int y = e.getY();
Graphics g = img.getGraphics();
g.fillOval(x, y, 3, 3);
g.dispose();
}
// ... other MouseListener methods ... //
}
The above example is incomplete (and not tested -- it definitely won't compile), but it gives an idea about how to implement a MyCanvas class in which a user can click on and draw circles.
The img object is used to hold the image of the canvas. The paintComponent method is used to paint the img object to the canvas. In the mouseClicked method, the Graphics object associated with img is retrieved in order to fillOval onto the image.
Since one the requirements is to paste images onto the canvas, it may be a good idea to hold some Images that you want to paste into the canvas. Perhaps something along the line of:
Image[] myImages; // Used to store images to paint to screen.
Then, in the routine to paint the image onto img stored in MyCanvas:
g.drawImage(myImage[INDEX_OF_DESIRED_IMAGE], 0, 0, null);
By using the drawImage method of the Graphics object, other Images can be drawn onto Images.
As for the question on AWT and Swing, yes, it is true that you do not want to mix components from the AWT and Swing, as they differ in the way they render GUI components. AWT is based on heavyweight components, meaning they native windowing for painting the GUI, while Swing is based on lightweight components, meaning the GUI is drawn by Java itself without using native components.
A good guide on the difference of AWT and Swing is provided in Painting in AWT and Swing article from Sun.
Simply subclass JComponent.
JPanel is an inappropriate class. It is often suggested as it appears to have setOpaque(true) invoked on it automatically. It's actually the PL&F which does that, and whether or not it actually happens is implementation and vendor dependent.
Canvas is a heavyweight component. That is to say that it is controlled by the underlying windowing system. The result is that it will typically be drawn over the top of Swing components, without respect to z-order or clipping (putting it in a scroll pane will give odd behaviour).
You might want to look at the Minueto API. It is a very simple to use graphics api, and you can combine the Java event listening with it to provide your drawing capability.
http://minueto.cs.mcgill.ca/