Java changing colour of shape - java

i'm trying to make a rectangle in Java, done. I can also fill it in with solid colour, done. But I want to actually change the solid colour of the shape itself. I know with Graphics you can use g.setColor(); but I have had my component setup a special way as shown below:
public class Design extends JComponent {
private static final long serialVersionUID = 1L;
private List<Shape> shapesDraw = new ArrayList<Shape>();
private List<Shape> shapesFill = new ArrayList<Shape>();
GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
int screenWidth = gd.getDisplayMode().getWidth();
int screenHeight = gd.getDisplayMode().getHeight();
public void paint(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
for(Shape s : shapesDraw){
g2d.draw(s);
}
for(Shape s : shapesFill){
g2d.fill(s);
}
}
public void drawRect(int xPos, int yPos, int width, int height) {
shapesDraw.add(new Rectangle(xPos, yPos, width, height));
repaint();
}
public void fillRect(int xPos, int yPos, int width, int height) {
shapesFill.add(new Rectangle(xPos, yPos, width, height));
repaint();
}
public void drawTriangle(int leftX, int topX, int rightX, int leftY, int topY, int rightY) {
shapesDraw.add(new Polygon(
new int[]{leftX, topX, rightX},
new int[]{leftY, topY, rightY},
3));
repaint();
}
public void fillTriangle(int leftX, int topX, int rightX, int leftY, int topY, int rightY) {
shapesFill.add(new Polygon(
new int[]{leftX, topX, rightX},
new int[]{leftY, topY, rightY},
3));
repaint();
}
public Dimension getPreferredSize() {
return new Dimension(screenWidth, screenHeight);
}
public int getWidth() {
return screenWidth;
}
public int getHeight() {
return screenHeight;
}
}
As you can see, instead of just drawing and filling, it uses a list to draw off of that. Is there a way I can change the colour inside the list< shape >? I preferably want the colour to be changeable inside each draw/fill shape.
Thanks for the help.
Updated from answer:
My class as follows from your ShapeWrapper example:
public class Design extends JComponent {
private static final long serialVersionUID = 1L;
private List<ShapeWrapper> shapesDraw = new ArrayList<ShapeWrapper>();
private List<ShapeWrapper> shapesFill = new ArrayList<ShapeWrapper>();
GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
int screenWidth = gd.getDisplayMode().getWidth();
int screenHeight = gd.getDisplayMode().getHeight();
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
for(ShapeWrapper s : shapesDraw){
g2d.setColor(s.color);
g2d.draw(s.shape);
}
for(ShapeWrapper s : shapesFill){
g2d.setColor(s.color);
g2d.fill(s.shape);
}
}
public void drawRect(int xPos, int yPos, int width, int height) {
shapesDraw.add(new Rectangle(xPos, yPos, width, height));
repaint();
}
public void fillRect(int xPos, int yPos, int width, int height) {
shapesFill.add(new Rectangle(xPos, yPos, width, height));
repaint();
}
public void drawTriangle(int leftX, int topX, int rightX, int leftY, int topY, int rightY) {
shapesDraw.add(new Polygon(
new int[]{leftX, topX, rightX},
new int[]{leftY, topY, rightY},
3));
repaint();
}
public void fillTriangle(int leftX, int topX, int rightX, int leftY, int topY, int rightY) {
shapesFill.add(new Polygon(
new int[]{leftX, topX, rightX},
new int[]{leftY, topY, rightY},
3));
repaint();
}
public Dimension getPreferredSize() {
return new Dimension(getWidth(), getHeight());
}
public int getWidth() {
return screenWidth;
}
public int getHeight() {
return screenHeight;
}
}
class ShapeWrapper {
Color color;
Shape shape;
public ShapeWrapper(Color color , Shape shape){
this.color = color;
this.shape = shape;
}
}
Now I am coding in Eclipse and everything works fine except for ONE thing!!
Every time it says shapesDraw/shapesFill.add() it says:
The method add(ShapeWrapper) in the type List is not applicable for the arguments (Rectangle)
So close! Please respond.

You can use something like:
private class ShapeWrapper {
private Color color;
private Shape shape;
public ShapeWrapper(Color color , Shape shape){
this.color = color;
this.shape = shape;
}
}
instead of plain Shape for storing Shape+Color.
And paint them like next :
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
for(ShapeWrapper s: shapesDraw){
g2d.setColor(s.color);
g2d.draw(s.shape);
}
for(ShapeWrappers s : shapesFill){
g2d.setColor(s.color);
g2d.fill(s.shape);
}
}
EDIT: according your exception, you try to add to typed list(ShapeWrapper) an object of another class(Shape), fix your methods like next :
public void drawRect(int xPos, int yPos, int width, int height) {
ShapeWrapper wr = new ShapeWrapper(Color.RED,new Rectangle(xPos, yPos, width, height));
shapesDraw.add(wr);
repaint();
}

Related

Strange behavior when I move a JComponent in a JPanel

I am in the process of implementing a simple graph editor. It should be possible to create any Node (Sphere object) by mouse click and move it by drag and move. It works as far as it goes, but it behaves very strangely. When I click on the node, it slides away from the cursor. The hitbox from every Sphere object is strange too, but I can't explain why. Is there a better solution for my code?
This behavior
public class EditorPanelView extends Panel
{
private static EditorPanelView instance = null;
private static GraphController graphController = GraphController.getInstance();
private EditorPanelView(Color color, int x, int y, int width, int height) {
super(new BorderLayout(), color, x, y, width, height);
addMouseAdapter();
}
private void addMouseAdapter() {
MouseAdapter mouseAdapter = new MouseAdapter() {
private Sphere sphere;
#Override
public void mousePressed(MouseEvent e) {
if (getComponentAt(e.getX(), e.getY()) instanceof Sphere) {
sphere = (Sphere) getComponentAt(e.getPoint());
}
}
#Override
public void mouseClicked(MouseEvent e) {
Sphere sphere = new Sphere(e.getX(), e.getY());
add(sphere);
System.out.println("MOUSE CLICKED ON EDITORPANEL; SPHERE CREATED!");
revalidate();
repaint();
}
#Override
public void mouseDragged(MouseEvent e) {
Point p2 = e.getPoint();
Point loc = sphere.getLocation();
loc.translate(p2.x - sphere.getX(), p2.y - sphere.getY());
sphere.setLocation(loc);
}
#Override
public void mouseReleased(MouseEvent e) {
sphere = null;
System.out.println("Mouse released!");
}
};
addMouseListener(mouseAdapter);
addMouseMotionListener(mouseAdapter);
}
public static EditorPanelView getInstance(Color color, int x, int y, int width, int height) {
return Objects.requireNonNullElseGet(instance, () -> new EditorPanelView(color, x, y, width, height));
}
}
public class Sphere extends JComponent{
private int positionX;
private int positionY;
private final int width = 50;
private final int height = 50;
public Sphere(int x, int y) {
this.positionX = x;
this.positionY = y;
}
#Override
public void paintComponent(Graphics graphics) {
Graphics2D sphere = (Graphics2D) graphics;
sphere.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
sphere.setPaint(Color.BLACK);
sphere.fillOval(positionX -(width/2), positionY -(height/2), width, height);
}
}
public class FrameView extends JFrame {
private static FrameView instance = null;
private static final Color FRAMECOLOR = Color.darkGray;
private FrameView() {
Dimension size = Toolkit.getDefaultToolkit().getScreenSize();
GraphController graphController = GraphController.getInstance();
getContentPane().setBackground(FRAMECOLOR);
setTitle("Graph Editor");
setSize((int) size.getWidth()-200, (int) size.getHeight()-200);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setResizable(false);
getContentPane().setLayout(new GroupLayout(getContentPane()));
setJMenuBar(MenuBarView.getInstance());
add(EditorPanelView.getInstance(Color.LIGHT_GRAY, 260, 53, getWidth()-270, getHeight()-113));
add(OverviewPanelView.getInstance(Color.gray, 10, 53, 240, getHeight()-113));
add(ButtonPanelView.getInstance(FRAMECOLOR, 5, 5, getWidth()-10, 42));
}
public static JFrame getInstance() {
return Objects.requireNonNullElseGet(instance, FrameView::new);
}
}
public class Panel extends JPanel {
LayoutManager layout;
public Panel(LayoutManager layout, Color color, int x, int y, int width, int height) {
this.layout = layout;
setLayout(this.layout);
setBounds(x, y, width, height);
setBackground(color);
}
}
I tried to change the x and y coordinates in EditorPanelView::addMouseAdapter()

Looking at YouTube and google I created Code for a simple Jpanel with Button However What the videos don't tell me is what Design patterns am i using

I created an application which allows instantiating shapes which can be circle rectangle or anything and used sorting technique (Bubble Sort) to sort the six shapes based on interfaces.
The problem is I am not familiar with Design patterns and what patterns are being used- I am new so i followed youtube videos and played around with it and it worked.
I have 1 main class where I have
MAIN :
public class Main {
public static void main(String[] args) {
JButton btnLoadShapes, btnSortShapes;
btnLoadShapes = new JButton("Load Shapes");
btnLoadShapes.setBounds(150, 10, 150, 30);
btnSortShapes = new JButton("Sort Shapes");
btnSortShapes.setBounds(310, 10, 150, 30);
JPanel panelShapes = new JPanel() {
public void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
Shape shape = new Shape();
g2d.setColor(Color.RED);
Square s = shape.getS();
g2d.fillRect(s.getX(),s.getY(),s.getWidth(), s.getHeight());
g2d.setColor(Color.BLUE);
Circle c = shape.getC();
g2d.fillOval(c.getX(),c.getY(), c.getWidth(), c.getHeight());
g2d.setColor(new Color(131, 21, 1));
Rectangle r = shape.getR();
g2d.fillRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());
g2d.setColor(Color.PINK);
Circle C1 = shape.getC1();
g2d.fillOval(C1.getX(),C1.getY(), C1.getWidth(), C1.getHeight());
g2d.setColor(Color.green);
Square S1 = shape.getS1();
g2d.fillRect(S1.getX(),S1.getY(),S1.getWidth(), S1.getHeight());
g2d.setColor(Color.magenta);
Rectangle r2 = shape.getR2();
g2d.fillRect(r2.getX(),r2.getY(),r2.getWidth(), r2.getHeight());
}
};
panelShapes.setBounds(10, 50, 560, 500);
panelShapes.setBorder(BorderFactory.createLineBorder(Color.BLACK));
panelShapes.setVisible(false);
btnLoadShapes.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
panelShapes.setVisible(true);
}
});
and i have created 3 different classes Circle Rectangle and Square - from which i call for rectangle = shape.getC();
For example
public class Circle {
private int x, y, width, height;
public Circle(int x, int y, int width, int height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
}
Now the lastly I created 2 more classes called Shape and Sorting
where in shape i intiated public shape s = new Square with dimensions and set getters and setters and lastly i used sorting technique.
Can someone help me understand what are the design patterns that are being used here?
( I assume that Factory method is being used = since i defined main (* interface) and created subclasses ( Shapes rectangle circle) to instantiate.
Sorry if i sound out the place- I am just trying to understand and learn it.
A "factory" creates "something", the important thing in this context is, you don't care "how" it's created, only that it conforms to the specified type.
For example, you have a ShapeFactory which can create different shapes, you don't care "how" those shapes are defined or implemented, only that they conform to the notion of a "shape"
So, lets start with a basic concept...
public interface Shape {
public void paint(Graphics2D g2d);
}
This just defines a basic concept and states that it can be painted.
Next, we need something to create those shapes...
public class ShapeFactory {
enum ShapeType {
CIRCLE, RECTANGE, SQUARE;
}
public static Shape create(ShapeType type, int x, int y, int width, int height, Color storkeColor, Color fillColor) {
return null;
}
}
Ok, as it stands, that's pretty boring, it's only ever going to return null right now, but this gives us a basic contract.
"Please factory, create me shape of the specified type, within the specified bounds, with the specified colors"
Now, as I said, the implementation is unimportant, to the caller, and we could have a dynamic factory which could delegate the creation to other factories which could create shapes differently based on a wide ranging set of needs ... but that's getting ahead of ourselves.
Let's go about creating some actual shapes...
public abstract class AbstractShape implements Shape {
private int x;
private int y;
private int width;
private int height;
private Color storkeColor;
private Color fillColor;
public AbstractShape(Color storkeColor, Color fillColor) {
this.storkeColor = storkeColor;
this.fillColor = fillColor;
}
public AbstractShape(int x, int y, int width, int height, Color storkeColor, Color fillColor) {
this(storkeColor, fillColor);
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
protected void setX(int x) {
this.x = x;
}
protected void setY(int y) {
this.y = y;
}
protected void setWidth(int width) {
this.width = width;
}
protected void setHeight(int height) {
this.height = height;
}
public Color getStorkeColor() {
return storkeColor;
}
public Color getFillColor() {
return fillColor;
}
#Override
public void paint(Graphics2D g2d) {
Graphics2D g = (Graphics2D) g2d.create();
Color storkeColor = getStorkeColor();
Color fillColor = getFillColor();
if (fillColor != null) {
g.setColor(fillColor);
paintFilled(g);
}
if (storkeColor != null) {
g.setColor(storkeColor);
paintStroked(g);
}
g.dispose();
}
abstract protected void paintFilled(Graphics2D g2d);
abstract protected void paintStroked(Graphics2D g2d);
}
public class CircleShape extends AbstractShape {
public CircleShape(int x, int y, int width, int height, Color storkeColor, Color fillColor) {
super(storkeColor, fillColor);
int size = Math.min(width, height);
x = x + ((width - size) / 2);
y = y + ((height - size) / 2);
setX(x);
setY(y);
setWidth(size);
setHeight(size);
}
#Override
protected void paintFilled(Graphics2D g2d) {
g2d.fillOval(getX(), getY(), getWidth(), getHeight());
}
#Override
protected void paintStroked(Graphics2D g2d) {
g2d.drawOval(getX(), getY(), getWidth(), getHeight());
}
}
public class SquareShape extends AbstractShape {
public SquareShape(int x, int y, int width, int height, Color storkeColor, Color fillColor) {
super(storkeColor, fillColor);
int size = Math.min(width, height);
x = x + ((width - size) / 2);
y = y + ((height - size) / 2);
setX(x);
setY(y);
setWidth(size);
setHeight(size);
}
#Override
protected void paintFilled(Graphics2D g2d) {
g2d.fillRect(getX(), getY(), getWidth(), getHeight());
}
#Override
protected void paintStroked(Graphics2D g2d) {
g2d.drawRect(getX(), getY(), getWidth(), getHeight());
}
}
public class RectagleShape extends AbstractShape {
public RectagleShape(int x, int y, int width, int height, Color storkeColor, Color fillColor) {
super(x, y, width, height, storkeColor, fillColor);
}
#Override
protected void paintFilled(Graphics2D g2d) {
g2d.fillRect(getX(), getY(), getWidth(), getHeight());
}
#Override
protected void paintStroked(Graphics2D g2d) {
g2d.drawRect(getX(), getY(), getWidth(), getHeight());
}
}
I always like a abstract class to carry the "common" functionality and to help make life a little simpler.
The important thing here is to note that both CircleShape and SquareShape, by their nature are, well, square (they have equal width and height). So, in this implementation, I define them to fit within the middle of the specified bounds - this is a "implementation" detail.
"But isn't that what I'm doing you?" you ask. Well, no, not really. When you call shape.getS(), for example, it's return a concrete class, which I assume has the same properties as the last object created by it, otherwise it will move all over the place.
Instead, what I'm doing is allowing you to define the properties you want the shape to have and then making it.
You want a cake? Sure, pass me the ingredients and I'll make you a cake, you still end up with a cake, but depending on the ingredients it's a different "type" of cake.
So, based on the above, we could do something like...
public class TestPane extends JPanel {
private List<Shape> shapes = new ArrayList<>(25);
public TestPane() {
shapes.add(ShapeFactory.create(ShapeFactory.ShapeType.CIRCLE, 10, 10, 200, 100, Color.RED, Color.BLUE));
shapes.add(ShapeFactory.create(ShapeFactory.ShapeType.RECTANGE, 10, 120, 200, 100, Color.BLUE, Color.GREEN));
shapes.add(ShapeFactory.create(ShapeFactory.ShapeType.SQUARE, 10, 240, 200, 100, Color.GREEN, Color.YELLOW));
}
#Override
public Dimension getPreferredSize() {
return new Dimension(220, 350);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
for (Shape shape : shapes) {
shape.paint(g2d);
}
g2d.dispose();
}
}
I could have made the ShapeFactory with dedicated createCircle, createRectangle and createSquare methods, I could have had them return interfaces of Circle, Square and Rectangle (and I would have based those of Shape because I'm like that) and it would still be a factory.
One of things to keep in mind is, a "factory" should be implementation independent. I should be able to make use of "different" shape factories to get different effects, but at the end of the day, they'd still just be generating Shapes
Remember, a factory will take something and it will create something from it.

How can I render a image with a certain field of view?

Good evening! I have successfully displayed an image using java and the graphics object.
This is my 'Renderer'-Class:
public class Renderer {
private static BufferStrategy bs;
private static Graphics g;
private static Window win;
public static final int MIN_BUFFER_COUNT = 1;
public static final int MAX_BUFFER_COUNT = 4;
public static void prepareRenderer(BufferStrategy bs) {
Renderer.bs = bs;
g = bs.getDrawGraphics();
}
public static BufferStrategy createBufferStrategy(Window window, int bufferCount) {
if(window.getCanvas().getBufferStrategy() == null) {
window.getCanvas().createBufferStrategy(bufferCount);
}
win = window;
BufferStrategy _bs = window.getCanvas().getBufferStrategy();
return _bs;
}
public static void clearWindow(Window window) {
g.clearRect(0, 0, window.getWidth(), window.getHeight());
}
public static void drawRectangle(int x, int y, int width, int height) {
g.fillRect(x, y, width, height);
}
public static void setColor(Color color) {
g.setColor(color);
}
public static void drawImage(BufferedImage image, int x, int y, int width, int height) {
g.drawImage(image, x, y, win.getWidth() / width * Config.getField_of_view(), win.getHeight() / height * Config.getField_of_view(), null);
}
public static void drawSprite(Sprite sprite, int x, int y, int width, int height) {
g.drawImage(sprite.getImage(), x, y, (int) (win.getWidth() / width * Config.getField_of_view()), (int) (win.getHeight() / height * Config.getField_of_view()), null);
}
public static void closeRenderer() {
bs.show();
g.dispose();
}
I made this strange code in the renderer because I want to have a certain field of view no matter what window size.
This is what I wrote in the Main-Class:
#Override
public void render() {
//Prepare
Renderer.prepareRenderer(Renderer.createBufferStrategy(window, Renderer.MAX_BUFFER_COUNT));
//Clear
Renderer.clearWindow(window);
//Draw
Renderer.drawSprite(sprite, 0, 0, 100, 100);
//Close
Renderer.closeRenderer();
}
But now I have a problem because when I make the window into a rectangle it looks pretty stretched.
This worked with Math.min(win.getWidth(), win.getHeight()) thanks

Switch between drawing a rectangle and by freehand

I have some issues with my paint program in Java.
I have a JComboBox where I can choose to draw either a rectangle or by freehand. The objects are added to an ArrayList. I want to be able to switch between drawing a rectangle and by free hand, and then back to drawing a rectangle, and then by free hand... and so on.
If I do that as the code looks like now, it first draws rectangles fine and then when I switch to free hand it draws lines fine, but then when I switch back to rectangles it still draws lines (or sometimes lines together with weird looking rectangles). The more I switch the weirder it gets.
Can anyone see what is wrong with the code, because I can't?
public abstract class Draw {
public int startX, startY, endX, endY, width, height, w, h;
public String color = "Black";
public Draw(int startX, int startY, int width, int height) {
this.startX = startX;
this.startY = startY;
this.width = width;
this.height = height;
}
public abstract void draw(Graphics2D g);
public int getX() {
return startX;
}
public void setX(int startX) {
this.startX = startX;
}
public int getY() {
return startY;
}
public void setY(int startY) {
this.startY = startY;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
public void setColor(String color) {
this.color = color;
}
}
public class Rectangle extends Draw {
public Rectangle(int x, int y, int width, int height) {
super(x, y, width, height);
}
#Override
public void draw(Graphics2D g2) {
g2.drawRect(getX(), getY(), getWidth(), getHeight());
}
}
public class FreeHand extends Draw {
public FreeHand(int x, int y, int width, int height) {
super(x, y, width, height);
}
#Override
public void draw(Graphics2D g2) {
g2.drawLine(getX(), getY(), getWidth(), getHeight());
}
}
public class PaintProgram extends JFrame implements ActionListener {
public ArrayList<Draw> shapeList = new ArrayList<>();
int startX, startY, endX, endY, w, h;
private JPanel topPanel;
private JPanel bottomPanel;
private JPanel leftPanel;
private JPanel rightPanel;
private JComboBox comboBox;
private final String[] boxOptions = new String[] {"Rectangle", "Freehand"};
Container cp = getContentPane();
private int count = 0;
public JavaApplication30(String title) {
super(title);
this.setLayout(new BorderLayout());
this.setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
this.setLocationRelativeTo(null);
this.setSize(840, 500);
this.initComponents();
this.setVisible(true);
}
private void initComponents() {
cp.setBackground(Color.WHITE);
comboBox = new JComboBox(boxOptions);
topPanel = new JPanel();
bottomPanel = new JPanel(new GridLayout(1,2));
rightPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
leftPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
comboBox.setSelectedIndex(0);
comboBox.addActionListener(this);
topPanel.setPreferredSize(new Dimension(0,40));
bottomPanel.setPreferredSize(new Dimension(0,30));
bottomPanel.setBackground(Color.LIGHT_GRAY);
topPanel.add(comboBox);
bottomPanel.add(leftPanel);
bottomPanel.add(rightPanel);
this.add(topPanel, BorderLayout.PAGE_START);
this.add(bottomPanel, BorderLayout.PAGE_END);
}
#Override
public void paint(Graphics g) {
if(count == 0) {
cp.repaint();
}
Graphics2D g2 = (Graphics2D) g;
for (Draw d : shapeList) {
d.draw(g2);
}
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setStroke(new BasicStroke(1));
if (startX != 0 && startY != 0 && endX != 0 && endY != 0) {
int width = Math.abs(startX - endX);
int height = Math.abs(startY - endY);
int minX = Math.min(startX, endX);
int minY = Math.min(startY, endY);
Rectangle r = new Rectangle(minX, minY, width, height);
g2.setPaint(Color.WHITE);
g2.fillRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());
r.setColor(pickedColor);
r.draw(g2);
}
}
#Override
public void actionPerformed(ActionEvent e) {
count++;
if (e.getSource().equals(comboBox)) {
JComboBox cb = (JComboBox)e.getSource();
if (cb.getSelectedItem().equals("Rectangle")) {
this.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
startX = e.getX();
startY = e.getY();
endX = startX;
endY = startY;
repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
endX = e.getX();
endY = e.getY();
int width = Math.abs(startX - endX);
int height = Math.abs(startY - endY);
int minX = Math.min(startX, endX);
int minY = Math.min(startY, endY);
Rectangle r = new Rectangle(minX, minY, width, height);
shapeList.add(r);
r.setColor(pickedColor);
startX = 0;
startY = 0;
endX = 0;
endY = 0;
repaint();
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
endX = e.getX();
endY = e.getY();
repaint();
}
});
}
else if (cb.getSelectedItem().equals("Freehand")) {
this.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
startX = e.getX();
startY = e.getY();
addCoordinate(startX, startY);
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
Graphics g = getGraphics();
Graphics2D g2 = (Graphics2D) g;
FreeHand fh = new FreeHand(startX, startY, e.getX(), e.getY());
shapeList.add(fh);
fh.setColor(pickedColor);
fh.draw(g2);
startX = e.getX();
startY = e.getY();
}
});
}
}
}
public static void main(String args[]) {
new PaintProgram("Paint");
}
}
You add MouseListeners but you do not remove them. Every time you choose something in the combobox, a new listener is added. So when you draw something every listener is applied and weird stuff will happen.
You should remove the previous MouseListener before adding a new one. You might have to remember it in an instance variable.
Alternatively, you can add all listeners at the start, but check the value of the combobox inside the listener. If the value does not correspond to what the listener is for, it should do nothing.
EDIT: Here is how you can remove all listeners
for (MouseListener listener : this.getMouseListeners()) {
this.removeMouseListener(listener);
}
for (MouseMotionListener listener : this.getMouseMotionListeners()) {
this.removeMouseMotionListener(listener);
}
Put this code in before you add the new listeners in the actionPerformed() method
As was stated here and here previously, do not add MouseListeners within your ActionListener, instead, create a single MosueListener and determine what you want to do based on the currently selected item.
Basically, you keep adding a new MouseListener each time actionPerformed is called...they are accumulating...
A solution would be to use a single MouseListener and a factory of some kind...
Start by defining the factory interface...
public interface DrawFactory {
public Draw createDrawing(int x, int y, int width, int height, Color color);
public void addPoint(Draw draw, int x, int y);
}
Create a implementation of the factory for each type of shape you want to draw...
public class RectangleFactory implements DrawFactory {
#Override
public Draw createDrawing(int x, int y, int width, int height, Color color) {
return new Rectangle(x, y, width, height);
}
#Override
public void addPoint(Draw draw, int x, int y) {
// Does nothing...
}
#Override
public boolean isMutable() {
return false;
}
#Override
public String getName() {
return "Rectangle";
}
#Override
public String toString() {
return getName();
}
}
public class FreeHandFactory implements DrawFactory {
#Override
public Draw createDrawing(int x, int y, int width, int height, Color color) {
return new FreeHand(x, y, width, height);
}
#Override
public void addPoint(Draw draw, int x, int y) {
if (draw instanceof FreeHand) {
FreeHand fh = (FreeHand)draw;
//fh.addPoint(x, y);
}
}
#Override
public boolean isMutable() {
return true;
}
#Override
public String getName() {
return "Free Hand";
}
#Override
public String toString() {
return getName();
}
}
Next, create a custom component that extends from JPanel which will act as the primary drawing surface, this will be repsonsible for monitoring the MouseLstener and painting the Draw instances, as was mentioned here
public class DrawSurface extends JPanel {
private DrawFactory factory;
private Draw currentDraw;
private List<Draw> shapeList = new ArrayList<>();
private Color drawColor;
public DrawSurface() {
shapeList = new ArrayList<>(25);
MouseAdapter ma = new MouseAdapter() {
private Point pressPoint;
#Override
public void mousePressed(MouseEvent e) {
pressPoint = e.getPoint();
}
#Override
public void mouseReleased(MouseEvent e) {
DrawFactory factory = getDrawFactory();
if (factory != null) {
Point p = e.getPoint();
if (factory.isMutable() && currentDraw != null) {
factory.addPoint(currentDraw, p.x, p.y);
} else {
int x = Math.min(p.x, pressPoint.x);
int y = Math.min(p.y, pressPoint.y);
int width = Math.abs(p.x - pressPoint.x);
int height = Math.abs(p.y - pressPoint.y);
Draw draw = factory.createDrawing(x, y, width, height, getDrawColor());
shapeList.add(draw);
if (factory.isMutable()) {
currentDraw = draw;
}
}
}
}
};
}
public DrawFactory getDrawFactory() {
return factory;
}
public void setDrawFactory(DrawFactory factory) {
this.factory = factory;
currentDraw = null;
}
public Color getDrawColor() {
return drawColor;
}
public void setDrawColor(Color drawColor) {
this.drawColor = drawColor;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
for (Draw draw : shapeList) {
draw.draw(g2d);
}
g2d.dispose();
}
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
Next, change your boxOptions from String to DrawFactory, this will make it easier to determine which factory you should use. Don't forget to add a reference to the DrawSurface
private final DrawFactory[] boxOptions = new DrawFactory[]{new RectangleFactory(), new FreeHandFactory()};
private DrawSurface drawSurface;
In your initComponents create a new instance of DrawSurface and add it to your frame...
private void initComponents() {
//...
drawSurface = new DrawSurface();
this.add(drawSurface);
}
Change your actionPerformed method to look more like...
#Override
public void actionPerformed(ActionEvent e) {
count++;
drawSurface.setDrawFactory((DrawFactory)comboBox.getSelectedItem());
}
Not sure how you are determining the current color as you example code is incomplete, but basically, you want to set the drawColor of the DrawSurface similarly.
Get rid of the paint method in the PaintProgram as you shouldn't be overriding the paint method of top level containers, which you've been advised against at least once, if not twice.
The point of all this is simple, when you want to add a new "drawing shape", you create a Draw and DrawFactory for it and add the factory to the combo box ... work done...

Java Graphics2D to erase to a alpha background

I'm making an application that has a drawing board where you draw with your mouse, it draws ontop of an Label in a BUfferedImage. What I'm trying to implement right now is an eraser, the problem is I cannot find anywhere help to make an eraser to clearRect() to an alpha background. (I cannot have a defined color background since the user can change the background to any image he wants). To sum up:
How can you erase/overwrite Graphics2D pixels with alpha pixels? The way i found was with clearRect but you need to specify a background color.
The following is my DrawBoard class which constains everything to draw.
public class DrawBoard extends JPanel implements MouseListener, MouseMotionListener{
public JLabel status;
private JLabel imgLabel; // this is where the drawing happens
public Point pstart, pfinish;
private List<Point> points = new ArrayList<Point>();
private List<BufferedImage> lines = new ArrayList<BufferedImage>();
private static final int BI_WIDTH = 1024;
private static final int BI_HEIGHT = 800;
private static int STROKESIZE = 7;
private BufferedImage bImage = new BufferedImage(BI_WIDTH, BI_HEIGHT,
BufferedImage.TYPE_INT_ARGB);
public Color currentColor;
public static boolean eraser = false;
private int xX1, yY1;
public DrawBoard(){
Graphics2D g2d = bImage.createGraphics();
g2d.dispose();
Dimension size = getPreferredSize();
size.setSize(1024,800); //w, h
setPreferredSize(size);
//status = new JLabel("default");
//add(status, BorderLayout.SOUTH);
addMouseListener(this);
addMouseMotionListener(this);
imgLabel = new JLabel(new ImageIcon(bImage)) {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
paintInLabel(g);
}
};
imgLabel.setOpaque(false);
setOpaque(false);
add(imgLabel, BorderLayout.CENTER);
}
private void paintInLabel(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(getColor()); // this colour is when mouse is pressed
g2d.setStroke(new BasicStroke(STROKESIZE));
if (points.size() < 2) {
return;
}
for (int i = 1; i < points.size(); i++) {
int x1 = points.get(i - 1).x;
int y1 = points.get(i - 1).y;
int x2 = points.get(i).x;
int y2 = points.get(i).y;
g2d.drawLine(x1, y1, x2, y2);
}
}
#Override
public void mouseExited(MouseEvent e){
}
#Override
public void mouseEntered(MouseEvent e){
}
#Override
public void mouseMoved(MouseEvent e){
}
// Where the drawing happens
#Override
public void mousePressed(MouseEvent e) {
//status.setText("you pressed down the mouse");
xX1 = e.getX();
yY1 = e.getY();
points.add(e.getPoint());
}
#Override
public void mouseDragged(MouseEvent e) {
//status.setText("you draged the mouse");
points.add(e.getPoint());
imgLabel.repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
//status.setText("you release the mouse click");
Graphics2D g2d = bImage.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(getColor()); // this is the final colour
g2d.setStroke(new BasicStroke(STROKESIZE));
if (points.size() >= 2) {
for (int i = 1; i < points.size(); i++) {
int x1 = points.get(i - 1).x;
int y1 = points.get(i - 1).y;
int x2 = points.get(i).x;
int y2 = points.get(i).y;
g2d.drawLine(x1, y1, x2, y2);
}
}
g2d.dispose();
points.clear();
imgLabel.repaint();
}
// End of where the drawing happens
public void clearDrawBoard() {
}
private Color getColor() {
return ColourToolbar.selectedColor;
}
private void setColor(Color col){
this.currentColor = col;
}
#Override
public void mouseClicked(MouseEvent e) {
//throw new UnsupportedOperationException("Not supported yet.");
}
}
You should set a custom Composite for your Graphics2D, specifically AlphaComposite.Clear before drawing the rectangle. Don't forget to reset the composite to the default (SRC_OVER) when you are done, because the same Graphics object will be reused to paint other components.

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