I was doing some JFrame work and I got into this problem. Basically I have a component, if I add it to my frame it's visible but if I add it to a panel it doesn't show up, anybody knows why?
This is my component (basically a geometric shape):
import javax.swing.*;
import java.awt.*;
public class RosaDeiVentiComponent extends JComponent {
private static int rdvRadius = 300;
private static int centerX = GraphicInterfaceManager.getBorderX() rdvRadius;
private static int centerY = GraphicInterfaceManager.getBorderY() rdvRadius;
private int xN = centerX; private int yN = centerY - rdvRadius;
private int xS = centerX; private int yS = centerY rdvRadius;
private int xE = centerX rdvRadius; private int yE = centerY;
private int xO = centerX - rdvRadius; private int yO = centerY;
private int xNO = centerX - 150; private int yNO = centerY - 150;
private int xNE = centerX 150; private int yNE = centerY - 150;
private int xSO = centerX - 150; private int ySO = centerY 150;
private int xSE = centerX 150; private int ySE = centerY 150;
private int xNtO = centerX - 55; private int yNtO = centerY - 55;
private int xNtE = centerX 55; private int yNtE = centerY - 55;
private int xStO = centerX - 55; private int yStO = centerY 55;
private int xStE = centerX 55; private int yStE = centerY 55;
private int xNOtN = centerX; private int yNOtN = centerY - 55;
private int xNEtE = centerX 55; private int yNEtE = centerY;
private int xSEtS = centerX; private int ySEtS = centerY 55;
private int xSOtO = centerX - 55; private int ySOtO = centerY;
public RosaDeiVentiComponent(){}
public void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.decode("#9999ff"));
int[] x1 = {centerX, xN, xNtO};
int[] y1 = {centerY, yN, yNtO};
g2.fillPolygon(x1, y1, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x2 = {centerX, xN, xNtE};
int[] y2 = {centerY, yN, yNtE};
g2.fillPolygon(x2, y2, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x3 = {centerX, xE, xNtE};
int[] y3 = {centerY, yE, yNtE};
g2.fillPolygon(x3, y3, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x4 = {centerX, xE, xStE};
int[] y4 = {centerY, yE, yStE};
g2.fillPolygon(x4, y4, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x5 = {centerX, xS, xStE};
int[] y5 = {centerY, yS, yStE};
g2.fillPolygon(x5, y5, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x6 = {centerX, xS, xStO};
int[] y6 = {centerY, yS, yStO};
g2.fillPolygon(x6, y6, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x7 = {centerX, xO, xStO};
int[] y7 = {centerY, yO, yStO};
g2.fillPolygon(x7, y7, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x8 = {centerX, xO, xNtO};
int[] y8 = {centerY, yO, yNtO};
g2.fillPolygon(x8, y8, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x9 = {centerX, xNOtN, xNO};
int[] y9 = {centerY, yNOtN, yNO};
g2.fillPolygon(x9, y9, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x10 = {centerX, xNOtN, xNE};
int[] y10 = {centerY, yNOtN, yNE};
g2.fillPolygon(x10, y10, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x11 = {centerX, xNEtE, xNE};
int[] y11 = {centerY, xNEtE, yNE};
g2.fillPolygon(x11, y11, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x12 = {centerX, xNEtE, xSE};
int[] y12 = {centerY, yNEtE, ySE};
g2.fillPolygon(x12, y12, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x13 = {centerX, xSEtS, xSE};
int[] y13 = {centerY, ySEtS, ySE};
g2.fillPolygon(x13, y13, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x14 = {centerX, xSEtS, xSO};
int[] y14 = {centerY, ySEtS, ySO};
g2.fillPolygon(x14, y14, 3);
g2.setColor(Color.decode("#9999ff"));
int[] x15 = {centerX, xSOtO, xSO};
int[] y15 = {centerY, ySOtO, ySO};
g2.fillPolygon(x15, y15, 3);
g2.setColor(Color.decode("#e5e5e5"));
int[] x16 = {centerX, xSOtO, xNO};
int[] y16 = {centerY, ySOtO, yNO};
g2.fillPolygon(x16, y16, 3);
g2.setColor(Color.BLACK);
g2.setFont(new Font("Serif", Font.ITALIC, 36));
g2.drawChars("N".toCharArray(),0,1,338,100);
g2.drawChars("S".toCharArray(),0,1,341,727);
g2.drawChars("O".toCharArray(),0,1,21, 411);
g2.drawChars("E".toCharArray(),0,1,655,411);
}
Adding it to my frame works:
public static void frameCreator() {
frame.add(new RosaDeiVentiComponent());
frame.setSize(width, height);
frame.setTitle("APP");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
If I set my layout as null it doesn't show up. Neither if I add it to a panel, like here.
public static void frameCreator() {
frame.setSize(width, height);
frame.setTitle("APP");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
rdvPanel.add(new RosaDeiVentiComponent());
rdvPanel.setBackground(Color.WHITE);
//Here I basically set the bound based on the shape dimension
rdvPanel.setBounds(new Rectangle(0,0, borderX RosaDeiVentiComponent.getRdvRadius()*2 200, height));
rdvPanel.setVisible(true);
frame.add(rdvPanel);
}
After the frameCreator method I set the frame as visible.
Can anybody tell me where I'm making a mistake? And possibly explaining way the absolute layout doesn't work even if I use absolute coordinate? Thx.
CodePudding user response：
You have to set prefferedSize to your component.
It would be also good, if you'd call super as a first line in your paintComponent:
public void paintComponent(Graphics g){
super.paintComponent(g);
//your code
}
By the way, you may initialize all your component's variables in contructor, as most probably you won't use them anywhere else:
public RosaDeiVentiComponent(){
int rdvRadius = 300;
int centerX = 500;
int centerY = 500;
//...
}
You may also consider shorten up creation of your Graphics.
Wind rose is made of only 1 triangle (or you can consider them as pair of triangles) only oriented in different directions (and different size or colour, if you want).
You can create only 1 or 2 triangles and add them in a loop, with different orientations. Creating each triangle separately looks redundant